My previous post discussed a little-known UN poll that has so far attracted seven million voters from all over the world and which despite being totally unscientific nevertheless provides some interesting insights about public attitudes towards climate change. Here I discuss another little-known climate change poll that also provides some interesting insights but which is otherwise about as different to the UN poll as it’s possible to get. Why? Because there were only 286 respondents, not seven million, and they aren’t just anybody. They’re all climate scientists.
I refer to the Bray & von Storch poll entitled A survey of the perceptions of climate scientists 2013 . It’s quite a poll. It doesn’t ask just a few questions. It asks no fewer than one hundred and thirty-one, some of them highly technical (“The current state of scientific knowledge is developed well enough to allow for a reasonable estimate of the effects on climate of surface albedo?”). Yet 286 of the 4,491 people to whom the poll was sent responded, and most of them to all 131 questions – a respectable level of response to an internet poll considering the time it would have taken to fill it out.
The poll is weighted towards the “consensus” viewpoint. The invitees included “authors of climate related papers in peer reviewed climate related journals …. authors who contributed to Oreskes’ (2004) published conclusions concerning consensus in the climate change issue …. the IPCC list of contributors” and those on “readily available email lists from institute web sites (i.e. NCAR (US National Center for Atmospheric Research), MPI (Max Planck Institute), AMS (American Meteorological Society)) etc”. Almost all the respondents were affiliated with universities or government-funded research organizations and almost half of them had been involved as authors or reviewers of IPCC reports.
But the poll contains a graphic that is arguably the best illustration yet published of what the climate change “scientific consensus” really looks like. We find it on page 59:
268 of 272 climate scientists think that humans have caused at least some of the warming since 1850, representing a 98.5% consensus. But if we use the IPCC’s claim that “most” (i.e more than 50%) of the warming was human-caused as the criterion the number drops to 81.2%, and if we insist on all of the warming being human-caused, which is essentially what the IPCC’s climate models show, it drops to only 6.3%. Clearly the “scientific consensus” on climate change can be quantified only if we put a hard number on what percentage of observed warming has to be caused by humans before climate change becomes “significant”. (A 12.5% human-caused warming threshold gives a 97.5% consensus among the respondents, incidentally. The oft-quoted 97.5% number seems to have originated in the 2009 Doran poll.)
(What’s your estimate of the percentage of human-caused warming since 1850? Feel free to provide a number. My estimate is either zero or 50% depending on which of my two pet theories sounds more plausible to me at the time, so I give it 25%.)
A full discussion of the results of the Bray & von Storch poll is beyond the scope of a single blog post, so here I will briefly touch on what I consider to be a few of the more revealing responses in something approximating a logical sequence:
First, most respondents regard climate change as a potential threat to humanity but aren’t unanimous as to how serious and dangerous it is:
They are also mostly in favor of taking immediate action to cut global greenhouse gas emissions (“mitigate” means emissions cuts, “adapt to” means higher sea walls etc.) although again there is no unanimity as to how great the need for immediate action is:
They are, however, somewhat less certain as to whether we can predict what the effects of climate change are going to be:
And they can’t agree at all as to whether recent climate-related disasters were caused by climate change or not:
They also have surprisingly little confidence in the predictive skill of climate models only 50 years into the future. In every one of the examples shown below the number of “very poor” votes in fact exceeds the number of “very good” votes. (Note that all the cases except sea level rise apply to regional rather than global climate models because regional models are usually used to evaluate specific climate change impacts. Levels of confidence in global models, however, are not much higher):
I’m going to let these results speak for themselves and leave it up to readers to form their own opinions.