A short summary of the supposed ‘consensus’

A commenter here raised the matter of the consensus about ‘climate change’, and pointed to the Cook paper. I felt a great weariness descend, but recognised that I would have to do the work — not of replicating the Cook paper, about which I have written before — but of setting out the history of this particular canard. Then Lo! Someone has done it for me, and you can read it for yourself on  the WUWT website, which sets it all out, with the appropriate references. What follows is my summary.

The NASA version of the consensus runs like this: “Ninety-seven percent of climate scientists agree that climate-warming trends over the past century are very likely due to human activities.” Note first that there is no mention here of any danger from such a trend. Note second that global temperatures rose in the first half of the 20th century, levelled out in the middle of the century, rose again in the second half, and have levelled out since. Are these all the work of human activities? If so, how? If not, why not?

The first person to talk in these terms (again without mentioning danger, or falls as well as rises) was a historian of science called Naomi Oreskes, who reviewed 928 abstracts of articles in the climate science field and reported in 2004 that 75 per cent supported the view that human activities were responsible for most of the warming in the last fifty years. Not only do articles not always support the claims made in the abstracts, but Ms Oreskes seemed somehow to have excluded   articles by scientists such as Christy, Lindzen, Michaels and Idso, all of them sceptics.

In 2009 Zimmerman and Doran asked scientists two questions: did they think that temperatures had risen and whether humans were significantly responsible. Again, no mention of dangerous consequences. On alternate days I’d probably answer ‘Yes’ to both questions myself. What does it mean? They narrowed the 10,257 who had been sent the questionnaires to the 3146 who had replied, and then to the 79 who said they were climate scientists and published more than half of their work on ‘climate change’, and found that 77 said yes to both questions. That gave them a 97 per cent figure.

A year later Anderegg explored the work of 200 of the most prolific writers on ‘climate change’ and found ‘that 97% to 98% of the 200 most prolific writers on climate change believe “anthropogenic greenhouse gases have been responsible for ‘most’ of the ‘unequivocal’ warming.”’So he got a 97 per cent figure. Again, no mention of any danger from warming. Again, so what?

In 2013 Cook et al looked at more than 12,000 abstracts, rated them according to whether or not they implicitly or explicitly endorsed the view that human activity had caused (wait for it) some of the warming, and again found the magic 97 per cent. See! It’s true!

Unfortunately for Cook, Legates and others later in the same year published a rebuttal. ‘They found that “only 41 papers – 0.3% of all 11,944 abstracts or 1.0% of the 4,014 expressing an opinion, and not 97.1% – had been found to endorse” the claim that human activity is causing most of the current warming. Elsewhere, Craig Idso, Nicola Scafetta, Nir J. Shaviv and Nils-Axel Morner and other climate scientists protested that Mr. Cook ignored or misrepresented their work.’

The authors of the WUWT article, Bast and Spencer, go on to refer to another article which I have not seen before: ‘Rigorous international surveys conducted by German scientists Dennis Bray and Hans von Storch – most recently published in Environmental Science & Policy in 2010 – have found that most climate scientists disagree with the alleged consensus on various key issues, such as the reliability of climate data and computer models. They also do not believe climate processes like cloud formation and precipitation are sufficiently understood to enable accurate predictions of future climate change.’

In short, the consensus is dreadfully thin in terms of real evidence, and is not about the projected catastrophe awaiting us, but only about whether or not human activity has caused some of the alleged warming over the past century/fifty years — about which there is substantial agreement anyway. Since survey research was one of my fields, I have thought how I would go about designing one. I think you would offer your respondents a set of questions for which there were several possible answers, of which Don’t Know, or ‘Impossible to say with current knowledge’ were options. Who would be the respondents? That’s much harder, since you need a representative sample, and they are hard to produce. But I would start with the learned academies and the university departments whose fields might encompass aspects of ‘climate change’, which is probably all of them.

But it is a footling exercise anyway, because appeals to authority are a last resort. In the case of ‘climate change’ the real questions are about the temperature data, its reliability and validity, and the worth of the climate models whose projections contain the alleged catastrophe awaiting us. None of the answers are well founded.

And of course, if there were really strong evidence that there is a catastrophe out there that is about a warmer world (we can reasonably accept that another glacial is out there, too) we wouldn’t be fussing about abysmally poor surveys at all. The data and the science would be powerful in themselves. They’re not, which is why we have this rubbishy stuff.

 

[Not all those links take you to the original papers, which in many cases are behind paywalls. Here I have to trust the veracity of the authors, who presumably do have copies from which they quote.]