Periodicities in solar variability and climate change: A simple model

Guest post by Javier who has a PhD in molecular biology and writes this Spanish blog.

1. Solar activity variability and its proxies

The Sun is a variable star and periodically changes its activity levels producing variations in radiation emission, magnetic field intensity, magnetic polarity, particle emissions, and surface convection. These changes affect the Earth in several ways that manifest through auroras, magnetic storms, changes in galactic (GCR) and solar cosmic rays, and a generally agreed small climate effect. Solar variability is included in some coupled general circulation climate models.

We have been observing the Sun with modern instrumentation for only a century. Prior to that solar variability can be inferred through proxies. Sunspot numbers have been reconstructed for the past 400 years, and before that we have auroras catalogues that extend with less reliability for a few centuries more. To reconstruct past solar activity for the last 11,000 years we rely on solar modulation of cosmogenic isotopes generated by GCR in the atmosphere, mainly 14C and 10Be.

14C is quickly oxidized to 14CO2 and then enters the carbon cycle and is removed from the atmosphere within years or decades by the oceans and the plants. Every year trees capture 14CO2 proportionally to its abundance in the atmosphere and permanently fix it into cellulose in their growth rings, where it can be measured thousands of years later. 14C data becomes contaminated around 1875-1900 from increasing human CO2 emissions and from 1950 due to atmospheric nuclear bomb tests. 10Be is deposited from the atmosphere to the surface both through a precipitation dependent and a precipitation independent pathway. Once it falls on polar snow, it can be recovered from ice cores whose layers can be dated, and measured. As both isotopes follow independent climate pathways, modern reconstructions based on their coincidence, beryllium deposition models, carbon budget models and geomagnetic reconstructions are believed to represent essentially solar modulation and are internally coherent between both isotopes.

2. Solar variability periodicities

Analysis of periodicities present in the proxy record of solar activity provides the means to study the possible existence of a significant response from Earth’s climate to Sun’s variability. Fourier analysis of solar modulation proxy records has been performed by multiple authors with similar results. Figure 1 shows the analysis performed by McCracken et al., 2013, on 10Be, 14C, and a solar modulation reconstruction from both isotopes carried out by Steinhilber et al., 2012. The main periodicities found in the three cases are shown in the table in figure 2. They are:

The 11-year Schwabe cycle (not shown in the analysis) displays a high variability from 8 to 15 years. Probably due to this variability from its most basic cycle, all solar periodicities are also highly variable in their duration. The duration of the Schwabe cycle is anticorrelated to its amplitude (Waldmeier’s rule)

Figure 1. The Fourier amplitude spectrum for GRIP 10Be, the modelled estimate of the 14C production rate and the modulation function (in MeV) computed from the EDML and GRIP 10Be data, and the INTCAL09 14C record with the periods of the stronger spectral peaks annotated in years. Left panel, periodicities 200 < T < 3000 years for the interval 9400 – 300 BP. Right panel, for the interval 4700 – 3500 BP, which does not contain Grand Minima. Notice the absence of the 208-year period on the right panel. Source: McCracken et al., 2013.

The 65-year periodicity seems to have lows at ~1905 and ~1970 and could thus be related to the ~ 60-year periodicity found in many climate phenomena, like temperatures and AMO.

The 87-year Gleissberg cycle also displays a high variability, and has been confirmed independently in aurora records since the fifth century AD (Feynman & Fougere, 1984), and in large solar proton events analysis (McCracken et al., 2001). The Gleissberg cycle is reported to affect the hydroclimate as this periodicity is frequently found in lacustrine varved sediments and flood records (Czymzik, et al. 2016). In Central Europe, flooding events appear to increase at the lows of the Gleissberg cycle.

Figure 2. Periodicities found in solar activity proxy data. Those squared in red are discussed here. The ~ 2500-year cycle will be named here the Bray cycle to honor its discoverer. Source: McCracken et al., 2013.

The 105-year periodicity is often mistakenly reported as being part of the Gleissberg cycle. The low in this periodicity of ~ 1910 would correspond to a present low.

The 208-year de Vries cycle is only apparent in cosmogenic records as prominent peaks of isotope generation with that spacing during one thousand-year period windows centered 2500 years apart. Despite its intermittent presence it is the dominant cycle in cosmogenic records and has been traced back in beryllium ice core records to the glacial period 50 kyr ago (Wagner et al. 2001). The de Vries cycle was discovered as a correspondence between high 14C records and narrow tree rings. As tree ring widths respond to both temperatures and precipitations that also change regionally, the correspondence is stronger in certain areas, like Central Europe or the Tibetan Plateau (Raspopov et al. 2008).

The 350, 510, and 708-year periodicities will not be discussed as they are seldom present in the literature.

The 976-year Eddy cycle, also referred as the millennial cycle, is one of the most constant solar periodicities reported. The Eddy cycle most clear climate correspondence is with several peaks in the Bond series of ice rafted debris that reflect cold periods in the North Atlantic area (figure 3)

Figure 3. Correspondence of the 12,000 years smoothed and detrended record of 14C with the averaged stacked ice rafted debris in North Atlantic sediments that is a proxy for iceberg discharges. Both series have peaks corresponding to the ~ 1000-year periodicity known as the Eddy cycle, most prominently during the first half of the Holocene, when this periodicity was dominant. Source: Bond et al., 2001.

The 1126-year periodicity has been reported by Humlum et al., 2011, in the GISP2 ice core record of Greenland temperatures for the past 4000 years.

The 1300, and 1770-year periodicities will not be discussed as they are seldom present in the literature.

The last clear Holocene periodicity is the 2500-year cycle. This cycle was identified by J. Roger Bray in 1968 from a consilience of geophysical, biological, and glaciological evidence contrasted with solar activity reconstructed from sunspot naked eye observations and aurora records. This proposed solar cycle was later confirmed by Sonnet and Damon by spectral analysis of the 14C record when it became available in the late 80’s and named Hallstattzei (later Hallstatt) for a late Bronze-early Iron cultural transition in an Austrian archeological site during the cycle’s previous to last minimum, 2800 years ago. However the name breaks the tradition of naming solar cycles after their discoverer, and so I propose the name to be changed to the Bray cycle. The lows in the Bray cycle coincide with the coldest periods of the Holocene, that are marked in its latest instances by major glacial readvances:

0.4 kyr BP. Little Ice Age
2.8 kyr BP. Sub-Atlantic Minimum. Greek Dark Ages.
5.3 kyr BP. Mid-Holocene Transition. Ötzi buried in ice. Start of Neoglacial period.
7.8 kyr BP. Boreal/Atlantic transition and precipitation change.
10.3 kyr BP. Early Holocene cooling event (Björck et al. 2001)
12.8 kyr BP. Younger Dryas cooling onset.

Figure 4. Variation in 14C after removal of the long-term trend. An oscillation of the ~ 2500-year Bray cycle is superposed on the data to indicate times when periods of very low solar activity would be expected to occur (arrows). As with every solar cycle, there is some variability in the spacing that complicates mathematical analysis. Adapted to show correct cycle length from Clilverd et al., 2003.

The ~ 2500-year Bray cycle besides being detected in temperature proxy records, vegetation changes and glacial expansions, has also been identified in polar atmospheric circulation changes by O’Brien et al., 1995.

3. Simple model of solar variability

Based on the information about solar periodicities from cosmogenic isotopes and the sunspot record reconstructed since 1610 a simple model can be proposed to try to explain the periodicities and known changes in activity. Figure 5 illustrates this model. It is proposed that solar activity during the period between 1910 and 2016 constitutes the basic unit composed of 9-10 Schwabe cycles (letters A or B in figure 5) and a duration of 100-110 years. This basic unit is divided in two subunits of 50-60 years (numbers 1-4 in figure 5) by one or more Schwabe cycles of lower activity in its center.

Figure 5. Model of solar variability. The basic unit (red letters) is composed of 9 or 10 Schwabe cycles of 8-15 years for a duration of 100-110 years and is divided into two subunits of 50-60 years (red numbers) by one to three Schwabe cycles of reduced activity at its center. The Gleissberg cycle (blue) is proposed to take place between deep minima (blue circles) that tend to occur near the end and beginning of solar units. The de Vries cycle is proposed to manifest by solar activity reduction of the fourth subunit of a double unit.

The Gleissberg cycle detected in auroras and large solar proton events is tentatively stablished between deep minima like the ones that took place in 1913 between cycles 14-15 and 2009 between cycles 23-24. These deep minima constitute also minima in both auroras and large solar proton events, and sometimes more than one of these deep minima are produced sequentially like in 1900 and 1913.

Two units of 100-110 years constitute a double unit. The last subunits of double units (number 4 in figure 5) are proposed to be responsible for the de Vries cycles, with an average spacing of 208 years, when the activity of the Schwabe cycles of that subunit is greatly reduced by the modulating effect of the ~ 2500-year Bray cycle, as it happened in 1650-1700 (Maunder Minimum) and 1875-1910 (Modern Minimum).

It is then proposed that the ~ 2500-year Bray cycle acts exclusively by greatly reducing the activity of every fourth subunit of any double unit close to the lows of the cycle (red filled dots in figure 6), while leaving unaffected double units close to the highs of the cycle (red empty dots in figure 6). The combination of the de Vries and Bray cycles would then be responsible for the Maunder and Spører grand solar minima, as well as the Homer, Greek and Oort grand solar minima. The ~ 1000-year Eddy cycle appears to reduce the activity of Schwabe cycles at different times of the solar unit and is proposed to be responsible for the Wolf and Roman grand solar minima, but appears also to reduce the solar activity of the Schwabe cycles between solar units, as in the Dalton grand minimum, and probably contributing to reduce the activity during the Greek, Spører and Maunder grand minima.

Figure 6. Adjustment of the solar variability model (red curve) to the sunspots groups number for the past 400 years and the solar activity reconstructed by Steinhilber et al., 2012, for the past 3000 years. The ~ 1000-year Eddy cycle is shown as a pink sinusoidal curve. The ~ 2500-year Bray cycle is shown as a yellow sinusoidal curve with the active phase as solid line and the inactive as dashed line. The ~ 208-year de Vries cycle is shown as red filled circles during the active phase, and as red empty circles during the inactive phase. The ~ 87-year Gleissberg cycle is shown in blue. Grand solar minima are named in black, warm periods in red and cold periods in blue. Known colder periods from temperature reconstructions are highlighted in turquoise. A quiet Sun mode during grand solar minima has been proposed by several authors and shown as a black dashed line.

Figure 6 presents an attempt to match the reconstruction of solar variability during the past 3000 years by Steinhilber et al., 2012, with the simple model. Although probably wrong in many details the adjustment shows that many of the past variations in solar activity might follow simple rules determined by the periodicities found in frequency analyses.

4. On the relationship between solar variability and climate

It is clear from the examination of the relationship between solar variability and climate change during the Holocene, that the longer the solar cycle the more significant it is the worsening of the climate change experimented at its lows. Thus the lows of the ~ 2500-year Bray cycle can correspond to very significant glacier readvances and near hemispheric vegetation changes. Lows in the ~ 1000-year Eddy cycle correspond to significantly increased iceberg discharges in the North Atlantic. Lows in the 208-year de Vries cycle significantly affect tree growth in ample regions, like Central Europe and the Tibetan Plateau. The de Vries and Gleissberg cycles are also proposed to affect the intensity of the summer monsoon (Fleitmann et al., 2003; Dykoski et al., 2005) and regional precipitation patterns. When we get down to the Schwabe cycle this decreasing effect becomes so low as to almost disappear within natural variability.

So to understand the effect of solar variability on climate change it is important to recognize that it requires a very long time to accumulate. The longer the time solar activity is reduced the more profound the effect on climate. The few years of a solar minimum between Schwabe cycles do not produce enough activity reduction to affect climate significantly.

To illustrate this concept I have chosen a figure from Svalgaard & Schatten, 2016, where a black box was traced by Dr. Svalggard in one of his presentations to point that “Solar activity reached the same levels in each of the last 4 centuries” (figure 7). If we mark those high levels with red boxes and periods with lower levels with blue boxes of height proportional to the missing activity we observe that high activity level red boxes tend to correspond to periods of temperature increase and lower activity blue boxes tend to correspond to periods when temperatures don’t increase. So it is clear that the recovery from LIA has taken place mainly during periods of solar activity similar to 20th century levels. This increase in temperatures was, according to Moberg et al., 2005, of 0.6°K for the Northern Hemisphere land between 1675 and 1950, much higher than the assumed 0.1°K that solar variability can contribute according to current understanding.

Figure 7. The recovery from the Little Ice Age in terms of solar activity illustrates the possible long term incremental effect of solar variability. Although every century has periods of high (or normal) solar activity, labelled as red boxes, there is a clear tendency towards a decrease in the periods of reduced activity (blue boxes). The result could play like a staircase where the red steps increase temperature (violet curve with the low-frequency component in blue) and the blue steps decrease or stall temperatures. If temperatures have not reached equilibrium, every high activity period increases them further, and the low-frequency component (blue curve) shows two steps up with the third one being modern warming (not available for the proxies used). Sources: Svalgaard & Schatten, 2016; Moberg et al., 2005.

However it has to be remembered that it is the climate who decides the response to the solar radiation and not the Sun. The planet received essentially the same amount of energy from the Sun during the Last Glacial Maximum and during the Holocene Climate Optimum, yet the climate was completely different. And it is not only the different distribution of that energy according to latitude and season, because we know that 65°N summer insolation anomaly was +36 W/m2 105 kyr ago versus only +30 W/m2 10 kyr ago, and in the first case the planet was in glacial conditions, while in the second it was in interglacial conditions and we do not know why. So if the planet is capable of giving a very different climate response to the same amount of solar energy and latitudinal insolation we should not discard heedlessly the possibility that small prolonged changes in solar output are also capable of eliciting significant climate responses.

It is also unwarranted to assume that the natural warming post-LIA ended in 1950, in the middle of a high solar activity period, as we have no evidence for that. Surely the post-LIA natural warming has to have an end, but we don’t know where to place it, and therefore we don’t know if or how much it has contributed to modern warming since 1975.

If we were to assume that indeed post-LIA natural warming has continued at about the same rate, 0.6°K in 275 years for northern hemisphere land, then in the last 66 years it should have contributed about 0.15°K to the northern hemisphere land temperatures. But remember that this is over an average of high and low solar activity periods, and those last 66 years correspond only to a high solar activity period, so it could be even more. And if we subtract from the average warming the cooling from vulcanism, that was more intense during LIA, well, who knows, perhaps half of the recent global warming or more could be attributed to the Sun without the need to invoke an out of the ordinary solar activity for the 20th century. Of course this is based on the assumption that climate responds very slowly to small changes in solar forcing and that equilibrium has not been reached since the cooling from the LIA ended.

5. On how solar variability could affect climate

Such a complex issue as the mechanisms by which solar variability affects climate has been hotly debated for decades and cannot be illuminated here. I will try however to give a reasoned opinion based on current literature. It is clear to me that solar modulation of galactic cosmic rays (GCR) cannot be such mechanism. We tend to forget that the main modulation of GCR is done by the Earth’s geomagnetic dipole that over the course of a few thousand years experiments a variation that causes changes in GCR an order of magnitude bigger than heliospheric magnetic field changes. As the climate does not change with the Earth’s geomagnetic dipole we can discard a significant magnetic or GCR effect on climate. There might be an effect, but not significant.

The climatic effect is also probably not due to changes in radiation reaching the surface, as we know they are very small. More reasonable hypotheses are those that propose an atmospheric effect that probably propagates from the stratosphere downwards to the troposphere. The energy for climate and weather manifestations is mainly provided by the poleward heat transport, that is due to more energy entering the Earth in the tropical areas that can leave, so the surplus is transported towards the poles where more energy is leaving the Earth than entering. The intensity of the poleward heat transport depends on the latitudinal thermal gradient (LTG). LTG is more intense during cold periods and less intense during warm periods for obvious reasons. And this is why predictions about weather extremes fail miserably, as with the warming LTG decreases and the weather becomes tamer, not wilder. About two thirds of the poleward heat transport are moved by the atmosphere, and the rest by the global oceanic currents. LTG also determines the position and extension of the Inter Tropical Convergence Zone (ITCZ) on which the intensity of the monsoon depends. Recent research has shown that tropical stratosphere temperatures depend on solar activity (Gray et al., 2010), and winter climate in the Northern Hemisphere correlates to those changes (Ineson et al., 2011; Gray et al., 2013). An atmospheric top down effect of solar variability has been proposed.

Figure 8. Correspondence between residual changes in 14C (IntCal04, broken line) and varve thickness in an Eastern Finland lake sediment (solid line). Grand minima in solar activity are highlighted with their name. MCA, Medieval Climate Anomaly. Varve thickness is regulated in Lake Lehmilampi mainly by organic matter accumulation changes that correlate with seasonal temperature and precipitation changes. Source: Haltia-Hovi et al., 2007.

A variety of studies are linking solar activity to both precipitation anomalies and pressure anomalies, like an increase in winter blocking of anticyclonic conditions in the North Atlantic that favor cold conditions over Central Europe during solar activity minima (Barriopedro et al., 2008; Woollings et al., 2010). These changes, that are regional in nature and barely above natural variability in intensity during regular solar minima appear to intensify and produce a significant climate change when their action spans over prolonged periods of low solar activity, and could reflect solar induced small continuous alteration of the atmospheric LTG that could affect global climate through the integration of regional changes. There is ample energy in the system to produce the observed changes if solar variability alters its distribution. There is no need for more variability in the Sun’s output to explain the correlation between solar variability and climate change.

6. Future projections of the solar variability model

If the present analysis turns out to be correct in general terms, then we can extend the variability model towards the future, with the caveat that several periodicities in solar variability have not been analyzed nor included in the model.

At present (2016) we are finishing a ~ 100-year cycle in solar activity that constitutes the first unit of a doublet (figures 5 and 6) that should end around 2022. For the next 55 years we could expect a repetition of the past 50 years backwards. Solar cycle 25 should be like SC24, SC26 like SC23, SC27 like SC22, and SC28 like SC21. Around 2065 a mid-cycle reduction in activity like the one that took place around 1970 (SC 20) should be expected (SC 29). From 2077 to ~ 2125 solar activity corresponds to a minimum of the ~208 -year de Vries cycle, but by then the de Vries cycle would have waned due to the ~ 2500-year Bray cycle being in its upper half, so no significant reduction in solar activity is expected either. So for the major part of the next hundred years the Sun should enjoy a similar level of activity to the second half of the 20th century. A grand solar minima or even a long period of reduced solar activity might not take place for a few centuries, as the long cycles are in a very favorable disposition. We might face a solar future similar to what the Romans enjoyed between 150 BC and 350 AD. A very positive development if true.

In terms of climate, the post-LIA natural warming should end soon if it hasn’t ended already, because these recovery periods from the lows in the ~ 2500-year Bray cycle rarely last for more than 400 years. As solar centennial activity cannot increase further, we are probably contemplating an end to natural warming.

But the temperature of the planet is set by the obliquity (tilt) of its axis, not by solar variability, and Earth’s obliquity is decreasing everyday at the fastest rate in forty thousand years (figure 9). Only once in the last million years have temperatures failed to fall with falling obliquity, but when this happened (during MIS 11, 400 kyr ago), 65°N summer insolation was very high, while now it is very low.

Figure 9. Holocene climate reconstruction. Major palinological subdivisions of the Holocene (names on top) match a 2500 regular spacing (grey arches on top). The global temperature reconstruction (black curve; Marcott et al., 2013 by the differencing method with proxy published dates) has been rescaled in temperature anomaly to match biological and glaciological evidence and instrumentation temperature measurements, resulting in the Holocene Climate Optimum being about 1.2°K warmer than LIA. The general temperature trend of the Holocene follows the Earth’s axis obliquity (purple), and significant downside deviations generally match the lows of the ~ 2500-year Bray cycle of solar activity (grey boxes labelled B-1 to B-5). Significant negative climate deviations manifested also by global glacier advances (blue bars; Mayewski et al., 2004) and strong increases in iceberg detrital discharges (red curve, inverted; Bond et al., 2001) generally agree well with the lows in the ~ 2500-year Bray cycle and ~ 1000-year Eddy cycle (not shown) of solar activity.

The rebound effect of the post-LIA natural warming together with any anthropogenic warming contribution has probably taken us above the temperature that corresponds to the present inclination of the axial tilt, since by a variety of biological and physical methods our present state appears to be similar, at least in the northern hemisphere, to the conditions around the Mid-Holocene transition ~ 5000 years ago. It is possible therefore that over the next 1-2 centuries global temperatures might naturally descend by 0.2-0.4°K to reach our obliquity target, regardless of solar activity.

I would expect significant cooling and climate change from reduced solar activity around 2600 AD when the next low in the ~ 1000-year Eddy cycle is expected. Glacial inception, the onset of the next glacial period, could take place around 4000 AD when the next low in the ~ 2500-year Bray cycle acting on a much lower obliquity should set the conditions for the growth of the ice sheets.

7. Summary and conclusions.

Solar variability is not random, but follows a series of periodicities of unknown cause. Periods of low solar activity, specially those belonging to the long periodicities, with a span of several decades, coincide with known periods of significant climate worsening for the last 11,000 years. The temperature increase between 1675 and 1950 has coincided with a progressive reduction in multi-decade periods of low solar activity. A simple model of double solar activity units of 100-110 years can be adjusted to fit several periodicities and solar activity reconstructions. The model infers that the ~ 2500-year Bray cycle and the ~ 1000-year Eddy cycle have different modes of action. The Bray cycle acts through the ~ 208-year de Vries cycle. In other words, the de Vries cycle is a manifestation of the Bray cycle. The model projects that solar activity during the 21st century should be similar to solar activity enjoyed during the second half of the 20th century. Please use sunscreen when outdoors for your skin protection.

8. Bibliography

Barriopedro, D., et al. (2008). Solar modulation of Northern Hemisphere winter blocking. Journal of Geophysical Research: Atmospheres, 113(D14).

Björck, S., et al. (2001). High-resolution analyses of an early Holocene climate event may imply decreased solar forcing as an important climate trigger. Geology, 29(12), 1107-1110.

Bond, G., et al. (2001). Persistent solar influence on North Atlantic climate during the Holocene. Science, 294(5549), 2130-2136.

Bray, J. R. (1968). Glaciation and solar activity since the fifth century BC and the solar cycle. Nature, 220, 672-674.

Clilverd, M. A., et al. (2003). Solar activity levels in 2100. Astronomy & Geophysics, 44(5), 5-20.

Czymzik, M., et al. (2016). Solar modulation of flood frequency in central Europe during spring and summer on interannual to multi-centennial timescales. Climate of the Past, 12(3), 799-805.

Dykoski, C. A., et al. (2005). A high-resolution, absolute-dated Holocene and deglacial Asian monsoon record from Dongge Cave, China. Earth and Planetary Science Letters, 233(1), 71-86.

Feynman, J., & Fougere, P. F. (1984). Eighty‐eight year periodicity in solar‐terrestrial phenomena confirmed. Journal of Geophysical Research: Space Physics, 89(A5), 3023-3027.

Fleitmann, D., et al. (2003). Holocene forcing of the Indian monsoon recorded in a stalagmite from southern Oman. Science, 300(5626), 1737-1739.

Gray, L. J., et al. (2010). Solar influences on climate. Reviews of Geophysics, 48(4).

Gray, L. J., et al. (2013). A lagged response to the 11 year solar cycle in observed winter Atlantic/European weather patterns. Journal of Geophysical Research: Atmospheres, 118(24).

Haltia-Hovi, E., et al. (2007). A 2000-year record of solar forcing on varved lake sediment in eastern Finland. Quaternary Science Reviews, 26(5), 678-689.

Humlum, O., et al. (2011). Identifying natural contributions to late Holocene climate change. Global and Planetary Change, 79(1), 145-156.

Ineson, S., et al. (2011). Solar forcing of winter climate variability in the Northern Hemisphere. Nature Geoscience, 4(11), 753-757.

Marcott, S. A., et al. (2013). A reconstruction of regional and global temperature for the past 11,300 years. science, 339(6124), 1198-1201.

Mayewski, P. A., et al. (2004). Holocene climate variability. Quaternary research, 62(3), 243-255.

McCracken, K. G., et al. (2001) “Solar cosmic ray events for the period 1561–1994: 2. The Gleissberg periodicity.” J. Geophys. Res 106.21: 599-21.

McCracken, K. G., et al. (2013) “A phenomenological study of the cosmic ray variations over the past 9400 years, and their implications regarding solar activity and the solar dynamo.” Solar Physics 286.2: 609-627.

Moberg, A., et al. (2005). Highly variable Northern Hemisphere temperatures reconstructed from low-and high-resolution proxy data. Nature, 433(7026), 613-617.

O’Brien, S. R., et al. (1995). Complexity of Holocene Climate as Reconstructed from a Greenland Ice Core. Science, 270(5244), 1962-1964.

Raspopov, O. M., et al. (2008). The influence of the de Vries (∼ 200-year) solar cycle on climate variations: Results from the Central Asian Mountains and their global link. Palaeogeography, Palaeoclimatology, Palaeoecology, 259(1), 6-16.

Steinhilber, F., et al. (2012). 9,400 years of cosmic radiation and solar activity from ice cores and tree rings. Proceedings of the National Academy of Sciences, 109(16), 5967-5971.

Svalgaard, L., & Schatten, K. H. (2016). Reconstruction of the sunspot group number: the backbone method. Solar Physics in press. arXiv preprint arXiv:1506.00755.

Wagner, G., et al. (2001). Presence of the Solar de Vries Cycle (~ 205 years) during the Last Ice Age. Geophysical Research Letters, 28, 303-306.

Woollings, T., et al. (2010). Enhanced signature of solar variability in Eurasian winter climate. Geophys. Res. Lett, 37, L20805.

This entry was posted in Climate change and tagged , , , , , , , , , , , . Bookmark the permalink.

35 Responses to Periodicities in solar variability and climate change: A simple model

  1. Euan Mearns says:

    Javier, many thanks for a great post. I wish I’d written it 🙂 Tying together all the various cycles is the right approach IMO. As I mentioned earlier, I disagree a little with your take on Bond and D-O cycles:

    Figure 3 Bond cycles compared with CO2 and historic climate cycles in Europe. While Bond et al counted 9 cycles (grey numbers starting at 0), I count 10 giving a mean cycle length of 1200 years. LIA = Little Ice Age; MWP = Medieval Warm Period; DA = Dark Ages; RWP = Roman Warm Period. There is no obvious connection between Bond Cycles and global CO2. Note that the way Bond et al plot their data, time is passing from right to left and warm is down and cold is up.

    Figure 6 Temperature and 10Be profiles from deeper/older levels of the GISP2 ice core, same references as before. Chart from an earlier Energy Matters post [ref 4].

    And if you use 10Be to define the D-O events, I see 20 D-O 10Be events in 23,ooo years giving a mean cycle length of 1150 years. So I see Bond Events and D-O events as the same thing, both linked to solar variability. But during the glaciations, a 10Be D-O event does not always result in a climate event. I have no problem imagining that during glaciations, these weaker solar driven events may not make any impact or leave an imprint.

    Following from this I’d see Bond and D-O linked to your 1126±71y cycle and not Eddy. But there is clearly a degree of subjectivity in how you count the cycles.

    http://euanmearns.com/bond-cycles-and-the-role-of-the-sun-in-shaping-climate/

    • Javier says:

      Euan,

      Thank you for your kindness in publishing the article.

      I do not think that you can trust 10Be to reconstruct D-O events that failed to make an impact in 18O changes in ice cores. The climate contamination of 10Be is just too big and not properly corrected when adjusted by snow precipitation changes.

      D-O oscillations are defined by several signature conditions. They are highly asymmetric with rapid warming in a few decades and slow cooling over at least 200 years followed by rapid cooling over at least 200 more years for a minimum duration of 400 years. They are matched by a similar peak of methane levels of similar amplitude and duration. And they are preceded by prior Antarctic warming that peaks about 220 years after the Greenland warming peak.

      Not only most of your red peaks fail to show that signature, but also some of the blue peaks, like number 2 and number 9 (not shown). One has to conclude that they do not represent D-O events, but abrupt climate changes unrelated to the D-O phenomenon.

      We have come a long way to understand D-O events recently (Dokken et al., 2013; Ezat et al., 2014; Petersen et al., 2013). They appear to be tied to oceanic-sea ice interactions, and are thus not solar in nature.

      Their periodicity is very strongly established at 1470 years ± 8% (Schulz, 2002; Rahmstorf, 2003), This periodicity is so tight that it has been suggested that it must have an astronomical origin. The Sun is certainly a lot less precise in its variability and shows no ~ 1500-year periodicity.

      With such tight periodicity, the D-O cycle can be followed through the Holocene. Its last appearance was the abrupt warming at the end of the Younger Dryas at 11.6 Kyr ago. Afterwards the 1470-year signal disappears. During the Holocene there are no abrupt warming events, so any claim that D-O events are still operating but related to cooling events (Bond events) instead of warming, must be accompanied by an explanation on why a warming oscillation has turned into a cooling one.

      Dokken T.M. et al. 2013. Dansgaard-Oeschger cycles: Interactions between ocean and sea ice intrinsic to the Nordic seas. Paleoceanography 28 491-502.

      Ezat, M.M. et al. 2014. Persistent intermediate water warming during cold stadials in the southeastern Nordic seas during the past 65 k.y. Geology 42 663-666.

      Petersen, S.V. et al. 2013. A new mechanism for Dansgaard-Oeschger cycles. Paleoceanography 28 24-30.

      Rahmstorf, S. 2003. Timing of abrupt climate change: A precise clock. Geophys. Res. Lett. 30 1510-1514.

      Schulz, M. 2002. On the 1470-year pacing of Dansgaard–Oeschger warm events. Paleoceanography 17 1014-1023.

  2. Beamspot says:

    Mmm, I guess he is Javier, AKA Knownuthing from Rankia community, blog Game Over:

    http://www.rankia.com/blog/game-over

    The articles related to Peak Oil are damn good.

  3. Euan Mearns says:

    Javier, but i think we agree on likely process where solar variation impacts the Stratosphere (shift in spectrum?) that feeds down to affect the troposphere.

    My belief is that this impacts the pattern of atmosphere and ocean circulation, where in Europe we can become stuck in very cold N and NE winds. We’ve just had about 6 weeks of that in Aberdeen. These N winds slow the Gulf Stream and blow sea ice ± Inuit southwards.

    But this may be balanced by S winds blowing northwards elsewhere. All linked to the geometry of a deeply meandering jet stream. With these conditions, its possible for climate to change “everywhere” without leaving a major imprint on global average temperature.

    • Javier says:

      Recently you posted a figure of the entire British Isles covered in snow, I believe that during the winter of 2010, one year after the deep solar minimum of 2009. The blocking anticyclonic climate signal has been proposed to lag 1-2 years the solar signal. We should have another window for increased probability of very cold winters over the British Isles after solar cycle 24 ends, about 2022.

    • Javier says:

      Your fit would improve by the inclusion of the Waldmeier’s rule. It would also change completely the residual.

  4. Alistair Buckoke says:

    One would certainly agree with the need for exploring solar variation to account for climate variation as far as it can possibly be taken, but certain loosenesses in Javier’s thesis are a little worrying.

    In Figures 3 and 4 the red lines or arrows have been ‘adjusted’ to fit with the other data. While variability in solar cycles is accepted, it is not good science to supply tendentious information and these interpretations would be better omitted. On similar lines, in Figure 5. one would note that 60 x 4 = 240, not the de Vries figure of 208. Again, the Gleissberg minima, as start points of 1/2 of the de Vries cycle, yield 87 x 2 = 174, not 208. That the Schwabe cycle underlies and connects this material is an assumption, and not much more.

    In Figure 6., it is to be noted that for the most part, the grand minima occur when the Eddy and Bray cycles are in negative synch, making a useful correspondence. However the Homer grand minimum is a departure from this thesis. Javier claims that the 2500 year Bray cycle acts through the de Vries cycle (a close to 12x multiple), yet Figure 9. shows that there are other minima apart from those covered by the grey (Bray) boxes, and the Bray boxes by no means always cover all of the Bond hematite maxima.

    The Bray periodicity is really quite problematic in the period between 10,000 BC and 7,000 BC (fig. 4).

    While more exhaustive computer modelling might help to resolve some of these mismatches, most of the data is observed phenomena rather than explained phenomena, which would weaken any premises used in modelling. Most of all, there are a great many cycles identified for the rate and extent of reaction in one single star, and all of these phases will impact on each other to some extent.

  5. We investigate solar/climate relationships using three basic approaches:

    1. We compare metrics like total solar irradiance, sunspot number, period of the solar cycle and the AA geomagnetic index with global temperature.
    2. We compare ”proxies” such as d81O, deuterium, 14C and 10Be with observed phenomena such as Bond cycles, Heinrich events and D-O events.
    3. We compare observations with solar cycles.

    How well do these approaches work? Approach 1 shows not only a generally poor correlation between TSI and temperature over the period of instrumental record but also that changes in total solar irradiance are far too weak to generate the observed 20th century warming. This is why the IPCC uses Approach 1 in its climate models.

    Approach 2 gets us involved in a huge number of what-ifs, not the least of which is what the proxy data actually mean. It’s widely assumed that d18O means temperature and 10Be the level of solar activity, but both d18O and 10Be in the GISP2 record are correlated almost 1:1 with K, Na, Ca etc. cations, which represent dust. To explain this in climate terms we need an abrupt increase in some component of solar radiation that causes an immediate increase in atmospheric dust and an immediate decrease in temperature. A more plausible explanation is simply an increase in precipitation, which enriches all of the atmospheric components of the ice core sample – 10Be, d18O and dust (and also, incidentally, methane) – at the same time. So the problem now becomes – what caused the increase in precipitation?

    Approach 3 is the most likely to yield results, as I think Javier’s Figure 6 illustrates. That solar output varies in accordance with cycles with periods of between ten and tens of thousands of years is not disputed and there is good evidence to suggest that at least some of these cycles have an impact on the Earth’s climate. The best example is probably Nicola Scafetta’s linking of the ~60 year cycle which is clearly visible in a number of climate variables to a 60 year solar cycle that is driven by the orbital periods of Jupiter and Saturn:

    https://www.google.com.mx/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0ahUKEwi22petidXMAhVGyoMKHQGUCGAQFggpMAE&url=http%3A%2F%2Fwww.fel.duke.edu%2F~scafetta%2Fpdf%2Fscafetta-JSTP2.pdf&usg=AFQjCNGdgh6CLw-RBvgZeDRlYKHdz2yPWQ&sig2=AHfE9WmWdwHFRwA8tJf83w

    I’ve had some fun myself working with solar cycles in the past too: https://tallbloke.wordpress.com/2011/05/23/global-warming-projections-using-solar-cycles/

    • Javier says:

      Roger,

      At that Tallbloke’s article you noticed that different cycles must have different effect, and asked why different solar cycles should generate different forcing impacts. According to my hypothesis presented here, and the climatic effects observed, the longer the cycle the higher the impact from the accumulated effect of the small solar activity missed or recovered. This hypothesis fits your finding that longer cycles required a higher forcing to fit the observed temperature change.

      • Thanks Javier. I never noticed the period-amplitude relationship.

        One case where it doesn’t work, however, is in the Friis-Christensen reconstruction, where longer-period Schwabe cycles are associated with cooling and shorter ones with warming (I think I have that the right way round).

        • Javier says:

          Yes, that is the Waldmeier’s rule: The longer the Schwabe cycle, the lower its activity. As far as I know, nobody knows why.

  6. Javier says:

    Alistair,

    In Figures 3 and 4 the red lines or arrows have been ‘adjusted’ to fit with the other data. While variability in solar cycles is accepted, it is not good science to supply tendentious information and these interpretations would be better omitted.

    Thanks for your opinion. However visual aids in figures to help the reader focus on the point being made are very common and generally accepted. Figure 4, that you find unacceptable, was originally published with the five arrows at the bottom, as you can check at Clilverd et al., 2003, yet it was acceptable both to authors and editors. This Figure from Ahn & Brook 2008, shows vertical lines and bars as visual aids to focus on the points being made by the authors. This is really standard practice.

    Solar cycles are highly variable. The 11-year Schwabe cycle is really 8-15 years, so it is actually 11-year ± 30%. As per McCracken et al., 2013, the Eddy cycle is 976 ± 53 years and the Bray cycle is 2310 ± 304 years, and even these periodicities vary significantly from one author to another. To that we have to add dating uncertainties. Figure 3 is original from the paper. The red vertical lines simply show that in the last 12,000 years at every XX,080 – XX,220 years before present (1950, with XX being 00 to 11) there has been a low in solar activity, and that low has generally coincided with a high in iceberg discharges. The same information is there with and without the red lines. I am sorry you don’t like them, but tendentious is too strong a word. It is not my fault that solar cycles are so variable.

    On similar lines, in Figure 5. one would note that 60 x 4 = 240, not the de Vries figure of 208. Again, the Gleissberg minima, as start points of 1/2 of the de Vries cycle, yield 87 x 2 = 174, not 208. That the Schwabe cycle underlies and connects this material is an assumption, and not much more.

    Sure, if you get the higher figures and multiply, the maths don’t add, but since Schwabe cycles vary by as much as ± 30%, at the end what you get is a population with different lengths and a long term average. That the Schwabe cycle underlies and connects this material is a hypothesis, and not much more.

    In Figure 6., it is to be noted that for the most part, the grand minima occur when the Eddy and Bray cycles are in negative synch, making a useful correspondence. However the Homer grand minimum is a departure from this thesis.

    There are always Solar Grand Minima at the lows of the Bray cycle. That’s how they are defined.

    Javier claims that the 2500 year Bray cycle acts through the de Vries cycle (a close to 12x multiple), yet Figure 9. shows that there are other minima apart from those covered by the grey (Bray) boxes, and the Bray boxes by no means always cover all of the Bond hematite maxima.

    One would not expect that solar variability should explain all climate variability. Nor that it should always exert the same effect. Solar cycles are very variable not only in their timing, but also in their amplitude.

    The Bray periodicity is really quite problematic in the period between 10,000 BC and 7,000 BC (fig. 4).

    Certainly. For some reason the low of the Bray cycle at ~ 7,800 yr BP had a lesser climate effect while the Eddy cycle low at ~ 8,200 yr BP, together with the Lake Agassiz discharge, had a more profound effect. This is the cause of a lot of confusion and why the Bray cycle is described by many authors as being between 2,200 – 2,400 years. However the clear lows at 10.3 and 12.8 kyr BP allow to resolve the uncertainty.

    Solar cycles are what they are. Schwabe solar cycle 24 came significantly later and with a lot less activity than almost every solar physicist had predicted. We should not expect Solar cycles to be what they are not until we understand what causes them and what affects them.

    Computer models are good for testing hypotheses, but they cannot teach us anything that we don’t know already when we program them. When we think that they can, we usually lose our way.

    Ahn, J. and Brook, E.J. 2008. Atmospheric CO2 and Climate on Millennial Time Scales During the Last Glacial Period. Science 322 83-85.

  7. Owen says:

    In plain mans language what is the upshot of this very in depth research?

    Viz a viz the climatechange debate?

    • Javier says:

      The conclusion is that solar variability must have a much bigger influence on climate that it is generally agreed on, and that despite claims to the contrary the long period of above average solar activity between 1925 and 2005 has probably contributed to global warming.

      For the climate change debate it would mean that anthropogenic global warming is lower than estimated by IPCC and therefore less or no dangerous.

      • Owen says:

        Thanks Javier.

        I posed the solar / climate question to a solar physicist lecturer in Trinity College, Dublin and he said that a change in the sun’s output only changes solar irradiance by 1/10 of 1%. So I took his reply to mean that the sun has very little effect.

        • Pedro J. says:

          That’s the point. Ask the expert, not outsiders writing on a blog about energy (by the way, I not going to trust this blog anymore) and contradicting all the serious research that one can find very easily by googling . And if someone is wondering if this is just an ad hominem comment, just an example

          Javier says:

          “I would expect significant cooling and climate change from reduced solar activity around 2600 AD when the next low in the ~ 1000-year Eddy cycle is expected. Glacial inception, the onset of the next glacial period, could take place around 4000 AD when the next low in the ~ 2500-year Bray cycle acting on a much lower obliquity should set the conditions for the growth of the ice sheets.”

          Three papers that the author of this post does not even bother to mention:

          A classic

          Archer, D., and A. Ganopolski (2005), A movable trigger: Fossil fuel CO2 and the onset of the next glaciation, Geochem. Geophys. Geosyst., 6, Q05003, doi:10.1029/2004GC000891.

          Another recent article very relevant

          Tzedakis, P. C., Channell, J. E. T., Hodell, D. A., Skinner, L. C. & Kleiven, H. F. Determining the natural length of the current interglacial. Nature Geosci. 5, 138–141 (2012)

          And a recent one

          Ganopolski, A., Winkelmann, R., Schellnhuber, H.J. (2016): Critical insolation-CO2 relation for diagnosing past and future glacial inception. Nature [DOI:10.1038/nature16494]

          Which concludes:

          “our analysis suggests that even in the absence of human perturbations no substantial build-up of ice sheets would occur within the next several thousand years and that the current interglacial would probably last for another 50,000 years. However, moderate anthropogenic cumulative CO2 emissions of 1,000 to 1,500 gigatonnes of carbon will postpone the next glacial inception by at least 100,000 years8, 9. Our simulations demonstrate that under natural conditions alone the Earth system would be expected to remain in the present delicately balanced interglacial climate state, steering clear of both large-scale glaciation of the Northern Hemisphere and its complete deglaciation, for an unusually long time.”

          • Javier says:

            Sorry Pedro J., but a 60,000 year interglacial is completely unprecedented. Just bother yourself into looking at the data.

            Such an extraordinary claim requires extraordinary evidence, and I am afraid there is no evidence available at all. After 35 years we have no clue of the climate sensitivity to CO2 and without that knowledge, predicting what is going to happen in 5000 or even 50 years due to elevated CO2 levels is useless as the inability to predict the pause has demonstrated.

            Just building computer models and claiming that they are capable of predicting future climate doesn’t make it so.

            On the other hand, since for the last 2.5 million years every interglacial has been followed by a glacial period, it is prudent and conservative to assume that this interglacial will not be any different to the dozens that came before.

          • Pedro J. says:

            And just bother yourself also into searching for a period in the geological history of Earth when something was able to release ~10 Pg C yr⁻¹ . Yes, completely unprecedented.

            “After 35 years we have no clue of the climate sensitivity to CO2”

            Come on! No clue? Aren’t you, perhaps, confusing uncertainty with lack of information? Or you bet that sensitivity is 10ºC/2xCO2 ?

            “Just building computer models and claiming that they are capable of predicting future climate doesn’t make it so.”

            Of course everybody is aware that opinions are the best tool available in scientific research. Thanks for the reminder.

            By the way, have you managed to publish your deep analysis in any peer-review journal? In any case, you should. The climatologists of the world need someone with no experience in climate science and geology to show them the right path to truth.

          • Javier says:

            “And just bother yourself also into searching for a period in the geological history of Earth when something was able to release ~10 Pg C yr⁻¹ . Yes, completely unprecedented.”

            Unless you can demonstrate that the CO2 has the effect that you think it has it doesn’t matter how unprecedented it is. And you can’t demonstrate it unless you know the climate sensitivity to CO2. And after 35 years of trying we do not know the climate sensitivity. It could be dangerous or it could be harmless. The last published estimate that I have seen this month is:
            Bates, J. R. (2016), Estimating climate sensitivity using two-zone energy balance models. Earth and Space Science, 3, doi:10.1002/2015EA000154.
            http://onlinelibrary.wiley.com/doi/10.1002/2015EA000154/epdf
            And it defends an ECS of 1°C. That would make the CO2 increase completely harmless.

            “By the way, have you managed to publish your deep analysis in any peer-review journal?”

            There is no need. Everything I say is based on published peer-reviewed scientific literature. There are already climatologists and paleoscientists saying and publishing the same things.

          • Pedro J. says:

            “Unless you can demonstrate that the CO2 has the effect that you think it has it doesn’t matter how unprecedented it is. And you can’t demonstrate it unless you know the climate sensitivity to CO2. And after 35 years of trying we do not know the climate sensitivity. It could be dangerous or it could be harmless.”

            And then your bet goes to

            “.And it defends an ECS of 1°C. That would make the CO2 increase completely harmless.”

            Funny. We don’t know but in the range of uncertainty you bet for an improbable choice, given all the literature on the subject.

            “Everything I say is based on published peer-reviewed scientific literature.”

            Based on cherry-picking the right papers one can show whatever it wants. I can show you GMO produces cancer, radiation from Fukushima induces quite a few cancers in US population, the Big Bang Cosmology is completely wrong and so on. The point is what a review of the literature says. And much better is one keeps up appearances trying to be fair and cite the literature which contradicts what one is trying to show. Above, I pointed to some literature that you have the obligation to criticize because, given the scientific literature on this subject, you are obviously making an extraordinary claim.

          • erl happ says:

            Reply to Pedro J in relation to this statement:

            “The point is what a review of the literature says.”

            I disagree, the literature is tainted by a belief that is entirely disconnected from reality. Surface temperature change, when surveyed according to latitude. indicates massive variability in January and July. The former month applies to all latitudes north of 30° south and the latter to all latitudes south of 30° south. The massive and consistent differences in temperature variability according to the month of the year indicates a reversible process of surface temperature variation connected with the ozonosphere at the poles. The extent of variability in the month of greatest variability increases with latitude.

            The existing literature on the annual modes is relevant. Unfortunately, climate scientists have yet to realize that the ozonosphere includes a large part of the troposphere. Until they work out how perturbations in the so called ‘stratosphere’ affect the troposphere they have no explanation for this major, mode of natural climate variation that impacts in the winter months. The problem is that climate science has yet to work out that density differences between 300hPa and 50hPa are related to the synoptic situation at the surface. Until they do this and and relate it to the distribution of ozone as the cause of these density differences they will not connect the dots.

            They can’t connect the dots because of the pre-existing assumption that the carbon dioxide content of the air determines surface temperature. A blind spot. No amount of surveying the literature is going to get us closer to reality.

            Climate scientists should have taken a little more notice of Gordon Dobson when he documented the fact that total column ozone maps surface pressure. Think for a moment. What that means is that the synoptic situation, wind direction, wind temperature and the extent of cloud cover is determined by the ozone content of the upper portion of the atmospheric column. We must look to the stratosphere to understand the troposphere. To understand the stratosphere we need to understand the impact of the sun on the atmosphere, not just in terms of Total Solar Radiance (invariable) but also via the impact of photolysis and the electromagnetic features of the Earth’s atmosphere, both highly variable. The solar wind and Galactic cosmic rays as they affect the atmosphere over the poles become important areas of study. The zonal wind and its variations assume more importance. The polar vortex gets closer attention. Sudden warmings are given closer attention. Wave theory is re-evaluated. The generation of polar cyclones is re-evaluated. The decline of surface pressure in high southern latitudes is observed and its implications and interrelatedness to change in surface pressure elsewhere is realized In short we need to understand the A-Z of ozone.

            When we look at the stratosphere we must see its fine texture. That texture is concealed by averaging processes. In fact stop averaging altogether. Start looking at textures.

          • Javier says:

            “Funny. We don’t know but in the range of uncertainty you bet for an improbable choice, given all the literature on the subject.”

            If we don’t know we have to go with the evidence. Global warming is 350 years old and has only been beneficial to humanity and most species. Dangers remain hypothetical, while benefits are real.

            “Based on cherry-picking the right papers one can show whatever it wants.”

            Certainly. That is why it is so important to ground science on solid evidence. Evidence that so far is lacking in the Catastrophic CO2 warming hypothesis. A belief based on assumptions, no matter how generalized it is, is not enough.

            “I pointed to some literature that you have the obligation to criticize because, given the scientific literature on this subject, you are obviously making an extraordinary claim.”

            The point I make is not extraordinary at all. After every interglacial, glacial conditions return due to Milankovitch orbital variations in insolation. Every single time for over 2 million years. Current insolation conditions are close to glacial inception. You should know if you have read Tzedakis et al., 2012. Nature Geosci. 5, 138–141, or Crucifix, 2011. How can a glacial inception be predicted? The Holocene, vol. 21, pp. 831-842 (doi:10.1177/0959683610394883).

            Ganopolski and others are the ones making an extraordinary claim. That this time is different. Their claim is based on the following assumptions that they cannot demonstrate:

            1. That CO2 changes are responsible for most of the warming in the glacial-interglacial cycles. The opposite might be true as CO2 also responds to changes in temperatures and it might contribute little to the warming.

            2. That current CO2 levels are high enough and produce enough warming to prevent glacial inception. We do not know how much warming current levels of CO2 produce, but we do know that since 2001 CO2 levels have increased by 38% of the total increase since 1950, and yet temperatures have barely risen. This assumption does not look very solid either.

            3. That CO2 levels will remain elevated for thousands of years regardless of our CO2 emissions. This claim goes against IPCC understanding that atmospheric CO2 half life is in the order of a few hundred years at most, and against the tremendous increase in CO2 sinks that has taken place as our emissions increased. The great majority of the CO2 produced by humanity is already gone.

            This hypothesis is so soft and full of holes as a Swiss cheese and smells equally bad. It does match however the current CO2 religion for which faith is a strong requirement. If it was true that CO2 could save the planet from a return to the glacial conditions that characterize the current ice age we should be making damn sure that we can keep its atmospheric levels high enough for thousands of years.

          • Pedro J. says:

            Erl Happ: “I disagree, the literature is tainted by a belief that is entirely disconnected from reality.”

            Javier: “It does match however the current CO2 religion for which faith is a strong requirement.”

            Got it! 🙂

            More fun:

            Javier “CO2 levels have increased by 38% of the total increase since 1950, and yet temperatures have barely risen.”

            Javier a few sentences later: “The great majority of the CO2 produced by humanity is already gone.”

            Much more fun:

            Javier: ” That CO2 levels will remain elevated for thousands of years regardless of our CO2 emissions. This claim goes against IPCC understanding that atmospheric CO2 half life is in the order of a few hundred years at most”

            So now the other sources are gone. 400 ppm by now but “The great majority of the CO2 produced by humanity is already gone.” So there is a CO2 free lunch in the atmosphere. Nice! I love particle physics also.

            And last but not least:

            “The point I make is not extraordinary at all. After every interglacial, glacial conditions return due to Milankovitch orbital variations in insolation. Every single time for over 2 million years. Current insolation conditions are close to glacial inception.”

            Typical levels of CO2 in the last 800,000 years were 180-280 ppm. Now they reach 400 ppm. So the past glacial-interglacial cycle is not a good model for the future anymore.

            So long and thanks for all the fish!

          • erl happ says:

            Reply to Pedro J ‘More fun……. So long and thanks for all the fish!’

            A corpse is laid out on a marble slab covered with a plastic sheet from head to toe. Blood oozes across the bench and drips onto the floor. Two forensics stand by.

            Before we lift the sheet let me guess says Pedro J. Methinks this person has been gored by a bull. Good enough for me says Climate Science as he lays down his scalpel. Let’s have a beer.

          • Javier says:

            Pedro J.,

            Besides repeating what I say and stating how much fun it causes you, you add nothing.

            I take it that you know that:
            “So far, land plants and the ocean have taken up about 55 percent of the extra carbon people have put into the atmosphere while about 45 percent has stayed in the atmosphere.”
            http://earthobservatory.nasa.gov/Features/CarbonCycle/page5.php
            It is common knowledge, although perhaps not to you.

            So it is obvious if you know simple math and the global increase in CO2 sinks with time that “The great majority of the CO2 produced by humanity is already gone.” Since given the increase in emissions and sinks, there is very little left in the atmosphere of all the CO2 that humanity produced prior to 1980. You seem to confound emissions with atmospheric levels.

            “Typical levels of CO2 in the last 800,000 years were 180-280 ppm. Now they reach 400 ppm. So the past glacial-interglacial cycle is not a good model for the future anymore.”

            Just because you say so, doesn’t make it so. You would have to demonstrate why 400 ppm is going to change the glacial-interglacial cycle. As far as we know the glacial-interglacial cycle is due to orbital changes that are not affected by CO2.

            That you support the hypothesis that 400 ppm of CO2 is going to abolish the glacial-interglacial cycle does not mean that the hypothesis is true. I rather stick to the >2 million years long evidence.

        • Euan Mearns says:

          Owen, mainstream climate science doggedly sticks to looking only at variations in irradiance and insolation reaching the surface while ignoring all other possible impacts that The Sun might have such as changes in spectral output, that may, as Javier points out, impact the stratosphere.

          When you see a strong correlation between cosmogenic isotopes and climatic indicators you know that The Sun is playing a much more prominent role than 0.1% and I don’t have too much time for those who wilfully chose to ignore this evidence.

          The trouble is that the actual process is not well understood.

          • Owen says:

            Euan / Javier,
            I suppose saying solar irradiance has very little effect on the climate is like saying that having a good goalkeeper has very small affect on the success of a football team. There are other solar forces at work, the goalkeeper is only one part of a team.

  8. Pingback: Periodicities in solar variability and climate change: A simple model – Climate Collections

  9. Javier says:

    That is correct, Owen. Changes in total irradiance are about 0.1%. That had me convinced for years that the Sun had little effect on climate. Then about six months ago I decided to check the data myself, and what I found is that the correlation between solar variability and climate change for the long cycles was too good to be due to any other factor. My position is shared by many scientists since over a hundred articles are published every year on the Sun-climate connection.

    So we know it is not the change in total irradiance, but that doesn’t mean that the observations are wrong. It means our knowledge is probably insufficient. New theories are being proposed to explain the Sun-climate connection that are not based on total irradiance changes.

    My favorite one tries to explain it through changes in UV that are 10 times bigger, and that through ozone changes or directly, change the temperature gradient of the Stratosphere (that has very little mass). These changes propagate to the Troposphere causing changes in pressure and cloud distribution that are the real cause of the climate change.

    It has been calculated that a 1% increase in cloud cover would completely negate the effect of all the CO2 added to the atmosphere, and nobody really knows how clouds change.

    There is so much we do not know about the climate that nobody can really say that it is not the Sun, although we do not have enough evidence to say that it is the Sun either.

  10. Ninety-nine-point-something of the heat in the oceans and the atmosphere is in the oceans. And since the ocean surface is generally warmer than the air above it there’s usually a net global heat transfer from the ocean to the atmosphere.

    The oceans are heated by the sun, mostly by UV radiation, which can penetrate to depths of over 100m. (The downwelling IR radiation from CO2, which according to global warming theory heats the sea as well as the air, penetrates only a few nanometers).

    And where does the ocean heat go?.Well, some of it will go up and return to the atmosphere. The rest will take off on a submarine journey that may last for years before it returns to the surface. The important point, however, is that some of the heat that enters the ocean at any particular moment remains in the ocean. (Attempts have been made to quantify the amount of stored heat with time by accumulating sunspot numbers above and below a “neutral” threshold, but no one really knows where this threshold is.)

    Another way of looking at it is that much of the solar heating of the atmosphere is governed not by heat exchange between the sun and the atmosphere but by heat exchange between the atmosphere and solar heat stored in the oceans. If so then we can’t ignore the oceans if we want to relate climatic changes to solar activity.

  11. erl happ says:

    This is a very interesting discussion.I am impressed by the manner in which Javier goes about his work, both in his presentation and his response to comments.In short, I am enthused.

    The bridge between solar activity and surface climate is missing. Javier’s speculations in this respect I will endorse unreservedly: I refer in particular to the following text:

    “More reasonable hypotheses are those that propose an atmospheric effect that probably propagates from the stratosphere downwards to the troposphere. The energy for climate and weather manifestations is mainly provided by the poleward heat transport……..The intensity of the poleward heat transport depends on the latitudinal thermal gradient ………About two thirds of the poleward heat transport are moved by the atmosphere, …………Recent research has shown that tropical stratosphere temperatures depend on solar activity (Gray et al., 2010), and winter climate in the Northern Hemisphere correlates to those changes (Ineson et al., 2011; Gray et al., 2013). An atmospheric top down effect of solar variability has been proposed………There is ample energy in the system to produce the observed changes if solar variability alters its distribution.”

    I have made a close study of the manner in which temperature at the surface of the Earth changes according to latitude and month of the year. The patterns are very interesting as described here: https://reality348.wordpress.com/2016/01/13/7-surface-temperature-evolves-differently-according-to-latitude/
    https://reality348.wordpress.com/2016/01/15/8-volatility-in-temperature/

    Cloud cover is modulated by the descent of ozone in high pressure cells in the mid latitudes in the manner described here: https://reality348.wordpress.com/2015/12/29/3-how-the-earth-warms-and-cools-naturally/

    The polewards transport of the energy acquired in the tropics is modulated by the planetary winds that depend on surface pressure relationships. The partial pressure of ozone in the global stratosphere is material in that there is a part of the troposphere and lower stratosphere where marked variations in the distribution of ozone give rise to differential heating (ozone is a greenhouse gas) responsible for differences in atmospheric density giving rise to strong winds (e.g Jet streams). There is an identity between jet streams and the synoptic situation at the surface. In mid and high latitudes ozone maps surface pressure as observed by Gordon Dobson in the 1920s. The manner in which the system modulates the planetary winds that determine the the poleward transport of heat and relate also to cloud cover is described here:
    https://reality348.wordpress.com/2016/04/03/18-the-ozone-pulse-surface-pressure-and-wind/
    https://reality348.wordpress.com/2016/04/08/19-shifts-in-atmospheric-mass-in-response-to-polar-cyclone-activity/
    https://reality348.wordpress.com/2016/04/17/20-the-distribution-of-atmospheric-mass-changes-in-a-systematic-fashion-over-time/
    https://reality348.wordpress.com/2016/04/24/21-the-weather-sphere-powering-the-winds/
    https://reality348.wordpress.com/2016/05/04/22-antarctica-the-circulation-of-the-air-in-august/
    https://reality348.wordpress.com/2016/05/14/23-the-dearly-beloved-antarctic-ozone-hole-a-function-of-atmospheric-dynamics/

    The primacy of the Antarctic circulation in determining all this is independently confirmed here: http://onlinelibrary.wiley.com/doi/10.1002/cjg2.1010/abstract This relates to the De Vries cycle.

    The observational evidence of the manner in which transfers of atmospheric mass manifest has been laid out by others in terms of the analysis of ‘Annular Modes’ of inter-annual and inter-decadal climate variation that has a very extensive literature and it is introduced here: http://www.atmos.colostate.edu/~davet/ao/introduction.html

    The Earth’s magnetic field is important in that there is a part of the atmosphere over the winter pole that responds to changes in the electromagnetic field wrought by the solar wind affecting what is called the ‘zonal wind’ that in turn reflects the rate of ingress of mesospheric air into the atmospheric column over the winter pole. This abstract describes just one of the latest in a long series of works that document a correlation between geomagnetic activity and many aspects of the global circulation and in particular matters stratospheric. http://onlinelibrary.wiley.com/doi/10.1002/2015JA022104/full

    There are may assertions here that depart from prevailing orthodoxy and I would be disappointed if some or all were not challenged.

    • Javier says:

      Thank you, Erl.

      I already found your interesting blog in one of my searches some months ago. It is clear to me that some of the points that you bring up ought to be researched in depth at the very least to increase our understanding on how they affect atmospheric circulation. The problem is, as you very clearly state, that this type of research is clearly out of favor in the current political and scientific situation, and thus it is only carried out by a few researchers that are pretty much ignored by the rest.

      The stratosphere, as you point out, and the oceans, as Roger does in the comment above yours, could very well respond to solar changes a lot more than it is generally assumed. Instead of researching every possible cause for global warming we are finding every possible excuse for why the rise in GHGs does not match the rise in temperatures as expected.

      • erl happ says:

        Thanks Javier. Yes, I agree, the oceans store and transport energy because they are apparently transparent, to short wave to a depth of up to 300 metres unless there is turbidity. All the fines settle in the deep and the beaches are continually worked by wave action so that only coarse particles remain.

        But, the oceans can only store extra energy if it is made available to them according to the state of cloud cover in the atmosphere.

        The key to understanding the flux in the input of energy into the ocean lies in understanding the flux in cloud cover. And that is where ozone comes into play. It is not generally realized that the atmosphere is only skin deep. We know that the flux in ozone in the upper half of the skin causes the temperature of the air to change but we have not tumbled to the realization that the absolute humidity of the upper half of the skin is fairly constant. So, relative humidity and condensation phenomena relate fairly strictly to the temperature of the air in the upper half of the skin. Multi-branching crystals of ice scatter light with great efficiency.

        It is observed that the surface warms when GPH increases. GPH is the height of a pressure level. It is a proxy for the kinetic energy in the atmosphere below that pressure level. It is further observed that when GPH increases at 200hPa it does so at 500hPa and 700 hPa. All these pressure levels are within the cloud domain.

        So, we actually already know how the oceans gain and lose energy.It’s not mysterious.

        Meteorologists measure GPH and there is a record available. The Chinese are very good at maths. http://onlinelibrary.wiley.com/doi/10.1002/cjg2.1010/abstract

        So, there you have it in a nutshell.

        There is only one greenhouse gas that has any significance so far as climate is concerned and its not CO2. Until we realize that we in the western world and Spain in particular is heading for a train wreck…..or has it already happened given your rate of youth unemployment and the burden of government debt .

Comments are closed.