In my column I pointed out that people who invoke the 97 per cent consensus often leave vague what is actually being agreed upon. John Cook does this too: Note that his wording is consistent with a range of interpretations, including that greenhouse gases definitely cause only a tiny bit of global warming.
He cannot claim that 97 per cent of scientists believe greenhouse gases cause a lot of warming and that this is a big problem, since the surveys either didn’t ask this, or did but didn’t find 97 per cent support.
Cook, being a PhD student in psychology with a background in communication studies, is hardly in a position to dismiss the membership of the American Meteorological Society as “fake experts.” As to fakery, I would refer readers to the analysis of Cook’s work by social psychologist Jose Duarte, noting that the word “fraud” appears 21 times in that essay alone, and it is not even the harshest of Duarte’s essays on Cook’s discredited methods. Economist Richard Tol has also published detailed excoriations of Cook’s work at as well as in the peer-reviewed literature, as have others.
The Illinois study asked 10,257 Earth Scientists “Do you think human activity is a significant contributing factor in changing mean global temperatures?” The question was vague to the point of meaninglessness. It only refers to “a,” not “the,” factor; it only refers to “human activity” in general, thus conflating land use change, conventional air pollution emissions and greenhouse gases; and it only refers to “changing” mean temperatures (since 1800), without specifying a portion of the total observed. So someone who thinks greenhouse gases caused only a small fraction of the warming would answer Yes, as would someone who thought they drove it all.
The Illinois authors received 3,146 responses. After seeing the answers they selected only 77 as being relevant, and of these 75 (97 per cent) said Yes. What puzzles me is why two answered No. And why the authors asked 10,257 experts for their views when they only considered 77 qualified to answer.
The Princeton study started with 1,372 experts and found that 97 of the ones they deemed the top-100 publishing scientists in the climatology field were also contributors to the IPCC or had signed statements supporting the IPCC position. Hence 97 per cent yadda yadda. But this study design may simply be a circular argument, since the top climatology journals are not double-blind, so it can be difficult for critics of the IPCC to get their papers published. In other words, this result might simply be a measure of the level of clique-citation and group think in the sample they selected. In this regard it is quite noteworthy that the AMS and Netherlands surveys were anonymous and they found nowhere near 97 per cent support for the IPCC conclusion.