Guest essay by Christopher Monckton of Brenchley

Environmental Research Letters ought to have known better than to publish the latest anti-scientific propaganda paper by John Cook of the dubiously-named Skeptical Science website. Here are just a few of the solecisms that should have led any competent editor or reviewer to reject the paper:

• It did not discuss, still less refute, the principle that the scientific method is not in any way informed by argument from consensus, which thinkers from Aristotle via Alhazen to Huxley and Popper have rejected as logically fallacious.
• Its definition of the “consensus” it claimed to have found was imprecise: that “human activity is very likely causing most of the current anthropogenic global warming”.
• It did not put a quantitative value on the term “very likely”, and it did not define what it meant by “current” warming. There has been none for at least 18 years.
• It cited as authoritative the unscientifically-sampled surveys of “consensus” by Doran & Zimmerman (2009) and Anderegg et al. (2010).
• It inaccurately represented the views of scientists whose abstracts it analysed.
• It disregarded two-thirds of the 12,000 abstracts it examined, on the unscientific ground that those abstracts had expressed no opinion on Man’s climatic influence.
• It declared that the one-third of all papers alleged to have endorsed the “consensus” really amounted to 97% of the sample, not 33%.
• It suggested that the “consensus” that most recent warming is manmade is equivalent to the distinct and far less widely-supported notion that urgent action to prevent future warming is essential to avert catastrophe. Obama fell for this, twittering that 97% found global warming not only real and manmade but also dangerous.

Yet the most remarkable conclusion to be drawn from Cook’s strange paper is that the “consensus” – far from growing – is actually collapsing.

A little history.

It was Naomi Oreskes, a “historian” of “science”, who started the “consensus” hare running in the literature in 2004 with a non-peer-reviewed essay in Science alleging that not one of 928 abstracts she had reviewed had disagreed with the “consensus” that “most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations”.

Oreskes’ definition of “consensus”, though less imprecise than Cook’s, falls well short of stating that manmade warming may prove catastrophic.

The conclusion of Oreskes’ essay was that three-quarters of the abstracts she reviewed endorse the “consensus” either explicitly or, by evaluating impacts or proposing mitigation, implicitly. A quarter took no view. None, she said, disagreed with the consensus position.

Schulte (2008) reviewed 539 papers in the three years following the period studied by Oreskes, using the same search term (“global climate change”) and the same definition of consensus. He found that “the proportion of papers that now explicitly or implicitly endorse the consensus has fallen from 75% to 45%.”

Only 2% of the papers reviewed “offer new field data or observations directly relevant to the question whether anthropogenic warming has prevailed over natural variability in the past half-century”.

Just one paper mentioned the possibility of catastrophic climate change, but without providing any evidence for catastrophe. No papers provided any quantitative evidence whatsoever for the consensus as defined, still less for catastrophe.

Schulte concluded: “There appears to be little basis in the peer-reviewed literature for the degree of alarm on the issue of man-made climate change which is being expressed in the media and by politicians.”

On no basis, Oreskes later asserted that Schulte had “misrepresented” her results. In fact he had reported them straightforwardly and had simply carried her method forward for a further three years.

Finally, Cook alleged that a third of the papers he had reviewed explicitly or implicitly endorsed the “consensus”. However, several of the scientists whom he said had endorsed the “consensus” say they had done no such thing.

Even if he had assessed the abstracts fairly, the 33% endorsement of the “consensus” that he reported is significantly less than the 45% endorsement that Schulte reported, and less again than the 75% “consensus” reported by Oreskes:

The “consensus” is indeed collapsing.

One might examine Cook’s 12,000 abstracts to discover how many (or, rather, how very few) explicitly or implicitly endorse the notion that catastrophe will follow if CO2 emissions continue to grow.

However, any such survey would be of no more scientific value than that of Cook. As the planet continues to fail to warm at anything like the rate that the usual suspects have so confidently but unwisely over-predicted, it will eventually become apparent to all that science was not, is not, and will never be done by mere headcount.

References

Anderegg, W.R.L., J.W. Prall J. Harold, and S.H. Schneider, 2010, Expert credibility in climate change, Proc. Nat. Acad. Sci. USA 107: 12107-9.

Cook, J., D. Nuccitelli, S.A. Green, M. Richardson, B. Winkler, R. Painting, R. Way, P. Jacobs, and A. Skuce, 2013, Quantifying the consensus on anthropogenic global warming in the scientific literature, Environ. Res. Lett. 8: 024024 (7 pp), doi:0.1088/1748-9326/8/2/024024.

Doran, P., and M. Zimmerman, 2009, Examining the scientific consensus on climate change, EOS Trans. Am. Geophys. Union 99: 22-23.

Oreskes, N., 2004, The scientific consensus on climate change, Science 306: 1686.

Schulte, K.-M., 2008, Scientific consensus on climate change?, Energy & Environment 19:2, 281-286, doi:10/1060/095830508783900744.