The Geological Society of London’s Statement on Climate Change

253 Responses to The Geological Society of London’s Statement on Climate Change

1. Euan Mearns says:

   January 15, 2018 at 8:28 am

   First of all I’d like to thank Dr Colin Summerhayes, his co-authors and the Committee of the Geological Society of London (GSL) for agreeing to this on-line discussion of The Society’s statement on climate change. However, I strongly disagree with much of its content.

   The two main issues I have are as follows, which I will deal with in greater detail in separate comments. What I conclude from the data is that there are two strong forces that modulate historic climate cycles 1) Earth’s orbit, especially the 41,000 y obliquity cycle and 2) variations in the geomagnetic activity of the Sun resulting in quasi ~ 1,200 year cycles known as Bond or Dansgaard- Oeschger (DO) cycles (barely mentioned in the GSL statement but with more detail in the addendum). Most of the observed climate change of the Holocene can be attributed to this ~1200 year solar cycle. The action of these primary strong forces, mainly obliquity, causes climate to change and this in turn causes the greenhouse gas content of the atmosphere to change. Albedo of high latitude and high altitude areas also changes, via the formation and collapse of ice sheets. Green house Gases (GHG) and albedo may well cause positive and negative feedbacks but they are demonstrably weak forces easily overridden by the strong.

   The general observation that GHG fluctuate with temperature over geological time needs to be interpreted with great care. The GSL Statement recognises the difference between cause and effect but then seems to lapse into the illogical position that GHG variations are primary causes of climate change. This is an illogical trap first created by Petit et al in their seminal paper on the Vostok ice core [1]. The fact that we currently have “unprecedented” 400+ ppm only has great significance if dCO2 is the primary cause of climate change which it has not been for the last 2.5 million years.

   Ice cores

   The GSL statement says this:

   The concentrations of CO2 and other gases in these bubbles follow closely the pattern of rising and falling temperature between glacial and interglacial periods.

   This is simply untrue. Petit et al recognise that this is untrue but then proceed with an interpretation that imagines that it is.

   The Vostok Ice Core provides one of the finest geochemical records ever assembled and provides key data on what actually drives Earth’s climate in two ways.

   1) At the glacial inceptions CO2 lags temperature by up to 14,000 years. This is a massive lag where full glacial conditions are established before CO2 begins to fall. This demonstrates that CO2 is not a significant driver of climate change during glacial periods. It simply follows temperature, closely at the terminations but with large time lags at the inceptions. The climate science community, starting with Petit et al, have simply brushed this key information under the carpet. The political, social and economic consequences of this error are too vast to imagine.

   2) At the main turning points of the Vostok temperature curve, at the temperature high, CO2 reaches a maximum and albedo a minimum. If these variables were significant drivers it should simply continue to get warmer, but the exact opposite happens. The strong force – obliquity – simply sweeps these weak forces away. At the temperature minima, the opposite occurs. The stage appears set for the whole world to freeze, but what happens next is the ice sheets collapse.

   The Sun

   The GSL statement does not mention the role of the Bond / D-O cycles at all. It does say this:

   In addition, the heat emitted by the Sun varies with time. Most notably, the 11-year sunspot cycle causes the Earth to warm very slightly when there are more sunspots and cool very slightly when there are few.

   This is a gross misrepresentation of facts as they are understood. Bond cycles are recorded as cyclical variations in sediment composition in the North Atlantic. D-O cycles are recorded as temperature variations in Greenland, but not Antarctic, ice cores. Similar cycles are also recorded in carbonate stalactites in Oman. In every case, these cycles correlate with fluctuations in the cosmogenic isotope record, either 14C  or 10Be. This tells us that it is variations in the geomagnetic field strength of the Sun that controls these climate cycles – NOT feeble variations in total solar irradiance stemming from sunspots!

   The 2013 addendum does however correct this omission but does not present the cosmogenic isotope data faithfully:

   Before the current warming trend began, temperatures in the Holocene (the last 11,000 years) were declining. This was due largely to insolation – the solar radiation received by the Earth’s surface – and dictated by the Earth’s orbit and the tilt of the Earth’s axis. Insolation declined throughout the Holocene. This cooling took Earth’s climate into a Neoglacial period, culminating in the ‘Little Ice Age’ (1450 – 1850).

   The addendum goes on to say:

   The changes in solar output can be detected via isotopes of carbon and beryllium produced in the upper atmosphere when solar activity is weak, and extracted from tree rings and polar ice cores 34. These fluctuations do not coincide precisely with palaeoclimatic events like the Medieval Climate Anomaly (although solar output was high during part of that time) or the Little Ice Age (during which there were some periods of minimal solar output).

   This seems to be an attempt to undermine the veracity of the isotope record. Bond cycles do not leave a significant mark on global average temperatures. But, their action does cause climate to change everywhere. Some areas warm while others cool. This is most likely down to a change in the pattern of atmospheric circulation from zonal to meridional. Research from the UK Met office has shown how changes in the spectral output of the Sun can control the pattern  of atmospheric circulation [2].

   We know the more recent Bond cycles as the Roman Warm Period, Dark Ages cold period, The Medieval Warm period, the Little Ice Age (LIA) and the modern warm period. The LIA was not a single cold event during the Holocene but one of several cold events. The fact that the LIA ended was due to the Sun coming back to life and probably has nothing to do with CO2 at all.

   Climate Sensitivity

   Finally, I want to touch on climate sensitivity. The 2013 addendum says this:

   Geologists have recently contributed to improved estimates of climate sensitivity (defined as the increase in global mean temperature resulting from a doubling in atmospheric CO2 levels). Studies of the Last Glacial Maximum (about 20,000 years ago) suggest that the climate sensitivity, based on rapidly acting factors like snow melt, ice melt and the behaviour of clouds and water vapour, lies in the range 1.5°C to 6.4°C.

   This is a bizarre and astonishing claim. The main thing that strikes me is that climate science community doesn’t seem to have a clue about the impact of CO2 on temperature. 1.5˚C is probably harmless, perhaps beneficial. 6.4˚C probably catastrophic. This provides zero basis for energy policy development.

   I suspect the reason for this chaotic message is that variations in glacial temperature have been wrongly attributed to variations in CO2, which as we have already established, varies in response to temperature. Temperature  in turn results from changes in obliquity. Ice core data cannot be used to say anything about climate sensitivity.

   A study of UK climate records I did jointly with Clive Best suggests climate sensitivity closer to a harmless 1.3˚C.

   [1] J. R. Petit*, J. Jouzel†, D. Raynaud*, N. I. Barkov‡, J.-M. Barnola*, I. Basile*, M. Bender§, J. Chappellaz*, M. Davisk, G. Delaygue†, M. Delmotte*, V. M. Kotlyakov¶, M. Legrand*, V. Y. Lipenkov‡, C. Lorius*, L. Pe ́ pin*, C. Ritz*, E. Saltzmank & M. Stievenard† (1999) Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. NATURE | VOL 399 | 3 JUNE 1999 |

   [2] Sarah Ineson et al (2011) Solar forcing of winter climate variability in the Northern Hemisphere Nature Geoscience PUBLISHED ONLINE: 9 OCTOBER 2011 | DOI: 10.1038/NGEO1282
   • donb says:

     January 15, 2018 at 11:04 pm

     Euan, I like and agree with what you say above. Below are some additional points.

     It is well known that major glacial inceptions occur in the northern hemisphere (NH) then spread to the SH. These are commonly attributed to differences in TOA (top of atmosphere) insolation caused by variations in Earth’s orbit. But these Milankovitch cycles alone cannot be the sole cause of glacial cycles, because TOA insolation over the entire Earth does not change. Rather orbital cycles change TOA insolation in one polar region relative to another. TOA insolation at 65 degrees north latitude at the start of the last glacial cycle fell about 100 watts/sq-meter. This would have been ample to initiate land glaciation, even on lower elevations of northern Canada, where two of the last glacial spreading centers began. However, insolation at 65 degrees south latitude increased by this amount, so the total Earth should not have cooled from this alone.

     Milankovitch cycles likely act as cold triggers for glaciation by allowing more land ice to form in the far north, survive summer melting, and grow. Until the NH chills, land ice will not survive summers across lower elevations typical of most of the NH. As land ice spread, it and spreading NH sea ice then decreased NH albedo and further cooled the polar region. Increased NH albedo from growing ice is probably insufficient to cool the entire Earth by the few degrees indicated by proxy data during major glaciations. Furthermore, some additional process must act to prevent concurrent extra SH heat (due to increased SH insolation) from flowing north and cancelling NH ice formation. Also without decreased SH temperature, what accounts for the increased growth in SH land ice (Antarctica & Patagonia), generally concurrent with NH glaciations (and not with orbital periods of decreased SH insolation)?

     Most likely, survival and growth of NH glaciers were permitted by a combination of two additional factors – retardation of movement of SH heat into the far north, and an increase in NH and possibly total Earth albedo. This would bring into play two uncertain factors in climate science (including today’s climate predictions), namely ocean circulation and cloud density and distribution. Major cooling of the NH likely slowed the movement of warmer Atlantic currents into the Arctic. Lowering of sea level from ice formation would also decrease entry points east of Greenland. Although speculative, cooling of the whole NH may have increased reflective cloud cover. Increased high albedo clouds and possible deep ocean storage of some surface heat would be efficient ways to lower Earth’s total surface energy. Earth’s average albedo today is about 30%, and only a 1% increase in this albedo would decrease TOA solar insolation by about 14 watts/sq-m, sufficient to induce a measurable global temperature decrease. Further, these extra factors (beyond just orbital cycles) could explain relatively sudden variations in NH temperature, such as D-O events and reversals of temperature as observed in ice cores, and also account for the lack of perfect concordance of global temperature with details of Milankovitch cycles. Additional factors such as changing land and plant albedo and uptake of CO2 by cooling oceans probably played supporting roles. Details of all these interactive processes would be hard to predict.

     Importantly, if such envisioned variations in past ocean cycles and cloud albedo, both of which are capable of relatively quick changes, influenced past Earth climate in such dramatic ways, what effects might they have on current climate and temperature?
     • Capell says:

       January 16, 2018 at 12:09 pm

       It is worth reading this article:
       https://cei.org/sites/default/files/Rupert%20Darwall%20-%20A%20Veneer%20of%20Certainty%20Stoking%20Climate%20Alarm.pdf

       The relevant quote about Milankovitch cycles is this:
       How do current anthropogenic forcings—the extra energy from the enhanced greenhouse effect—and those caused by Milanković cycles compare? William Collins of the Lawrence Berkeley National Laboratory was asked this at the APS 2014 climate workshop by New York University theoretical physicist Steven Koonin, who served as undersecretary in the Department of Energy during President Obama’s first term. As noted, the APS workshop is unique in the history of climate science: on one side, three experts subscribing to the consensus and three expert critical of it, moderated by non-climate scientists, including Koonin.
       “In some cases, six watts,” answered Collins.
       “Locally, it’s 100 watts per square meter in the summer Arctic,” MIT’s Dr. Richard Lindzen added from the IPCC critics’ bench.19 Lindzen returned to the topic later in the session. Annually averaged over the globe, you had almost no forcing from the Milanković cycles getting a big climate response, Lindzen observed. Averaging the annual change in radiative forcing caused by Milanković cycles over the entire globe conceals the magnitude of the change toward the poles. What Lindzen called the “currently fashionable paradigm” requires changes in CO2 to produce the cycle of ice ages. Was the global climate so sensitive that forcings of 1.5 watts per square meter from the extra CO2 found in ice cores sufficient to cause profound climate change? “I think that makes no sense,” Lindzen said.
     • Euan Mearns says:

       January 16, 2018 at 5:15 pm

       Thanks Don, I have no reason to disagree with what you say. I ceratinly accept an albedo feedback. I would also accept a secondary GHG feedback, but the problem is that the data show this not to be the case.

       I am quite certain that changes in ocean circulation, especially the Gulf Stream are important and perhaps impact in two ways. First, the sink point moves well south removing the transport of warm air to high latitude. And second, I wonder about the rate of over-turning. The thermohaline circulation is vital for cooling the oceans – transporting heat from the tropics to high latitude where the heat is lost and cold salty water sinks. If that conveyer speeded up the rate of cold bottom water formation would also rise.

       One thing I have wondered about is if changing obliquity may actually “deflect” the gulf stream causing it to change?
   • Halken says:

     January 16, 2018 at 3:57 pm

     Regarding sensitivity

     I would say that it is likely (in IPCC parlance) that co2 is a contributor to the climate, but the real question is not if, but how much it contributes.

     If we discard the problematic models and look to late estimates based on observations, then they point to a much lower sensitivity than what is implied by the IPCC.

     https://climateaudit.org/2017/11/18/reconciling-model-observation-reconciliations/boxplot_tlt_glb_20171117-2/

     https://judithcurry.com/2016/04/25/updated-climate-sensitivity-estimates/

     https://climateaudit.org/2017/11/18/reconciling-model-observation-reconciliations/

     https://www.thegwpf.org/oversensitive-ipcc-hid-good-news-global-warming-2/
     • Halken says:

       January 16, 2018 at 4:01 pm

       https://climateaudit.files.wordpress.com/2017/11/boxplot_tlt_glb_201711171.png?w=1024
     • Roger Andrews says:

       January 16, 2018 at 4:14 pm

       Energy Matters predicted these results over three years ago 🙂

       http://euanmearns.com/zeroing-in-on-the-true-value-of-climate-sensitivity/
       • Halken says:

         January 17, 2018 at 12:46 pm

         That was before I started to follow this excellent blog
2. Euan Mearns says:

   January 15, 2018 at 8:53 am

   Lessons from the Vostok Ice Core

   In my introductory comment I noted that the following statement made by the GSL is simply untrue:

   The concentrations of CO2 and other gases in these bubbles follow closely the pattern of rising and falling temperature between glacial and interglacial periods.

   Let us begin by taking a look at the data that I first presented in my 2015 post The Vostok Ice Core: Temperature, CO2 and CH4 (10,863 reads) and elaborated on in 2017 with a post called The Vostok Ice Core and the 14,000 Year CO2 Time-Lag (5,396 reads).

   NOTE THAT IN ALL CHARTS TIME IS PASSING FROM RIGHT TO LEFT

   

   Figure 1 Methane and temperature variations. Note how methane and temperature are particularly strongly aligned at the terminations and during subsequent decline back to glacial conditions.

   Methane and temperature are very closely aligned in Vostok. Does this mean that tiny variations in methane concentration (delta ~ 0.4 ppm) controls Earth’s climate? Of course it doesn’t. Methane is simply responding to temperature changes from well known geological processes. When the Earth warms during the inter-glacials vast swathes of permafrost melt releasing methane and CO2 and coastal wetlands are flooded as sea level rises releasing more methane.

   

   Figure 2 CO2 and temperature appear well-correlated in a gross sense but there are some significant deviations. At glacial terminations, the alignment is as good as observed for methane. But upon descent into the following glaciation there is a time lag between CO2 and temperature of several thousand years. Petit et al [1] make the observation but fail to offer an explanation and to take the significance into account preferring to make instead unsupportable claims about CO2 and CH4 amplifying orbital forcing.

   The pattern of CO2 is markedly and significantly different to methane. At the terminations  temperature and CO2 are quite closely aligned. But at each inception there is a time lag of several thousand years. In fact at the post-Eemian inception the time lag is ~14,000 years (Figure 4). Again, the reasons for this behaviour are well understood. At the termination melting permafrost and warming ocean releases CO2 immediately which therefore follows temperature up. At the inception a time lag occurs through a combination of two processes. The first is that it takes time for the oceans to cool and to pump down CO2 – it is easier to release CO2 from a bottle of Champagne than it is to put it back in. The second is that dying Boreal forest adds CO2 to the atmosphere combatting the desire for CO2 to fall with temperature.

   Regardless of the process, the large time lag at the inceptions shows that CO2 and CO2 feedback is not significant in controlling the glacial cycles. All the data are adequately explained by both CO2 and CH4 responding to changes in temperature and not causing it!

   

   Figure 3 CO2 lags methane in a manner similar to the lag between CO2 and temperature. This time lag requires an explanation rooted in the geochemical environments that are both emitting and sequestering these gases. Petit et al [1] devote surprisingly little space to explaining the physical processes behind the CO2 and methane variations at all.

   To close this out, the plot of CO2 and CH4 shows that they are not closely aligned (Figure 3). The CO2 lag at the inception shows that CO2 and CH4 respond in different ways to cooling. This is not surprising since these two gasses have different geochemical pathways.

   

   Figure 4 Detail of the post-Eemian inception.

   Figure 4 shows detail of the post-Eemian inception. Temperature at Vostok fell by 4.5˚C without any assistance or amplification from falling CO2. The idea that variations in CO2 amplify orbital effects is basically disproven by this data. As I have already said all of the CO2 and CH4 variance in Vostok can be explained by dT causing dCO2 and dCH4 and not the other way around.

   The climate science community has fretted over the time lag for years but the response to it is nothing short of astonishing. In 2013 Parrenin et al [3] published a paper that revised the ice age to gas age corrections and their abstract says this:

   Understanding the role of atmospheric CO2 during past climate changes requires clear knowledge of how it varies in time relative to temperature. Antarctic ice cores preserve highly resolved records of atmospheric CO2 and Antarctic temperature for the past 800,000 years. Here we propose a revised relative age scale for the concentration of atmospheric CO2 and Antarctic temperature for the last deglacial warming, using data from five Antarctic ice cores. We infer the phasing between CO2 concentration and Antarctic temperature at four times when their trends change abruptly. We find no significant asynchrony between them, indicating that Antarctic temperature did not begin to rise hundreds of years before the concentration of atmospheric CO2, as has been suggested by earlier studies.

   It has to be considered a dubious practice to change a calibration to make data more amicably fit the model. But the real problem here is focussing on the trivial time lag of a few hundred years  at the termination while totally ignoring the 14,000 year lag at the inception. Since CH4 and CO2 are largely measured on the same samples and use the same ice age to gas age calibration, it becomes impossible to fix the inception time lag via a recalibration of the data since CH4-T has a perfect fit across the inception (Figure 5).

   

   Figure 5 Vostok dT and dCH4 over the post-Eemian glacial inception. CH4 follows temperature down as cooling causes the sinks to exceed the sources and the fact that CH4 has a short residence time in the atmosphere. 

   The 2013 GSL addendum picks up on this point saying:

   While the older data reported in the initial GSL statement on climate change suggested that the rise in Antarctic temperature at the end of the last glacial maximum probably began a few centuries before the CO2 showed any reaction, new data indicate that CO2 most likely rose at the same time as temperature in East Antarctica [44,45,46] and ahead of the global rise in temperature [1]. This is new and stronger evidence that CO2 is an agent capable of turning a local and small climate change in insolation into a global event.

   This statement simply ignores the 14000 pound elephant in the room. I would appreciate the authors of the GSL statement clarifying their position on the status of CO2, temperature and CH4 at the inceptions and what this part of the ice core data tells us?

   What Petit et al said

   Petit et al make the correct observations confirming all of the observations I make above:

   The CO2 decrease lags the temperature decrease by several kyr and may be either steep (as at the end of interglacials 5.5 and 7.5) or more regular (at the end of interglacials 9.3 and 11.3). The differences in concentration – time profiles of CO2 and CH4 are reflected in the power spectra (Fig. 4). The 100-kyr component dominates both CO2 and CH4 records. However, the obliquity and precession components are much stronger for CH4 than for CO2.

   What they fail to do is to draw the correct conclusion from the several thousand year time lag which is that CO2 is not a potent driver of climate change. Instead they make a number of conflicting and unsupported statements:

   Atmospheric concentrations of carbon dioxide and methane correlate well with Antarctic air-temperature throughout the record. Present-day atmospheric burdens of these two important greenhouse gases seem to have been unprecedented during the past 420,000 years.

   and

   There is a close correlation between Antarctic temperature and atmospheric concentrations of CO2 and CH4 (refs 5, 9). This discovery suggests that greenhouse gases are important as amplifiers of the initial orbital forcing and may have significantly contributed to the glacial–interglacial changes [14–16].

   These two statements directly contradict statement 1 where it is recognised that at inceptions CO2 and temperature are not correlated at all. They go on to say:

   The overall correlation between our CO2 and CH4 records and the Antarctic isotopic temperature [5,9,16] is remarkable (r2 1⁄4 0.71 and 0.73 for CO2 and CH4, respectively). This high correlation indicates that CO2 and CH4 may have contributed to the glacial–interglacial changes over this entire period by amplifying the orbital forcing along with albedo, and possibly other changes [15,16]. We have calculated the direct radiative forcing corresponding to the CO2, CH4 and NO changes [16]. The largest CO2 change, which occurs between stages 10 and 9, implies a direct radiative warming of DTrad 1⁄4 0.75˚C. Adding the effects of CH4 and N2O at this termination increases the forcing to 0.95˚C (here we assume that N2O varies with climate as during termination I37). This initial forcing is amplified by positive feedbacks associated with water vapour, sea ice, and possibly clouds (although in a different way for a ‘doubled CO2’ situation than for a glacial climate [38]). The total glacial–interglacial forcing is important (3 Wm−2), representing 80% of that corresponding to the difference between a ‘doubled CO2’ world and modern CO2 climate. Results from various climate simulations [39,40] make it reasonable to assume that greenhouse gases have, at a global scale, contributed significantly (possibly about half, that is, 2–3˚C) to the globally averaged glacial–interglacial temperature change.

   It is impossible for geologists and glaciologists to ignore this simple observation:

   The CO2 decrease lags the temperature decrease by several kyr

   Doing so has led science, society, politics and the economy on a wild goose chase. Does the Geological Society of London stand ready to correct this gross error?

   [1] J. R. Petit*, J. Jouzel†, D. Raynaud*, N. I. Barkov‡, J.-M. Barnola*, I. Basile*, M. Bender§, J. Chappellaz*, M. Davisk, G. Delaygue†, M. Delmotte*, V. M. Kotlyakov¶, M. Legrand*, V. Y. Lipenkov‡, C. Lorius*, L. Pe ́ pin*, C. Ritz*, E. Saltzmank & M. Stievenard† (1999) Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. NATURE | VOL 399 | 3 JUNE 1999 |

   [3] Synchronous Change of Atmospheric CO2 and Antarctic Temperature During the Last Deglacial Warming: F. Parrenin,1* V. Masson-Delmotte,2 P. Köhler,3 D. Raynaud,1 D. Paillard,2 J. Schwander,4 C. Barbante,5,6 A. Landais,2 A. Wegner,3† J. Jouzel2. 1 MARCH 2013 VOL 339 SCIENCE
   • Hubert Flocard says:

     January 15, 2018 at 2:10 pm

     I have a question to you and/or to the geologists.
     First three remarks
     1) What we, inhabitants of earh, are presently interested in, is a potential warming of the earth as a result of large human emissions of CO2 and CH4.
     2) In your discussion you concentrate on the delay between dCO2 and dT in periods when earth is cooling not warming.
     3) From the curves you show in the periods when dT>0, the T and CO2 curves appear synchronous. Sometimes the CO2 curve is slightly ahead (T increase at – 325 000 y).

     Questions
     1) Does your discussion focusing on geological periods which do not correspond to present situation render your criticism of geologists irrelevant for us humans living in a XXIst century with 400 ppm CO2 concentration and just show that not everything is understood ?
     2) What could be the explanation for this asymetry in the behavior of CO2 curve with respect to T curve when T is growing or decreasing ?
     3) Could the fact that CO2 lingers more in the atmosphere when T is decreasing while it is synchronous when T is growing explain why the temperature gradient is steeper when T grows that when T decreases ?

     Hubert
     • Euan Mearns says:

       January 16, 2018 at 9:08 am

       Hi Hubbert, I replied to your questions yesterday, but somehow the comment got lost.

       The rise and fall of CO2 needs to be considered in terms of kinetics between sources and sinks. When the sources exceed the sinks CO2 rises and vice versa. At the terminations (end of glaciation) the N hemisphere ice sheets collapse quickly and the climate warms quickly. Permafrost around the ice sheets releasing CH4 and CO2. Oceans warm, releasing CO2. Sea level rises flooding coastal bogs releasing CH4. All this happens together and quickly. This is what the splendid data tells us.

       At the inception (the onset of glaciation) CH4 falls with temperature. Here the CH4 sink is actually CO2. The residence time of methane~8 years before it oxidises to CO2 + H2O. And so when the accelerated release gets switched off, CH4 simply “disappears”. At the inception, it is different for CO2. First, at the inception we get a new source in the form of dying boreal forest. And second we can speculate there is a time lag between the onset of glaciation and the oceans cooling – that’s what the data tells us. Thus it takes time for the cooling planet to pump CO2 down. The vital observation here is that it is climate change that drives CO2 and not vice versa.

       Finally, think about the twin towers. They took many years to build and only a few moments to collapse. Once the ice sheets begin to collapse it happens quickly. When they start to grow again, the process is more gradual and ragged. That is why the data that explains this story are not symmetrical. The final part of the riddle is that from 2.8 to 1.2 million years ago the glaciations beat to a ~41,000 year drum. but from 1.2 million year ago to present they have begun to beat to multiples of 41,000 years meaning that the forces that once caused the ice sheets to collapse regularly have been overcome. We published this in our 2016 Alpine Journal article. It has since been confirmed in this paper:

       A simple rule to determine which insolation cycles lead to interglacials
       P. c. Tzedakis1, M. crucifix2, T. Mitsui2 & e. W. Wolff3
       doi:10.1038/nature21364

       Notably Dr Wolff is a member of the Geol Soc working group.

       
   • David B. Benson says:

     January 16, 2018 at 8:56 am

     I link to
     http://www.climatedata.info/proxies/ice-cores/
     because there is a graph of EPICA Dome C temperature proxy and CO2 as well as a comparison of EPICA Dome C and Vostok temperature proxies. The former does not appear to show a large lag of CO2 downtrend at the post-Eemian glacial inception and the later suggests wide horizontal error bars for the temperature proxies, under the assumption that the temperatures were actually highly correlated at the two sites.

     Possibly Euan Mearns would care to encorporate these in the analysis of Antarctic temperatures versus carbon dioxide levels over time.
     • Euan Mearns says:

       January 16, 2018 at 9:23 am

       David, I think you need to get new specs. The CO2 time lag at the inceptions is plain to see.

       

       More importantly, I obviously wanted to cross check the Vostok data with EPICA but I have never been able to find CO2 data for the 0 – 400,000 year interval. Charts exist with the data on it, like the one you linked to, but I have never been able to find the EPICA CO2 data. I have queried both Colin Summerhayes and Clive Best on these pages about this and they post links to the supposed data, but I have never been able to find it. Perhaps you could post a link to it and I will make my own chart.
       • David B. Benson says:

         January 16, 2018 at 10:37 am

         Dear Euan, I recently had my eyes checked and despite having artificial lens as my cataracts were removed, with reading glasses I see 20/20. 🙂

         The variations between the temperature proxy and CO2 for ealier inceptions is plain. My comment was only about the most recent glacial inception, where possibly the lag is less. Note well the graph comparing the temperature proxies for the two ice cores.

         In my explorations using this little mobile device I found a site which pointed out that the source of water vapor over Greenland changed from solely the Atlantic Ocean to include the Pacific Ocean as well during the Younger Dryas initiation. As the two oceans have different isotope ratios, this made for a difficult to interpret temperature proxy in Greenland ice cores.

         Much the same shift might have occurred in the two Antarctic ice cores in question, confounding the dating. I only offer the suggestion as a partial answer to why the temperature proxies give such different datings to what are presumably simultaneous events.

         As to the source of the graphs in the link, I suggest asking the author. My ability to find stuff using this mobile device is severely limited. Oh yes, there is a central source for all ice core data on a NOAA site, but it appears to be quite a pain to use it.

         My searching is unable to locate a single paper giving the carbon dioxide for any of the 4 northern Greenland ice cores, those deep enough to have a record for the post-Eemian glacial inception.

         Despite all this, I opine you have the beginnings of a useful contribution to the peer reviewed literature, should you care to continue.
         • Euan Mearns says:

           January 16, 2018 at 5:21 pm

           Variations in input isotope ratio may vary the absolute temperature estimate but not the timing or pattern.

           And remember, every time you call into question the veracity of the T curve, you also call into question the excellent fit of methane to the temperature curve (Figure 1).
       • Clive Best says:

         January 17, 2018 at 9:32 pm

         Euan,

         I think this is the CO2 data that I am using !

         ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/antarctica2015co2composite.txt

         It is really a composite .

         # Description_and_Notes
         # Description: Revised EPICA Dome C and Antarctic composite ice core atmospheric CO2 data. This new version of CO2 composite
         # replaces the old version of Luthi et al. (2008), which contains the analytical bias described in Bereiter et al. 2015
         # and lower quality data in other sections. For details about the improvements relative to the previous version see supplementary
         # information of Bereiter et al. 2015. For detailed references of all records refer to the supplemetary information of
         # Bereiter et al. 2015. For latest anthropogenic data refer to NOAA/Mauna Loa record. Age unit is in years before present (yr BP)
         # where present refers to 1950 AD. Note, not all records shown in Excel worksheet “all records” are part of the composite.
         • Euan Mearns says:

           January 17, 2018 at 10:42 pm

           Clive, thanks. I’ve had a look at your link and would characterise the data as a dogs dinner. We have what is one of the biggest scientific questions of all time before us. And we can’t be bothered, it seems, measuring CO2 through the whole of the EPICA ice core.

           Eric Wolff (UoCambridge) is a member of the 2010 Geol Soc Working Group and evidently chaired the science committee in charge of EPICA coring and analysis.

           Eric Wolff is a Royal Society Research Professor in the Department of Earth Sciences at Cambridge University. After graduating as a chemist, he has studied ice cores from the Antarctic and Greenland for the past 30 years, using them to understand changing climate, as well as changing levels of pollution in remote areas. He also carries out research into the chemistry of the lower parts of the Antarctic atmosphere. Until June 2013, he led a programme at the British Antarctic Survey. He chaired the science committee of the European Project for Ice Coring in Antarctica (EPICA), which produced 800,000 year records of climate from the Dome C (Antarctica) ice core and co-chairs the international initiative (IPICS) to coordinate future ice core research. His main research goal is to understand the causes of climate evolution over recent glacial cycles. He was elected as FRS in 2010. He chairs the Royal Society’s Global Environmental Research Committee, and led the Royal Society team in a joint initiative with the National Academy of Sciences on explaining climate science “Climate change: evidence and causes” in 2013.
3. David E says:

   January 15, 2018 at 9:11 am

   Thank you for the above summary which I find very clearly presented and reasoned. I would like to make the following points:

   What is climate change, and how do geologists know about it?

   The sentence ‘[the climate] is never static, but subject to constant disturbances, sometimes minor in nature and effect, but at other times much larger’ is perfectly correct but it is incomplete. It ignores the fact that the climate system is chaotic. Even if it was subject to no ‘external’ disturbances whatsoever (e.g. unchanged Earth orbit, constant solar output, no change in atmospheric composition etc;), it would still exhibit changes at all timescales.

   What drives climate change?

   Again this paragraph fails to mention the chaotic nature of the climate system itself (see above). The system drives itself to change.

   Secondly, and this may not be surprising from a group of scientists heavily biased towards the geological disciplines, a major source of climate change is undoubtedly biological. The evolution of photosynthesis and thus the arrival of oxygen in the atmosphere undoubtedly had significant climatic consequences. Current changes in atmospheric composition are, as correctly noted, due to biological causes (the activities of an interesting organism called homo sapiens and associated species).

   What is the Greenhouse Effect?

   This explanation is misleading because it attributes the so-called ‘Greenhouse Effect’ only to the presence in an atmosphere of ‘certain gases… so-called greenhouse gases’. The ‘so-called greenhouse gases’ in the Earth’s atmosphere are a necessary but not a sufficient condition for the greenhouse effect. The effect itself also depends on what is known as ‘pressure broadening’, for which a dense atmosphere of any composition, is required. In the Earth’s case, this role is carried out chiefly by nitrogen (78%) and oxygen (21%) even though these are not considered as ‘so-called greenhouse gases’.

   To illustrate this point, consider the case of Mars whose atmosphere contains (per unit column area) 40 times as much carbon dioxide as Earth’s yet whose greenhouse effect is an order of magnitude less than Earth’s.

   If we compare the one-bar pressure levels on planetary bodies with dense atmospheres in the solar system (so Venus, Earth, Jupiter, Saturn, Titan, Uranus and Neptune) we find that the atmospheric opacities down to this level are comparable even though chemical compositions vary vastly.

   The exact chemical composition of an atmosphere does, of course, have a bearing on opacity but the most important element is atmospheric bulk which causes the broadening of the infrared absorption/emission lines that are responsible for the greenhouse effect.

   Many of the changes in the Earth’s climatic history may therefore be due to variations in bulk constituents in the atmosphere, such as nitrogen and oxygen, quite as much as trace components such as carbon dioxide.

   When was CO2 last at today’s level, and what was the world like then?

   ‘The most recent estimates [35] suggest that at times between 5.2 and 2.6 million years ago (during the Pliocene), the carbon dioxide concentrations in the atmosphere reached between 330 and 400 ppm.’

   I don’t believe we can make any such conclusion.

   The ice core results are subject to methodological doubts, particularly as to what happens when the cores are brought up (physically) and down to ambient atmospheric pressure – the solubility of carbon dioxide in ice/water is pressure dependent.

   Furthermore there are other methods of assessing (pre-)historical levels of atmospheric carbon dioxide. A particularly overlooked one is that of plant stomata sizes (obtained from fossils). The historical plant stomata data is in no way compatible with the ice core data.

   There are methodological doubts about the stomata data, too, of course. But it is clear that one of these two methods is unreliable. It is also very possible that both are unreliable.

   Finally there is a problem of statistical sampling intervals. As we go back in time, the time resolvability of samples (whether ice cores or fossilised plants) becomes more and more uncertain – we don’t know exactly when these samples derived. An inhabitant of Alpha Centauri attempting to detect the 20th/21st century spike in carbon dioxide levels on the basis of ice cores or fossil plants would not be able to do so without a sampling frequency of at least once per century.

   But going back thousands or millions of years, we are not able to sample at such frequencies. In other words, if humans had evolved in prehistory, pumped loads of carbon dioxide into the atmosphere over a time period of a century, and then vanished, we would not be able to resolve this event in the currently available geological record.

   We therefore cannot draw the above conclusion that current carbon dioxide levels have not been reached in the last 5 million years on the basis of geological evidence. This is furthermore the case given that excursions in atmospheric carbon dioxide based on (fast-moving) biological factors are very likely to have taken place then, as they are doing right now.
   • donb says:

     January 16, 2018 at 12:22 am

     I agree with some of these comments above but disagree with others.

     Water vapor is a far more important determinant of warming then CO2, and Mars has little H2O.

     Pressure broadening is the phenomenon by which increased gas pressure broadens a given quantum absorption band for that gas. As N2, O2, and Ar absorb little in the IR or visible, they have little effect on CO2 IR absorption. However, the time constant for absorption and emission of an IR photon by a gas molecule in the atmosphere is very short (kinetic transfer of absorbed IR energy is even shorter), such absorption and emission processes are not the major cause of greenhouse effects. Rather, the cause is an increase in the final emission height for IR emission (where the photon escapes to space) produced by increasing gas concentration, AND the fact that Earth’s atmospheric temperature (in most places) decreases with altitude at the emission height, thereby slowing the rate of emission. So, the vertical temperature structure of a given planet would play a role in any greenhouse effects.

     I point out that CO2 in ice cores is measured in bubbles, not CO2 dissolved within the ice/water. However, CO2 diffusion among phases over time is hard to estimate.
     • David E says:

       January 16, 2018 at 1:16 pm

       Hi donb,

       N2, O2 and Ar have a crucial role to play in the opacity of the Earth’s atmosphere because they provide 99.7% of the gas pressure which is responsible for pressure broadening.

       In fact it is not really correct to say that absorption takes place by, say, H2O or CO2 molecules. In the lower atmosphere (below about 50km), absorption takes place by interception of photons by DIMERS (this is what pressure broadening means). The most important dimers are therefore (in order): N2:H2O, O2:H2O, N2:CO2 and O2:CO2.

       Under pressure (i.e. ice buried underground), CO2 ‘dissolves’ (if you want to use that term) or combines chemically with ice to form a clathrate. When the pressure releases (e.g. when you take an ice bore), this reaction reverses and some/all of the CO2 returns to the gas phase.
       • donb says:

         January 16, 2018 at 3:06 pm

         Hi David,
         Pressure broadening of IR absorption is interpreted at both a molecular kinetic level and at a quantum level. What determines the range of IR energy that an electron bond can & will absorb is what it can do with that absorbed energy. A hypothetical CO2 molecule alone is limited in the IR energy range of a photon it can absorb because that energy must initially go entirely into the particular C-O bond. But, when many other molecules are present and colliding with that CO2 (e.g. around one atmospheric pressure), the collision frequency exceeds the time constant for IR absorption and relaxation. In this case, the IR photon absorbed may have a wider range of energy because some of the absorbed energy can be immediately shared and distributed into other bonds of colliding molecules. Thus, increased gas pressure broadens the IR absorption.

         So in this sense N2 and O2 play a role in pressure broadening, although only the CO2 determines IR absorption. N2 and O2 certainly receive much of the kinetic effects of IR warming. But N2 and O2 cannot absorb IR because they have no permanent dipole moment. (CO2 actually does not have such either, but has induced dipole.)
         • David E says:

           January 16, 2018 at 3:17 pm

           Hi donb,

           I totally agree with your first paragraph, I think we are expressing the same thing in different ways.

           You’re right that CO2 does not have a permanent dipole moment (unlike H2O) but actually this is not relevant to IR absorption.

           What’s important is that some of the vibrational modes (flexing along the CO2 bond axis) do produce a CHANGE in the dipole moment. This vibration has a spectral line associated with it.

           N2 and O2 also lack a permanent dipole moment. They also have, in vacuo, no vibrational modes associated with a change in dipole moment. So an isolated N2 or O2 molecule will not have an IR spectrum.

           Nonetheless N2 and O2 DO interact with IR in a real atmosphere. This is not only through their action in pressure broadening (by forming a dimer with molecules such as H2O or CO2) but also because collisions between N2/O2 and other molecules will produce TEMPORARY dipole moments (due to asymmetries in their outer electron clouds). These will create IR spectra (but very blurred ones). They contribute to so-called ‘continuous absorption’ spectra that are important as atmospheres get denser.

           So N2:N2, N2:O2 and O2:O2 dimers also have a (small) contribution to Earth’s greenhouse effect. This effect is more pronounced in colder atmospheres such as Titan’s where N2:N2 absorption is significant.
4. Javier says:

   January 15, 2018 at 9:39 am

   What are in fact the grounds for concern about global warming?

   Climate change is a reality attested by past records. Concerns about preparing and adapting for climate change are positive. However, the idea that we can prevent climate change from happening is dangerous and might be anti-adaptive. Certain energy policies that are doubtful to have any effect on climate change could make us less able to adapt.

   Physics shows that adding carbon dioxide leads to warming under laboratory conditions. It is generally assumed that a doubling of CO₂ should produce a direct forcing of 3.7 W/m² [1], that translates to a warming of 1°C (by differentiating the Stefan-Boltzmann equation) to 1.2°C (by models taking into account latitude and season). But that is a maximum value valid only if total energy outflow is the same as radiative outflow. As there is also conduction, convection, and evaporation, the final warming without feedbacks is probably less. Then we have the problem of feedbacks that we don’t know and can’t properly measure. For some of the feedbacks, like cloud cover we don’t even know the sign of their contribution. And they are huge, a 1% change in albedo has a radiative effect of 3.4 W/m² [2], almost equivalent to a full doubling of CO₂.

   So in essence we don’t know how much the Earth has warmed in response to the increase in CO₂ for the past 67 years, and how much for other causes. That is the reason why, after expending billions on the question of climate sensitivity to CO₂, we have not been able to constrain its value range between 1.5° C and 4.5° C [3] in the 39 years that have passed since the Charney Report was published [4]. A clear scientific failure.

   Climate is a very complex system, and adding CO₂ to the atmosphere in great amounts since 1950 led first to cooling, then to warming, and lately to a stilling of temperatures until the 2014-16 El Niño. A different explanation is required for every period when the expected warming doesn’t take place, an approach that leaves Occam’s beard unshaved.

   A very big assumption underlies the 2010 Statement and 2013 Addendum by the Geological Society of London. And in science assumptions are very dangerous, because they are not subjected to the scientific method. The big ugly assumption in these reports is that past changes in CO₂ were responsible for planetary temperature changes. At most, what we can extract from past data is a correlation between both, and even that correlation is tentative, as the quality and nature of the data makes questionable to extract the conclusions that the statement and addendum claim. We do know that temperature affects CO₂ levels, as an increase in temperature leads to a release of CO₂ by the oceans, due to gas solubility dependence on temperature. So the causality is confusing. Is the CO₂ mainly the result of temperature changes or is the temperature mainly the result of CO₂ changes? We don’t know. The proposed positive feedback in which each one potentiates the other must be very limited, if significant, or we wouldn’t be here to start. The extraordinary claims by the authors of the Geological Society reports are not accompanied by extraordinary evidence. Quite the contrary.

   We believe that over hundreds of millions of years CO₂ levels have been decreasing manyfold in Earth’s atmosphere. We also believe that over that time Earth’s temperature has been kept within a very narrow range compatible with life. So a clear relationship between both does not exist. Some evidence suggests ice ages are compatible with high CO₂ values. “The last (and thus best known) Late Ordovician Saharan ice sheet formed during a time of high (16 × the modern value) atmospheric CO₂. The ice sheet may have been comparable in size to the last North American Laurentide Ice Sheet (∼36×10⁶ km³) and expanded eastward from North Africa onto the Arabian platform.” [5].

   Using the Paleocene-Eocene Thermal Maximum (PETM) as an analog is misleading. We don’t know what caused it, although hypotheses have been proposed. However, we must consider that the PETM took place during a warm (hothouse) period of the planet, while currently we are in a cold (icehouse) period, as attested by the massive ice sheets over Antarctica and Greenland. The long-term real danger for humankind is a return to the average glacial conditions of the Late Pleistocene, as our interglacial is already long in the tooth. The report final paragraph: “the massive injection of carbon into the atmosphere 55 million years ago that led to the major PETM warming event,” shows the authors’ overreaching assumption. They simply lack the evidence to say that CO₂ caused the PETM, or even to say how much of the warming was caused by the increase in CO₂.

   The authors also talk about more recent abrupt shifts in climate during the last glacial stage (100,000 – 11,500 years ago), known as Dansgaard-Oeschger events. This is the best example we have of abrupt climate change (it was actually the basis of that concept), but the report should mention that although the temperature shifts were accompanied by changes in methane, CO₂ records in most cases don’t show them [6]. The best example we have of abrupt climate change, not driven by orbital changes, has nothing to do with CO₂.

   So the first question we should ask ourselves is how unusual is present global warming. This is a difficult question to answer, as we now measure temperatures with a resolution we cannot achieve with past temperatures. Last 2015-16 El Niño caused a temperature increase of 0.4°C over the course of two years that is now being retraced. We are not able to see this short-term fluctuations in past temperatures from proxies that at best have a decadal resolution and represent local conditions. And most proxies cannot be trusted to faithfully reproduce recent changes as they usually lack enough resolution. Biology offers us an answer. The tree line represents the limit where climatic conditions allow the establishment of new trees. Every year new tree seedlings attempt to establish themselves further up the mountain and generally fail. 52% of studies show the tree line has been going up over the past century, and only 1% show a line receding, indicating that mountain trees are generally responding to global warming and increased CO₂ by raising the tree line [7]. However many studies show that at most places present tree line is still 100-250 meters below Holocene Climatic Optimum tree line levels [8][9][10].

   

   https://i.imgur.com/vcfr3pm.png

   Figure 1. The approximate Holocene timberline and treeline elevation (m above sea level) in the Swiss central Alps based on radiocarbon-dated macrofossil and pollen sequences [8].

   We have to take into account that present elevated CO₂ levels are a huge bonus to tree growth, so if placed at similar climatic conditions present trees would have a significant but unquantifiable advantage over Early Holocene trees. So the first answer to the question of how unusual is present global warming is that it is not unusual enough to have returned us to Holocene Climatic Optimum conditions. Therefore, present global warming is within Holocene variability. Reasoner and Tinner [8] quantify the summer temperature difference in the Alps between now and the Holocene Optimum as: “Assuming constant lapse rates of 0.7° C / 100 m, it is possible to estimate the range of Holocene temperature oscillations in the Alps to 0.8–1.2° C between 10,500 and 4,000 cal. yBP, when average (summer) temperatures were about 0.8–1.2° C higher than today.”

   Without question we have undone most or all of the cooling that took place between the Medieval Climatic Anomaly at ~1100 AD and the bottom of the Little Ice Age at ~1650 AD. Is this countertrend, multi-century, global warming we are experiencing worrisome? By objective reasons, the Little Ice Age was very worrisome. Glaciers advanced to their highest Holocene extent, destroying farms and villages. Crops failed repeatedly causing famines like the one that killed one third of Finland’s population in 1696. Population in Iceland declined from 77,500 in 1095 to 38,000 in 1780 [11]. Conditions have improved greatly since the Little Ice Age, coinciding with Global Warming.

   It is only since 1950 that anthropogenic forcing (human GHG emissions) has really taken off. Professor Phil Jones, former director of the Climatic Research Unit at the University of East Anglia, admitted in an interview on the BBC in 2010 [12], that “for the two periods 1910-40 and 1975-1998 the warming rates are not statistically significantly different.”

   Period Length Trend (° C per decade) Significance
   1860-1880 21 0.163 Yes
   1910-1940 31 0.15 Yes
   1975-1998 24 0.166 Yes
   1975-2009 35 0.161 Yes

   So to explain why the warming rate has not accelerated despite the huge addition of CO₂, we are told that prior to 1950 global warming was mostly natural, and after 1950 is human-made. A convenient explanation for which there is no evidence, just assumptions on top of assumptions.

   And it is not only temperature, but rising sea levels that show little to no acceleration [13], in sharp contrast to predictions. Reducing our emissions will not significantly affect sea level rate of increase, because increasing them didn’t.

   

   https://i.imgur.com/mZvIuUA.png

   Figure 2. The rise in sea level [14] predates IPCC calculated anthropogenic forcing [15], and shows no clear response to it.

   The CO₂ hypothesis of global warming has been consistently wrong in its predictions. In science, if your hypothesis predictions fail, there is something wrong with it. In 1990 the IPCC predicted a warming rate of 0.3° C/decade [16] for the next century, nearly double the observed rate for the past 27 years. It also predicted a 1° C warming by 2025 (0.5° C observed). In 2001 the IPCC predicted that milder winter temperatures would decrease heavy snowstorms [17]. In 2007 the IPCC claimed that by 2020, between 75 and 250 million of people were projected to be exposed to increased water stress due to climate change. In some countries, yields from rain-fed agriculture could be reduced by up to 50 % [18]. It later had to recant that prediction. Arctic sea ice predictions have also been consistently wrong with many polar scientists predicting the demise of summer Arctic sea ice by dates as early as 2008 [19] to as late as 2030 [20]. The reality is that in September 2017 there was more sea ice in the Arctic than 10 years earlier. And we could continue with many other predicted climate horrors that have failed to pass, regarding polar bears, sinking nations, food shortages, climate refugees, and extreme weather events, too long to detail [21], but that show a shameless promotion of alarmism based on unrealistic worst case scenarios.

   Most of these predictions arise from models that have not been properly validated and do not adequately represent the climate response to increased CO₂. The current crop of models used by IPCC, CMIP5, shows a worrisome deviation from observations just a few years after being initialized in 2006 (figure 2).

   

   https://i.imgur.com/3Hbjtsz.png

   Figure 3. Model CMIP5 temperature anomaly under the RCP 4.5 scenario, compared to observed HadCRUT4 temperature anomaly, both relative to 1961-1990 baseline.

   Despite the recent El Niño, temperatures do not show a significant deviation from a linear increase since 1950, while models predict a much higher rate of warming.

   Geologists should be aware that some emission scenarios being promoted as business as usual are completely unrealistic. RCP 8.5 contemplates a shift to a mainly coal economy with total disregard for coal reserves. How can unlimited coal growth be business as usual? Fossil fuels are finite resources and their abundance has to be taken into account. Climate alarmism is being promoted as if fossil fuels were unlimited. The burning of 100 % of oil, gas, and coal proved reserves (BP Factbook of World Energy) would increase atmospheric CO₂ levels to 620 ppm [22]. By using a supply-side analysis the value reached is equivalent, 610 ppm maximum this century [23]. RCP 8.5 based predictions require 950 ppm by 2100. The alarmist projections clearly lack any rational basis, and are agenda-driven. The reality is that we have had no problem adapting to a global warming that has been taking place since at least 1860, and there is no evidence that we will have problems adapting to future global warming until it ends.

   By writing the 2010 statement and 2013 addendum, the authors are just setting the Geological Society of London in line with the politically promoted consensus on global warming. It is not different from what many other scientific societies have done recently, but it is a breach of the scientific principles that should guide the Society and an attack on the plurality of views that characterize healthy scientific debate over a hypothesis that so far is short on evidence and long on claims.

   As a scientist myself, with an interest in the history of science, I am well aware that skepticism and disagreement foster scientific progress, while group thinking, enforced views, and shared assumptions are the sign of stagnation in a mistaken paradigm.

   [1] IPCC TAR. http://www.ipcc.ch/ipccreports/tar/wg1/
   [2] Farmer G.T., Cook J. (2013) Earth’s Albedo, Radiative Forcing and Climate Change. In: Climate Change Science: A Modern Synthesis. Springer, Dordrecht.
   [3] IPCC AR5. http://www.ipcc.ch/report/ar5/wg1/
   [4] Charney Report (1979). http://www.ecd.bnl.gov/steve/charney_report1979.pdf
   [5] Eyles, N. (2008). Glacio-epochs and the supercontinent cycle after ∼ 3.0 Ga: tectonic boundary conditions for glaciation. Palaeogeography, Palaeoclimatology, Palaeoecology, 258 (1), 89-129.
   [6] Ahn, J., & Brook, E. J. (2014). Siple Dome ice reveals two modes of millennial CO2 change during the last ice age. Nature communications, 5.
   [7] Harsch, M. A., Hulme, P. E., McGlone, M. S., & Duncan, R. P. (2009). Are treelines advancing? A global meta‐analysis of treeline response to climate warming. Ecology letters, 12 (10), 1040-1049.
   [8] Reasoner, M. A., & Tinner, W. (2009). Holocene treeline fluctuations. In Encyclopedia of Paleoclimatology and Ancient Environments (pp. 442-446). Springer Netherlands.
   [9] Cunill, R., Soriano, J. M., Bal, M. C., Pèlachs, A., & Pérez-Obiol, R. (2012). Holocene treeline changes on the south slope of the Pyrenees: a pedoanthracological analysis. Vegetation history and archaeobotany, 21 (4-5), 373-384.
   [10] Pisaric, M. F., Holt, C., Szeicz, J. M., Karst, T., & Smol, J. P. (2003). Holocene treeline dynamics in the mountains of northeastern British Columbia, Canada, inferred from fossil pollen and stomata. The Holocene, 13 (2), 161-173.
   [11] Lamb, H. H. (1995). Climate, history and the modern world. 2nd edition. Routledge. London. Pg. 172.
   [12] BBC News. February, 3, 2010. http://news.bbc.co.uk/2/hi/science/nature/8511670.stm 13
   [13] Fasullo, J. T., Nerem, R. S., & Hamlington, B. (2016). Is the detection of accelerated sea level rise imminent?. Scientific reports, 6, 31245.
   [14] Jevrejeva, S., Moore, J. C., Grinsted, A., & Woodworth, P. L. (2008). Recent global sea level acceleration started over 200 years ago?. Geophysical Research Letters, 35 (8).
   [15] IPCC AR5. https://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter08_FINAL.pdf
   [16] IPCC FAR. 1990. http://www.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_spm.pdf
   [17] IPCC TAR WG2. 2001. http://www.ipcc.ch/ipccreports/tar/wg2/index.php
   [18] IPCC AR4 Synthesis Report. 2007. https://www.ipcc.ch/publications_and_data/ar4/syr/en/mains3-3-2.html
   [19] National Geographic. June 20, 2008. http://news.nationalgeographic.com/news/2008/06/080620-north-pole.html
   [20] The Telegraph. September 16, 2010. http://www.telegraph.co.uk/news/earth/earthnews/8005620/Arctic-ice-could-be-gone-by-2030.html
   [21] Javier 2017. Some Failed Climate Predictions. https://wattsupwiththat.com/2017/10/30/some-failed-climate-predictions/
   [22] Fernando Leanme 2014. https://21stcenturysocialcritic.blogspot.com.es/2014/09/burn-baby-burn-co2-atmospheric.html
   [23] Wang, J., Feng, L., Tang, X., Bentley, Y., & Höök, M. (2017). The implications of fossil fuel supply constraints on climate change projections: A supply-side analysis. Futures, 86, 58-72.
   • Roger Andrews says:

     January 15, 2018 at 9:42 pm

     Javier: An excellent summary. Thank you

     A few more points to ponder:

     200 years have gone by since human emissions first began to raise atmospheric CO2 concentrations above the 280 ppm “pre-industrial” level. So far these increased CO2 levels have had only two impacts that can be regarded as proven. One is a minor decrease in upper ocean pH, and the other a large increase in vegetation growth rates.

     With one exception all of the other alleged impacts of man-made CO2 are either speculative or contradicted by the available evidence. Man-made CO2 is supposedly causing more extreme weather events, hurricanes, tropical storms, etc., but in the AR5 even the IPCC had to admit that it was unable to find any evidence that it is. Man-made CO2 is alleged to be causing species to go extinct, but despite strenuous efforts no one has yet been able to identify a single species that has been driven extinct by it. It’s supposed to be killing people, but no one can put a name to anyone who can be conclusively proven to have died because of it. It’s alleged that it’s spreading diseases, but there’s no evidence for that either.

     The exception is temperature. Here the conclusions are predetermined. The climate models that are used to simulate temperatures are bound to show that all of the recent warming was caused by man-made CO2 because man-made CO2 is effectively the only input the models get. (I discussed this in my http://euanmearns.com/co2-in-co2-out/ post. Every model output variable I looked at – rainfall, geopotential height, even soil moisture content – tracks CO2 almost exactly. I could in fact replicate CMIP5 model temperatures almost exactly using CO2 forcings only.) The models are, in short, self-fulfilling prophecies. They tell us nothing about how the Earth’s climate really works.

     All of which raises the question of how the Geological Society managed to conclude that climate change is real and threatening. It certainly wasn’t through any objective analysis of the data. Most of what the GS has to say in fact seems to have been lifted straight from the climate change playbook. And if geology is the study of rocks, which is what I did during my years as a professional geologist, then little of what the GS claims as geologic evidence for dangerous human interference with the climate has anything to do with geology.
     • David B. Benson says:

       January 16, 2018 at 4:47 am

       Geology according to the OED:
       https://en.oxforddictionaries.com/definition/geology
       is more than just rocks. The big meeting in the USA is the annual convention of the American Geophysical Union.
   • jfon says:

     January 16, 2018 at 6:47 am

     ‘The reality is that in September 2017 there was more sea ice in the Arctic than 10 years earlier.’
     The 2007 ice cover was dramatically below the average decline, while 2017’s figure is slightly above the line. https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/hires/2017/6-arcticseaice.jpg
     The ten lowest annual minima, from the 38 year satellite record, have all been in the last ten years, and the winter maxima for the last three years were all at record lows. ‘NSIDC director Mark Serreze said, “I have been looking at Arctic weather patterns for 35 years and have never seen anything close to what we’ve experienced these past two winters.”’
     https://nsidc.org/news/newsroom/arctic-sea-ice-maximum-record-low-third-straight-year
     • Javier says:

       January 16, 2018 at 11:02 am

       Mark Serreze told AP in 2007 that “the Arctic is screaming.”
       http://www.foxnews.com/story/2007/12/12/scientists-arctic-is-screaming-global-warming-may-have-passed-tipping-point.html

       And a year later said that “Arctic ice is in a death spiral and may disappear in the summers within a couple of decades.”
       http://news.nationalgeographic.com/news/2008/09/080917-sea-ice.html

       This was just the year when the current 10-year pause in Arctic sea ice melting started. I don’t think we can trust Mark Serreze to know or even understand what is happening in the Arctic.

       But the current pause in Arctic sea ice melting was predicted. In 2006 Divine & Dick published an article:
       Divine, D. V., & Dick, C. (2006). Historical variability of sea ice edge position in the Nordic Seas. Journal of Geophysical Research: Oceans, 111 (C1).
       In which they said: “Given the last cold period observed in the Arctic at the end of the 1960s, our results suggest that the Arctic ice pack is now at the periodical apogee of the low-frequency variability… We suppose therefore that during decades to come, as the negative phase of the thermohaline circulation evolves, the retreat of ice cover may change to an expansion.”

       In 2014 two new articles abounded on the role of natural variability on Arctic sea ice melting.

       Miles, M. W., Divine, D. V., Furevik, T., Jansen, E., Moros, M., & Ogilvie, A. E. (2014). A signal of persistent Atlantic multidecadal variability in Arctic sea ice. Geophysical Research Letters, 41 (2), 463-469.
       “…it follows that a change to a negative AMO phase in the coming decade(s) could —to some degree— temporarily ameliorate the strongly negative recent sea-ice trends.”

       Wyatt, M. G., & Curry, J. A. (2014). Role for Eurasian Arctic shelf sea ice in a secularly varying hemispheric climate signal during the 20th century. Climate dynamics, 42(9-10), 2763-2782.
       “this [sea ice decline] trend should reverse… Rebound in West Ice Extent, followed by Arctic Seas of Siberia should occur after the estimated 2006 minimum of West Ice Extent and maximum of AMO”

       And another one in 2017:

       Årthun, M., Eldevik, T., Viste, E., Drange, H., Furevik, T., Johnson, H. L., & Keenlyside, N. S. (2017). Skillful prediction of northern climate provided by the ocean. Nature communications, 8, 15875.
       “The future prediction of winter Arctic sea ice extent is a relatively low ice cover, but with a general increase between 2017 and 2020.”

       Your linear extrapolation tool, and 38 years of observations are a very poor toolset to predict or even understand a process that involves long term cyclical natural variability. And your faith in the power of anthropogenic emissions blinds you to understand the causes of what is happening.

       The pause in Arctic sea ice melting is most likely going to continue. All you will do will be to adjust up your linear trend. Here you have two projections from my model.
   • A C Osborn says:

     January 16, 2018 at 12:35 pm

     Javier says: January 15, 2018 at 9:39 am “For some of the feedbacks, like cloud cover we don’t even know the sign of their contribution.”

     Are you sure about that?

     http://www.climate4you.com/images/HadCRUT3%20and%20TropicalCloudCoverISCCP.gif
     • Javier says:

       January 16, 2018 at 1:51 pm

       Clouds are a very complicated factor. High clouds are believed to reduce warming by increasing albedo. Low clouds can cool during the day by screening the Sun, or warm during the night by reducing radiative loss. Also during the winter cloudy days can be warmer than clear sky days. That’s why low clouds are believed to increase warming. But nobody knows the relative contributions of all those factors for all the different types of clouds and we are not very good at measuring clouds. So I would say that nobody really knows what the contribution of clouds is to global warming.

       As cloud cover is only one of the many factors that affect global temperature, I don’t think we can extract any solid conclusion from comparing tropical cloud cover and global temperature. To extract causality from a correlation one has to really understand the relationship, which is not the case.
       • A C Osborn says:

         January 16, 2018 at 2:06 pm

         Did you look at the Graph, the loss in Cloud cover inversely correlates with Temps far better than CO2 can possibly do, even after all their “Adjustments” to the temp data.
         • A C Osborn says:

           January 16, 2018 at 2:09 pm

           There is also the work done by Jonathan Lowe at the Gust of Hot Air, unfortunately his graphs have disappeared due to lack of maintenance of his website, but his words are still there.
           http://gustofhotair.blogspot.co.uk/
         • Javier says:

           January 16, 2018 at 5:48 pm

           Did you look at the Graph, the loss in Cloud cover inversely correlates with Temps far better than CO2 can possibly do

           I did, and I answered to that. Correlation doesn’t imply causation, and a better correlation doesn’t imply a better causation.

           We are very far from being able to assign a value to cloud cover effect on global warming.

           Is a warmer world a world with less clouds or more clouds? We can’t even answer that.
         • Philip Mulholland says:

           January 22, 2018 at 10:49 am

           unfortunately his graphs have disappeared due to lack of maintenance of his website

           Sometimes the WayBack Machine on Archive.org can help.
       • Ron Clutz says:

         January 16, 2018 at 7:15 pm

         Agree that cloud cover is not well understood but progress is being made. The work on global brightening/dimming at ETH Zurich is interesting.

         https://rclutz.files.wordpress.com/2017/07/dimming-brightening.png

         Changes in surface solar radiation observed in regions with good station coverage during three periods.(left column) The 1950s–1980s show predominant declines (“dimming”), (middle column) the 1980s–2000 indicate partial recoveries (“brightening”) at many locations, except India, and (right column) recent developments after 2000 show mixed tendencies. Numbers denote typical literature estimates for the specified region and period in W m–2 per decade. Based on various sources as referenced in Wild (2009).

         https://rclutz.wordpress.com/2017/07/17/natures-sunscreen/
       • oldfossil says:

         January 21, 2018 at 2:50 am

         AFAIK (source climate4you.com, Ole Humlum) low cloud does most of the albedo work. Mid and high cloud is fairly transparent to visible spectrum but opaque to IR.
       • A C Osborn says:

         January 22, 2018 at 3:42 pm

         Philip, thank you very much for that.
       • Ulric Lyons says:

         January 29, 2018 at 8:56 pm

         Javier writes:
         “Is a warmer world a world with less clouds or more clouds? We can’t even answer that.”

         Clearly less cloud cover allows greater surface warming. The real issue is whether the decline in cloud cover is the result of a net increase in climate forcing, or the result of a net decrease in climate forcing. Which is directly teleconnected to the issue of why negative North Atlantic Oscillation states increased from the mid 1990’s driving a warm AMO phase.
     • Leo Smith says:

       January 17, 2018 at 3:25 am

       small factoid that people can check. I found this whilst looking for an answer to the above.

       The AVERAGE temperature of deserts is almost identical to the AVERAGE temperature of wetlands at the same altitude.

       perhaps clouds are not as important as we suppose.
       • Leo Smith says:

         January 17, 2018 at 3:27 am

         latitude, not altitude..
         • A C Osborn says:

           January 17, 2018 at 8:51 pm

           Of course the Average is, it is the Swing that H2O controls.
           Check the Daily Max & Min.
     • Ulric Lyons says:

       January 29, 2018 at 8:55 pm

       Javier writes:
       “Is a warmer world a world with less clouds or more clouds? We can’t even answer that.”

       Clearly less cloud cover allows greater surface warming. The real issue is whether the decline in cloud cover is the result of a net increase in climate forcing, or the result of a net decrease in climate forcing. Which is directly teleconnected to the issue of why negative North Atlantic Oscillation states increased from the mid 1990’s driving a warm AMO phase.
   • Halken says:

     January 16, 2018 at 1:48 pm

     “Certain energy policies that are doubtful to have any effect on climate change could make us less able to adapt.”

     This is an important point, Javier. If we spend our limited resources on reducing co2 emissions we put all our money on the bet that co2 is the primary driver of CAGW.
     However if we spend the resources on mitigation of the mpact of climate change, it will work regardless of if co2 is the culprit or if nature is behind it.
     Hence from the precautionary principle we should use our resources on mitigation instead of co2 reduction.

     There is however one technology that can allow us to have our cake and eat it. Nuclear power can provide co2 free energy at that same cost as coal. That in essence means we can take out an insurance against co2 as the climate driver (by reducing anthropocentric emissions significantly) without committing any significant of our resources to do it, allowing us to use the resources on climate mitigation.

     So the clever one will suggest that powering our society with nuclear power is the smart thing to do, while simultaneously spending money on climate impact mitigation.
     • Ron Clutz says:

       January 16, 2018 at 9:39 pm

       Halken, I agree entirely with your point. Isn’t it interesting that fossil fuel activists call treaties to reduce CO2 emissions “mitigation”? They term your approach, with which I agree, “adaptation.”
   • Mike Roberts says:

     January 16, 2018 at 11:22 pm

     Not sure why you start such a long comment with a straw man: “the idea that we can prevent climate change from happening is dangerous”. I don’t think anyone is suggesting that idea. The concern is that human actions are changing a relatively stable climate over the last 10,000 years or so into a very changeable climate, the effects of which could have significant consequences for humans (though I’m also concerned about other species, given the interactions). Change at paleoclimate rates is much less of a problem than the rate of change we see today.
     • Leo Smith says:

       January 17, 2018 at 3:29 am

       “human actions are changing a relatively stable climate over the last 10,000 years or so into a very changeable climate”

       Well, actually, no.
       neither half of that statement is true.
     • Javier says:

       January 17, 2018 at 8:53 am

       I don’t think anyone is suggesting that idea.

       The proposition is to reduce CO₂ emissions to prevent sea levels from rising faster, global temperature anomaly from reaching +2° C, and sea ice from melting, at the same time preventing stronger hurricanes, more frequent wildfires, worse floods and droughts, and so on.

       What a fantastic tale. Harry Potter mentality all over.

       human actions are changing a relatively stable climate over the last 10,000 years or so into a very changeable climate

       You just don’t know what you are talking about and bought a digested fake story. Climate has been everything but stable during the Holocene.

       Just an example:
       “two independent high-resolution RSL (relative sea level) proxy records from Belitung Island on the Sunda Shelf … both reveal a RSL history between 6850 and 6500 cal years BP that includes two 0.6 m fluctuations, with rates of RSL change reaching 13±4 mm per year (2s). Observations along the south coast of China, although of a lower resolution, reveal fluctuations similar in amplitude and timing to those on the Sunda Shelf. The consistency of the Southeast Asian records, from sites 2,600km apart, suggests that the records reflect regional changes in RSL that are unprecedented in modern times.”

       Meltzner, A. J., Switzer, A. D., Horton, B. P., Ashe, E., Qiu, Q., Hill, D. F., … & Natawidjaja, D. H. (2017). Half-metre sea-level fluctuations on centennial timescales from mid-Holocene corals of Southeast Asia. Nature Communications, 8.
       https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5309900/

       So sea level in Southeast Asia fell 0.6 m abruptly, and about 100 years later it went back up abruptly. The rate of change was about seven times the present rate. That’s Holocene stability.
     • Euan Mearns says:

       January 17, 2018 at 8:57 am

       The concern is that human actions are changing a relatively stable climate over the last 10,000 years or so into a very changeable climate,

       🙂 Where on earth do you get the idea from that the climate has been stable for 10,000 years? Sure, we have not lapsed back into a new glaciation (obliquity) but we have had very substantial climate change everywhere down to the solar geomagnetic cycle – Bond / D-O.

       

       River Thames London circa 1800.
   • David E says:

     January 17, 2018 at 8:24 am

     Javier,

     I like very much your point about using tree lines in mountainous areas (both present and (pre-)historical) as a climate proxy.

     However, the hard struggle for existence of trees also depends on how easily they can get carbon dioxide from the atmosphere – given that something like 93% of their mass comes from fixing that gas.

     So, all things being equal, trees will be able to grow at a higher altitude/lower average temperature if there is more carbon dioxide in the air. So any possible movement upwards of tree lines in the last century or so might simply be a DIRECT reflection of enhanced CO2 levels in the atmosphere, regardless of any warming or not (whether local or global).

     Just a thought,

     David E
     • Javier says:

       January 17, 2018 at 11:54 am

       Yes, I discussed that point. All we can say is that if the treeline was now at the same height as during the Holocene Hypsithermal, since CO₂ levels are now much higher, temperature could still have been higher at the Hypsithermal. Since present treeline is below Hypsithermal treeline, despite the CO₂ advantage, it absolutely demonstrates that summer temperature was higher then.

       Some authors cleverly select proxies to try to hide the obvious fact, that glaciers and sea levels are also telling. After several centuries of global warming we have not reached the warmest period of the Holocene, that was significantly warmer than now.
   • Clive Best says:

     January 17, 2018 at 7:50 pm

     Javier,

     Brilliant. Precise and to the point. I couldn’t have put it better myself !
5. Robert Davies says:

   January 15, 2018 at 9:58 am

   Skimming this I am left with the opinion that there is an awful lot of noise in the short term and that long term signals of cause and effect are hard to determine.
   • Mike says:

     January 16, 2018 at 10:48 pm

     I think that is about right. i think there is a bit of a problem in that the geologists work in much longer time scales than those pertinent to what we see now.

     Sure, there is noise but looking at the trends, especially many shown in this forum so far, I see rising CO2 due to human activity, rising temperatures, rising sea levels and descriptions of reducing ocean pH and increasing severity of hurricanes.

     By all means people may quibble about how much change and where but I don’t think anyone can just keep saying these things are coincidence or that correlation is not causality especially since all this has been predicted by mainstream atmospheric science for a hundred years.
     • Chris Matchette-Downes says:

       January 16, 2018 at 11:26 pm

       No, it is that geologists look over the entire past (in some cases in considerable detail) – not just capture a small window of the recent past (weather) or worse still try to forward model (climate) with incomplete or inaccurate input data.
       Reading the thread thus far, yes a rise in CO2, one that is disconnected with rising or falling temperatures, that is not significant, most likely beneficial and a distraction from issues that we can do something about.

       (I believe the pH concern is in fact acidification of the oceans not the reverse).

       There is no evidence to support any increase in severity of hurricanes – we have just over populated the coastal regions around the globe and have better means of reporting severe weather (which effects more people as the population grows).

       I believe the predication is the current interglacial will end soon, preceded by pronounced temperature fluctuations as seen in the recent geological sedimentological record, but I do hope this July will be warmer than January.

       Some fascinating insights have been aired on this blog and I really hope someone can capture them and perhaps the GSL rethink their statement on this matter.
       • Mike says:

         January 17, 2018 at 8:16 am

         Identifying trends in hurricane intensity is tricky. Category 5 is the max category but not all category 5 hurricanes are equal.

         I think a better bet is to look at the records: –

         Based on central pressure, of the 10 deepest 8 have been since 1980.

         Of the 18 strongest based on peak windspeed 11 have been since 1980.

         Of course we will have better chances of knowing the windspeed and pressure of hurricanes in the last 100 years but it is still s bit of a coincidence. I do find it hard to believe that this is not a result of increased sea temperatures.

         Regarding pH, you are indeed right and I was pedantic! Falling pH means acidification. In the past I’ve had complaints when referring to ‘acidification’ and ‘reduced alkalinity’ is a bit unwieldy!
         • Euan Mearns says:

           January 17, 2018 at 8:41 am

           The fact we have warming is not disputed. When you tout statistics like this the underlying message is always that it is Man that caused it. IF what you say is true, where is the evidence that it is Manmade? Or do you believe that climate should be stable and never-changing?
         • It doesn't add up... says:

           January 17, 2018 at 3:39 pm

           Hurricane records have changed out of all recognition since we had satellite coverage.
         • Chris Matchette-Downes says:

           January 17, 2018 at 3:51 pm

           Hurricanes are recorded throughout history – reeking havoc on the early explorers of America for instance. Cuba had its worst hurricane for 80 years last year – the recent observations are just that – its not hard to contemplate that heating of the oceans will increase activity – that is what we see in the record.
           We should more concerned regarding violent climate phenomena related to the ending of inter-glacial periods.
           To attribute global warming (just) to increased CO2 is clearly wrong along with all the predictions and models based on this premise. Whether man has or has not contributed to some of that C02 is therefore almost irrelevant, a red red herring. We are fighting the wrong battles. Agree with aporiac1960 – some kind virtue-signalling plus its easy to close the debate on this subject.
           Regarding pH, you are indeed right, I misread your statement, agree falling pH means decreased alkalinity, but again world ocean pH values have fluctuated through time.
         • Euan Mearns says:

           January 17, 2018 at 4:00 pm

           

           Figure 4 Comparison of pH and C content of the Pacific and Atlantic Oceans [2]. The deep Pacific has much lower pH and higher carbon content than the Atlantic.

           http://euanmearns.com/the-carbon-cycle-a-geologists-view/
     • Euan Mearns says:

       January 16, 2018 at 11:27 pm

       Mike, you just wandered off the reservation. I just put you to comment moderation.
6. Capell says:

   January 15, 2018 at 10:31 am

   In the first statement the section titled ‘What is the Greenhouse effect?’ is somewhat obtuse. Each and every gas molecule contributes to lifting the earth’s temperature 30 C above that of a black body in the vacuum of space. The atmosphere stores and transports energy, it’s temperature is a measure of the energy of motion of the molecules of the atmosphere. A classical physics analysis along these lines provides an elegant, well established model of this behaviour, perfectly summed up in the combined gas law: PV=RT. On these lines even an argon ‘particle’ contributes to lifting the surface temperature of the earth.
   The so-called greenhouse molecules (CO2, CH4, water vapour) have an additional method of ‘absorbing’ energy which does not lead to a change of motion. These are quantum mechanical energy trapping phenomena that involve changing the energy level of the molecular bonds of these molecules. The energy source is usually taken to be energy quanta or photons – we view the energy radiation from the earth’s surface as flux of these photons each with a certain energy (and thus optical wavelength/frequency). This absorption process has several properties:
   The photons must have a particular energy range – too low and they cannot drive the shift in molecular bonding and so no trapping occurs – too high, and again trapping cannot occur – the traps only ‘appear’ over a small photon energy range. Note that when trapping occurs, the gas molecule does NOT change its motion (temperature) so apparently, at the time of trapping, these molecules have apparently cooled the atmosphere!
   So how do these trapping molecules heat the earth’s surface. The traps are ’emptied’. The elevated energy of the molecular bonds snap back to their lower energy state, and the energy photon is released. Note that these released photons have a very precise energy (colour). And the global warming effect depends on the concept that these molecules are releasing this energy back towards the earth’s surface. They should create a hot spot in the atmosphere where this happens, and thus we have the Tropical Tropopause Hot Spot.as described in one of the IPCC’s reports – but never observed!
   Why not? Well, obvious reasons come to mind:
   At the point of energy release, there’s nothing to distinguish a greenhouse molecule’s behaviour from the usual energy exchange within the atmosphere caused by classical gas behaviour.
   The hot spot occurs high in the tropopause where convection forces are likely to erase any hot spots (or in other words, radiation at those levels is not the primary energy transport mechanism).
   Because the energy trapping process has split the trapped photon energy into two parts, one equal to the trap depth, the other the surplus, we have pushed some energy into photons that are far removed from the IR band.
   In summary. I remain very sceptical about the strength of this process. I cannot see it having anything but a small effect on the existing greenhouse temperature boost.
   • donb says:

     January 16, 2018 at 12:57 am

     My comments on a few of your comments above.
     When a CO2 or H20 molecule absorbs an IR photon, its internal energy is increased. Typically that molecule transfers part of that increased energy to another atmospheric molecule such as N2 or O2 (or even Ar) via kinetic collisions. A mixture of atmospheric gas molecules will show a distribution of kinetic energies and thus translation velocities. Thus, that same molecule that absorbed then lost that IR energy will at some point be struck by a gas molecule (N2 or O2) of higher energy and gain additional energy. That additional energy permits this molecule (CO2 or H2O) to then emit an IR photon.
     That is how IR absorption warms the whole atmosphere.

     Some of the overall IR photons emitted will be emitted downward and some of those will be absorbed by Earth’s surface, warming it. That is how greenhouse warmed atmospheric gases can warm the surface above the amount expected from direct absorption of solar radiation alone.

     The above processes are not the major manner by which the greenhouse effect produces overall warming. That is produced because adding more greenhouse gas to the atmosphere increases the height at which final IR emission to space occurs — the emission height (for CO2 a few miles). Because (in most places) the atmosphere cools with height, the emission height is forced into colder regions. As the IR emission rate is proportional to the fourth power of temperature, loss of IR photons decreases and the atmosphere and surface must warm for the equilibrium rate to be re-established.
     • Capell says:

       January 16, 2018 at 9:10 am

       I agree with all your points entirely.

       But just one point, which I didn’t think I had space to discuss: consider your second paragraph. Carbon traps releasing energy will, indeed create a photon flux, part of which will be towards the earth’s surface (and this flux will be a very small proportion of the total flux). But any energy exchange amongst ‘classical physics’ gas particles will also have, in part, a downward flux. It’s difficult to see, therefore, how a quantum mechanical energy release differs from any ‘normal’ gas particle collisions.
     • A C Osborn says:

       January 16, 2018 at 1:05 pm

       Donb, do you realise that photons which head downwards is about 48% of the total.In the lower atmosphere H2O molecules outnumber CO2 by a factor of aroud 65 to 1.
       So where H2O is not present is where CO2 molecules are most effective, at that height of qaround 10km and above there is 10km of Atmosphere to negotiate before a CO2 photon can reach the surface.
       The Mean Free Path of an IR photon is approximately 25 metres, which means at roughly every 25 metres the photon encounters another molecule. At which point it will absorbed, reflected or scattered.
       Of those absorbed and re-emitted 52% will again head back upwards.
       Thereby reducing the flood of CO2 photons by 52% every 25 metres.
       How does a photon therefore negotiate 10km of ever increasingly denser Atmosphere.
       According to Quantum mechanics molecules loose much more excess energy due to collisons than by emmitting a photon.

       Also increasing the number of CO2 molecules actually increases the LWIR leaving the Atmosphere as described by NASA at the 2013 AGU.

       Another point is the actual energy contained in Sunlight 4eV is far higher than the energy contained in LWIR 0.08eV.
       This allows Sunlight to penetrate the Oceans and Seas to greater depths and means much more long term storage of energy.

       As you said up post the Big player is H2O, you only need to compare the Tropics to Dry Deserts to see how H2O controls the swings in Diurnal Temperatures experienced by airless bodies like the Moon.
       • donb says:

         January 16, 2018 at 3:21 pm

         A.C. I generally agree with your comments above.

         We probably overly emphasize the effects of IR photons from CO2 and H2O that are emitted downward and absorbed by the surface. Although these are an additional means by which the surface receives energy, IT IS THE WARMING OF THE WHOLE ATMOSPHERE THAT IS THE REAL DRIVER. The only place to lose energy is at the top. Emission of IR photons upward, downward, and sideways is just a means by which energy gets spread around — an energy loop.
         • A C Osborn says:

           January 16, 2018 at 4:32 pm

           donb, but at night it is only a short delay in getting from the surface to the TOA.
           The graph I posted on Tropical cloud cover versus Global Temperature very strongly suggests that overall even H2O does more cooling than warming.
           This is where the IPCC theory breaks down completely, even after all these years we still do not have definitve studies of what H2O levels actually do.
           Mostly because there is too much emphasis on CO2, some of the Scientists involved appear to have lost the desire to actually understand how the Climate works.
         • A C Osborn says:

           January 20, 2018 at 3:18 pm

           donb, the latest work by Mr Eschenbach at WUWT on the Ceres data shows without doubt that H2O & clouds control the Atmospheric changes in Temperature brougth about by Solar Radiation.

           https://wattsupwiththat.com/2018/01/18/ceres-edition-4-and-the-cloud-radiative-effect/
7. Peter Lang says:

   January 15, 2018 at 11:04 am

   Evidence from the geological record is consistent with the physics that shows that adding large amounts of carbon dioxide to the atmosphere warms the world and may lead to: higher sea levels and flooding of low-lying coasts

   It is important to provide context of the time scale, and the rate of sea-level rise compared with the rate of adaptation. Highly regarded climate economist, Professor Richard Tol, projects that the economic impacts of projected sea-level rise over the 21st century would be negligible https://link.springer.com/article/10.1007%2Fs10584-012-0613-3#page-1 (see Figure 3).

   There is now widespread concern that the Earth’s climate will warm further, not only because of the lingering effects of the added carbon already in the system, but also because of further additions as human population continues to grow.

   What are the validated evidence to support this concern? The damage functions, which are used to estimate costs and benefits of climate change and of mitigation policies, are so uncertain as to be unsuitable for justifying ‘climate’ policies.

   Arguable, the optimum global average temperature for life is about 7C warmer than now. Why? Because that was the average temperature of the planet over the past 542 million years (see Scotese, 2016, Figure 15 here: https://www.academia.edu/12082909/Some_thoughts_on_Global_Climate_Change_The_Transition_from_Icehouse_to_Hothouse ), which is most of the time that complex life has thrived on Earth. Life thrived when the planet was warmer than now and struggled when colder. Furthermore, according to geologist and instigator of the Paleomap project, Professor Christopher Scotese, Earth is currently in about the severest Icehouse Phase it has experienced in that time.
   • jfon says:

     January 17, 2018 at 7:09 am

     ‘Arguable, the optimum global average temperature for life is about 7C warmer than now.’
     You could argue that such a world might be better for a tyrannosaurus or a trilobite, but maybe not for species such as homo sapiens sapiens, wheat, rice, corn, and potatoes, when the former evolved mostly in a colder climate, and the latter have been bred for the one we have.
     Places where the annual peak electricity use is for air conditioning could also be seen as being above the optimum for humans – for example, the upcoming world football cup being assigned to Qatar was widely regarded as being dangerous for the players, never mind the poor guys who had to build the stadiums. Having watched workers mixing concrete by hand in Madurai, southern India, I would not wish another 7C on them.
8. Chris says:

   January 15, 2018 at 1:04 pm

   I still remain uncertain that measuring CO2 on the upper slopes of an active volcano (Mona Loa) is the best place to measure atmospheric CO2 concentration. Whilst it is straight forward to differentiate volcanic & anthropocentric CO2 via stable isotope abundances – i am not sure that this done
   • donb says:

     January 16, 2018 at 1:02 am

     Measuring 13C/12C ratios to determine the carbon sources is commonly done.
     Further, the Hawaii CO2 measurements over past decades show little influence from various volcanic emission, suggesting that the data are little influenced by such.
     • Mike says:

       January 16, 2018 at 7:49 am

       It is also confirmed by measurements at other sites, not least at Halley in Antarctica.
   • Roger Andrews says:

     January 16, 2018 at 7:14 pm

     The Mauna Loa CO2 record matches other CO2 records in the Pacific. There’s no sign of contamination by volcanic CO2. The data are available at http://scrippsco2.ucsd.edu/data/atmospheric_co2/ should anyone wish to check.
     • John F. Hultquist says:

       January 17, 2018 at 5:13 pm

       One needs only to read the material of the Mona Loa site. They clearly explain what is done, and how. There is no reason to be “uncertain” about measuring atmospheric CO2 concentration there. The word “best”, as used in Chris’ comment, is meaningless, however.
       • Chris Matchette-Downes says:

         January 17, 2018 at 6:29 pm

         Thank you for the link John. That has cleared up one uncertainty for me.
9. steve says:

   January 15, 2018 at 2:30 pm

   The noted inception and termination on the Vostok charts may be causing confusion with non-experts such as myself, as the termination comes before the inception. We are looking at the spike in temperatures and CO2 and would usually think of the inception being the beginning of the rise and the termination being the fall. Just sayin.
   • Javier says:

     January 15, 2018 at 9:18 pm

     as the termination comes before the inception.

     Inception and termination refer to glacial periods. They don’t refer to interglacials. Last inception took place ~ 118,000 years ago, and the termination took place ~ 18,000 years ago. In a few millennia, a new inception could take place, starting a new glacial period.
10. Roger Andrews says:

    January 15, 2018 at 3:57 pm

    From the Geological Society 2013 Addendum:

    (The current) rate of increase of CO2 is unprecedented, even in comparison with the massive injection of carbon into the atmosphere 55 million years ago that led to the major PETM warming event ….

    How do we know that the carbon caused the PETM warming and that it wasn’t the warming that caused the carbon?
    • Peter Lang says:

      January 15, 2018 at 10:30 pm

      Its also important to note that it is highly misleading to compare rates of change of CO2 concentration over different durations; i.e comparing the change over say 100 years now, with the change over 10,000 years during the PETM
11. Ron Clutz says:

    January 15, 2018 at 4:08 pm

    From Bill Illis in 2015: “There are also d18O isotopes which have proven to be very reliable proxies for temperature in the distant past. There are even International Standards for how to use these proxies to estimate temperature. Search Vienna Standard Mean Ocean Water if you want to know more about this.

    There are d18O isotopes which have been dated going back all the way to 2.6 billion years ago. In total, there are 40,000 dated dO18 proxies covering the periods back to this time. 40,000 reliable proxies is more than enough to make a call about this history.

    Here are the temperature estimates and all of the CO2 estimates over the last 40 million years (the data used in the paper are in this chart but I am using all the reliable numbers that there are, so rather than 8 data points, there is a total of 16,000 datapoints here between temps and CO2).”

    https://i2.wp.com/s19.postimage.org/59fwa1fv7/CO2_Temps_Last40_Mys.png

    When one runs the numbers in the proper way with these isotopes, one gets very close to Scotese’s temperature history. They can produce a higher resolution history than Scotese, however, which matches to a “T” the major developments in climate history that we know about from other disciplines like geology, paleontology etc.” Bill Illis

    http://wattsupwiththat.com/2015/04/15/strong-evidence-for-rapid-climate-change-found-in-past-millenia/#comment-1908208
    • donb says:

      January 16, 2018 at 1:17 am

      One should always remember what the measured 18O/16O ratio used for estimating temperature actually measures. It does not directly measure temperature, except on a relative basis. Rather it reveals the amount of isotopic fractionation (changes in 18O/16O) that occurred when the oxygen phase measured — whether snowfall from earlier ocean evaporation or carbonate phase from sea water — actually formed. As the 18O/16O in the source material may change, so that will influence any calculated temperature. And when going into deep time in Earth’s history, possible variations in the nature of source material becomes harder to constrain.
12. Professor Tony Trewavas FRS says:

    January 15, 2018 at 5:39 pm

    Although I read some of the literature on climate change, I am not a climate scientist. My concerns perhaps are more peripheral. I think it is necessary to distinguish between the use of two words, projection and prediction. Good climate scientists are well aware that what they produce in their models are projections. In a projection the present circumstance is taken and usually a single change added in-in this case say a doubling CO2 levels. From that all kinds of future circumstance are deduced.
    Unfortunately by the time a projection has run the mill of some scientists and the media, projections simply become equated with predictions. To make a prediction of 70-100 years off necessitates knowing everything that is going to happen in the meantime. Given, as stated, that Homo sapiens is the claimed present (sole?) cause of climate change, it is the state of mankind that is assumed in a prediction of say 2090. But I do not know what the world economy will be like by 2090, the state and novel kinds of technology, the actual world population, the kinds of agriculture, land occupation forest sizes, atmospheric CO2 etc. Thus I regard the human factor supposedly the only critical one, as unknowable by 2090. Care is needed in clarifying the difference between projection and prediction
    Because interaction between people with different knowledge generates new technology, the web is the greatest source of change probably in the last 100 years, most particularly in technology but in social interactions too. Will we not have solved the feared problems by then? In megacities surely agriculture will be aerofarms and in the countryside agriculture under massive glass houses with controlled circumstances and 10-15 or up to 60 fold increases in yield thus releasing land for other less intensive purposes or even back to forest. Population increase is in general decline and anywhere from 8.5 to 11 billion predicted. Artificial intelligence to control climate agriculture. Universal translators introduced as a chip in the brain. As for the world economy surely it will be merged by then. Drone deliveries, or make your own with cheap 3D printers. It’s the speed of change that becomes difficult to assess.
    The green revolution once it got under way took only 3-4 years for major change of crop yield. How quickly did the mobile phone emerge, decades or less than decades. LED bulbs and so on.
    The last IPCC gave a temperature range of 1.5-4.5 C for a doubling of CO2. This variation reflects the fact that the climate is extremely complex coupled with numerous ill-understood feedback effects. If there is a justification for doing something it’s because we don’t understand it and thus prudence dictates that we respond. The variable problems of ill-understood climate conditions are adequately described in Stevens and Bint 2013. Modellers need to show a little more humility.
    But I do object to the way that politicians have responded to climate concerns at least here. Nuclear power is the obvious way to sort out energy problems given that energy is so basic to everything we do and yet in Scotland we have set about destroying the landscape something of immense value with unreliable sources of energy because climate responses have become and as usual mixed up with other political stances, in this case independence. But in looking at what models make reasonable sense to me, it is that provided by Otto et al, 2013. Even I as a plant biologist can understand the methodology. Assessing the sensitivity of the present climate to CO2 change is to my mind the most sensible approach. I don’t doubt that climate modellers discuss and can criticise Otto et al and a second paper by Lewis and Curry (2014) but always bear in mind that science will always be a debate, it is never finished until the protagonists die off. Attempts to shut down dissenting voices is fundamentally at odds with scientific enterprise and belief.
    N. Lewis, and J.A. Curry, “The implications for climate sensitivity of AR5 forcing and heat uptake estimates”, Climate Dynamics, vol. 45, pp. 1009-1023, 2014. http://dx.doi.org/10.1007/s00382-014-2342-y
    2. A. Otto, F.E.L. Otto, O. Boucher, J. Church, G. Hegerl, P.M. Forster, N.P. Gillett, J. Gregory, G.C. Johnson, R. Knutti, N. Lewis, U. Lohmann, J. Marotzke, G. Myhre, D. Shindell, B. Stevens, and M.R. Allen, “Energy budget constraints on climate response”, Nature Geoscience, vol. 6, pp. 415-416, 2013.
    3. Stevens, B. and Bony, S. What are climate models missing? Science, 340 1053-1055.
    • Javier says:

      January 15, 2018 at 9:28 pm

      So, what do you think that when Peter Wadhams says:

      Next year or the year after that, I think it will be free of ice in summer and by that I mean the central Arctic will be ice-free. You will be able to cross over the north pole by ship. There will still be about a million square kilometres of ice in the Arctic in summer but it will be packed into various nooks and crannies along the Northwest Passage and along bits of the Canadian coastline. Ice-free means the central basin of the Arctic will be ice-free and I think that that is going to happen in summer 2017 or 2018.

      https://www.theguardian.com/environment/2016/aug/21/arctic-will-be-ice-free-in-summer-next-year

      Is he making a projection or a prediction?
13. peter9381 says:

    January 15, 2018 at 8:23 pm

    ” CO2 levels were already high at the time, but the additional CO2 injected into the atmosphere and ocean made the ocean even warmer,”

    Isn’t there supposed to be a logarithmic relationship between CO2 and temperature?
    • peter9381 says:

      January 15, 2018 at 9:54 pm

      Also, how exactly does CO2 warm the oceans? I thought it was the sun that directly warmed the oceans and the oceans warmed the atmosphere.

      We are told that the oceans contain 99% of the combined atmosphere/oceans heat so it hard to comprehend the atmosphere heating the oceans if that is what they are alleging.
      • Roger Andrews says:

        January 15, 2018 at 10:52 pm

        Long-wave (infrared) radiation “trapped” by CO2 can penetrate only a few nanometers into the sea. So it’s reasonable to assume that CO2 doesn’t warm the oceans.

        But if we make this assumption then the key AGW concept that temperatures will take centuries to stabilize after man-made CO2 emissions finally cease because of the time it will take the oceans to release all the heat introduced by man-made CO2 falls apart. And since AGW theory is inviolate the oceans must therefore be warmed by CO2.

        Ocean-atmosphere heat transfer triggered by ENSO events can in fact explain most if not all of the recent warming with no contribution from CO2 at all.

        http://euanmearns.com/the-staircase-hypothesis-an-alternative-explanation-for-the-recent-global-warming/
        • A C Osborn says:

          January 16, 2018 at 2:02 pm

          Roger, yes CO2 DWIR if it can reach the surface at all does not have the energy that solar radiation has.
          What is not considered and I forgot to mention up post is that Clouds block High Energy Sunlight and only emit low Energy IR at night, so on balance even they cool more than they warm.
          See the graph I posted, unfortunately it does not appear as a graph, just a link to a comparison of Tropical cloud cover related to Global Temperature.
14. Mike brettle says:

    January 15, 2018 at 9:19 pm

    I’m a bit sceptical of the relevance of climate changes in the distant past. The current scenario of a sudden increase in greenhouse gases is very different to previous climate change caused by various other effects. For example there is no doubt that the rise in CO2 is down to human activity not any other cause. Discussions of whether rising temperatures followed rising CO2 or vice-versa is irrelevant.

    Rising temperatures following rising CO2 was predicted before anyone reading this was born and has been mainstream atmospheric science for decades. Details may be up for grabs but the underlying science is surely well verified? I don’t see any other explanation for what we see.
    • Ron Clutz says:

      January 15, 2018 at 10:31 pm

      No doubt that the rise in CO2 is down to human activity? Even though estimates of human emissions are less than the error range in estimates of natural fluxes?
      • David B. Benson says:

        January 15, 2018 at 11:32 pm

        There is no doubt as determined by C13/C12 ratios.
        • Jim Ross says:

          January 16, 2018 at 11:06 am

          David,

          The 13C/12C ratio (usually reported as δ13C) of the incremental CO2 is circa -13 per mil. The δ13C of fossil fuels is estimated at -28 per mil. Please explain why this leaves you in no doubt.
      • Mike says:

        January 16, 2018 at 7:55 am

        Yes, we know that human emissions cover the increase twice over.

        I don’t see any reason to dismiss this as coincidence. It would also beg the question as to what was getting rid of the human emissions while simultaneously some as yet unidentified natural flux was rapidly increasing.
        • donb says:

          January 16, 2018 at 3:39 pm

          I agree with Mike’s comment.
          Views like Ron expresses above — “estimates of human emissions are less than the error range in estimates of natural fluxes” — ignore the difference between rates of equilibrium exchanges of carbon phases (e.g. CO2) and disturbance of equilibrium.

          Take CO2 in seawater as an example. CO2 molecules are constantly being absorbed and degassed into the atmosphere at something like 70 giga-tons of C per year. This exceeds by an order of magnitude the rate of addition of new CO2 by fossil fuel burning. But, that ocean-air exchange rate of CO2 is constant until something disturbs the concentration on one side of the equilibrium. Addition of more human-produced CO2 disturbs that exchange equilibrium, and has increased the ocean-air exchange rate by about 2 giga-tons C per year. The equilibrium concentration of CO2 is driven toward higher values in both the sea and air. (Ocean heating drives CO2 the other way.)
          Similar equilibrium effects exist for land-air CO2 exchange.

          In spite of the much smaller CO2 contribution from human activities compared to natural CO2 exchange among reservoirs, human caused CO2 has a major effect on various CO2 reservoirs.
      • Ron Clutz says:

        January 16, 2018 at 8:16 pm

        From Global warming, human-induced carbon emissions,and their uncertainties FANG JingYun et al. 2011

        “However, the current global carbon balance is disturbed by two factors: one is anthropogenic carbon emissions from fossil fuel combustion and land use change, which are 9–10 Pg C per year [74], i.e. equal to 1/22–1/26 of the natural emissions from terrestrial and oceanic biospheres; and the other is that increasing temperature can result in a positive feedback of carbon emissions caused from a greater soil heterotrophic respiration and from oceanic ecosystems [77, 78]. This increased emission will be reserved in atmosphere and contribute to the increase of atmospheric CO2 concentration if it cannot be absorbed by ecosystems.

        In this sense, in addition to the anthropogenic carbon emissions, the positive feedback of terrestrial and marine ecosystems to global warming may be another important source of the increasing atmospheric CO2 concentration. The estimation of global carbon budget indicates that a total of the natural and anthropogenic emissions are 250 Pg C per year, whereas the total of absorption by the natural ecosystems and the atmosphere is estimated as 230 Pg C per year (Table 2).

        This generates a gap of 20 Pg C between the global emissions and absorptions, which is twice the current total anthropogenic emissions (9–10 Pg C/yr). Therefore, there is a great uncertainty in the sources of the increased atmospheric CO2, and we may not reach to the conclusion that elevating atmospheric CO2 concentration is mainly from human activities.”
15. Jack Broughton says:

    January 15, 2018 at 9:20 pm

    A lot of good comments above about the report. A few comments that I hope might support your views, which are almost always as mine.
    Unfortunately the Geological society seem to have accepted the consensus view about the role of CO2 in climate change without scientific questioning. They also do not question the data-homogenisation by algorithmic alterations of climate data by NAOO, whose management are mainly committed climate change supporters.
    The evidence against CO2 as a driving global warming agent is in 4 main areas:
    1. The long term information points to temperature rise leading carbon dioxide increases by quite long periods. This may be partly due to the decreased solubility of CO2 at higher temperatures, given the massive amount stored in the oceans compared to the atmosphere.
    2. The IPCC technical reports assess CO2 without allowing for the massive interaction with moisture (and even clouds) in defining their values for the Radiative Forcing Factors (RFF): the RFF is the driver of all the global warming theory and values in the IPCC report can vary from – 1 W/m2 to 8.5 W/m2: the latter value requiring an unproven and unprovable feedback mechanism, a committee selected and recommended value for this critical value with little real scientific evidence to back this up.
    3. There have been much warmer periods in the last 2000 years (the Roman and Medieval warm periods) when CO2 was allegedly very low: why did they happen??? And why did the temperature rise between 1930 and 1940 as fast as in the 1990s?
    4. The evidence from chemical analyses of atmospheric CO2 which show much larger variations in CO2 over the last 2 centuries, using accurate analytical methods, have been discounted by IPCC. A good peer reviewed reference is Beck E-G, Energy and Environment, vol. 18, No 2,2007. 100 Years of Atmospheric CO2 gas analysis by Chemical Methods.
16. peter9381 says:

    January 15, 2018 at 10:14 pm

    “Nevertheless, after 1900 the overall decline in temperature sharply reversed.”

    Seems they believe the hockey stick! but the earth actually started warming somewhere around 1650-1700 after the little ice age peaked. It was sporadic but there is ample historical evidence confirming this. EG Alaskan glaciers were observed retreating in the late 1700s.

    By 1900, CO2 had risen from 280ppm to 290ppm and to 305ppm in 1950!

    Seems to me that just like in the ice cores, CO2 is following temperature change. While it’s true that anthropogenic CO2 is a factor, a warming ocean and deforestation also release co2.
    • Mike says:

      January 16, 2018 at 6:08 pm

      So what is happening to the anthropogenic CO2 which covers the measured increase twice over?

      The mystery is where is the excess human released CO2 going. Adding other sources just adds to the mystery.

      There is aboslutely no room for doubt. The increase in CO2 is down to us.
      • Euan Mearns says:

        January 16, 2018 at 8:22 pm

        Mike, one of your comments will have disappeared along with the one I deleted. You were entirely correct.

        ~50% of human emissions are being sequestered mainly by the terrestrial biosphere.
        • Jim Ross says:

          January 16, 2018 at 8:38 pm

          The IPCC view (as per CDIAC, but not necessarily my view) is that approx 27% is absorbed by the oceans every year (regardless of actual level of emissions) and the average absorbed by the terrestrial biosphere is the same, except that it varies from o% (or even negative) to over 50% per year depending on the state of ENSO. This comment is based on the 2016 release as I have yet to study the 2017 version, which definitely has some changes.
        • Jim Ross says:

          January 17, 2018 at 11:58 am

          My comment above was a bit rushed and may have been a bit too cryptic for some. CDIAC is the Carbon Dioxide Information Analysis Center, which has produced a Global Carbon Budget for a number of years. The budget shows on an annual basis estimated CO2 emissions, including land use changes, atmospheric growth, oceanic uptake and (by simple arithmetic) uptake by the terrestrial sink. The 2016 version is here:
          http://cdiac.ess-dive.lbl.gov/GCP/carbonbudget/2016/

          There is now a 2017 version, which differs from 2016 in that it now estimates the terrestrial uptake separately and hence there is now an additional category for “budget imbalance”. It can be found here:
          http://www.globalcarbonproject.org/carbonbudget/17/data.htm

          Note that I am providing the references for information only; I do not necessarily agree with the assumptions or methodology underlying the budget figures.
17. Peter Lang says:

    January 16, 2018 at 12:39 am

    Life on Earth has survived large climate changes in the past, but extinctions and major redistribution of species have been associated with many of them. When the human population was small and nomadic, a rise in sea level of a few metres would have had very little effect on Homo sapiens. With the current and growing global population, much of which is concentrated in coastal cities, such a rise in sea level would have a drastic effect on our complex society, especially if the climate were to change as suddenly as it has at times in the past. Equally, it seems likely that as warming continues some areas may experience less precipitation leading to drought. With both rising seas and increasing drought, pressure for human migration could result on a large scale.

    Most of the consequences of warming stated here are not derived from geological evidence. They are pure speculation and repetition of arguments presented by other research groups. Representative scientific bodies should stick to then area of expertise of the profession they represent. Avoid propagating misinformation and arguments based on ideology.
18. Jan Ebenholtz says:

    January 16, 2018 at 3:49 am

    Should not the societies climate experts comment Euans claims first in a more structured way? Hard to follow the debate when everyone is barking.
    • Euan Mearns says:

      January 16, 2018 at 5:38 pm

      That’s not a bad idea. Polar Scientist has been in rather short supply. I could invite them to submit a formal response to the various points raised and publish as a separate post.
      • Jan Ebenholtz says:

        January 17, 2018 at 12:26 am

        That would certainly be valuable and helpful.
19. alfredmelbourne says:

    January 16, 2018 at 6:00 am

    An aside, so please forgive me.

    I happen to be reading Mlodinow’s excellent “How Your Unconscious Mind Rules Your Behaviour”

    The “In-Groups and Out-Groups” explains quite well how powerful a force consensus is. People naturally divide into sex, profession, age group, religion, nationality, race, locality, sports team and so on. This whole climate debate falls into that category. We have two disparate groups of people who don’t agree much on anything regarding climate. The fake “97% of scientists …” consensus business is just another way of drumming up support for one of these groups by trying to bypass peoples’ critical faculties.

    What is especially striking is that the author is Jewish – and a extraordinarily large number of his examples, quotes and references are from people of his faith. I don’t believe a single one of his hundreds of anecdotes comes from anywhere other than the USA, Israel and Europe.

    There must be some truth in what he writes. 🙂
    • Jan Ebenholtz says:

      January 19, 2018 at 12:42 am

      Your anti-semitic statement is of no value and actually discredit the blog.
      You are not writing in der Stürmer.
      • Mike says:

        January 19, 2018 at 5:51 pm

        Jan, I see where you are coming from but I don’t think AlfredMelbourne is guilty of anti-semitism. I read his statement several times before I was sure. He is simply using an example of a social phenomena regarding religious, political or other groups that happens to be based on the Jewish community. His point is valid and not anti-semitic (though I do not actually agree with it).
        • Jan Ebenholtz says:

          January 20, 2018 at 8:33 pm

          To connect a certain group of people with a cunning plan of making life miserable for the rest of us is in this case anti-semitic. It is like saying Arabs are all terrorists. Pointless and an intellectual coremelt. Stick to the subject, is global varming manmade or not.
20. edhoskins says:

    January 16, 2018 at 7:10 am

    It seems that even the Geological Society of London has bought into the CO2 causes climate change scare, or may be they are forced to, to maintain their current credibility in the warped scientific community.

    However I am surprised that they avoid mentioning the following in their section:

    “What is the Greenhouse Effect?”
    • the Greenhouse effect is essential to all life on earth, without that warming effect of ~+33°C the planet would be a very cold and uninhabitable place indeed.
    • the world needs its atmospheric CO2 for the survival and fertilisation of plant life: it thus supports all life on earth. And a concentration of atmospheric CO2 < 200 ppmv equivalent to ~77% of CO2’s Greenhouse effectiveness is essential to maintain photosynthetic plant life and thus to maintain life on earth.
    • atmospheric CO2, whether Man-made or mostly naturally occurring, cannot therefore be pollutant.
    • that the ~33 °C GHG effect is probably ~ 95% caused by water vapour and clouds. And thus only ~5% is attributable to the other minor Greenhouse gasses including CO2.
    http://www.geocraft.com/WVFossils/greenhouse_data.html
    • the effectiveness of CO2 as a Greenhouse gas rapidly diminishes logarithmically with increasing concentration.

    https://edmhdotme.wordpress.com/the-diminishing-effect-of-increasing-concentrations-of-atmospheric-carbon-dioxide-on-temperature/

    • at the current level of ~400 ppmv, (only twice the level needed for planetary photosynthetic survival), only ~13% of the effectiveness of CO2 as a Greenhouse gas remains.
    • increasing CO2 in the atmosphere can only lead to very limited further warming and certainly not to any catastrophic and dangerous temperature increase.

    https://wattsupwiththat.com/2016/06/20/greenpeace-co-founder-pens-treatise-on-the-positive-effects-of-co2-says-there-is-no-crisis

    • so little of the effectiveness of CO2 as a greenhouse gas now remains that there is no possibility of Man-made CO emissions ever attaining the much feared +2°C temperature rise, that is considered to be so catastrophic by climate alarmists and sadly also by so many convinced Western world politicians.
    • a doubling of CO2 concentration from 400 ppmv to 800 ppmv, (climate sensitivity), can only result in a temperature increase of ~0.37°C according to the likely median case and the worst case warming could only ever result in less than +1.0 °C
    • mankind’s attempts to control global temperature by the limitation of its CO2 emissions only about 3% of the overall transport of CO2 from combustion of fossil fuels can only ever have marginal or immeasurable effects.

    It should be noted that these calculations ignore the possibility of a massive positive feedback mechanism suddenly operating as a result of man-made COP2 emissions. This is a fabrication which is essential to make climate models predict massive temperature increases in accordance with the IPCC future climate models.
21. Phillip Bratby says:

    January 16, 2018 at 8:21 am

    The 33°C GHG effect is based on a flat earth model in which the energy flux from the sun is reduced by a factor 4 to allow for the fact that the earth’s surface area is 4 times the cross-sectional area. It also assumes constant energy flux, i.e. no day/night effect. The 33°C GHG effect is thus a completely fake effect.
22. phil chapman says:

    January 16, 2018 at 9:38 am

    Like the IPCC, the GSL apparently assumes that the only solar influence on climate is through variations in the total solar irradiance, due to changes in the brightness of the Sun and/or the orbit and polar inclination of the Earth. This neglects changes in the spectral distribution of sunlight and, more importantly, the possible effects of galactic cosmic rays on low cloud cover (and thus the effects of changes in sunspot acrivity and/or the geomagnetic field). It is absurd to seek the One True Cause of such a complex phenomenon as climate change, and it is not only stupid but unacceptably arrogant to ignore plausible hypotheses without serious consideration.

    A more fundamental problem is the assumption, again shared with the IPCC, that the climate is a first-order linear system. The whole idea of radiative forcing – i.e., that the response of the climate equals the sum of responses to separate forcings – depends on this fundamental mistake.

    This is like a house that has some insulation but no heating system. The room temperature in such a house follows but lags behind changes in the outside temperature. A house with little insulation (e.g., a tent) follows the external temperature closely, but one with good insulation adjusts more slowly: it may show only a small daily temperature fluctuation, but it will certainly be colder in winter than in summer.

    In reality, the climate is more like an insulated house in which a thermostat switches on a powerful heating system when the room temperature T falls below a preset lower limit T1, and switches it off when the room temperature reaches a preset higher limit T2. As long as the external temperature Te is less than T1, the room temperature rises rapidly to T2, slowly cools back down to T1, and then repeats the cycle. Changes in the external temperature affect the time taken for the cooling phase, and hence the frequency of the internal temperature cycle, but not its amplitude. A single external cold pulse can change the phase of the oscillation, and a sequence of cold pulses can control the frequency. If however Te rises above T1, the heater never turns on so the house behaves linearly, like the one without a heater.

    This behavior is an example of a limit cycle – i.e., an autonomous (self-sustained) oscillation in the absence of any periodic external driving force. This particular type is called a relaxation oscillation, because the temperature rises quickly to the upper limit, then “relaxes” back to the lower limit, so the waveform is a sawtooth. The oscillations can continue indefinitely, as long as there is a source of energy (in this case, the fuel for the heater).

    Many very different nonlinear systems exhibit sustained cycles of this kind, including electronic oscillators, flashing signal lights, a bowed violin string, prey-predator relations, the heartbeat, aerodynamic flutter, the pulsations of variable stars, and a wide variety of climate subsystems.

    As long ago as 1984, Saltzman & Sutera proposed [1] that the alternation of glacial and interglacial stages is the result of a relaxation oscillation synchronized by Milankovitch (astronomical) forcing. They certainly exhibit the characteristic sawtooth waveform. If this is correct, it means that the ice age transitions would continue even in the absence of external forcing, but their frequency could change — as in fact happened 800 kiloyears ago, when the period of glacial stages abruptly increased friom about 40,000 to 100,000 years. It may not be coincidence that this event, known as the Middle Pleistocene Transition, coincided with the last full, semi-permanent reversal of the geomagnetic field (i.e., the boundary between the Matuyama chron and the current Brunhes chron).

    The D-O events may also represent relaxation oscillations, but their origin is not at all obvious.

    The behavior of complex nonlinear systems with multiple coupled limit cycles is a major subject of current research, with many puzzles still unsolved. It is however known that many such systems exhibit chaos, which means that extremely small changes in the inputs to such systems may cause large and absolutely unpredictable changes in the phasing and/or the frequency of limit cycles. Moreover, interactions between different cyclic systems may entrain the oscillations, synchronizing them so that the ratio of the frequencies is a rational number.

    There is now an extensive literature on this subject [2] but most of it is quite technical. In 1994, Steven Strogatz published an excellent introductory textbook [3] at the advanced undergraduate level, and in 2004 José Rial et al provided a very useful, accessible survey [4] of the effects of nonlinearity in the climate system, including many examples. Both of these should be required reading for anybody seriously interested in climatology.

    Many physicists (I am one of them) believe that nonlinear dynamical systems theory, including chaos theory, is one of the three greatest advances in our understanding of nature that occurred in the 20th Century (the other two were relativity and quantum mechanics). This new branch of mathematics is not intuitive, but climatology is crippled without it.

    Almost all the complex General Circulation Models that are le dernier cri at the IPCC are linearized, which means that they are virtually worthless. Every climatologist wannabe without a strong background in nonlinear mathematics is just a soothsayer, who might as well make predictions by examining the entrails of slaughtered chickens.

    [1] Saltzman, B. & Sutera, A., “A Model of the Internal Feedback System Involved in Late Quaternary Climatic Variations,” Journal of the Atmospheric Sciences 41 #5 (1984) 736-745, at http://journals.ametsoc.org/doi/pdf/10.1175/1520-0469%281984%29041%3C0736%3AAMOTIF%3E2.0.CO%3B2

    [2] Crucifix, M., “Oscillators and Relaxation Phenomena in Pleistocene Climate Theory,” The Royal Society, Philosophical Transactions A 372 #1962 (March 2012), at http://rsta.royalsocietypublishing.org/content/370/1962/1140

    [3] Strogatz, S.H., “Nonlinear Dynamics and Chaos” (Addison Wesley, 1994). Available as a .pdf download (free) from http://detritus.fundacioace.com/pub/books/Strogatz%20-%20Nonlinear%20dynamics%20and%20chaos.pdf

    [4] Rial, J.A. et al, “Nonlinearities, Feedbacks and Critical Thresholds Within the Earth’s Climate System,” Climatic Chage 65 11-38 (2004). Available online at http://www.globalcarbonproject.org/global/pdf/pep/Rial2004.NonlinearitiesCC.pdf
    • Javier says:

      January 16, 2018 at 11:35 am

      The D-O events may also represent relaxation oscillations, but their origin is not at all obvious.

      In my opinion D-O events have been elucidated. The source of energy that drives them is warm water brought North by the North Atlantic Current, that enters the Nordic Seas below the ice, below the layer of fresh cold water, and below the halocline. This stratification that allows the build up of a huge pool of warm subsurface water is inherently unstable as the amount of energy below the halocline increases. When it breaks down, the warm subsurface water ascends and after melting the ice warms the atmosphere to equilibrium. The relaxation phase is the simultaneous cooling of atmosphere and ocean until the initial conditions have been restored. The evidence for this has been published.
      Dokken, T. M., Nisancioglu, K. H., Li, C., Battisti, D. S., & Kissel, C. (2013). Dansgaard‐Oeschger cycles: Interactions between ocean and sea ice intrinsic to the Nordic seas. Paleoceanography, 28 (3), 491-502.

      The periodicity must be externally imposed and in my opinion it is due to a lunisolar cycle that creates powerful tides capable of disrupting the stratification in the Nordic seas every 1500 years. You can read about it in my article:
      https://judithcurry.com/2017/02/17/nature-unbound-ii-the-dansgaard-oeschger-cycle/
      • Euan Mearns says:

        January 16, 2018 at 5:52 pm

        Javier, I will have a post on Bond / D-O cycles on Friday. Both correlate with 10Be and I see a ~1150 year solar cycle that controls it. This comes back to spectral changes in solar output affecting atmosphere circulation. When the Sun goes queit, the jet stream meanders and we get frequent, strohg N wind that slows the Gulf stream, and I hope one day before I die, blows ice bergs far south in the Atlantic Ocean.

        That’s a tremendous artice you link to. Don’t have time to read it right now.
      • Clive Best says:

        January 17, 2018 at 9:07 pm

        Javier,

        Tides also act as a catalyst in terminating ice ages. Terminations for the last 800k years have always been coincident with maxima in eccentricity. Why? An increasingly elliptical orbit reduces the perihelion distance to the sun which then amplifies spring tides (1/R^3). As a result your 1500 year cycle can become a 100k super-cycle.

        http://clivebest.com/blog/?p=5464
    • Rob Slightam says:

      January 16, 2018 at 5:34 pm

      We cannot solve navier stokes soi how can we make climate models work?
    • Mike says:

      January 16, 2018 at 6:19 pm

      Nevertheless I can expect that July 16 2020 will be warmer than January 16 2020.

      The climate is indeed chaotic along with so many other things but they are still amenable to prediction.
      • Occam says:

        January 17, 2018 at 8:56 am

        Assuming you refer to the UK, your expectation (i.e. 16 July 2020 -v- 16 January 2020) is reasonable but not entirely a certainty. It remains possible that specific weather at the time might deliver a contracy outcome. 19 C in January and 15C in July remain entirely possible and have been observed. So your first sentence poorly supports your second.
23. Frederick Colbourne says:

    January 16, 2018 at 11:53 am

    Geologists who have studied changes in sea level on the west coast of Peninsular Malaysia point to sea level two meters higher about 5,000 years ago. Vertical land movement was ruled out because Peninsular Malaysia is part of a stable kraton.

    Moreover, on Penang Island, rivers are incised into the land. In the absence rising of the land since 5,000 years ago, the entrenched rivers indicates a fall in sea level. This this fall was dated at 5,000 years before the present by the Quaternary Research Group of the Geological Department.

    The conclusion is that 5,000 years ago, during the Hypsithermal, also called the Climatic Optimum, sea level was higher than now by about 2 meters. That also means that global climate was warmer than now by at least one degree Celsius.

    Geologists of the past had ample evidence that still shows that global climate was able to rise in recent times above its present level without a rise in CO2. Occam’s Razor tells us two things.

    The Greenhouse gas hypothesis does not explain the present. First, because adding that new assumption about Greenhouse gases does not add to our understanding of the past or the present. So it is useless.

    Second, we ought to find an assumption that does explain both the past and the present, because as it stands now we cannot explain why climate changes, apart from orbital parameters originating in celestial mechanics (Milankovitch theory). We do have now a more general theory of cosmoclimatology based on Galactic Cosmic Ray particles. (Svensmark and others).

    We really ought to spend more money and effort to determine if Svensmark’s theory is as powerful as he and his colleagues claim. If cosmoclimatology is successful in explaining climate change over the last billion years, then cosmoclimatology plus plate tectonics would account for Earth’s entire geological history.

    Geologists would have to go back to school, as I did at age 70, to understand better both geology and climate and in the process to obtain an M.S. in Earth science.
24. Geoff Rickards says:

    January 16, 2018 at 9:57 pm

    Yes indeed, Roger.
    The MEI at https://www.esrl.noaa.gov/psd/enso/mei/ says it all, no?
25. Leo Smith says:

    January 17, 2018 at 3:40 am

    I already indicated a way to check on cloud effects, by looking at desert and wetland regions at the same latitude.

    There is equally a way to assess the impact of the alleged ‘positive feedback’ on climate change, since the feedback is not restricted to CO2 induced warming or cooling, but to any increased warming or cooling.

    I have, with utter disbelief, read of how feedbackless climate change due to volcanic events has been superimposed on alleged CO2 induced warming complete with feedback, in the same paper…

    Finally, another angle on that damned elusive feedback: My brother in law, a paleogeologist, merely remarked ‘the geological record of relative stability is completely inconsistent with positive temperature feedback;

    In short if that feedback exists, the past as we know it, does not….neither is the effect of volcanic eruptions as small as it has been maesured to be.

    Only extreme practitioners of double-think can square the circle.
26. Javier says:

    January 17, 2018 at 12:00 pm

    At the core of this issue is the fact that, as far as we know, CO₂ levels are currently very unusual for the Late Pleistocene, about twice the average, while temperatures, sea levels, and ice are within Holocene variability range, which is a lot narrower than Late Pleistocene variability range.

    The only conclusion that can be extracted from these facts is that CO₂ is not a primary climate driver. That so many scientists maintain the opposite is astounding.
    • Chris Matchette-Downes says:

      January 17, 2018 at 12:43 pm

      It is astounding. However it is the public’s view endorsed by the Pope, Blair, JK Rowling, Attenbough and many others – more reason to update the GSL position else we continue to fight the wrong battles.
    • Don Cox says:

      January 17, 2018 at 8:10 pm

      I think you are underestimating the time scale involved. If you double the CO2 concentration now, my understanding is that changes will be seen over the next couple of centuries. Conversely, if we reduce the CO2 now, it will take centuries to undo the effects.

      And ice sheets take a very long time to melt away. Or in other words, human lifespans are short.

      The mistake made by the climatologists is to imply that disastrous changes will happen in a few years.
      • Javier says:

        January 17, 2018 at 8:34 pm

        Where did you get that idea? There is a thing called Transient Climate Response (TCR), that is what you get in the short term after raising CO₂ levels, and another thing called Equilibrium Climate Sensitivity (ECS), that is what you get over a few centuries as the ocean equilibrates.

        Of course nobody knows their values, but depending who you ask the TCR/ECS ratio is somewhere between 0.6-0.8, meaning that it is believed that you get 60-80% of the effect in just a few years. After all we are talking about instantaneous effects as soon as the CO₂ molecule is up in the air doing its deed.
        • Occam says:

          January 18, 2018 at 12:26 pm

          There is a new academic study published in Nature and reported widely in the UK press today, which suggests a narrower range to ECS than previously postulated.

          https://www.nature.com/articles/nature25450

          The abstract of the paper is as follows:

          Equilibrium climate sensitivity (ECS) remains one of the most important unknowns in climate change science. ECS is defined as the global mean warming that would occur if the atmospheric carbon dioxide (CO2) concentration were instantly doubled and the climate were then brought to equilibrium with that new level of CO2. Despite its rather idealized definition, ECS has continuing relevance for international climate change agreements, which are often framed in terms of stabilization of global warming relative to the pre-industrial climate. However, the ‘likely’ range of ECS as stated by the Intergovernmental Panel on Climate Change (IPCC) has remained at 1.5–4.5 degrees Celsius for more than 25 years1. The possibility of a value of ECS towards the upper end of this range reduces the feasibility of avoiding 2 degrees Celsius of global warming, as required by the Paris Agreement. Here we present a new emergent constraint on ECS that yields a central estimate of 2.8 degrees Celsius with 66 per cent confidence limits (equivalent to the IPCC ‘likely’ range) of 2.2–3.4 degrees Celsius. Our approach is to focus on the variability of temperature about long-term historical warming, rather than on the warming trend itself. We use an ensemble of climate models to define an emergent relationship2 between ECS and a theoretically informed metric of global temperature variability. This metric of variability can also be calculated from observational records of global warming3, which enables tighter constraints to be placed on ECS, reducing the probability of ECS being less than 1.5 degrees Celsius to less than 3 per cent, and the probability of ECS exceeding 4.5 degrees Celsius to less than 1 per cent.
          • Javier says:

            January 18, 2018 at 8:12 pm

            There is always a new article, but we are dealing with an issue that shows no significant progress in 36 years. The new paper obviously uses models and makes an assumption on them, so it is an assumption on top of an assumption. Unsurprisingly it gets the same mean ECS as models, ~ 3° C per doubling. It couldn’t get any other. The problem is that estimations from observations are significantly lower than their constrained value. That’s why we don’t observe the warming predicted by models.

            And it is troublesome that they not even use all CMIP5 models for their study, They have practiced a selection and use a subset of models. The reason for this selection is unclear. Perhaps the result is more to their liking.

            Anyway, the approach to the question of climate sensitivity from models is not new. It gives an answer. It remains to be demonstrated that the answer is meaningful and related to the real world.
          • A C Osborn says:

            January 18, 2018 at 10:08 pm

            Javier, I think it has already been demostrated that compared to the real world it is a failure.
27. The_Iceman_Cometh says:

    January 17, 2018 at 12:43 pm

    “The Greenhouse Effect arises because certain gases (the so-called greenhouse gases) in the atmosphere absorb the long wavelength infrared radiation emitted by the Earth’s surface and re-radiate it, so warming the atmosphere. This natural effect keeps our atmosphere some 30˚C warmer than it would be without those gases. Increasing the concentration of such gases will increase the effect (i.e. warm the atmosphere more)”

    The fixation on greenhouse gases defined usually as carbon dioxide, methane and a few other trace gases completely overlooks the role of water vapour. It is the major absorber of long-wave infra-red. Importantly, there is a significant region at around 15 microns where water does not absorb. It is also the region where carbon dioxide absorption peaks. So increasing carbon dioxide in the atmosphere merely shrinks the small spectral hole in the water absorption spectrum through which infrared would not be scattered and escape directly to space if there were no carbon dioxide. The effect increases logarithmically with increasing concentration. At 400ppm the hole is nearly closed; doubling the concentration will make little difference to the long-wave infrared that is scattered.

    “The present warm period (known as the Holocene) became established only 11,500 years ago, since when our climate has been relatively stable.” The ice core record shows that in the 8200 years since the cooling spike in the global temperatures, the change in temperature over a century has a standard deviation of ~1 degree C. [1], which indeed confirms the stability, However, it also means that the claimed observation of ~0.8 degrees C in the last century is well within the bounds of natural variability. Moreover, about half that 0.8 degrees C change occurred between 1910 and 1945, when growth in carbon dioxide in the atmosphere was slow and unlikely to have been the driver.

    “Nevertheless, after 1900 the overall decline in temperature sharply reversed. According to one recent study, it is likely that the area- weighted global average temperature for the 30 year period from 1970 to 2000 was higher than at any time in nearly 1,400 years.” According to many studies, the homogenisation of raw temperature data has had the effect of distorting the global average temperature records, generally to cool the past. The review of some 200 papers by Soon and Baliunas [2] showed that present day temperatures were not unusual in the past millennium.

    “Tree ring data confirm that recent warming is unprecedented in central Europe over the past 2,500 years, and in eastern Europe over the past 1,000 years.” Tree ring data as a proxy for temperature became discredited when the fact that tree rings narrowed during the warming observed in this century was hidden by what emails called “Mike’s trick” – the data was deleted, and the proxy series claiming to show rapid temperature rise replaced by actual temperature records.[3]

    [1] Lloyd, Philip J. An estimate of the centennial variability of global temperatures. Energy & Environment, 26(3), pp. 417–424 2015. DOI: 10.1260/0958-305X.26.3.417
    [2] Soon, Willie; Sallie Baliunas (January 31, 2003). “Proxy climatic and environmental changes of the past 1000 years” Climate Research. Inter-Research Science Center. 23: pp89–110. doi:10.3354/cr023089.
    [3] Montford, A.W. 2012. Hiding the decline. CreateSpace Independent Publishing. ISBN13: 9781475293364
28. aporiac1960 says:

    January 17, 2018 at 1:33 pm

    Does anyone know of any precedents for professional/learned societies releasing public assessments of a complex and very broad topic that is only obliquely connected to their own area of expertise?

    It seems rather strange, and even inappropriate for the Geological Society of London to engage in this enterprise given that they must necessarily include assessments of the state of science in a number of areas that are not really their bag. Furthermore, it seems rather silly because they couldn’t really do anything other than try to discover the prevailing orthodoxies in the respective areas of climate science and then endorse those views because it would cause a God-almighty ruckus and scandal otherwise. I’m not speaking about the impossibility of an individual geologist taking a contrarian view, but about the impossibility of a group of geologists speaking in an institutional capacity.

    It seems to me to be a kind of virtue-signaling exercise.

29. Pingback: The Geological Society of London’s Statement on Climate Change | NOT A LOT OF PEOPLE KNOW THAT

30. polar scientist says:

    January 18, 2018 at 6:38 pm

    RESPONSES TO VARIOUS POSTS IN THE DISCUSSION OF THE GSL STATEMENT ON CLIMATE

    The GSL statement on climate was made entirely independently of the IPCC, by a group of geologists and geochemists who have spend most of their working lives (in some cases 50 years or more) working on one or other aspect of climate change in the geological context.

    They note a rise in temperature will supply CO2 from the ocean, which will feed back causing further temperature rise (case “A”); and that a rise in CO2 (case “B”), e.g. from prolonged volcanism, will cause a rise in temperature, which, in turn, will lead back to case “A”. The geological record demonstrates that you can have both cases “A” and “B”. A key example of case “B” is the Paleocene-Eocene Thermal Maximum, when a massive injection of CO2 caused global temperatures to rocket by 5-6C. There is no plausible source for this massive sudden temperature rise apart from a natural massive emission of CO2 and/or methane (which would convert rapidly to CO2 in the atmosphere), most likely stimulated by volcanic activity associated with the opening of the northern North Atlantic.

    Several respondents seem confused about the origin of the greenhouse theory of climate change. It did not originate with the IPCC. It has a long pedigree, starting with Fourier in 1824 (who realised that the atmosphere was warmer then it should be), followed by Tyndall in the 1860s (who conducted experiments that showed that the minor atmospheric gases CO2, H2O, O3 and N2O all absorbed and re-emitted infrared radiation), then Arrhenius in the 1890s (who conducted the first climate model, which showed that emissions from fossil fuel burning would warm the planet, while halving the CO2 in the atmosphere would create a new ice age), continuing with geologist T C Chamberlin in the 1890s (who produced the first geological model of climate change). That model is like the one we hold today: volcanoes emit CO2, causing warming; chemical weathering of minerals takes CO2 out of the atmosphere, transferring it to the oceans; the development of coal swamps prevents dead trees from decomposing, providing a second sink for CO2; the balance between these forces over time will give us change between warm and coal climates.

    That notion was taken up in 1923 by geologist Robert Sherlock, in his book “Man as a Geological Agent” (supported by geologist Arthur Smith Woodward). Amateur meteorologist Guy Callendar showed in the 1930s, 40s and 50s that air temperature was linked closely to the concentration of CO2 in ‘background air’ (air away from cities and industrial zones); in the 1950s the US Military funded classified research into the full spectrum of CO2, and Gilbert Plass used the declassified results in the mid 50s to early 60s to refine Arrhenius’s calculations and demonstrate that human emissions were changing the climate. That stimulated Roger Revelle to examine CO2 in the oceans in the late 50s, and to get funding for Charles Keeling to set up a collecting station for CO2 in ‘background air’ in 1957. In 1965 Revelle, Keeling and Wally Broecker reported to President Johnson on the dangers inherent in continuing the emission of CO2. By 1967 Manabe and Wetherald had remodelled the effects of CO2 in the atmosphere, also taking into account the behaviour of water vapour, which differs from CO2 in being directly tied to temperature. Concerns about rising emissions were raised at the first World Climate Conference, in 1979, and Jules Charney and his team produced a comprehensive report on greenhouse gases and their effects on the atmosphere that same year. Then in 1981 and 1982 Jim Hansen began applying his knowledge of the atmospheres of other planets to understanding the workings of the Earth’s atmosphere and the roles of the greenhouse gases. In 1985 a major meeting on CO2 and global warming was held at Villach in Austria, and that and the data accumulated from this and multiple research papers led to the proposal in 1988 that the topic should be investigated globally by an intergovernmental panel, the IPCC, which was duly formed and then published its first report in 1990.

    By this time the evidence accumulated form these and multiple other ongoing studies made it plain that human emissions of greenhouse gases were likely to be changing the climate, and that perception has grown stronger with each passing IPCC report. There is no evidence to suggest that what we are seeing now is natural. Indeed, temperatures go on warming, ice goes on melting, and sea level goes on rising much as predicted, although since 1990 sunspot activity has been in decline, which in the past has led to global cooling. Hence the theory of human influenced climate change is (a) not new; (b) not attributable to the IPCC; (c) backed up by experiments and calculations dating back to the mid 1800s.

    The CO2 works by blocking the path of IR from the Earth’s surface, as shown in any plot of the flux of infrared radiation against wavelength (or wave number). As you add more CO2, the CO2 pit in the plot both deepens and widens, which prevents IR from getting out swiftly and warms the atmosphere further. How to calculate the effect? It’s complicated. First you need the full line spectrum of CO2, which has tens of thousands of absorption lines. Then you calculate the absorption at each line, and integrate over wavelength for every absorption line (> 60,000 for CO2 alone), using data from laboratory measurements. Then you have to account for effects of temperature and pressure on the broadening of the lines (more laboratory measurements). Then you integrate over all angles at all levels in the atmosphere. And you do this for each CO2 increase. It’s a supercomputer task. You can simplify this by using empirical data – i.e. you can see that there is an exponential rise in CO2 from 1750, and you can measure its log relation to temperature. The upshot is that the link between CO2 and temperature since 1750 is not an assumption – it is the product of highly detailed calculations.

    Some people ask – why do we not see a 1:1 relationship between CO2 and temperature? It’s because the temperature is also dependent on other variables, e.g. changing albedo from the loss of sea ice; or the emission of heat and CO2 from the Pacific during El Nino (warm) Events, or the cooling of the Pacific and absorption of CO2 during La Nina (cold) Events, or the same changes during the longer wavelength positive or negative phases of the Pacific Decadal Oscillation.

    Many people, including some geologists, focus on the relation between CO2 and temperature in ice cores, as if that were the only factor telling us about the climate of the past. Ice cores actually tell us that the fluctuations between glacial and interglacial were driven by Milankovitch oscillations in incoming solar radiation (insolation) driven by changes in the Earth’s orbit and axis. Increasing insolation warmed the oceans, which released CO2, which fed back through positive feedback to further warm the atmosphere. Water vapour was an accessory, increasing with temperature. The original ice core data from the Vostok ice core suggested that there were significant delays between temperature rise and CO2, although that was brought into question in 2013 by the work of Parrenin et al, in Science. But in any case the primary driver during rising insolation was the orbital/axial insolation itself, and the secondary driver was temperature. CO2 was secondary.

    It has long been noticed that while rising temperature at the ends of each glacial period were closely paralleled by CO2, falling temperature was not. There are good reasons for that. For instance, falling insolation drove falling temperature, which in turn led to rapid sea ice formation, limiting the exchange of atmospheric CO2 with the ocean. Falling temperatures also caused sea level to fall, limiting the areal expanse of the ocean, further limiting the exchange of CO2 with the ocean. Declining vegetation in polar regions meant less CO2 being pulled out of the atmosphere by plants, while rotting marine vegetation on exposed continental shelves put CO2 back into the atmosphere. These and related things kept CO2 from falling as fast as temperature as the world cooled towards glacial maxima. Gradually, nevertheless, CO2 did fall until it was at its lowest when temperatures reached their nadir just before glacial terminations warmed things up again. These processes are both natural and understandable. They do not tell us much about what happened BEFORE the last ice age.

    Recently Foster et al (Nature Comms. April 2017) showed that proxy measures of CO2 have varied through time about a declining trend over the past 420 million years. At the same time, like all stars of its type, the Sun’s output has steadily increased. The higher CO2 and lower solar output of 420 million years ago shared much the same climate as the lower CO2 and the higher solar output of more recent times – in effect the two climate drivers tended to cancel one another out via a thermostat effect. Data on past CO2 comes from proxies like the stomata in fossil leaves, but also from multiple other sources, including marine plankton, and from carbon isotope data. These are backed up by data on the depth at which deep sea carbonates dissolve (the carbonate compensation depth or CCD), which rises in the ocean as seawater absorbs more CO2 from a CO2 rich atmosphere, and falls during times when atmospheric CO2 is less abundant. As atmospheric CO2 rises, the ratio of Mg/Ca decreases because with more CO2 dissolved in the ocean, marine basalts are weathered more easily. Marine floras and faunas change in a corresponding way, with more Low-Mg Calcite chalks when Mg/Ca ratios are low (as in the mid to late Cretaceous), and more aragonitic corals and High-Mg Calcite fossils when Mg/Ca ratios are high (as in the earlier Cretaceous and after the main period of chalk deposition. This is what Zalasiewicz refers to as ‘the calcite metronome’. In my experience few geologists are familiar with these data. Yet we have known since at least 1980, from the work of geochemist Mike Arthur, that ocean chemistry reflects past atmospheric composition. The latest exponent of this approach is Dietmar Muller from the University of Sydney (see Geology 2013).

    As Muller points out, variations in past levels of CO2 owe much to plate tectonics. For example take the rapid northward movement of India during the early Cenozoic as modelled by Kent and Muttoni. As India moved north, the carbonate-loaded deep sea Tethyan seabed in front of it would have been subducted beneath the Asian margin, providing an ample source of volcanogenic CO2. That source dried up 50 million years ago when India itself plunged into the Asian margin. Subsequent mountain building provided minerals for chemical weathering to act upon, taking CO2 back out of the atmosphere and into the ocean. Here we see Chamberlin’s changing balance between sources and sinks at work, giving rise to warming up to 50 million years ago and cooling thereafter. Undoubtedly, Milankovitch variation was superimposed on these long, slow, changes, possible giving rise to periodic short-term warming or cooling events.

    The fall in CO2 from the Silurian to the Carboniferous may owe something to plate tectonic processes, in that this was a time when continents were coming together to form Pangaea. Equally, it was the time when land plants were slowly conquering the land and becoming larger and taking up more CO2 with time, lessening the amount of CO2 in the atmosphere. That lowering of CO2 culminated with the trapping of CO2 in trees in coal swamps, and the great Carboniferous glaciation.

    Repeated rapid climate change is obvious from the intermediate stages of Ice Age climate cycles. It seems that the climate system at these times – half way between full glacial and full interglacial – was unstable, and oscillated between warm and cold intervals with a frequency of about 1500 years. These climate cycles are identified in Greenland ice (Dansgaard-Oeschger or D-O Cycles) and in North Atlantic ice cores (Bond Cycles). Groups of three cycles commonly lead progressively to more and more cold events where massive iceberg outbreaks occurred, scattering rock debris across the North Atlantic in so-called Heinrich Events. The cold events in Greenland occur in parallel with warm intervals in Antarctica, giving rise to the concept of a bipolar seesaw. It seems that the formation of extensive areas of sea ice in the north turn off the oceanic Thermohaline Conveyor, such that heat builds up in the south. Eventually this situation becomes unstable and the heat moves north, causing ice melt and releasing iceberg armadas there. The north warms as the south cools, then the process begins again. Contrary to popular belief the warm intervals are associated with 20ppm increases in CO2 in Antarctic ice cores. As for most glacial-interglacial change, the CO2 is a response to, not a driver of, temperature change, but it does provide positive feedback.

    Bond Cyles continue, though very much reduced, into the Holocene. Their cold peaks are associated with extended rains across western Europe (see papers by Magny et al). They parallel 10Be and 14C isotopes, which reflect increased cosmic ray input to Earth’s outer atmosphere, which in turn reflects a decrease in the solar wind and solar energy output. Possibly the latest cold Bond Cycle peak was the Little Ice Age (1250-1850). Smaller peaks and troughs in solar output (the 208-year Suess Cycle) seem to control smaller peaks and troughs in the temperature record of the past 2000 years. Among the peaks were the Medieval Warm Period and the Roman Warm Period (Steinhilber et al, 2012). However those were superimposed on a baseline of declining northern hemisphere orbital insolation that led Earth in to a neoglacial period over the past 4000 years following the Holocene climatic optimum. Combining the solar and orbital record we can see that the Roman period would have been warmer than the Medieval period even though their solar input was the same, because the underlying orbital insolation was higher in the earlier period.

    Orbital insolation is now virtually flat, so the main natural change controlling climate, apart from the odd volcanic eruption, is solar variability. So, what has the Sun been doing? A re-evaluation of sunspot activity by Clette et al in 2014 showed that solar output (the 11 year sunspot cycle) peaked in the 1780s, the 1860s, and around 1980-90, with basically no difference between these periods. That makes it difficult to call on solar activity to explain the rise in temperature since 1900. Instead we need to invoke some other forcing factor, the logical culprit being the exponential rise in greenhouse gas emissions since 1750. Furthermore, temperature has gone on rising, consistent with greenhouse gas emissions, while sunspot activity has fallen sharply since 1990.

    These few remarks should make it plain that there is indeed much geological evidence for plate tectonic driven changes in CO2 leading to changes in climate over the long term, and that during the cooling of the Pleistocene (and probably the 34 million years since the first great ice sheet formed on Antarctica) the low amounts of CO2 in the atmosphere led to a situation in which the main driver of climate change, in contrast, was Milankovitch orbital/axial insolation, which changed temperature, which fed back onto CO2, and thence back to temperature. CO2 can indeed either lead or follow temperatures, depending on geological circumstance, just as described in the GSL statement. Textbooks explaining these geological relationships include Mike Bender’s “Palaeoclimates” (Princeton Uni Press, 2013), Bill Ruddiman’s “Earth’s Climate: Past and Future” (2013), and “Earth’s Climate Evolution” (Summerhayes, WILEY, 2015).
    • A C Osborn says:

      January 18, 2018 at 8:22 pm

      You have not answered any of the questions that others have asked, you have merely re-iterated the standard Global Warming CO2 theory.
      Anyone who thinks that CO2 with 1/65th the number of Molecules as H2O in the Atmosphere can have “control” of warming needs to explain the Mechanics of this process, not just the physics.
      So please explain how the CO2 molecules in the area where H2O does not totally dominate the processes can have sufficient “power” to cause the warming that is required in the Oceans (70%) of the Surface to change the overall balance of Global Temperatures in the long term.
      All of the current GHGs can barely prevent the Atmosphere and the Surface from losing more warmth at night than the Sun can provide during the day.

      Also explain why at night CO2 cannot stop the Dry Deserts losing 20 Degrees C of it’s heat from the daytime?

      The last point is that more CO2 leads to more Upper Atmosphere Cooling as demonstrated by NASA at the 2013 AGU, so it is not just a problem of a logorithmic relationship.
      • jfon says:

        January 18, 2018 at 10:45 pm

        ‘…more CO2 leads to more Upper Atmosphere Cooling as demonstrated by NASA at the 2013 AGU’
        Upper atmosphere cooling is a result of less heat making it up from the troposphere – where water vapour, and convection, dominate – to the upper stratosphere, which is dry. A colder upper atmosphere implies that less heat radiates to space. This change has been measured by satellite, for cloud-free areas. https://link.springer.com/content/pdf/10.1007%2Fs40641-016-0039-5.pdf
        • A C Osborn says:

          January 18, 2018 at 11:22 pm

          No, more heat Radiates to Space from the mesosphere, which cools the Atmosphere, view the 2013 AGU presentation.
    • Jim Ross says:

      January 18, 2018 at 9:10 pm

      polar scientist,

      I think most of us here really appreciate the longer posts such as yours which attempt to explain the bigger picture for us less knowledgeable geophysicists.

      I do have one question at this stage. You state that “They note a rise in temperature will supply CO2 from the ocean”; well, we all know about the temperature dependence of water to the absorption (or release) of CO2, but my understanding is that the position of the IPCC, based on CDIAC, is that the (warmer) ocean is actually an increasing net sink for CO2. So, can you please explain for us the reason why warmer waters are absorbing more CO2 and, critically, can you show us the d13C-CO2 balance that supports that argument? Thank you.

      Incidentally, you go on to say: “Some people ask – why do we not see a 1:1 relationship between CO2 and temperature? It’s because the temperature is also dependent on other variables, e.g. changing albedo from the loss of sea ice; or the emission of heat and CO2 from the Pacific during El Nino (warm) Events, or the cooling of the Pacific and absorption of CO2 during La Nina (cold) Events, or the same changes during the longer wavelength positive or negative phases of the Pacific Decadal Oscillation.” Perhaps I am misunderstanding you here, but you appear to be saying that warm ENSO events will lead to more release (emission) of CO2 from the oceans. This does not sound unreasonable, but that is clearly not the position of the CDIAC, so please excuse me for being a bit confused.
      • polar scientist says:

        January 19, 2018 at 4:40 pm

        Jim, this is the way it works: El Nino Events release a bunch of warm subsurface water to the surface, which warms the lower atmosphere. That subsurface water had contained CO2 for example from rotting planktonic remains, which was released at the same time. Now, the CDIAC position, I think, is that cold water absorbs gases from the atmosphere, while warm water releases them to the atmosphere. However, the ocean does regularly and routinely exchange CO2 with the atmosphere across the air-water interface. So, as we add more CO2 to the atmosphere, more will enter the ocean – presumably more in cold than warm regions. Eventually an equilibrium is reached between the ocean and atmosphere concentrations. We are not there yet. An additional part of the story is that rising deep water containing lots of CO2 from planktonic decomposition, releases that to the atmosphere as it gets to the surface. At the same time, that process is balanced by sinking of surface water (e.g. as Antarctic Intermediate Water) which can take surface absorbed CO2 down deep again. So it is dynamic picture. I don’t think any of this conflicts with what the CDIAC would say if asked in detail what was going on.

        I hope that helps.
        • Jim Ross says:

          January 19, 2018 at 7:57 pm

          Thank you for your response. I shall try to explain the reason for my question. I appreciate that it is somewhat OT, given that it focusses on only the very recent data, but you made a comment that I would like to discuss further.

          Many commenters, including yourself, refer to El Niño releasing more CO2 into the atmosphere due to the warmer surface waters that are associated with the process. The “routine” exchange of CO2 between its absorption into the colder waters towards the poles and its release back into the atmosphere in the tropics is not the issue here. The issue is about the net effect. In making your point about the effect of El Niño, this implies that more CO2 would be released than would be the case with neutral ENSO conditions and it would be less under La Niña conditions. This sounds very reasonable to me, but it is not the CDIAC position and I am seeking only to highlight that fact, because the CDIAC model is the “explanation” referenced by the IPCC.

          There is very good evidence that short-term changes in the rate of growth of atmospheric CO2 (as reflected in the annual cycle) are driven by temperature. During an El Niño, the rate of growth increases, while the opposite occurs during a La Niña event. This view is widely accepted. The underlying long-term CO2 growth rate (circa 2.5 ppm per year in recent times) is generally ascribed in its entirety to anthropogenic emissions, since these are estimated to be roughly double the long-term atmospheric growth rate. This is the CDIAC position. Consequently, the CDIAC model (which is perhaps better described as a consolidation of many models) assumes that that the excess CO2 must be taken up by the oceanic and terrestrial biosphere sinks.

          Thus, in the CDIAC model the increased rate of atmospheric growth associated with a strong El Niño is predominantly caused by reduced uptake of emissions by one or both the sinks, not by greater release from any natural source. Further, the δ13C (and O2/N2) data impose an additional constraint on the CDIAC model, requiring that essentially all the variability in short-term growth is caused by changes in the terrestrial sink, with uptake varying annually between 0% and over 50% of total emissions, while the oceanic uptake steadily grows in size year by year, at around 27% of total emissions every year. It is worth noting that during a strong La Niña and also years with major volcanic eruptions, the sinks apparently are happy to absorb almost 80% of total emissions.

          So, in the CDIAC model, ENSO has virtually no net effect on oceanic uptake/release; it is entirely reflected in huge annual changes in the sink capacity of the terrestrial biosphere.

          I am somewhat sceptical of this view, to put it mildly, hence my original question. Although there seems to be little interest in discussing the δ13C data here, it provides extremely important information about the actual processes that are occurring, including the often obscured or ignored fact that the δ13C values actually increase sometimes (a variation which appears to be linked to La Niña events, which as you know are associated with increased upwelling of nutrient-rich cold waters). Incidentally, I do agree with you that phytoplankton are an important aspect of the process.

          I provided links to the 2016 and 2017 CDIAC data up thread. Their spreadsheets are very comprehensive and easy to review. There are also associated technical papers if you wish to delve further. I can also provide links to recent papers that show that there are still problems with the models.
          • Javier says:

            January 19, 2018 at 9:01 pm

            Jim,

            Your questions are not difficult to answer. Over past geological periods warming is associated with CO₂ released from the oceans, while the response by the biosphere is more complex, more dynamic and often opposite. This warming period is different. Despite the warming the oceans are not releasing CO₂, they are a net sink. This is due to the increase in atmospheric CO₂ partial pressure and Henry’s law.

            The response of atmospheric CO₂ levels to El Niño is well known since the mid-70’s. Bacastow, a collaborator of Keeling, nailed it.
            Bacastow, R. B. (1976). Modulation of atmospheric carbon dioxide by the Southern Oscillation. Nature, 261 (5556), 116-118.

            The causes of this response are multiple, as it is due not only to SST changes, but also to changes in precipitation mainly in the Amazon basin. El Niño is associated to an increased draught and an increased release of CO₂ by tropical forests.
          • Jim Ross says:

            January 20, 2018 at 11:26 am

            My original question was directed to polar scientist as I wanted to know if their views differed from that of CDIAC; if so, I would have been very be interested hear such views.

            Bacastow’s position was that “a principal cause of the variation [in annual growth rate of atmospheric CO2] may be a change in the rate of removal of CO2 by the oceans”. Note: “by the oceans”.

            As I commented above:
            So, in the CDIAC model, ENSO has virtually no net effect on oceanic uptake/release; it is entirely reflected in huge annual changes in the sink capacity of the terrestrial biosphere.
        • Ashley Francis says:

          January 20, 2018 at 9:25 pm

          Dr Roy Spencer has a very compelling series of comparisons between data and models showing their complete failure to model el nino events and AMO. His conclusions that (a) models completely fail to reproduce decadel oscillations and (b) decadel oscillations can account for most modern warming are very convincing.

          As Tommy Wils said in the Climategate emails: “What if climate change appears to be just mainly a multidecadal natural
          fluctuation? They’ll kill us probably…”.
    • Javier says:

      January 18, 2018 at 10:30 pm

      A key example of case “B” is the Paleocene-Eocene Thermal Maximum, when a massive injection of CO2 caused global temperatures to rocket by 5-6C.

      Where is the evidence that the increase in CO₂ was the cause of the increase in temperature? Is this an educated guess?

      There is no plausible source for this massive sudden temperature rise apart from a natural massive emission of CO2 and/or methane

      “Argumentum ad ignorantiam,” a logical fallacy. That we don’t know what caused something so ancient as the PETM doesn’t mean that we can choose what we believe the most probable cause and decide that it was it. For all we know a gigantic coronal mass ejection could have hit the Earth and half cooked it.

      By this time the evidence accumulated form these and multiple other ongoing studies made it plain that human emissions of greenhouse gases were likely to be changing the climate

      You have given an account on how the hypothesis became consensual, but it was not the evidence the cause for that. It was the arrival of a new warming period. While the world was cooling during the 1940-75 period the hypothesis failed to gain traction. So it is not the science or the evidence that sustains the consensus, but the coincidence of a hypothesis that predicts warming with a warming period. That’s why the lack of warming is such a problem for the hypothesis. The science behind it is weak and the evidence lacking.

      The upshot is that the link between CO2 and temperature since 1750 is not an assumption – it is the product of highly detailed calculations.

      This is false. The Equilibrium Climate Sensitivity, the amount of warming that a doubling of CO₂ produces, is unknown. Therefore all those highly detailed calculations amount to nothing but a hypothesis or an assumption. The main assumption being that since 1950 all warming is anthropogenic. Natural warming conveniently stopped the moment we started emitting great amounts of GHGs.

      Water vapour was an accessory

      Water vapor is the main GHG by far. There is about 60 molecules of water vapor for each of CO₂, and unlike CO₂ its concentration changes greatly and responds a lot more to temperature changes. Saying that water vapor is an accessory is a huge misstatement.

      CO2 have varied through time about a declining trend over the past 420 million years. At the same time, like all stars of its type, the Sun’s output has steadily increased.

      This is another nice hypothesis without any evidence for it. The idea that the decreasing CO₂ forcing, by coincidence has been exactly matched by the increasing solar forcing in both rate and time, is difficult to believe. One of its main problems is that CO₂ forcing has a logarithmic effect on temperatures, so to match a linear increase in solar forcing, the decrease in CO₂ forcing should have been exponential. There is no evidence for an exponential decay in atmospheric CO₂ over hundreds of millions of years. The most logical explanation is that the huge water content of the planet is responsible for its temperature homeostasis.

      The north warms as the south cools, then the process begins again. Contrary to popular belief the warm intervals are associated with 20ppm increases in CO2 in Antarctic ice cores.

      This again is inexact. Ahn and Brook [1] have shown that most Greenlandic stadials (Greenland warm DO events) show absolutely no CO₂ response.

      https://curryja.files.wordpress.com/2017/02/figure-24.png

      It is difficult to build a CO₂ narrative when the best examples of abrupt climate change, that regionally were a lot more extreme than anything we have seen, had absolutely no involvement from CO₂.

      A re-evaluation of sunspot activity by Clette et al in 2014 showed that solar output (the 11 year sunspot cycle) peaked in the 1780s, the 1860s, and around 1980-90, with basically no difference between these periods. That makes it difficult to call on solar activity to explain the rise in temperature since 1900.

      We know very little about how solar variability affects climate. So little that it is premature to rule out a role for the Sun in 20 century global warming. Sunspot records and temperature reconstructions don’t look that different.

      https://i.imgur.com/yvrMXFy.png

      

      Wanner et al., 2008 [2] meta-reconstruction and sunspot group number.

      [1] Ahn, J., & Brook, E. J. (2014). Siple Dome ice reveals two modes of millennial CO2 change during the last ice age. Nature communications, 5.
      [2] Wanner, H., Beer, J., Bütikofer, J., Crowley, T. J., Cubasch, U., Flückiger, J., … & Küttel, M. (2008). Mid-to Late Holocene climate change: an overview. Quaternary Science Reviews, 27 (19), 1791-1828.
      • David B. Benson says:

        January 18, 2018 at 11:20 pm

        A web search on
        PETM ocean pH
        immediately finds a half a dozen papers which point out that boron isotope studies show the change in pH due to increased carbonates during PETM.

        Gutjar, et al., Nature, 2017, goes further to state that the excess carbon is mostly volcanic. Indeed the North Atlantic Igneous Province is implicated for reasons given in the paper.
        • Javier says:

          January 19, 2018 at 10:42 am

          The problem is the lack of evidence on causality between the increase in CO₂ and the increase in temperatures. The usual response is “we don’t know of anything else,” as if that was considered evidence.

          Then the story usually gets more complicated with more evidence. At the End-Permian mass extinction:

          “By dating the various sediment layers, researchers realised that the mass extinction of the Permian-Triassic boundary is represented by a gap in sedimentation, which corresponds to a period when the sea-water level decreased. The only explanation to this phenomenon is that there was ice, which stored water, and that this ice age which lasted 80,000 years was sufficient to eliminate much of marine life. Scientists from the UNIGE explain the global temperature drop by a stratospheric injection of large amounts of sulphur dioxide reducing the intensity of solar radiation reaching the surface of Earth. “We therefore have proof that the species disappeared during an ice age caused by the activity of the first volcanism in the Siberian Traps,” added Urs Schaltegger. This ice age was followed by the formation of limestone deposits through bacteria, marking the return of life on Earth at more moderate temperatures. The period of intense climate warming, related to the emplacement of large amounts of basalt of the Siberian Traps and which we previously thought was responsible for the extinction of marine species, in fact happened 500,000 years after the Permian-Triassic boundary.”
          https://www.sciencedaily.com/releases/2017/03/170306091927.htm

          Ouch. The usual story, Volcanism -> CO₂ Injection -> Global Warming -> Mass Extinction, might not be true after all.

          And let’s remember that massive SO₂ release also causes ocean acidification. That was the basis of the acid-rain scare.
      • polar scientist says:

        January 19, 2018 at 3:28 pm

        I notice that you did not dispute the argument about Cretaceous warming, only focusing on the PETM. I also notice that you chose to ignore the fact that Ahn and Brook did map out 20ppm changes in CO2 associated with the Antarctic warming that preceded Greenland’s D-O events.
        • Javier says:

          January 19, 2018 at 10:12 pm

          I am not disputing any data, just the interpretation, not based in evidence, that the cause of the warming is the increase in CO₂.

          The sudden North Atlantic warming events that were the basis of the abrupt climate change concept, are obviously not caused by the very modest CO₂ increases caused by the CO₂ released by the Southern Ocean in response to Atlantic cooling.

          Ahn and Brook are very clear about it:
          “We find that CO₂ does not significantly change during the short Greenlandic stadial events, implying that the climate system perturbation that produced the short stadials was not strong enough to substantially alter the carbon cycle.”

          The idea that CO₂ changes could have driven the stadials is not even in the cards.
    • Jan Ebenholtz says:

      January 19, 2018 at 12:53 am

      Now it is getting interesting. Someone actually knowing something. Polar scientist please continue to answer the questions asked otherwise this exercize is of no value.
    • Euan Mearns says:

      January 19, 2018 at 12:06 pm

      Colin, thanks for this lengthy and informative reply. I have delayed posting my second contribution on Bond-D-O cycles until Monday since I am drowning in stuff here and there is more than enough in your comment to be going on with.

      You’ll find that most commenters here accept that human CO2 emissions lead to some warming and so the question boils down to how much? Is it essential that we shut down the FF industries within decades – which is outwith any organisations control. Or with CS ~ 1.5˚C can we be more relaxed, and allow use of FF to decline naturally as they become too expensive to extract?

      By this time the evidence accumulated form these and multiple other ongoing studies made it plain that human emissions of greenhouse gases were likely to be changing the climate, and that perception has grown stronger with each passing IPCC report.

      I don’t think this statement is true. IPCC AR4 WG1 2007 on climate sensitivity.

      It is likely to be in the range 2°C to 4.5°C with a best estimate of about 3°C, and is very unlikely to be less than 1.5°C.

      IPCC AR5 WG1 2013

      Equilibrium climate sensitivity is likely in the range 1.5°C to 4.5°C (high con dence), extremely unlikely less than 1°C (high con dence), and very unlikely greater than 6°C (medium con dence)16.

      The notion that there is consensus on climate change is nothing short of a joke – the GSL statement should make this plain. Between 2007 and 2012 the already high level of disagreement got bigger and was biased in the direction of less alarm. While its fine to have huge disagreements in science, my view of this is that such large variance exists because some parties doggedly refuse to acknowledge some of the data.

      The CO2 works by blocking the path of IR from the Earth’s surface, as shown in any plot of the flux of infrared radiation against wavelength (or wave number). As you add more CO2, the CO2 pit in the plot both deepens and widens, which prevents IR from getting out swiftly and warms the atmosphere further.

      I’m not sure this is correct. The effect of raising CO2 ppm is to lift the emission height of IR that lies close to the tropopause. Raising the height lowers the emission temperature making CO2 a less efficient conductor of heat away from the surface. (I may have got this wrong, its been a while since I last got my head around the enormously complex physics). Should the emission height fall in the stratosphere then the opposite effect will occur.

      Subsequent mountain building provided minerals for chemical weathering to act upon, taking CO2 back out of the atmosphere and into the ocean.

      I’m glad to see that you do not talk about a rock weathering sink. I remain unconvinced, however, that weathering is a significant factor in the kinetics of removing CO2 from the atmosphere.

      The main point I wish to make at present is that I am not in substantial disagreement with much of what you say here. But I’m unsure what you say here is entirely reflected in the GSL statement and addendum. For example, the Sun is barely mentioned in the 2010 statement and in the 2013 addendum Bond and D-O cycles get a mention but are scrambled together with Marcott. You propose neo-glacial conditions beginning ~ 6000 years ago and yet the Vikings settled a partly ice free S Greenland ~1000 years ago. This discussion can wait until Monday.
      • Ashley Francis says:

        January 19, 2018 at 1:35 pm

        Picking up on Euan’s point about the 2013 addendum referencing Marcott. For those that don’t know, Marcott’s Science paper (2013) shows a Holocene maximum, slowly declining temperatures and then a huge uptick “hockey stick” in the modern era. This can be still seen in a propaganda piece at the BBC, the Marcott Science version is the purple line:

        http://www.bbc.co.uk/news/science-environment-24204323

        (As an aside the BBC will not correct the misleading image because “it is in a peer-reviewed paper”. The BBC have even more egregiously overlaid another proxy reconstruction (suspiciously looking like Mann’s “hockey stick”) and labelled it “observed temperature” – despite it going back to the 15th Century, hundreds of years before modern global temperature records begin!)

        That uptick in the modern era in the published version of Marcott (2013) is totally without merit. The uptick is the result of statistical shenanigans The paleo-estimate only has temporal resolution of at best 300 years. The modern period would therefore plot as a single point if presented at the same resolution. Such graphical representations are intended to mislead, so I find it surprising that the GeolSoc Addendum is referencing this paper.

        More relevant is the fact that Marcott’s PhD thesis from which the graph (and paper) was taken does not show the uptick “hockey stick” in the same graph in the PhD thesis. When this new “hockey stick” in Marcott (2013) was challenged by both Roger Pielke and by Steve McIntyre, Marcott eventually accepted the problem in a public response to a question at RealClimate with the following:

        Q: Is the rate of global temperature rise over the last 100 years faster than at any time during the past 11,300 years?
        A: Our study did not directly address this question because the paleotemperature records used in our study have a temporal resolution of 120 years on average, which precludes us from examining variations in rates of change occurring within a century. [edit due to space here…]. We showed that no temperature variability is preserved in our reconstruction at cycles shorter than 300 years, 50% is preserved at 1000-year time scales, and nearly all is preserved at 2000-year periods and longer. Our Monte-Carlo analysis accounts for these sources of uncertainty to yield a robust (albeit smoothed) global record. Any small “upticks” or “downticks” in temperature that last less than several hundred years in our compilation of paleoclimate data are probably not robust, as stated in the paper.

        .

        As a result of that admission the Met Office withdrew the article about Marcott as the basis for showing “unprecedented warming” from its website. I find it surprising that the Geol Soc is referencing Marcott in the Addendum, the original PhD work simply shows the Holocene maximum circa 10,000 – 6,000 BP with a slow decline into the modern era – hardly cause for concern. But of course any casual observer checking Marcott (2013) by following the GeolSoc addendum reference would be easily mislead by what is essentially a marketing poster for alarmist warming.
        • polar scientist says:

          January 19, 2018 at 3:47 pm

          Marcott currently has the best marine core analytical record for Holocene temperatures. He has admitted that it was unwise to add to his Holocene data the record for modern warming.
          • Ashley Francis says:

            January 19, 2018 at 4:38 pm

            To state that “he has admitted it was unwise to add to his Holocene data the record for modern warming” is very polite!

            Marcott in its unadulterated form shows a perfectly respectable reconstruction of temperature through the Holocene. But this would then tell us that temperatures were high some 10,000 – 6,000 years ago and that they have been cooling consistently to date – as seen through the lens of the resolution of the study. We might possibly infer a MWP as well. Few additional conclusions can be drawn from Marcott and, in its original form, it would suggest a little modern warming might not even take us back to the temperatures of the Holocene optimum.

            The GeolSoc Addendum references Marcott 2013 but (a) fails to note that the graph has been adulterated in an unacceptable way by adding modern data and that (b) the author has admitted that this is the case in a public forum. The GeolSoc is referencing a paper that in its published form is highly misleading and gives the impression to any reader not familiar with the truth that Marcott (2013) demonstrates “unprecedented modern warming”.

            The GeolSoc is a scientific organisation. Referencing Marcott (2013) without specifically acknowledging its misleading presentation in its primary graphic is completely unacceptable. Either the authors of the GeolSoc Addendum are unaware of the issues with Marcott (2013) or they reference it without comment or clarification because…well what is the intent? What is the purpose of referencing Marcott (2013) except to offer it as evidence of global warming? Except it cannot say anything about modern warming whatsoever, as shown by the original PhD and by the public admission of the author. It has a nominal resolution of about 300 years, nearly twice the length of the modern temperature record. This habit of splicing datasets together with totally different resolution and making alarmist claims is a common tactic of supporters of global warming (“Mike’ Nature Trick”) along with truncating data that disagrees with theory (“Hide the Decline”). This practice is not science, its propaganda.

            Is the GeolSoc basing its views on science, or on a global warming poster child paper that should have been withdrawn from publication after the admission by Marcott?

            Note that this piece of global warming propaganda is still up on the BBC website and they will not take it down or correct it as it is “in a peer reviewed paper”. I have pointed out to them that even the author admits the problem, but hey ho. Such is the issue with global warming propaganda. Just never thought the GeolSoc would perpetuate this type of misleading paper without qualification.
      • polar scientist says:

        January 19, 2018 at 3:44 pm

        Actually, neoglacial conditions are considered to have begun 4000 years ago, not 6000. They are a product of declining orbital insolation in the northern hemisphere. The Vikings did not start their rovings until the late 700s (Lindisfarne Priory raid AD 793). That was before the Medieval Warm Period began. The Viking expansion continued through the Medieval Warm Period, which was best developed in the Northern Hemisphere and was a response to increased solar output as recorded in 10Be and 14C data. That was a solar warming ‘blip’ superimposed on the underlying orbital insolation decline. Once the MWP was past, the neoglacial conditions made Greenland uncomfortable for the Viking settlers. They died out as the Little Ice Age began, which was the product of solar cooling superimposed on continued orbital cooling.

        There’s no getting away from the fact that Clette’s 2014 appraisal of sunspot activity shows that the peak recent sunspot activity of 1980-1990 was no different from what it was in 1780 or 1860, meaning that the late 20th century should have been no warmer. In contrast what we see is continued warming. Please explain how that can be the case when sunspots are in decline.

        It is worth adding that a better way to assess global warming is to check the rise in global ocean heat content, since the inner ocean is not subject to the things that cause surface temperatures to jump up and down. See the latest EOS magazine for a good review. The OHC rises steadily from the 1960s, as does sea level. Both are better representation of warming than is surface temperature.
        • A C Osborn says:

          January 19, 2018 at 4:09 pm

          I just love it, all the old meaures of what constitutes warming are not working very well, so switch to the OHC, where there is very little Actual data, especially before Argo buoys.

          But it is really an admission that CO2 does nothing and the Oceans & Seas rule the Earth’s Atmosphere, I can live with that.

          You do know that CO2 Back Radiation and the Atmosphere CANNOT warm the Deep Oceans I assume?

          Only Solar Radiation can do so.
        • Euan Mearns says:

          January 19, 2018 at 4:40 pm

          Colin, I’ll repeat an earlier point. You now seem to be fully on board with Bond and D-O cycles and their link to solar activity. But you seem unable to accept that the Modern Warm Period is one of these cycles and that is why (in part) it is warm. Much of what you are saying in comments simply does not exist in the GSL statements. I have a comprehensive post on Bond D-O on Monday.

          Have you been following what is going on around the world? Huge snow in The Alps and -60˚C in Siberia.

          

          

          Solar cycle 24 has just about died. The warmists tell us that snow will be a thing of the past. The sceptics say that low solar activity is associated with severe N hemisphere winters. If we get a run of winters like this then it is not beyond my imagination to see glacier expansion in the Alps. Where will the reputation of science be then?

          https://www.weathertoski.co.uk/weather-snow/
          • jfon says:

            January 20, 2018 at 2:22 am

            ‘Have you been following what is going on around the world? Huge snow in The Alps and -60˚C in Siberia.’
            I’m sorry, you’re not allowed to talk about that, it’s just weather ( same as I’ll shut up about record high temperature here last week.) Give it 300 years first 🙂
          • Euan Mearns says:

            January 20, 2018 at 12:11 pm

            @ jfon, I’m not sure if your comment is tongue in cheek. But it makes an important point that I will elaborate on Monday. Changes in solar activity modify the ocean – atmosphere circulation pattern. The jet stream has changed in recent years. This can change climate everywhere with some places getting warmer and others colder with little impact on global average temperature. Loads of inertia in the system though.

            Increasingly I believe the fixation of global mean temperature is a mistake. T≠climate. I’m not saying its irrelevant, just that there is a lot more to the story. Its this lack of understanding and acceptance that is the root cause of this deep controversy.
          • A C Osborn says:

            January 20, 2018 at 2:50 pm

            Jfon, the point is it is not just the Alps & Siberia, cold records have been broken throughout last year in both the Northern and Southern hemispheres.
            Some of them with devistating losses of crops and livestock, it doesn’t take too many of those before people are in danger of suffering loss of employment or even starvation.
            You will not see anything much about it in the MSM, but you can in the local media.
            That is what IceAgeNow collates for us.
          • Euan Mearns says:

            January 20, 2018 at 5:13 pm

            Don’t know why your comments are no appearing AC.
          • A C Osborn says:

            January 20, 2018 at 8:02 pm

            Euan, the logo at the top appears with “Blog Rules” highlighted, if that means anything to you.
        • Javier says:

          January 19, 2018 at 11:17 pm

          There’s no getting away from the fact that Clette’s 2014 appraisal of sunspot activity shows that the peak recent sunspot activity of 1980-1990 was no different from what it was in 1780 or 1860, meaning that the late 20th century should have been no warmer. In contrast what we see is continued warming. Please explain how that can be the case when sunspots are in decline.

          What a simplistic view. What we know is that periods of high solar activity, ~ 1780, 1860, 1980, were all periods of warming, and periods of low solar activity, ~ 1670, 1810, 1900, were all periods of cooling. Pretending that periods of equally high solar activity should have equally high temperatures is a false proposition that ignores that the planet has a huge thermal inertia and getting out of the Little Ice Age has been a very long process.

          How can we see warming while sunspots are in decline? Easy. First, sunspots may be in decline and still solar activity be above average and produce warming, and second, solar activity is not the only factor affecting temperature, so the final effect depends on what all the factors are doing. Also we don’t see continued warming. Solar activity is below average since 2006, and we haven’t seen much warming outside a big El Niño event.

          It is worth adding that a better way to assess global warming is to check the rise in global ocean heat content

          Agreed. A new method of measuring ocean temperature changes based on determination of Xenon and Krypton in ice bubbles has been recently published by Bereiter et al., 2018.
          https://phys.org/news/2018-01-thermometer-global-ocean.html

          Their estimate is that in the past 50 years the oceans have warmed by 0.1° C. The oceans therefore are not warming much.
          • Euan Mearns says:

            January 20, 2018 at 12:21 pm

            Well put Javier. It is naive to believe that sunspot number = temperature. Solar variability impacts the ocean – atmosphere circulation which has a lot of inertia. The effects on temperature can be aggregative.

            With The Sun a change takes place and a few years to decades later it works through the system changing climate. The only reliable data we have for CO2 and T is Vostok where T changes and CO2, the supposed agent of change, follows 14,000 years later.
31. Euan Mearns says:

    January 18, 2018 at 7:27 pm

    A note to Mike, Phil Chapman was an Apollo astronaut. Was mission scientist on Apollo 14. So I cut him a little loose. But I deleted it.
    • Mike says:

      January 18, 2018 at 9:37 pm

      Many thanks, I don’t envy you the responsibilities of moderator!
32. A C Osborn says:

    January 18, 2018 at 7:57 pm

    Eaun, this appears to be a concerted efforts by Geologists to push AGW.
    See
    https://wattsupwiththat.com/2018/01/18/the-american-geophysical-union-thinks-climate-intervention-is-a-viable-area-of-research/
    • polar scientist says:

      January 19, 2018 at 3:58 pm

      No, the GSL’s report was an attempt to investigate and demonstrate the evidence from the geological record for past global warming. What it demonstrated to the authors’ satisfaction was that the geological record contained ample evidence for global warming having been influenced by CO2, but not during the Pleistocene Ice Age, when CO2 values seemed too low to have had a substantial influence on climate change compared with the over-riding influence of Milankovitch orbital/axial insolation variation. That is quite a different thing to the GSL deliberately trying to push the AGW agenda. It so happens that our conclusions did match those of the IPCC, which were reached by radically different approaches. That ought to give people pause for thought.
      • Howard Dewhirst says:

        January 20, 2018 at 9:01 am

        Indeed, Colin, ‘A 4-6C jump in temperature is rather large,’ but, as I understand it, CO2 rose ~100ppm following the end of the last ice age, while temperatures increased by ~8oC, both by the start of the Industrial Revolution – (a proxy for the birth of Anthropogenic CO2’s career). Subsequently CO2 has increased by ~125ppm, but temperature by only ~1oC. You argue that Pleistocene CO2 is too low to affect temperature yet, with its logarithmic decline in heating effectiveness, it is the lower values that should have the most effect? And at what level in your opinion, do ppm CO2 start to cause warming? And then there is the Holocene conundrum, with C02 rising by~25ppm, while temperatures declined overall. And I am sure that I am not alone in finding it difficult to understand why anthropogenic CO2 should behave differently to Pleistocene CO2, as is implied and claimed in much of the literature. Finally, to give but one more recent example from the Late Jurassic, previous ice ages, seem to have been accompanied by anomalously high levels of CO2. All such ‘events’ seem to suggest that CO2 (anthropogenic or otherwise) does not drive temperature upwards?
        • jfon says:

          January 22, 2018 at 12:10 am

          You need to move the decimal point one place to the left in your temperatures.
          • petroalbion says:

            February 2, 2018 at 6:33 am

            Thanks Jfon, You are correct, the o is/was the degree symbol that has slipped down, and the decimal point got lost somewhere
      • A C Osborn says:

        January 20, 2018 at 3:12 pm

        I am afraid not.
        When a society adopts the language of the IPCC and finds data to reinforce the IPCC position as far as I am concerned it is a sell out.
        The Geology Society are not the only ones, we have had Medical jumping on the band wagon with ridiculous climate related studies, we have had the Royal Society also supporting the IPCC, much to the disdain of their membership.
        So no pause for thought at all.
        You have still not answered my questions up post about “How” CO2 does what the IPCC and yourself say it does.
        Not just the Physics involved but also the mechanics as well.
      • A C Osborn says:

        January 20, 2018 at 3:25 pm

        No I am afraid it gives me no “pause for thought” whatsoever.
        When a Society adopts IPCC language and finds data to support the IPCC then I take it that they fully accept the IPCC position.
        Wheras as Euan and others have pointed out there is just as much evidence to the contrary.
        You also have not answered my questions up post about “How” CO2 does what Climate Scientists and you say it does.
        That applies not only to the Physics, but also the mechanics of how the physics can achieve it.
33. Euan Mearns says:

    January 19, 2018 at 4:15 pm

    I’ve done some digging around the PETM (Palaeocene Eocene Thermal Maximum).

    The best estimate of the age seems to be ~56Ma and it is characterised by a short lived injection of CO2 over about 15-20,000 years. Most of the sources I’ve looked at by default assume that injection of CO2 caused large amounts of warming. I don’t believe the data has the resolution to say whether CO2 came first and the Earth warmed or vice versa. The observation of high T and high CO2 quite simply cannot be used as evidence to say that CO2 caused the warming. Similarly it is not disproved either.

    This creates a geological conundrum. What could happen that resulted in a vast amount of CO2 being released into the atmosphere? One of the favoured hypotheses is melting gas hydrates – but what happens to suddenly destabilise them? They in fact have a wide temperature stability range.

    Colin’s favoured hypothesis is volcanism associated with rifting of the Atlantic (see below). This process began in the S Atlantic where activity is focussed 105 to 135 million years ago. In the N Atlantic activity is focussed 54 to 61 Ma. So rifting took place over 81 Ma and right at the end of it one volcano suddenly decided to spew a vast amount of CO2 into the atmosphere?

    I’m not buying into either hypothesis.

    

    

    http://sp.lyellcollection.org/content/specpubgsl/197/1/1.full.pdf
    http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.1013.7399&rep=rep1&type=pdf

    https://people.earth.yale.edu/paleoceneeocene-thermal-maximum
    https://www.e-education.psu.edu/earth103/node/639

    The most logical way to get a lot of CO2 into the atmosphere is to suddenly warm the Earth and as Javier points out the most likely candidate to do that would be The Sun. Suddenly warming the Earth would melt gas hydrates – these need to be ocean floor since no polar ice caps back then.

    The articles above describe polar water temperatures ~ 20˚C and warm deep water too. My conclusion therefore is that geologically the best way to get a lot of CO2 into the atmosphere quickly is to roast the Earth. However, I’m entirely uncertain about process and if it is feasible for The Sun to do this.
    • polar scientist says:

      January 19, 2018 at 4:30 pm

      And therein lies the problem. I have a mechanism, which you don’t like, and you have a mechanism for which there is no proof whatsoever. Actually, as Bryan Lovell has pointed out, the opening of the northern North Atlantic was a reasonably discrete event, which lifted Scotland and led to deposition of the sands of the Forties Field, after which Scotland apparently subsided. The eruptions associated with these events along the UK’s west coast, at around the Palaeocene-Eocene boundary, would themselves have added CO2 to the atmosphere. In addition, it has been proposed that they were associated with earthquakes that destabilised nearby continental slopes where sediments contained methane clathrates that then rapidly decomposed providing a methane boost that converted rapidly to CO2. Investigations continue. Personally I would rather thoroughly investigate in-world concepts before jumping to solar solutions. A 4-6C jump in temperature is rather large, you’ll have to admit, and would require something very unusual from what we know of the Sun’s behaviour.
      • Jan Ebenholtz says:

        January 21, 2018 at 10:33 pm

        So this is it. Euan has no answer to recent warming and the Polar scientist has CO2-increase and what happened before is a big assumption on solar activities etc.. and co2- release we do not know anything about. But only can guess. Brilliant.
        So the only thing remaining is to verify that the CO2 really are the culprit by dissecting the algorithms used for predictions so Euan can check that it is not biased for CO2. Well do it.
        In the mean time we all promote nuclear energy so it becomes the main energy source for thermal and electric energy as fast as possible so the current insane way of promoting solar and wind locking us to fossil for a long long time is thrown away on the history dump.
    • David B. Benson says:

      January 20, 2018 at 8:38 am

      Earlier I pointed to Gutjahr et al. , Nature, 2017:
      http://www.nature.com/articles/nature23646
      as strongly implicating the North Atlantic Igneous Province as the source of the initial excess carbon dioxide for the PETM excursion.

      Some eruptions produce much CO2 and others not so much. I live on the Columbia Flood Basalts which despite the ample area, depth and rapid spreading leave little indication of an atmospheric carbon dioxide excursion. I suppose the Mid-Miocene Climatic Optimum can be attributed to these flood basalts erupting; not so impressive. Other flood basalt eruptions, forming Trapps, leave a much greater indication in my geologic record. So the lack of anything spectacular from the opening of the remainder of the Mid-Atlantic Rise is not an indicator for the more northern part.
    • David B. Benson says:

      January 20, 2018 at 9:13 am

      As an addendum to my just prior comment, it occurred to me that the North Atlantic Igneous Province may have ignited coal fields. This would have been analogous to the Siberian Trapps, which did. Indeed, Norilsk, on the edge of the Siberian Trapps, used to mine coal and possibly still does. As Scotland used to have mineable coal, this hypothesis has some support. I suppose the d13C studies from PETM time might be interpreted in that light.
    • A C Osborn says:

      January 20, 2018 at 3:04 pm

      Euan, one of the things that really vexes me is the Hubris of Scientists who think they know exactly what took place millions or billions of years ago.
      That applies to both the Earth and the Sun, especially the Sun.
      We cannot even be sure that the Earth is still on the same orbit it was that long ago, let alone other changes that have taken place, like Magnetic Pole swaps etc
      Do we even know if we have always had the Moon where it is now?
      • David B. Benson says:

        January 21, 2018 at 12:20 am

        A. C. Osborn — The implied good questions are considered in the study of the philosophy of science. The Wikipedia page is a place to begin; there are a variety of textbooks; the University of Edinburgh offers a highly regarded online Coursera series on this subject.

        As for your final question, Luna formed from a collision with the early Terra over 4 billion years ago. It was originally in quite a low orbit and has been spiraling outwards ever since. At the same time, Terra rotates about its axis through the poles ever more slowly. Both are the result of tidal friction. All that and much more can be found in volumes giving the history of Terra, usually from the perspective of a geologist.
        • Euan Mearns says:

          January 21, 2018 at 10:43 am

          I have to delve into my undergraduate geology to answer questions about length of day and orbit etc. Understanding could have changed since. Briefly, ~400 million years ago, there were ~ 400 days in a year. The Earth is slowing down due to tidal forces converting angular momentum into heat. Think IO.

          https://arxiv.org/pdf/physics/0304093.pdf
          • David B. Benson says:

            January 21, 2018 at 6:28 pm

            No. Tides dissipate energy by conversion to heat. In response, Terra slows down its rotation. By the conservation of angular momentum, Luna rotates in its orbit a bit further out.

            Angular momentum is always conserved. In this case of the Terra-Luna system.
          • Euan Mearns says:

            January 21, 2018 at 7:33 pm

            🙂 My credibility is shot 🙁

            But its not just the moon, there are lunar tides and solar tides. What happens to the whole system?

            If its not angular momentum then KE of rotation that gets converted to heat?
          • David B. Benson says:

            January 21, 2018 at 8:07 pm

            Euan Mearns, I don’t think that you need to worry about your credibility. 🙂

            For more details about tides see the Wikipedia page. A more general account than I gave would go so far as to take the entire universe into effect but tidal forces fall off as the inverse of the cube of the distance.

            Yes, it is the kinetic energy of rotation that tidal friction converts to heat.
        • A C Osborn says:

          January 21, 2018 at 12:08 pm

          David, there you go again, stating it as FACTS, when you should be using words like “Calculated” or the “Evidence points to” or the “Concensus is”.
          You have exactly demonstrated my point, that because it is written, it is a fact, when it is purely conjecture based on the evaluation of the available data.

          There was nobody there at the time to record it so it is an Educated Guess, it may be a very well educated guess, but still a guess.

          There a lots of old “Facts” that no longer are.

          ps, do you know what is the Guess for what collided with Earth that just happened to leave the Earth in the Goldilocks orbit?
          • A C Osborn says:

            January 21, 2018 at 12:30 pm

            David, perhaps I should have added a few other desciptive words like,
            current theory,
            assumption,
            to the best of our knowledge,
            You did use the word “perspective” which means “how something is considered” by Geologists so I suppose you did back off a bit from your initial presentation.

            The words I do not use are “proved”, “facts” etc.
          • David B. Benson says:

            January 21, 2018 at 6:43 pm

            I do recommend that you read at least the Wikipedia page on the Philosophy of Science. Science is always contingent and nothing is ever proved, in the sense of logic and mathematical theorems. However, some parts, such as the conservation of angular momentum, are as certain as on could wish for; read about Emmy Noether’s theorems.

            As for change in the length of the day, NIST adds a millisecond or two every few years; computer operating systems are designed to be aware of this. Indeed, there is geologic evidence. Consult a good book on geology for the places to go look for yourself.

            As for your final question, nothing is certain about the origin of the Moon. Consult the Wikipedia page for an overview.
          • Jim Ross says:

            January 21, 2018 at 8:51 pm

            This conversation is completely bizarre. AC grumbled that you (David) were overstating the certainty of some of your statements and you responded by demonstrating the validity of AC’s complaint by saying that “Science is always contingent and nothing is ever proved”. Let me just remind everyone that you said (up thread) that “There is no doubt as determined by C13/C12 ratios”. You then failed to respond to my query as to why there was no doubt, given the known discrepancy in δ13C values.
          • David B. Benson says:

            January 21, 2018 at 9:21 pm

            Jim Ross — See the Wikipedia page on the Seuss effect as well as many other Web sites on the change in isotope ratios occasioned by the massive burning of fossil fuels. As examples, Skeptical Science has an article as does Real Science. A web search on suitable terms locates many papers in the geophysical literature.
          • A C Osborn says:

            January 21, 2018 at 11:56 pm

            David, you just lost quite a bit of credibility by quoting Skeptical Science and Real Science.
          • David B. Benson says:

            January 22, 2018 at 1:33 am

            A. C. Osborn — I did not cite Skeptical Science; I did not cite Real Science. Both are reasonable places to find what I shall call snippet science; short takes by the knowledgeable on various aspects of climatology.

            If you actually went to the effort of learning some climatology you would discover that both are sources of normal science, delivered in little chunks. I recommend reading W.F. Ruddiman’s “Earth’s Climate: Past and Future” and then acquiring enough background to study Ray Pierrehumbert’s “Principles of Planetary Climate”, through Chapter 6. Then perhaps you will agree about Skeptical Science and Real Climate. As it is, you simply appear ill-advised, sorry.
          • Jim Ross says:

            January 22, 2018 at 9:48 am

            David, I prefer to study the actual data than to rely on “snippet science”.

            If atmospheric δ13C-CO2 levels are dropping then, yes, that means that the additional CO2 must have, on average, a lower δ13C content than the current atmospheric level. Not rocket science. Burning fossil fuels is estimated to be currently emitting CO2 with a δ13C value of circa -28 per mil. Atmospheric δ13C is currently around -8.5 per mil and is (on average) dropping (becoming more negative). Apparently this is sufficient proof for some people that all atmospheric growth is from anthropogenic emissions.

            There is just one minor problem with this. Sites like SKS never mention the fact that we know what the average δ13C content of the incremental atmospheric CO2 actually is. It is, on average, -13 per mil. So we are adding CO2 with an average content of -13 per mil (not -28 per mil) and hey the atmospheric level (of -8.5 per mil) is dropping. Further, while the average content of the incremental CO2 is -13 per mil, there is evidence that it decreases during El Niño (i.e. the content of the incremental CO2 becomes more negative) and that it increases during La Niña periods. This latter point is particularly interesting, because the atmospheric δ13C level can actually increase, demonstrating that the incremental CO2 during such periods has a higher (less negative) δ13C content than current atmosphere (i.e. it’s between -8.5 per mil and zero).

            Despite the fact that they do not seem to like to discuss these “facts”, some climate scientists are well aware of this issue. There is a published model that seeks to explain the large discrepancy, which is sometimes referred to as “ocean thinning” but, as we all know, a model is simply one possible explanation of the data and can never be construed as a fact. See, for example, Randerson et al, 2002 (particularly Figure 5): “A possible global covariance between terrestrial gross primary production and 13C discrimination: Consequences for the atmospheric 13C budget and its response to ENSO”.

            Indeed, only last year, Ralph Keeling et al published a paper (“Atmospheric evidence for a global secular increase in carbon isotopic discrimination of land photosynthesis”) where they admitted that having incorporated the most recent δ13C data, their model could not match the actual observations without the addition of a new variable. They state that “no plausible combination of sources and sinks of CO2 from fossil fuel, land, and oceans can explain the observed 13C-Suess effect unless an increase has occurred in the 13C/12C isotopic discrimination of land photosynthesis”.

            So, when you say “There is no doubt as determined by C13/C12 ratios”, you should perhaps reveal which model you are basing that view upon.
          • David E says:

            January 22, 2018 at 9:55 am

            Thank you Jim for your comments

            I indeed recently published an article on this very blog on the same subject. I used a simple model to show that the 13C/12C isotope ratios point to: (i) a much shorter timescale for CO2 equilibration than the models used by the IPCC (a reasonable figure is 20 years, distinct from the residence timescale which is 4 years) (ii) the likelihood that there is a considerable source of CO2 not of hydrocarbon origin – I propose ‘excess’ respiration by humans and their associated domestic animals (+ unintended recipients of our largesse i.e. rats, cockroaches, plant fungus etc;)

            The URL is http://euanmearns.com/atmospheric-carbon-dioxide-a-tale-of-two-timescales/

            David Ellard
          • Jim Ross says:

            January 22, 2018 at 3:34 pm

            David E, Thanks for the link – had a quick look, but it will take me sometime to get my head around all the details!
          • A C Osborn says:

            January 22, 2018 at 3:49 pm

            Mr Benson, how very condescending of you.
            I am 71 years of age and have for the last 14 years been “learning some climatology”.
            However I now use Sites and Forums that offer something other than the IPCC view of the “Science”.
          • David B. Benson says:

            January 23, 2018 at 5:10 am

            David Ellard — Well done!
            Jim Ross — You may now call me Simplicius. David Ellard’s essay is the best I have read regarding the point at hand.
          • Jim Ross says:

            January 23, 2018 at 8:01 pm

            David Ellard,

            Very interesting paper. A quick question as I work my way through it. When you refer to:
            “ratio of total ‘excess’ carbon dioxide to ‘excess’ marked carbon dioxide” and then switch to δ13C data, you state that:

            “The proportion of atmospheric carbon dioxide which has a hydrocarbon fuel origin is given by: (d13C(atmosphere, present day) – d13C(atmosphere, pre-industrial)) / (d13C(hydrocarbon) – d13C(atmosphere, pre-industrial))”
            … you appear to be assuming a linear relationship between δ13C and CO2, since the initial basis for the above equation appears to have been the related CO2 levels (present day, pre-industrial, etc.). Is this correct or am I misunderstanding how you get from the CO2 relationship to the δ13C relationship?

            As you are probably aware, atmospheric CO2 and its δ13C content are not linearly related as illustrated by the following plot (note the left and right scales). A linear change in atmospheric δ13C corresponds to a linear change in the reciprocal of CO2 (which, incidentally, is consistent with a constant δ13C content of the incremental CO2 as per the Keeling equation).

            http://www.ferdinand-engelbeen.be/klimaat/klim_img/sponges.gif

            Thanks.
          • David E says:

            January 24, 2018 at 2:07 pm

            Dear Jim,

            Thank you very much for your kind comments. Mass of CO2 in the atmosphere is additive, so if we mix two sources of mass M0 and M1 with respective delta13C of D0 and D1, then the delta13C of the mixture is given by: (M0 x D0 + M1 x D1) / (M0 + M1).

            This doesn’t mean that the HISTORICAL relationship between mass of CO2 and delta13C in the atmosphere will be linear – that depends on the trends in sources and sinks, although it looks like it is approximately linear (for a small change, the delta in 1/CO2 and CO2 will be the same, with an opposite sign).

            Thanks for your comments.

            David Ellard
          • Jim Ross says:

            January 28, 2018 at 9:41 am

            David,

            I appreciate you taking the time to respond, thank you. Sorry for the delay at my end. The equation in your first paragraph is fine with me. It incorporates an approximation that 12C and 12C+13C can be treated as equivalent when deriving 13C quantities, but that is a common and acceptable approach given the relative proportions. 14C is small enough to be ignored for these purposes, again, fine with me.

            What this equation tells us, using your numbers of 300 and 400 ppmv, and -6.5 and -8 per mil (pre-industrial and current, respectively), is that all of the incremental atmospheric CO2 since pre-industrial times has had, on average, a δ13C content of -12.5 per mil. Using my preferred numbers (pre-industrial and current, respectively) of 280 and 405 ppmv, and -6.5 and -8.5 per mil, I get -13.0 per mil, so not materially different. Separately, if I apply the Keeling equation (Keeling plot) to the Scripps seasonally-corrected monthly data (i.e. plotting measured δ13C against 1/CO2), I get -13.2 per mil at Point Barrow, -13.3 per mil for Mauna Loa and -13.1 per mil at the South Pole. The δ13C observations only go back to around 1980, but there are published data for Law Dome that give -13.1 per mil (see reference below) and even the scales on the plot I referenced in my previous comment equate to a constant value of -12.8 per mil. There is, therefore, pretty good evidence that the δ13C value of the incremental CO2 has been around -13 per mil (but with variations linked to ENSO) since the start of growth of CO2 following pre-industrial times.

            Call me pedantic, but for some odd reason, I consider this to be a rather important piece of information that must be honoured by any hypothesis (or else, disproven)!

            Of course, the value of -13 per mil is a net figure, so it certainly does not preclude a combination of sources and sinks, with some adding CO2 and some removing CO2, all with different δ13C characteristics. The problem, however, is that it is difficult to come up with a model which incorporates multiple time-variant input parameters (source and sink assumptions) that would be consistent with the evidence for a constant δ13C content (on average). For reference, the δ13C of fossil fuel emissions is estimated to have decreased from around -24 per mil in 1750 to -28 per mil currently. I’ll leave it there for now.

            Reference mentioned above:
            Kőhler et al (2006): “On the application and interpretation of Keeling plots in paleo climate research – deciphering δ13C of atmospheric CO2 measured in ice cores”
            Available at: http://www.biogeosciences.net/3/539/2006/bg-3-539-2006.pdf

            See Figure 1 in the paper. Note that they also show Point Barrow observed data and get intercepts of -25 per mil (detrended) and -17 per mil (original). The “detrended” value reflects the annual cycle and is consistent with it being driven by vegetation. Their “original” value is unfortunately a mixture of the long term trend and the annual cycle, and suffers from aliasing (i.e. it is meaningless). If you use the data after removal of the annual cycle (as published by Scripps), you get -13.2 per mil, as I noted above.
34. Jan Ebenholtz says:

    January 19, 2018 at 8:28 pm

    What do you make oyt of this?
    https://www.nature.com/articles/nature25450
    • Javier says:

      January 19, 2018 at 11:22 pm

      We have already discussed it above. You are not following the debate.
      http://euanmearns.com/the-geological-society-of-londons-statement-on-climate-change/#comment-36685
35. Scottish Sceptic says:

    January 22, 2018 at 10:43 am

    I have to take exception with this section:

    What is the Greenhouse Effect?

    The Greenhouse Effect arises because certain gases (the so-called greenhouse gases) in the atmosphere absorb the long wavelength infrared radiation emitted by the Earth’s surface and re-radiate it, so warming the atmosphere. This natural effect keeps our atmosphere some 30˚C warmer than it would be without those gases. Increasing the concentration of such gases will increase the effect (i.e. warm the atmosphere more) [19].

    If as they suggest IR is absorbed then re-radiated then there would be no greenhouse effect, because by the laws of physics there is no asymmetry in the IR spectrum between absorption and emission. The difference between absorbed and emitted radiation is SOLELY because the CO2 is in the cooler atmosphere … and indeed if the atmosphere were warmer, CO2 would be a cooling gas.

    At the very least this must be rephrased to be something like “emitted by the warmer Earth’s surface and re-radiate it at the colder temperature of the atmosphere” … thus causing a reduction in outgoing IR and warming the earth. However, the warming effect from cooler clouds is identical to that of individual molecules. So, to attribute the greenhouse effect solely to gas molecules is also quite absurd … because it results in a circular definition: the greenhouse effect is the increase in temperature caused by greenhouse molecules and … greenhouse molecules are molecules that cause the greenhouse effect.
    • A C Osborn says:

      January 22, 2018 at 4:01 pm

      I have yet to find anyone who can satisfactorily explain how less than half the few CO2 molecules in the upper troposphere manage to send their low energy 0.08eV photons all the way through 10kms of ever denser Atmosphere to reach the Surface as they propose it does and they say they can measure.

      The accepted science is that an IR Photon has a MeanFree Path length of just 25 metres.
      So 25m before it collides with another molecule and half of the resulting energy is again sent spacewards.

      Compare that energy with Solar Radiation which varies from 0.08 to well over 4eV and can penetrate the Oceans to far greater depths.
36. Dick Kleeman says:

    January 22, 2018 at 11:03 pm

    A FEW POINTS NOT MENTIONED.
    There is no such thing as average temperature, any more than there is average weather, so to propose that the world has an average temperature is abstract nonsense. Temperature, being directly proportional to pressure is changing all the time, at every location and altitude. Pressure patterns are what determine our weather and climate – after the sun, moon and other influences have had their effect. Wind speed and the surface it has traveled over. https://earth.nullschool.net/#current/wind/isobaric/1000hPa/orthographic=-243.87,8.27,333 There is nothing average about what you see here nor will there ever be. It is certainly not hotter where I live in Australia, being decidedly cooler than thirty to forty years ago. Apart from actual cooler summers we are not getting the severe storms and cyclones that occurred then and which require significant heat for those to form.
    We rarely see storms with tops much above 30,000′ these day whereas back in the 1970’s it was quite common to have 400 mile long storm fronts with tops to 70,000′. With over 53 years in aviation and being a retired Airline Captain I can state the above as fact. In the mid 1970’s on an evening flight from Brisbane to Cairns we had to manoeuvre our way through a line of storms 1300 klms long, something you would not see today. A good example of why pressure systems control our weather and climate and not CO2 was an occurrence I saw in February 2015 where the temperature at 2.30 PM at Amberley, Qld was 29.6C and yet at Gatton 23 miles to the west at the same time and altitude it was 40.8C.
    It was not CO2 but a hot westerly at Gatton and a cooler easterly at Amberley. that caused such a temperature difference.
    • Euan Mearns says:

      January 22, 2018 at 11:26 pm

      

      http://euanmearns.com/temperature-adjustments-in-australia/
    • Javier says:

      January 23, 2018 at 2:22 pm

      It is certainly not hotter where I live in Australia, being decidedly cooler than thirty to forty years ago.

      If “There is no such thing as average temperature, any more than there is average weather, so to propose that the world has an average temperature is abstract nonsense,” I don’t know what is the basis for your statement that it is “cooler than thirty to forty years ago.” You won’t be averaging temperatures, will you?

      In light of your affirmation that average temperature is nonsense, please provide the exact times, temperatures (without any averaging), and location where it was cooler, so we can evaluate what you say. Because if we can’t average temperature we can’t say that it was warmer or cooler in the past, as we would be referring to a temperature average.
37. David B. Benson says:

    January 23, 2018 at 5:41 am

    A. C. Osborn — Apologies as I certainly didn’t intend condenscension.

    I have little use for the IPCC reports anymore. WG1 is biased by the politicians; WG2 always seems stale dated although sometimes useful; WG3 isn’t climatology. What does matter is the geophysical literature, which might be viewed as summarized by the big AGU meeting every year. An overview is given in Real Climate.

    Incidentally, the latest post there is a critical look at the latest attempt to determine the so-called equilibrium climate sensitivity. In general, Real Climate gives the perspective of a number of climatologists; worthy of knowing, especially if one doesn’t agree with it.

    However, my degrees are from CalTech so I think I am fairly proficient in separating the wheat from the chaff. However, Euan Mearns often offers some unusual perspectives worth following, even when I don’t agree. The disagreements make for progress in understanding.
38. Roy Clark says:

    January 23, 2018 at 7:38 am

    This discussion has focused mainly on the effect of changes in atmospheric CO2 concentration on climate over the geological record. The short summary is that the observed changes in CO2 have had no effect on the earth’s climate for at least the half a billion years or so. Climate change can be explained in terms of ocean oscillations, variations in the solar flux and plate tectonics, with perhaps a little help from cosmic rays. However, there are two other parts to this discussion that need to be addressed in more detail. The first is a proper explanation of climate energy transfer related to the greenhouse effect and the determination of surface temperature. The second is the massive fraud associated with the climate models and IPCC assessments.

    Needless to say, the climate energy transfer processes are quite complex and require a very clear and detailed understanding of the underlying physics. The basic concept of an ‘equilibrium average climate state’ that has been used to create the global warming fraud for the last 50 years or so has to be abandoned and replaced with a set of coupled thermal reservoirs that function together as an open cycle tropospheric heat engine. Simplistic conservation of energy arguments have to be abandoned in favor of a set of time dependent rates of heating and cooling. The downward long wave IR (LWIR) from the lower troposphere to the surface provides a non-equilibrium exchange energy that limits the net LWIR cooling emission from the surface. In order to dissipate the absorbed solar flux, the surface layers warm up until the excess heat is removed by convection and evaporation. The coupling of the moist convection to the gravitational potential and angular momentum (rotation) of the earth produce the basic weather patterns we observe. The tropospheric heat engine decouples the surface LWIR flux from that emitted to space by the atmosphere. The observed increase in atmospheric CO2 concentration of approximately 120 ppm has produced a slight increase in the downward LWIR flux reaching the surface. However, this cannot couple into the tropospheric heat engine in a way that can produce an observable change in surface temperature.

    The climate modeling fraud can be traced back to the original paper on ‘radiative convective equilibrium’ that was published by Manabe and Wetherald in 1967. The basic assumptions were clearly and honestly stated on the second page of this paper. They included an exact flux balance between a 24 hour average absorbed solar flux and the LWIR emission to space. The surface was a blackbody surface with zero heat capacity. The atmosphere had a fixed relative humidity so that any increase in temperature had to increase the water vapor concentration. These assumptions create global warming as a mathematical artifact of the model algorithms. The model was really just a mathematical platform for the development of radiative transfer algorithms. Various ‘improved’ versions of this model were used create the global warming ‘predicted’ in the Charney report in 1979. Once the basic equilibrium assumptions are accepted, the mathematical derivations appear correct and the models were not challenged. Global warming from CO2 was the expected result and became a lucrative source of research funding. Instead of changing the fundamental model assumptions, additional layers of invalid [fraudulent] algorithms were added. The blackbody surface was replace by an ocean layer. Unfortunately, the physics of the ocean surface energy transfer was ignored and the atmospheric flux was simply coupled into a water layer. The fact that the penetration depth of the LWIR flux into the oceans is only 100 micron was conveniently ignored. Later modeling additions included the use of radiative forcing constants. This is nothing more than empirical pseudoscience that assumes a linear relationship between ‘surface temperature’ and an increase in LWIR flux. ‘Predictions’ of more ‘extreme weather’ were also made. The climate modeling fraud can be found in almost its present form in the 1981 Science paper by Hansen et al. ‘Climate impact of increasing carbon dioxide’.

    Rather than enter into a detailed discussion here, I have written two detailed review papers. The first discusses the physics of the greenhouse effect. The second discusses 50 years of climate fraud. Both contain an extensive set of references that I hope will be useful in this discussion. The papers are available as .pdf files on my website at

    http://venturaphotonics.com/files/Climate_Greenhouse_Effect.RC.VPM003.1.pdf

    http://venturaphotonics.com/files/50YearsClimFraud.RC.V1.Oct.2017.pdf
39. popesclimatetheory says:

    January 24, 2018 at 5:55 am

    Global sea level is very sensitive to changes in global temperatures. Ice sheets grow when the Earth cools and melt when it warms. Warming also heats the ocean, causing the water to expand and the sea level to rise. When ice sheets were at a maximum during the Pleistocene, world sea level fell to at least 120 m below where it stands today. Relatively small increases in global temperature in the past have led to sea level rises of several metres.

    Ice ages happen when more ice is on land and oceans are lower. Ice comes from snowfall. Snowfall is much more when oceans are high and warm and thawed. Snow falls on land and piles up and advances and promotes colder and more snow until it gets cold enough and the oceans get low enough that there is not enough thawed oceans to sustain the snowfall. It these cold times, it does not snow much and ice on land depletes and then retreats and allows warming. Ice is not a result of temperature changes, ice causes temperature changes. The ice cycles cause temperature cycles and sea level cycles.
40. Ulric Lyons says:

    January 24, 2018 at 11:43 am

    “While these past climatic changes can be related to geological events, it is not possible to relate the Earth’s warming since 1970 to anything recognisable as having a geological cause (such as volcanic activity, continental displacement, or changes in the energy received from the sun) [43]. This recent warming is accompanied by an increase in CO2 and a decrease in Arctic sea ice, both of which – based on physical theory and geological analogues – would be expected to warm the climate [44].”

    Well their physical theories for the response to changes in solar output, and the decrease in Arctic sea ice, are both false, AMO and Arctic warming are normal during a solar minimum, because weak solar wind states increase negative Arctic and North Atlantic Oscillation conditions, which drives a warm AMO phase.
    https://www.nature.com/articles/s41598-017-13246-x/figures/2

    UAH lower troposphere satellite data shows that the north pole region cooled from Dec 1979 to Mar 1995, and the upper ocean heat content of the northern North Atlantic cooled from the early 1970’s.
    https://bobtisdale.files.wordpress.com/2012/10/4-northern-no-atl.png

    “According to one recent study, it is likely that the area- weighted global average temperature for the 30 year period from 1970 to 2000 was higher than at any time in nearly 1,400 years. Tree ring data confirm that recent warming is unprecedented in central Europe over the past 2,500 years, and in eastern Europe over the past 1,000 years.”

    Not according to Esper et al 2014:
    https://wattsupwiththat.files.wordpress.com/2014/12/esperetal2014b.jpg
41. A C Osborn says:

    January 24, 2018 at 12:14 pm

    Mr Clark, that is a very comprehensive Paper on the greenhouse effect, expanding on all the things that I understand about it.
    However I do think that thre may be 2 items that could do with more exposure.
    1. The ratio of CO2 Molecules to H2O molecules, which at approximately 16:1, which means that H2O composes approximately 94% of the Greenhouse Gas molecules.
    2. You have data of various areas of the Surface, but unfortunately do not have anything on Hot Dry Desert areas. They expose the greenhouse ability of CO2 for what it is, absolutely minimal.The Average Temperature is not only slightly higher than most places on Earth, but the Temperature swings tell the real story when it can drop well below Zero at night from 40C during the day.

    I also assume when you use “path” you are talking about the mean free path of photons?
    • A C Osborn says:

      January 24, 2018 at 12:29 pm

      Mr Clark, there is also another area that appears to be missing the Sea Level Rise section, which is Humans removing fresh water, particularly underground, from various areas of the world and pumping it in to the Seas.
42. polar scientist says:

    January 27, 2018 at 8:37 am

    Despite all the arguments back and forth, the geological case for climate change over Phanerozoic time being driven by fluctuations in atmospheric CO2 remains as solid today as it was when T. C. Chamberlin first proposed it in 1899 (with the exception that temperature drove CO2 during the Ice Age). It is a product of plate tectonic activity, with more CO2 in the atmosphere when there are more mid ocean ridges and faster sea floor spreading, and less when there are fewer such ridges and weaker spreading as well as when there is more mountain building and associated chemical weathering combined with more deposition of deep sea carbonate (e.g. see Muller et al, in GEOLOGY, 2013). The topic has been thoroughly researched by students of sedimentary geochemistry, especially since the advent in 1968 of the deep-sea drilling project and its modern successors. Sedimentary geochemists have played a prominent role in establishing the principles, foremost among them Bob Berner of Yale and Mike Arthur of Princeton, beginning in the early 1980s, their work supported in due course by that of palynologists like Dana Royer of Wesleyan, and Dave Beerling at Sheffield. It is not clear to me that any of the respondents in this blog are aware of their work. Nor is it evident that many of the respondents have taken the time to read the literature cited in support by the GSL statement. Respondents wanting to know more about the geological and geochemical perspective of climate change through long slow periods of geological time might find it useful to read Mike Bender’s “Paleoclimate” (Princeton University Press), or Bill Ruddiman’s “Earth’s Climate: Past and Future”, or Summerhayes’ “Earth’s Climate Evolution”, or Bill Hay’s “Experimenting on a Small Planet”, or Bob Berner’s “Phanerozoic Climate: O2 and CO2”. The GSL statement was based on works like these, and not on the IPCC. Indeed, it is the other way around – the IPCC’s case rests in part on the use of palaeoclimate records like those used by the GSL. The rise in temperature since 1980, when sunspots (hence TSI) began to fall, helps to make the geological point. We are now experiencing declining orbital insolation and falling solar output, so climate should be cooling as it did in the past when such conditions prevailed.
    • Javier says:

      January 27, 2018 at 1:42 pm

      the geological case for climate change over Phanerozoic time being driven by fluctuations in atmospheric CO2 remains as solid today as it was when T. C. Chamberlin first proposed it in 1899

      Except, Colin, that we have done the ultimate experiment to test the hypothesis. Over the past 67 years we have raised CO₂ levels to almost double their Late Pleistocene average. This is a hugely unusual CO₂ level not seen perhaps in millions of years.

      Antarctic ice cores show a correlation of CO₂ levels and Antarctic temperatures of ~ 5 ppm / °C. This agrees well with the calculated 8 ppm of CO₂ released by global oceans when they warm by 1°C. Modern increase in CO₂, however, is a gasping 125 ppm. And Antarctica hasn’t changed its temperature. It is estimated that global oceans have warmed by only 0.1°C in the last 50 years, and it is clear that global surface temperature is still within Holocene variability. Perhaps unusual, but not for this interglacial.

      Indeed the rate of warming since 1950 fits better a linear increase that is not significantly different from the 1900-1950 rate of warming.

      We have done the experiment. We have raised CO₂ levels to hugely unusual levels and the temperature has failed to respond. It was warming before (since about 1715, the climax of the LIA), and it is warming now, but not differently. Climate shows a weak response to the huge increase in CO₂. The hypothesis that CO₂ drives climate has been falsified. All its proponents offer is that the warming will eventually come, but each passing decade makes their position more untenable. Some of them (James Hansen, Gavin Schmidt, et al., 2018), are preparing for a new pause in temperatures.
      http://www.columbia.edu/~jeh1/mailings/2018/20180118_Temperature2017.pdf
      A great increase in CO₂, that has created a big warming in the pipeline, should make such pauses highly unusual. Temperature is just refusing to comply with the CO₂ hypothesis. And when the evidence doesn’t support your hypothesis it is time to change it.

      Those books that you cite are going to be as valid as Ptolemy’s Almagest and its epicycles.
      • polar scientist says:

        January 28, 2018 at 1:02 pm

        Actually, Javier, Antarctica has warmed. See Mayewski et al 2017 Quaternary Science Reviews 155, 50-66, and references therein, e.g. Bromwich et al 2013 Nature Geoscience 6. There is modern warming in both West and East Antarctica. The Pine Island Glacier is melting back fast in W Antarctica, and the Totten Glacier in E Antarctica is melting from below. Ice cores from both east and west Antarctica confirm recent warming. It also seems highly likely that globally the current rise of 1.2C since 1900 has taken us to levels last seen in the Holocene climatic optimum. Don’t forget that we should not see a simplistic change with CO2 increase. Other variables also affect temperature. Currently, the world is warming, the ocean is warming to progressively greater depths, permafrost is melting, sea ice is melting, land ice is melting, and sea level is rising. How much more evidence do you need?
        • Roger Andrews says:

          January 28, 2018 at 4:33 pm

          Actually, Javier, Antarctica has warmed. See Mayewski et al 2017

          Mayewski et al present only one temperature time series in their paper (their Figure 14). It shows cooling since 1979.

          
        • Javier says:

          January 29, 2018 at 10:59 am

          Colin,

          If you don’t know that Antarctica has not responded to the increase in CO₂ and shows no warming for the past 200 years, and has been cooling for at least 2000 years, perhaps you should change your nickname. This is the reason polar amplification became Arctic amplification.

          The Peninsula has been warming in the recent past, but its attribution is complicated due to its very active geology, and a cooling trend since 1990.

          Essentially all the data shows no warming. Satellite measurements 60-86°S, ice core data, station data. Specially the places where the long ice cores have been drilled show a cooling trend, despite the huge increase in CO₂.

          Therefore, Antarctic ice core data and Antarctic instrumental measurements do not support the position that CO₂ drives temperatures.

          The evidence supports that temperatures have a weak effect on CO₂ levels of about 16 ppm / ° C.

          And if one doesn’t assume that all observed warming for the past 67 years is due to the increase in CO₂, the evidence supports that CO₂ has a very weak effect on temperatures. Climate sensitivity might indeed be lower than 1.

          Some bibliography on Antarctic temperature changes:

          Steig, E. J., Schneider, D. P., Rutherford, S. D., Mann, M. E., Comiso, J. C., & Shindell, D. T. (2009). Warming of the Antarctic ice-sheet surface since the 1957 International Geophysical Year. Nature, 457(7228), 459.

          Jones, J. M., Gille, S. T., Goosse, H., Abram, N. J., Canziani, P. O., Charman, D. J., … & England, M. H. (2016). Assessing recent trends in high-latitude Southern Hemisphere surface climate. Nature Climate Change, 6 (10), 917.

          Turner, J., Lu, H., White, I., King, J. C., Phillips, T., Hosking, J. S., … & Deb, P. (2016). Absence of 21st century warming on Antarctic Peninsula consistent with natural variability. Nature, 535 (7612), 411.

          Stenni, B., Curran, M. A., Abram, N. J., Orsi, A., Goursaud, S., Masson-Delmotte, V., … & Steig, E. J. (2017). Antarctic climate variability on regional and continental scales over the last 2000 years. Climate of the Past, 13 (11), 1609.
          • Ulric Lyons says:

            January 29, 2018 at 12:49 pm

            UAH lower trop for the south pole region shows very slight warming up to the mid 1990’s, and cooling since then, the reverse of the north pole trends which cooled to 1995 and warmed since then.
        • A C Osborn says:

          January 29, 2018 at 4:33 pm

          ” globally the current rise of 1.2C since 1900″.
          At least 0.5C of which is purely down to the Adjustments to the Temperatures as outline in the Mene paper here.

          ftp://ftp.ncdc.noaa.gov/pub/data/ushcn/papers/menne-etal2009.pdf
    • Euan Mearns says:

      January 27, 2018 at 11:29 pm

      Colin, are you going to respond to the new thread on cosmogenic isotopes from lat Monday?

      http://euanmearns.com/the-cosmogenic-isotope-record-and-the-role-of-the-sun-in-shaping-earths-climate/

      CO2 rising through the Holocene (Law Dome)
      LR04 benthic foram T rising through the Holocene

      Quite simply, these are incompatible with the GSL statement.

      E
43. tobyglyn says:

    January 27, 2018 at 8:52 am

    “We are now experiencing declining orbital insolation and falling solar output, so climate should be cooling as it did in the past when such conditions prevailed.”

    Wow, if you are right it’s damn lucky we have all that warming anthropogenic CO2 in the air these days. Imagine if the ice sheets started advancing again!!!
44. A C Osborn says:

    January 27, 2018 at 11:41 am

    polar scientist says: January 27, 2018 at 8:37 am

    I can see from your response that you have no intention of answering the questions on HOW CO2 does what you say.
    You obviously did not read the paper by Roy Clark, as you do not try in any way to rebutt what he has written.

    Which is pretty much par for the course where CAGW proponents are concerned.
45. crusty old lobster says:

    January 27, 2018 at 5:24 pm

    I am an occasional visitor to this excellent site and had not realised this debate was going on.

    As a simple biologist, I am sorry to say all the geological and physical technical arguments above are beyond me.

    However as a concerned inhabitant of our planet, I would be fascinated if any contributor who is so inclined could answer a simple question: How likely is it that man-made CO2 production has caused and will continue to cause unnatural heating of the biosphere? Please answer on a sliding scale of 1 to 10, where 1 is not at all likely and 10 is very likely.

    Thank you!
    • A C Osborn says:

      January 27, 2018 at 8:53 pm

      1.

      Water does it.
    • Euan Mearns says:

      January 27, 2018 at 10:19 pm

      10
      • Euan Mearns says:

        January 27, 2018 at 10:33 pm

        I need to qualify that answer. If the emission height of CO2 lies in the troposphere, which we are led to believe that it currently does, then the answer is 10. If it lies in the stratosphere, then increased CO2 will cause cooling. Crusty, it’s a very good question which allows me to parse a response that illustrates the VAST uncertainty in what is actually going on.

        Did you know that over Antarctica there is no troposphere? The troposphere depends upon secondary radiation of incoming ultra violet as infrared converted by black bodies (rock, soil and vegetation) on the surface, re-emitted which is captured by green house gas in the atmosphere to cause the heat we enjoy. The surface of Antarctica lies in the stratosphere.
        • David B. Benson says:

          January 28, 2018 at 9:36 am

          Something warms the interior of Antarctica even in the long polar night, i.e., winter. For the surface temperature of the Lunar surface drops to -173 °C over the 2 week night while the surface air temperature of interior Antarctica is always at least 90 K warmer than that, over the nominally 6 month winter night.

          It can’t be “warm” air blowing in from the Southern Ocean as the typically 11 kts wind blows clockwise around and slightly to the north via the coriolis effect. It can’t be muchly due to water vapor as there is almost none; Antarctic interior is the dryest large area on the face of Terra, nominally 5% relative humidity although I suspect that it is actually lower than that in the winter.

          The highest point in Antarctica is Mt Vinson at 4,897 meters. From
          http://www-das.uwyo.edu/~geerts/cwx/notes/chap01/tropo.html
          we have that the height of the tropopause in Antarctica, in winter, is (around) 8,000 meters.
          • Euan Mearns says:

            January 28, 2018 at 10:19 am

            David, thank you for this valuable commentary. I’m sure I’ve seen charts that show the tropopause attenuated at the edge of Antarctica. Unfortunately I don’t have time today to look for this.

            In the interest of helping Crusty understand, the troposphere is heated by infrared radiation that is re-emitted from “black bodies” on the surface. This heat is trapped by green house gasses – overwhelmingly water vapour. The further you get from the surface, the colder it gets. That’s why when you go up it gets colder – snow capped mountains. But it doesn’t keep getting colder for ever – at the top of the troposphere is the tropopause that marks the boundary with the stratosphere. The stratosphere is heated directly by in coming UV, and hence as you get closer to the source, ie. the Sun, it gets warmer. So in the stratosphere it gets warmer as you go up.

            David, in answer to the very good point you make, I think it is perhaps linked to catabatic winds that blow continuously from the centre of Antarctica to the margin. By definition, these are sucking air out of the stratosphere that is warmed by incoming UV. Please note that I am way, way out of my comfort zone here, recalling fragments of information that I have read in the past, a lot of it based on the writings of Clive Best.
          • Philip Mulholland says:

            January 28, 2018 at 1:57 pm

            Euan,

            I’m sure I’ve seen charts that show the tropopause attenuated at the edge of Antarctica.

            Have a look at Fig 1. in this paper by Pan, W et al. 2002 The temperature structure of the winter atmosphere at South Pole it demonstrates the presence of a winter tropopause at an elevation of 8km at the South Pole. The vertical temperature profile in May and June clearly shows that, above the surface inversion layer associated with the radiative cooling of the ice surface, there is a fall in temperature as height increases, a standard feature of a troposphere, namely a vertical lapse rate.
            So the ice surface of East Antarctica, even in winter, is still in the troposphere. Other comparative planetology studies of atmospheres elsewhere have shown that a planet’s tropopause is determined by atmospheric pressure rather than air temperature. See Robinson, T.D. & Catling, D.C. (2014) Common 0.1 bar tropopause in thick atmospheres set by pressure-dependent infrared transparency.
            The troposphere is the weather layer and the work by Robinson, T.D. & Catling shows that it occurs as a pressure defined sphere in the gravitationally bound atmospheres of terrestrial planets. The dry adiabatic lapse rate can be established from first principles and so while we can apply the Stefan-Boltzmann equation of state to the infrared radiative properties of the isothermal stratosphere, instead for the semi-transparent properties of the troposphere, where the opacity is such that the quenching distance of thermal infrared radiation is only a few metres, a modified form of Maxwell’s ideal gas equation can be used to predict the average annual surface temperature based on the values of pressure, gas mean molecular weight and gas density.
            It is the inappropriate application of the Stefan-Boltzmann equation of state to the troposphere in an attempt to explain its thermal profile that has produced the fictitious science of back radiation from greenhouse gases. In the troposphere it is Mawxells’s equation of state that need to be used.
            It is the process of adiabatic auto-compression of a dense gas in a planetary gravitational field that fully explains the tropospheric average annual surface temperature of the terrestrial planets under varying values of the orbital distance controlled rate of heating by solar insolation.
            See this presentation by mining engineer Frolly for further details:-
            “Greenhouse” effect is invalidated
            
        • polar scientist says:

          January 28, 2018 at 12:16 pm

          Hi Euan, Sorry to disappoint but the troposphere over Antarctica does indeed exist, though it is only about half as thick as it is at the equator.
          • Euan Mearns says:

            January 28, 2018 at 1:36 pm

            Colin, I’m not disappointed since I am way out of my comfort zone. I’m going to ask Clive to step in with his expertise with his expertise which is substantially greater than mine on such matters. Can you explain how air over Antarctica is heated by upwelling IR in winter when there is no black body and no Sun.
          • Clive Best says:

            January 28, 2018 at 4:58 pm

            In the Antarctic winter solar insolation is zero and vertical convection stops.

            The temperature lapse rates in the troposphere vary by latitude, climatic zone and season, varying between less than 0 °C/km (i.e. increasing with height) at the winter poles to more than 8 °C/km over a summer sub-tropical ocean. In the mid-latitudes the temperature reduces with increasing height at varying rates but averaging 6.5 °C/km or about 2 °C per 1000 feet, although within any tropospheric layer temperature may actually increase with increasing height. This reversal of the norm is a temperature inversion condition. Should the temperature in a layer remain constant with height then an isothermal layer condition exists. At night, particularly under clear skies, the air in the mixed layer cools considerably but the long wave radiation from the higher levels is weak and the air there cools just 1 °C or so. Consequently a nocturnal inversion forms over the the mixed layer, the depth of which depends on the temperature drop and the amount of mechanical mixing.
          • Philip Mulholland says:

            January 29, 2018 at 9:10 pm

            Euan,
            You ask:-

            Can you explain how air over Antarctica is heated by upwelling IR in winter when there is no black body and no Sun?

            Clive replies:-

            In the Antarctic winter solar insolation is zero and vertical convection stops.

            Let me add to Clive’s comment.
            There is no upward vertical convection of air in winter over the vast bulk of East Antarctica, there is instead a continuous downward vertical movement of air towards the ice surface, namely the polar vortex.

            I assume that you are familiar with the weather phenomena of the daytime Sea Breeze and its night time counterpart the Land Breeze?
            The sea breeze arises because of the enhanced rate of daytime heating of the land surface by sunlight compared to the sea. The land breeze arises because of the differential rate of night time cooling of the solid land surface by infrared radiation to space compared to that of the liquid seawater that has a much higher heat capacity and is able to replenish by fluid overturn during surface cooling.

            Convection is a process by which air rises vertically upward, specifically for this case air that has been warmed by contact with an illuminated surface that is converting solar energy to heat. Obviously this insolation driven process takes place during the daytime, but what happens at night when the corresponding land breeze forms? In this case air cooled by contact with a solid ground surface that is radiating heat to space, increases in density and flows down slope, off the land and out to sea. This land breeze caused by the differential cooling of the land, is not associated with the vertical upward convection of warmed air, rather it is associated with the down slope lateral advection of cooled air; but what is the name of the night time process that generates this flow of dense air from the land to the sea?

            A digression:-
            The root convect in convection is derived from the Latin word convectus to carry from one place to another i.e to convey. The word convect is loosely related to the term convex which is used in optics to describe the shape of a bulging lens that is thickest in the middle. Convection in Meteorology can therefore also relate in concept to the upward bulging of the atmosphere that we observe in the formation of cumulus clouds, we see a similar process of upward vertical bulging in a lava lamp. In optics the opposite of convex is concave; a lens that is thinnest in the middle. Cave, cavity & cavitation are all related examples of words used to describe an enclosed space, a hollow, or a gap from which material has been removed.

            Consider Antarctica, we have there the world’s largest and most isolated island continent. In winter the central high ice plateau of East Antarctica, south of 80S, experiences a night that lasts for months. As a consequence of the geography of Antarctica the ice surface in winter cools so intensely that the strongest night breeze in the world is created, the katabatic wind. What we observe on the ice plateau of east Antarctica in winter is a vigorous process of thermal cooling of the ice surface by radiative heat loss to space through the transparent infrared atmospheric window. This cooling demonstrates that solid surfaces are the most efficient thermal emitters, because solids can transmit flexural shear waves, whereas fluids and gases cannot. Solid surfaces are therefore more efficient thermal radiators than gases because it is the process of flexure that determines if a gas molecule can intercept and emit infrared radiation, something that only polyatomic molecules can achieve.
            The cooling of the air at ground level in East Antarctica creates a dense air mass that is then advected down slope off the ice plateau as a vigorous katabatic wind. Consider a stack of cards from which the lowest card is continuously been removed, the stack will fall into the cavity generated at its base. I want to introduce here a term I have adopted to describe this phenomena of cold dense air being generated by night time radiative cooling of a solid surface, the word is concavetion. Concavetion is the process that permits the vertical descent of air into the “cavity” created both by the radiative cooling at the ground surface and the associated lateral advection that exports the cold dense basal layer to the side as a ground hugging katabatic wind. Concavetion is therefore the opposite of convection and is a process driven by night time ground surface cooling rather than day time ground surface heating.

            A few years ago during 2008 there was a live data stream from the automatic weather station (AWS) based on Dome Argus in Antarctica. The AWS located there measured temperature both above and below ground (the ice surface) in a continuous daily record. Three sensors measuring air temperature were placed at elevations of +4 m, +2m & +1m while four more sensors, placed at sub-surface depths of 0.1m, 1 m, 3m & 10m, measured the ice temperature in the ground.
            The location of the Dome Argus AWS at latitude: 80 22′ 02″S, longitude: 77 32′ 21″E and with a surface elevation of 4,084m provided a unique insight into the climate of East Antarctica. During the austral winter of 2008 Dome A was in darkness for 24 hours a day from sunset on 16th April 2008 at 0725 UTC until sunrise on 26th August 2008 at 0556 UTC. During this period of 142 days Dome Argus receives no direct sunlight and the air temperature sensors of the AWS recorded the night time cooling and the formation of an intense thermal inversion layer at the ground as the high level ice surface radiated heat to space through the thin dry winter air.

            Because of its unique winter location we can be sure of the following features of the weather at Dome Argus.
            1. No direct solar heating by sunlight can possibly have occurred at this time during the depths of winter.
            2. The crestal elevation of the site means that all advected surface air that reaches here has to climb up the dome to reach the plateau and therefore must be cooled by adiabatic lift.
            3. The residual summer heat in the ground ice cannot be heating the descending air above 4m because of the thermal inversion caused by radiative cooling at the surface of the ice prevents direct thermal contact.
            4. So the only source of energy that can maintain the higher air temperatures at 4m and above is the heating of descending air from aloft by tropospheric adiabatic auto compression.

            Let’s have another look at Fig 1 in Pan, W. et al. 2002. The temperature structure of the winter atmosphere at South Pole this figure records the presence of a winter tropopause at an elevation of 8km at the South Pole. The vertical temperature profile in May and June clearly shows that, above the surface inversion layer associated with the radiative cooling of the ice surface, there is a fall in temperature as height increases, a standard feature of a troposphere, namely a vertical lapse rate.

            But there is no insolation at the South Pole in winter and so no radiant energy to heat the ice surface and cause buoyancy driven atmospheric convection. So how is this lapse rate maintained? What we observe on the ice plateau of East Antarctica is the winter night time process of concavetion, which results in the downward vertical motion of air in the polar vortex falling under gravity towards the ice surface. This fall causes the descending upper air to loose potential energy and to thereby gain heat by adiabatic auto compression so maintaining the observed lapse rate in the tropospheric winter air above the South Pole.
          • Euan Mearns says:

            January 30, 2018 at 1:04 am

            Philip, I am following along as closely as I can in very stretched time.

            And I am way out of my competence depth on such issues, but did pick on the Katabatibc winds in this comment (even though I couldn’t spell it :-):

            http://euanmearns.com/the-geological-society-of-londons-statement-on-climate-change/#comment-37023

            As a geologist, I tend to classify observations by process. The troposphere is the layer of atmosphere heated by secondary emitted IR from black bodies on the surface that is captured by GHG.

            Thanks for your very informative commentary.
          • Philip Mulholland says:

            January 31, 2018 at 3:38 pm

            Euan,

            Thank you for hosting this very important thread.

            The atmosphere at the South Pole in mid-winter is in a state of continuous darkness. But the atmospheric profile has a vertical lapse rate. Let us suppose we fired a rocket vertically into space from the South Pole. At what height above the icecap would the rocket pass from the night shadow of the Earth and out into sunlight?

            This question can be solved using simple Pythagoras right angle triangle geometry.

            The answer is that the rocket would have to climb to an elevation of 568 km above Antarctica before it became sunlit. The formal definition for the edge of Earths atmosphere is the Kármán line and this is at a vertical height of 100 km, so it is clear that in mid-winter no part of the atmosphere above the South Pole can be lit by the sun.

            Clearly the idea that the temperature profile in the Earth’s troposphere is maintained by thermal radiation is in trouble when we look at the temperature profile data for the South Pole in mid-winter.

            The answer to the problem is that the tropospheric lapse rate is maintained by gravity. It is gravity that binds an atmosphere to a terrestrial planet and it is the strength of the gravity field (determined by the planet’s mass) that determines the escape velocity of that planet. Escape velocity is fundamental. A small planet (such as Mercury) has a low escape velocity and so under the high insolation of its close solar orbit it cannot retain an atmosphere. If however we moved Mercury out to the orbit of Pluto, then this same planetary mass would be able to easily retain a low molecular weight atmosphere, albeit a very cold one!

            I Hope that the following two links will be useful here:-

            Steve Zell’s comment on Lapse Rate

            Frolly’s video on Climate Sensitivity
        • Clive Best says:

          January 28, 2018 at 4:42 pm

          The CO2 molecule is excited both by collisions with N2 and O2 molecules and by absorbing IR photons emitted by other CO2 molecules. Vibrational modes of CO2 are a series of quantum excitation states of different energy, emitting IR photons of this energy when they de-excite. On earth the important band is the 15micron band. This is what the line intensity looks like

          http://clivebest.com/blog/wp-content/uploads/2013/02/CO2-lines.png

          The effective emission height is that where most (>50%) of photons emitted upwards escape to space. This height is determined essentially by the exponential fall-off of air density with altitude. Such photons will not encounter another CO2 molecule before they reach outer space. The effective emission height looks like this

          http://clivebest.com/blog/wp-content/uploads/2013/02/smoothed-CO2-emissionheight1.png

          The emission height increases with increased CO2. The earth can only cool by IR radiation to space. The CO2 Enhanced Greenhouse Effect is caused by a slight reduction in the net IR flux because the temperature of the new emission height is in general colder. (Local Thermodynamic Equilibrium). However, this is not always the case.

          The special cases are:
          1) The central spike in the 15 micron spectrum. This already emits way up in the Stratosphere where temperature increases with height. Emissions increases with CO2 – adding a cooling effect.
          2) The Polar Arctic/Antarctic winter. For nearly 6 months of the year there is no solar heating of the surface. As a result convection stops and the lapse rate no longer has a power source to maintain it. The Tropopause collapses in height and would otherwise disappear, without air mixing in from lower latitudes. Ground temperatures of -90C in Antarctica have been recorded which is far colder than the average tropopause temperature of -60C. Therefore a higher emission height in the Polar winter can also further cool the surface, whenever there is a temperature inversion with height.
46. Jonathan Madden says:

    January 27, 2018 at 7:52 pm

    1

    Thank you for your question! (Although I have not contributed to this discussion)
47. ralfellis says:

    January 29, 2018 at 5:17 pm

    Several points to make, so I will make them separately.

    Firstly, the signature of increased greenhouse warming is increasing Downwelling Longwave Radiation (DLR). It is the increased DLR from the upper troposphere, that warms the surface. And yet I cannot find any record of DLR actually increasing. And if DLR remains static, then there is no increasing greenhouse warming.

    Graph of CERES and TAO buoy data, courtesy if Willis Eschenbach.

    https://wattsupwiththat.files.wordpress.com/2015/02/tao-and-ceres-sst-downwelling-longwave-equator.jpg

    Ralph
48. ralfellis says:

    January 29, 2018 at 5:20 pm

    Second point:

    During the ice ages, when CO2 concentrations were high, the world cooled into a glacial period. When CO2 concentrations were low, the world warmed into an interglacial. It is unlikely that the climate would respond in this fashion, if CO2 was the primary feedback agent.

    Ralph
49. ralfellis says:

    January 29, 2018 at 5:34 pm

    Third point:

    My peer-review paper strongly suggests that it is LOW CO2 that causes warming.

    Low CO2 is detrimental to plant life, especially at arid high altitude locations like the Gobi. The low CO2 conditions at the LGM caused huge CO2 deserts to form across the Gobi region, and therfore greatly increased dust, which settled on the northern ice sheets causing lower ice sheet albedo and increased insolation absorption. This change in albedo is orders of magnitude more powerful as a feedback agent than CO2, when measured locally, and this change caused rapid melting and an interglacial.

    Ice Age Modulation via Dust and Albedo.
    https://www.sciencedirect.com/science/article/pii/S1674987116300305

    Unlike the CO2 feedback theory, the dust-albedo theory explains everything.

    It explains why the interglacial world can cool, because increasing ice albedo (caused by orbital changes) trumps any other (gasseous) feedback. Increasing ice results in less terrestrial insolation absorption.

    It explains why orbital warm periods during the glacial period are often ignored, because ice albedo trumps orbital warming. The increasing northern latitude insolation is all reflected and rejected.

    It explains why an interglacial can arise, because dust from the Gobi can settle on the ice, lowering ice albedo from 0.9 to 0.5, and causing a huge increase in insolation absorption. This sudden increase in dust is fully recorded in the ice core record.

    But if the dust-albedo theory is accepted, then CO2 becomes such bit-player in this drama that it is virtually insignificant.

    Ralph
50. ralfellis says:

    January 29, 2018 at 5:45 pm

    Fourthly…

    LGM climate models may be significanly in error, due to a misunderstanding about the role of CO2.

    It has been assumed that LGM tropical treelines are controlled by temperature. But the treelines are strangely low, meaning much lower high-altitude temperatures than expected, and therefore much higher lapse rates than expected. And these high lapse rates translate into a dryer LGM climate. And this data is used in LGM climate models and present climate models.

    However, it is my assertion that LGM treelines were actually controlled by low CO2, not temperature. (The partial pressure of CO2 is lower at altitude, starving plants of a vital nutrient and causing a CO2-controlled treeline.). This releases temperature from the analysis – meaning that the lapse rate could have been lower, and the moisture content higher, than has been claimed.

    So the LGM climate models may be significantly in error, because of a misunderstanding of the role of CO2 on flora and fauna alike.

    Ralph

    .
    • David E says:

      January 29, 2018 at 5:59 pm

      Great comments ralfellis, I always wondered why no one ever seemed to think about measuring downward IR fluxes, this after all being the key prediction of the increased CO2 greenhouse theory. What else would you spend your climate research money on? The fact that there actually appears to be no measurable increase is pretty much the nail in the coffin. Also agree, it’s always necessary to disentangle the biological from the climatic effects of CO2 – the former is known and proven and the latter is highly speculative yet the former gets ignored. Thanks again!

      David E
51. Ulric Lyons says:

    January 29, 2018 at 10:37 pm

    The North Atlantic is a major CO2 sink, so atmospheric CO2 levels are naturally higher during a warm AMO phase. The AMO is always warm during solar minima because of increased negative North Atlantic Oscillation states. Which points to higher CO2 levels being a natural negative feedback at inter-decadal scale.

    Atlantic Ocean CO2 uptake reduced by weakening of the meridional overturning circulation:
    https://www.nature.com/articles/ngeo1680

    Warm SST’s SE Greenland during solar minima:
    https://media.springernature.com/m685/springer-static/image/art%3A10.1038%2Fs41598-017-13246-x/MediaObjects/41598_2017_13246_Fig2_HTML.jpg

52. Pingback: Energy And Environmental Newsletter – January 29th 2018 | PA Pundits - International

53. HJDodwell says:

    January 31, 2018 at 4:21 pm

    The Geological Society of London (GSL) present their findings with confidence, despite the heavy use of speculative and conditional language throughout their statements suggesting large uncertainties in the research. This is apparent in Polar Scientist’s comments, for example, “the geological case for climate change over Phanoerozoic time being driven by fluctuations in CO2 remains as solid today as it was……first proposed in 1899. It is a product of plate tectonic activity, with more CO2 in the atmosphere when there are more mid-ocean ridges and faster sea floor spreading and less when there are fewer such ridges and weaker spreading as well as when there is more mountain building and associated chemical weathering combined with more deposition of deep sea carbonate”.

    So the hypothsis is:
    – Rifting and rapid sea-floor spreading = increasing CO2 and temperature (associated with volcanism).
    – Slower spreading and continental uplift = decreasing CO2 and temperature (associated with chemical weathering and carbonates).

    As evidence for this hypothesis, the GSL cite 3 sudden global warming events associated with increases in atmospheric carbon, occurring at 55Ma (Paleocene-Eocene boundary), 120Ma (Early Cretaceous, Aptian) and 183Ma (Early Jurassic), but only describe the 55Ma event. The GSL state the 55Ma Paleocene-Eocene Thermal Maximum (PETM) ‘was perhaps triggered by volcanic activity superimposed on an underlying gradual global warming trend’ associated with the opening of the North Atlantic (Polar Scientist in comments).

    To investigate this hypothesis, I summarised the major plate tectonic events, global climate, and CO2 during these times, as interpreted by Christopher Scotese in his Paleomap project (see below):
    http://www.scotese.com
    http://www.biocab.org/Carbon_Dioxide_Geological_Timescale.html

    In conclusion:
    – The Permian was dominated by continental collision, uplift and volcanics, temperature rapidly increased (to peak at the same temperatures as during the PETM) and CO2 remained low.
    – The Triassic to Early Cretaceous was dominated by rifting, continental break-up and volcanics, temperature mostly remained high and CO2 gradually increased.
    – The Late Cretaceous was dominated by rapid sea-floor spreading and extensive warm-shallow seas, temperatures were high and CO2 decreased.
    – The Paleocene to Eocene saw both rifting and spreading (Greenland from North America, Greenland from Europe) and major continental collision and uplift (India with Asia), temperatures peaked after long-term increase and CO2 continued to gradually decrease.
    – The Oligocene to Miocene was dominated by continental collision and uplift, temperature and CO2 both increased slightly from their long-term decline.

    Based on this there does not seem to be any geological evidence on a global scale to support the hypothesis that rifting and rapid sea-floor spreading = increasing CO2 and temperature nor that continental uplift = decreasing CO2 and temperature.

    Permian (300-250Ma):
    – The Pangea Supercontinent dominated, created during the Devonian to Early Permian by the north-south collision between Euroamerica and Gondwana continents, closing the Rheic Ocean, and forming the broad, extensive Central Pangean mountain range (equivalent to the modern Himalayas). This orogeny was associated with widespread volcanics.
    – Early Permian climate was ‘Ice House’ (Southern Hemisphere was covered by ice as glaciers pushed northward), but by the Late Permian it rapidly changed to ‘Hot House’ (equatorial rainforest disappeared as deserts spread across central Pangea, southern ice sheets disappeared) with temperatures increasing ~10degC coinciding with the end Permian extinction event (99% of life).
    -This climate swing is related to the continued uplift and migration north of the Central Pangean mountains blocking moisture-laden equatorial winds; the Northern Hemisphere became desert like.
    – CO2 remained low throughout at ~200ppm.

    Triassic to Early Cretaceous (250-100Ma):
    -Break-up of the Pangea Supercontinent began in the Triassic as the Arctic rift system between North America and Europe propagated southwards, and continued during the Jurassic to Early Cretaceous as the Americas rifted away from Africa opening the Atlantic Ocean; rifting was associated with extensive volcanics along the Atlantic margins.
    – By the mid-Triassic temperature had decreased from end Permian maximum, but the climate remained in a ‘Hot House’ (no ice at the poles) into the mid-Jurassic; During the Late Jurassic to Early Cretaceous the climate changed due to the break-up of Pangea and temperature decreased ~3degC to a mild ‘Ice House’ (snow and ice during the winter, cool temperate forests at the poles).
    – CO2 gradually increased (~200pm in the Triassic to ~350 ppm in the Early Cretaceous).

    Late Cretaceous (100-65Ma)
    – Rapid sea-floor spreading in the South Atlantic and the Eastern Indian Ocean; rifting between Australia and Antarctica, uplift of the Rocky Mountains; high sea level in part due to the creation of new rifts and mid-ocean ridges that displaced water onto the continents.
    – Temperature increased ~3degC from the Early Cretaceous mild ‘Ice House’ to the Late Cretaceous ‘Hot House’ (no ices, dinosaurs and palm trees at the poles) in part due to extensive shallow seaways enabling the transport northwards of warm equatorial water warming the polar regions and having an ameliorating effect on local climates (similar to the modern Mediterranean Sea).
    – CO2 decreased throughout the Cretaceous from it’s early peak to ~300ppm.

    Paleocene-Eocene (65-35Ma)
    – Continued extension and opening of the Atlantic margin, Australia began to move rapidly northward away from Antarctic, rapid rifting and spreading between North America and Greenland and India began to collide with and Asia forming the Tibetan plateau and Himalayas; development of the North Atlantic hot spot (extensive volcanics in East Greenland and northwest Britain) followed by rifting and spreading between Greenland and Europe.
    – Climate continued to be ‘Hot House’ (palm trees in Greenland, Patagonia and Alaska, mangrove swamps in southern Australia, swamps in the north Pole), gradually increasing in temperature from the Late Cretaceous to a peak at the PETM (55Ma).
    – CO2 continued to decrease throughout.

    Oligocene-Miocene (35-5Ma)
    – A major phase of continental collisions formed high mountains (India with Asia forming the Himalayas, Spain with France forming the Pyrenees, Italy with France and Switzerland forming the Alps, Greece and Turkey with the Balkan States forming the Hellenide and Dinaride mountains, Arabia with Iran forming the Zagros mountains, India with Asia, Australia with Indonesia).
    – Climate was cooling rapidly from the PETM but the Miocene saw a slight increase in temperature from the long-term decline and was warmer than today (Antarctica covered in ice, palm trees and alligators in England and Northern Europe, Australia was less arid than now).
    – CO2 increased slightly from it’s long-term decline.
54. Philip Mulholland says:

    February 2, 2018 at 7:09 pm

    The Role of Geochemical Weathering in the Sequestration of Lithic Carbonates
    With this post I want to address the issue of the geological formation and sequestration of lithic carbonates.
    Key features of carbonate rocks:-
    1. Carbonate sediments are chemical precipitates and therefore critically require liquid water for their formation.
    2. Carbonates are Arrhenius salts formed by the neutralisation of a soluble acid, in this case carbonic acid, by a soluble base, typically calcium hydroxide (but also magnesium hydroxide in the case of dolomites).
    3. On Earth lithic carbonates are the primary sedimentary reservoir that sequesters carbon dioxide gas (unlike Venus where, because there is no liquid water to facilitate the geochemical reaction, carbon dioxide has remained as a gas effectively stored in its atmosphere throughout the eons of that planet’s existence).
    4. On Earth there is a continuous generation of new calcium and magnesium cations from the geochemical weathering of basalt; in particular subaerial basalt lavas exposed to weathering in monsoonal tropical environments which have undergone pedogenesis. This results in the formation of laterites and bauxite with the release of the soluble cations of the alkaline earth metals.
    5. This release of alkaline earth metals cations and their fluvial transport as solutes dominates the environmental process of geochemical weathering and results in the alkaline buffered ocean of the modern world.

    The twin roles of crystal fractionation and chemical weathering in the formation of acidic continental crust:-
    1. Our Victorian geological predecessors identified that on Earth there exist two distinct types of crust. They called these crustal rocks SIMA and SIAL respectively.
    2. SIMA refers to the silicon and magnesium rich basic rocks that form the denser low lying oceanic crust.
    3. SIAL refers to the silicon and aluminium rich acidic rocks that form the less dense elevated continental crust.
    4. Modern geology accepts the paradigm of plate tectonics and the role that subduction has in recycling basaltic ocean crust back into the mantle.
    5. With oceanic plate subduction there is a consequent partial melting of the subsumed water rich descending basalt crust that creates magma batholiths in which the process of crystal fractionation occurs.
    6. Crystal fractionation is a gravity assisted density separation of crystals in a magma melt that results from the formation of early high temperature crystals of dense basic minerals and their subsequent physical separation from the remaining lighter acidic melt of low temperature of crystallisation acidic minerals such as quartz. This process of crystal fractionation in magma chambers leads to the formation and extrusion on the surface of andesite and acidic rhyolite lavas.
    7. Surface pedogenesis of acidic lavas creates mineral clays and quart sands in a process that produces the sedimentary mineral precursors for more SIAL continental crust to be added to the Earth’s continents.
    8. It is the transport of these clastic sand and clay minerals into marine geological basins, the subsequent lithification of the clastic sediments and the lateral accretion of these rocks, as part of the process of mountain building obduction and continental wedge accretion that has caused the continents to grow around the cores of the initial Archean shields throughout the geologic ages of the Earth.
    Is the subduction of Oceanic Pelagic Carbonates an ancient process?
    In geology we expect to use the paradigm that the present is the key to the past. With carbonate sediments however this is not always true because we are obliged to take into account the process of biological evolution. Of particular interest for ocean crust deposition of pelagic carbonate sediments is the development in the Mesozoic of the coccolithophorid phytoplankton. This group arose to prominence in the Cretaceous and has developed the biological ability to convert soluble bicarbonate ions from seawater into insoluble calcium carbonate, thereby releasing dissolved carbon dioxide into their cells which they then use for photosynthesis. So while we can easily accept that modern ocean sediments deposited in abyssal depths that are shallower than the carbonate compensation level will contain marine carbonates of biological origin, it is clear that older Palaeozoic ocean abyssal sediments will not, because the biology of Panthalassic Ocean was dominated by marine acritarchs rather than the coccolithophorids.
    Consequently while subduction of Mesozoic ocean crust can include some pelagic organic carbonates preserved below the overburden of the deep abyssal siliceous ooze, it is clear from outcrop geology of Palaeozoic sediments, such as the Silurian/Ordovician greywackes that form the Southern Uplands of Scotland, an obducted accretionary prism created during the destruction of the Iapetus Ocean, that no such organic pelagic carbonate sediments were included into this descending oceanic plate in the Palaeozoic.

    https://paleonerdish.wordpress.com/2013/11/12/the-origin-of-modern-phytoplankton/
55. Arion Chrysaor says:

    February 6, 2018 at 6:30 am

    Thanks for the opportunity to comment on the Geological Society of London (GSL) statements Euan. I have enjoyed reading some of the comments that have resulted.

    Dr Colin Summerhayes and his working party co-authors from the GSL are to be commended for agreeing to on line discussion of their 2010 statement and the subsequent addendum statement in 2013 on Climate change : evidence from the geological record.

    It is disappointing that neither of the statements managed to present a more nuanced and geologically informed overview of a topic they describe as …a defining issue for our time.

    Despite their emphasis on CO2 levels and acknowledging some of the multiple other interacting factors that can effect global temperature and climate, the working group statements seem to infer that all these other factors, (and obviously those that were not considered important enough to be worth mentioning), are insignificant compared to CO2 levels as a cause of the observed rise in earths temperature in the last century.

    For statements issued by a Geological Society I found these two comments astounding.
    In the 2010 statement: …..
    it is not possible to relate the Earth’s warming since 1970 to anything recognisable as having a geological cause (such as volcanic activity, continental displacement, or changes in the energy received from the sun).
    and in the GSL addendum statement in December 2013: …
    there is now greater confidence than in 2010 that the only plausible explanation for the rate and extent of temperature increase since 1900 is the exponential rise in CO2 and other greenhouse gases in the atmosphere since the Industrial Revolution..

    Geologically speaking this is an amazingly short term time frame to comment on and seems to overlook the importance of their earlier observations that ………
    The Earth’s climate has been gradually cooling for most of the last 50 million years….………Over the past 2.6 million years (the Pleistocene and Holocene), the Earth’s climate has been on average cooler than today, and often much colder. That period is known as the ‘Ice Age’, a series of glacial episodes separated by short warm ‘interglacial’ periods that lasted between 10,000-30,000 years. We are currently living through one of these interglacial periods.

    Changes in the tilt and precession of the axis of the Earth relative to the plane of its orbit as well as the eccentricity of the orbit of the Earth cause variations in the radiative forcing from the Sun. This has a major influence on climate cycles. Discussion of the effects of these natural phenomena is not adequately addressed by statements like…
    Before the current warming trend began, temperatures in the Holocene (the last 11,000 years) were declining. This was due largely to insolation – the solar radiation received by the Earth’s surface – and dictated by the Earth’s orbit and the tilt of the Earth’s axis. Insolation declined throughout the Holocene. This cooling took Earth’s climate into a Neoglacial period, culminating in the ‘Little Ice Age’ (1450 – 1850).

    The GSL statements should have also have pointed out that in the current interglacial period the pattern of climate variation over the past 3,000 years has been one of cooling and recovery. In this geologically short time period warm periods like the Minoan and the Roman and the Medieval as well as the current warm periods have occurred. The available evidence suggests that the earlier warm periods within this current interglacial period were probably warmer than our current warm period. The GSL statements do not mention these warm periods, but state more broadly, and in a way that serves to obfuscate, that
    ….The present warm period (known as the Holocene) became established only 11,500 years ago, since when our climate has been relatively stable.

    In the IPCC Fifth Assessment Report (AR5) in section 5.7 titled:
    Evidence and Processes of Abrupt Climate Change it is noted ……..
    This assessment of abrupt climate change on time scales of 10-100 years focuses on Dansgaard-Oeschger (DO) events and iceberg meltwater discharges during Heinrich Events.
    and then goes on to say …
    In spite of the visible presence of DO events in many paleoclimate records from both hemispheres, the underlying mechanisms still remain unresolved.

    It surprised me that these abrupt climate change events, and the uncertainty about their mechanisms, (which may turn out to be due to a complex and variable combination of the effects of the sun, moon, tides and seasons), were not considered worthy of any mention or discussion in the GSL statements. Especially given their recognised ability to have major and abrupt effects on climate.

    The 2010 GSL statement notes that:…….
    Estimating past levels of CO2 in the atmosphere for periods older than those sampled by ice cores is difficult and is the subject of continuing research. Most estimates agree that there was a significant decrease of CO2 in the atmosphere from more than 1000 ppm at 50 million years ago (during the Eocene) to the range recorded in the ice cores of the past 800,000 years.
    but then go on to state that …..
    This decrease in CO2 was probably one of the main causes of the cooling that led to the formation of the great ice sheets on Antarctica….

    The statement implies that CO2 decrease is the cause of the cooling. A reference for this statement is given but it is not mentioned in the text of the statement that this is a conclusion based on a model simulation. No other evidence that CO2 decrease is the probable cause of Antarctic ice sheet formation is presented.

    It should be emphasised that tectonic plate movements resulted in the opening of the Drake Passage south of Africa around 41 million years ago. This resulted in the joining of the Atlantic and Pacific Oceans and allowed the Antarctic Circumpolar current to become established. This is a more probable main cause for the cooling of Antarctica than the atmospheric level of CO2. The significance of these geologically important developments is not adequately emphasised or discussed by the statements later concession that ……
    Changes in ocean circulation around Antarctica may also have also played a role in the timing and extent of formation of those ice sheets.

    Over long periods of time tectonic plate movements change both ocean and land surface topography of the Earth. These changes will be associated with changes in local climate patterns and changes in the mode and efficiency of the transport of heat from the tropics to the poles by both oceanic and atmospheric circulation. It is very likely that these changes will cause climate change which may be associated with changes in CO2 levels and sea levels, but this does not establish that CO2 levels are a primary driver of climate change.

    In the 2010 statement from the GLS clouds get no mention at all. In the 2010 addendum there are just two passing references ….
    Studies of the Last Glacial Maximum (about 20,000 years ago) suggest that the climate sensitivity, based on rapidly acting factors like snow melt, ice melt and the behaviour of clouds and water vapour, lies in the range 1.5°C to 6.4°C….. and ………Many model-based estimates suggest that the short-term climate sensitivity lies in the range 1.5oC to 4.5oC….They are based on fast changes like those involving snow melt, ice melt, and the behaviour of clouds and water vapour.

    The amount of water vapour in the atmosphere will influence global temperature through its influence on cloud formation as well as through its influence on the greenhouse effect. The balance of the effects of clouds on global albedo and the greenhouse forcings of the water vapour will determine if clouds warm or cool the surface of the Earth. Surely clouds deserve more discussion than has been given in these statements.

    Volcanism and spreading ridges are another major source of heat release and gases into the oceans and atmosphere. The intensity of volcanic activity on land and in the oceans has varied significantly over the history of the Earth. As well as this the timing of volcanic activity is unpredictable and the effects can be major.

    In the 2008 statement the GSL working group does note………
    Major volcanic eruptions eject gas and dust high into the atmosphere, causing temporary cooling. Changes in the abundance in the atmosphere of gases such as water vapour, carbon dioxide and methane affect climate through the Greenhouse Effect. Carbon isotopic data show that this warming event (called by some the Paleocene-Eocene Thermal Maximum, or PETM) was accompanied by a major release of 1500-2000 billion tonnes or more of carbon into the ocean and atmosphere. This injection of carbon may have come mainly from the breakdown of methane hydrates beneath the deep sea floor, perhaps triggered by volcanic activity superimposed on an underlying gradual global warming trend that peaked some 50 million years ago in the early Eocene.

    A significant comet strike possibly occurred around the time of the Paleocene-Eocene Thermal Maximum (PETM) http://science.sciencemag.org/content/354/6309/225.
    This may or may not be the case, but the possibility of extra terrestrial factors like asteroid and comet impacts and cosmic rays having a potential impact on the Earth’s climate surely warrants some mention and discussion in the GSL statements.

    The GSL should have pointed out that it is highly likely that it has been warmer at other times in this currrent interglacial period and that sea levels have likely been higher than they are now during this interglacial period.

    It should also have been pointed out that there is evidence that the sea levels rose very rapidly during the early Holocene, but over the last 7000 years the rate of rise has been much more gradual. The accuracies of the techniques of estimating eustatic (global) sea levels now, and in the past, and the confidence limits of the recent reports of acceleration of the rates of sea level rise above the rate of sea level rise over and above that observed in the last 500 years surely warrants more robust discussion. The uncertainties are substantial.

    The GSL 2013 addendum statement addresses the topics of climate sensitivity…….
    climate sensitivity (defined as the increase in global mean temperature resulting from a doubling in CO2)
    and also Earth system sensitivity………
    The Earth System sensitivity is important because it reflects the full consequences of atmospheric CO2 increase and its influence on long term changes in climate and sea level….. Studies of the Last Glacial Maximum approximately 20,000 years ago) suggest that the climate sensitivity is unlikely to be less than 1.4 C or above 6.4 C

    This is a ridiculously wide temperature range to appropriately inform future planning. The expected effects on humans with this temperature range would vary from “probably beneficial” to “probably catastrophic”. There is not enough precision to guide future energy policy planning and it just serves to highlight some of the major uncertainties about the effects of CO2 levels on climate.

    Both the 2010 and the 2013 statements strongly emphasise that CO2 levels tend to be higher at times when the temperature is higher. There is no doubt about that association but what is important is the relative timings of the association.
    In the 2010 statement the GSL note that…….
    although the best estimate from the end of the last glacial is that the temperature probably started to rise a few centuries before the CO2 showed any reaction
    There is evidence that at the onset of glacials that the CO2 decrease can lag behind the temperature fall by up to 14,000 years. This observation was surely worthy of more robust discussion by the GSL working group as it strongly infers that CO2 levels are not the prime driver of global temperature change.

    No mention is made of the difficulties of estimating an average global temperature and the confidence in the estimates now or in the past. There is also no discussion of the usefulness of average global temperature as a concept.

    The hypothesis that rising levels of CO2 is the primary driver of the recent observed rise in temperature is still unproved and remains controversial At this time the hypothesis lacks comprehensive supporting evidence and predictions based on the hypothesis have been inaccurate.

    I believe the GSL working group statements have embraced this populist hypothesis too readily and with unwarranted enthusiasm given the uncertainty of the supporting evidence for the hypothesis. They have not given appropriate weighting to the interacting roles of multiple other factors affecting the climate. They do not adequately acknowledge the significant uncertainties of many aspects of our current state of knowledge about the climate.

    There is no question we should be preparing for climate change. The climate is chaotic. As the GSL statements correctly point out about the climate……….
    It is never static, but subject to constant disturbances, sometimes minor in nature and effect, but at other times much larger. In some cases these changes are gradual and in others abrupt.

    There is also no question that sea level rise associated with tidal surges and storms is a real threat to low-lying coastal areas and cities or that this should be appropriately planned for and addressed.

    Directing a major part of our resources at reducing CO2 levels is not sensible given the uncertainties about the role of CO2 as the primary driver of climate change. In particular it is not sensible to adopt energy policies that are making energy costs more expensive. In reality this is unlikely to have any meaningful effect on global CO2 levels or on the climate and may reduce our ability to respond to the effects of climate change appropriately.

    More appropriate conclusions for the GSL’s statements would be that
    • There are significant uncertainties about how much the Earth has warmed since the beginning of the industrial age.
    • There are significant uncertainties about the exact nature of the association of the increase in atmospheric CO2 with the observed temperature change since the industrial period began, and
    • There are significant uncertainties about how much of the observed warming is due to other causes.

    More emphasis on the “big picture” was expected from a Geological Society The two statements from the GSL are not comprehensive or well balanced and for statements titled…… Climate change: evidence from the geological record…. they fall well short in presenting a balanced geological perspective of what is a very complex topic.
    • Chris says:

      February 7, 2018 at 6:26 pm

      I have to agree with Arion Chrysaor’s temperate analysis and suggested conclusions and very much hope that the arguments and observations provided over the past few weeks can be recorded in a more public forum and that the GSL will re-examine their position.
      CO2 remains a distraction from real issues, issues that man could actually do something about.
    • David B. Benson says:

      February 7, 2018 at 10:24 pm

      A senior chemist offers a very short explanation of how Terra stays warm:
      http://www.realclimate.org/index.php/archives/2018/01/the-global-co2-rise-the-facts-exxon-and-the-favorite-denial-tricks/comment-page-3/#comment-690734
      It is greenhouse gasses wot done it.
      • Euan Mearns says:

        February 8, 2018 at 12:40 am

        David, I haven’t even bothered opening your link. Earth is warm because of the Sun. Anyone wanting to argue otherwise is quite simply insane.
        • David B. Benson says:

          February 8, 2018 at 2:58 am

          I suppose I should say stated “as warm as it is” since the surface of Terra is warmer, on average, than the surface of Luna.
      • A C Osborn says:

        February 12, 2018 at 12:04 pm

        Unfortunately he does no such thing, there is just the standard CO2 does this without a single shred of actual evidence.
56. Philip Mulholland says:

    February 14, 2018 at 3:18 pm

    Euan,
    In this post I want to go back to the basics, the real basics of planetary atmospheres using Maxwell’s Ideal Gas Law and try to answer this question: –
    “How many completely independent physical variables can we identify that govern the nature of a terrestrial planet’s atmosphere?”

    Well #1 on my list is the size of the planet. Planetary mass determines the strength of the gravity at the solid surface upon which the atmosphere rests (the datum level for the potential energy equation). The planet’s gravity at the surface determines the escape velocity; it is the escape velocity and its upper limit on atmospheric kinetics that determines the minimum molecular weight of a species of gas that can be retained in the atmosphere under a given loading of incoming solar radiation.

    So that means that #2 on my list is the average orbital distance of the planet from its parent star. This distance (and orbital trajectory) determines the maximum surface temperature that a solid planet without an atmosphere can achieve. Mercury, with an escape velocity of 4.3 km/s, does not retain an atmosphere. The moon Titan, orbiting the Sun at the distance of Saturn, has a lower escape velocity of 2.64 km/s and yet, unlike Mercury, it retains a cold nitrogen rich atmosphere that is denser than the Earth’s.

    The next independent variable on my list #3 (and possibly the most contentious one) is the speed of the planet’s rotation. The speed of a planet’s daily rotation determines the latitudinal reach of the primary atmospheric cell, the Hadley Cell. On Earth, a fast rotating planet, the Hadley Cell is constrained by the “Coriolis force” and does not extend beyond the tropics due to the conservation of planetary angular (rotational) momentum. Poleward moving air at the top of the Hadley Cell is eventually forced down and returns to the surface. This forced descent allows the development in the Earth’s atmosphere of two more high latitude cells, the Ferrel Cell and the Polar Cell. On Venus however, a slowly rotating planet that does not have an equatorial bulge, the Hadley Cell extends across each hemisphere from the equator to its poles. It is the latitudinal reach of a planet’s Hadley Cell that determines the amount of solid surface area that can achieve direct ground to space radiative cooling. So in essence the faster a terrestrial planet spins the more it is able to cool.

    So now let’s look at the gaseous constituents of planetary atmospheres and how these are affected by variables #1 & #2. The closer a planet is to a star, and the smaller its mass and escape velocity, the higher will be its atmospheric mean molecular weight. This is because the solar radiation loading will effectively “boil off” the lower molecular weight gases with elapsed time. Therefore Venus, with a lower escape velocity of 10.36 km/s than the Earth’s 11.18 km/s, and its closer orbit to the sun, can only retain the high molecular weight gas carbon dioxide rather than the low molecular weight gases such as nitrogen and critically water vapour. Add to this the slow rotational speed of Venus and its consequent poor ability to loose atmospheric heat by ground thermal radiation to space and we have a credible explanation for the dense carbon dioxide nature of the Venusian atmosphere.

    So let us go back to the use of the Ideal Gas Law to predict the average surface temperature of a terrestrial planet. Gravity is an independent variable that determines the maximum particle velocity of a species of gas that can be retained under a given thermal loading. This then means that planetary atmospheres evolve with time to have a molecular weight that is in balance with these forces.
    The higher a planet’s mass, the greater its escape velocity and so the greater can be the mass of its retained atmosphere and consequently the higher its surface pressure can be. This is the potential energy part of the hydrostatic balance equation. The greater the radiation loading of a planet the higher will be its atmospheric mean molecular weight. This is the kinetic energy part of the hydrostatic balance equation. Therefore we can use two variables of surface atmospheric pressure (potential energy) and surface mean molecular weight (kinetic energy) derived from Maxwell’s Ideal Gas Law and expressed in a gravitational field to predict the third unknown, the average surface temperature of a terrestrial planet.

    See Vertical structure of the atmosphere – Hydrostatic balance
    h/t Stephen Wilde
57. popesclimatetheory says:

    February 15, 2018 at 3:41 am

    Global sea level is very sensitive to changes in global temperatures. Ice sheets grow when the Earth cools and melt when it warms.

    Ice sheets grow after it snows more in warm times and the ice advance causes cooling.
    Ice sheets deplete after it snows less in cold times and the ice retreat and allows warming.

    Ice core data shows that this is true. They have the basic cause and result backwards.

    Ice ages happened because there was more ice extent. More snow only fell when oceans were warm and thawed. Warm times happened because there was less ice extent. Less snow only fell when oceans were cold and frozen.

    Study actual data.
58. popesclimatetheory says:

    February 15, 2018 at 4:20 am

    So let us go back to the use of the Ideal Gas Law to predict the average surface temperature of a terrestrial planet.

    When 3/4 s of a planet is covered with water and ice, and the atmosphere is filled with water vapor and clouds, the Ideal Gas Law becomes a bit player. Water, in all of its states, and with its special properties, takes a large role in what happens. Water and ice and water vapor and clouds are not just a result, they play major roles.

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