The ninety seven percent solution

The Problem

Climate Change (CC) dominates today’s environmental concerns. We are daily bombarded with the message that it will lead to future catastrophe for humanity, if not for the planet. Human emissions of greenhouse gasses are the primary cause and only drastic societal change will enable us to avoid our fate. Under its earlier and more specific title of Catastrophic Anthropogenic Global Warming (or CAGW), the meme grew from small beginnings in the 1980s to progressively capture scientific institutions, mainstream media, politicians and finally – the last but one bastion – captains of finance and industry. The phrase is overworked these days, but I quote it here because of its appositeness: a perfect example the long march of left activists through the institutions: subversion from within.

But opinion poll after opinion poll shows that the public, by and large, faced by the immediate problems of life, place the perceived threat of future climate disaster low on their list of priorities (see September 2022 IPSOS Poll).

The problem for CAGW proponents therefore is how to get the public to abandon their apathy and accept their prescriptions of radical change in lifestyles as the only cure for the predicted disasters. The grit in the shoe of those who see a looming existential crisis is that there are a substantial number of scientists who reject the idea that human activities are the sole or even the dominant drivers of climate change, or that the observed mild warming and increase of atmospheric CO2 of the last 160 years will be other than net beneficial for humanity. These scientists may be mistaken in this view, but they are highly qualified and their credentials impeccable.[1]: their knowledge and expertise demand a hearing in the climate debate. But the alarmists don’t want debate, they know that debate would only expose the uncertain and shaky foundations of their own entrenched belief and weaken their message. They want to shut the sceptics down, to demonise and cancel them. They use the argument that the sceptical scientists are a tiny minority of deniers who can, and should, be ignored. But “tiny minority” is a vague term. How inconsequential are these “deniers”? This is science, dammit. We need a number to drive the point home.

The underlying thinking seems to be that scientific truth is determined by a show of hands (see my blog post: The purpose of science is to seek truth, not proclaim it)



The Solution

One of the first attempts by the champions of CAGW to count the votes on their side was made in a 2004 paper (LINK) in Science by Naomi Oreskes. Specifically, she wanted to find how many published scientists agreed with the Intergovernmental Panel on Climate Change (IPCC) statement that read at that time “most of the observed warming in the last 50 years is likely to have been due to the increase in greenhouse gas concentrations.” (my italics). Reviewing the abstracts of 928 peer-reviewed climate papers published between 1993 and 2003, Oreskes found that 75% of them “explicitly or implicitly” endorsed the IPCC position. As implicit endorsement, Oreskes included papers on mitigation, methodology or paleoclimatology which she admitted took no position whatsoever on the role or extent of human activities in driving the recent warming trend. The 25% who did not make the cut presumably “explicitly or implicitly” rejected the IPCC statement, which they might well have done because of the implications of the two words italicised in the quote above. Oreskes does not seem to have considered that there are many scientists (myself included) who accept that greenhouse gasses do have a warming influence on climate but only to a modest amount which evidence suggests is, and for the foreseeable future will be, net beneficial. Oreskes’ survey therefore did not prove anything much, except that at least 75% of scientists believe that greenhouse gasses are real and operate as their name implies to some undefined amount.

To her credit, Oreskes concluded her paper with this disclaimer, which I heartily endorse: “The scientific consensus might of course be wrong. If the history of science teaches us anything, it is humility, and no one can be faulted for failing to act on what is not known.”

A few years later (2009), in a paper published in EOS, the newsletter of the American Geophysical Union (LINK), Peter Doran and Maggie Kendal Zimmerman claimed to quantify the scientific acceptance of the statement that “human activities are the major cause of warming”. Doran and Zimmerman sent a “2-minute” on-line survey to 10,257 North American Scientists of whom 3146 responded. Of these, 90% answered yes to the question “have temperatures risen since the 1800s”. On the second question “has human activity had a significant role in temperature rise”, 82% agreed (but only 64% of meteorologists and 47% of Economic Geologists). Since the authors of the paper did not define “significant’, the survey did not at that stage prove anything very much, except that around 80% – 90% of NA Scientists believe that greenhouse gasses are real and do what it says on their label[2]. But Doran and Zimmerman realised that they had cast their net too widely (they had to get rid of these pesky geologists and meteorologists).  Based on a personal assessment of which responders were “the most specialised and knowledgeable with respect to climate change”, they selected a subset of  just 77. Of these, 75 had answered yes to the two questions above. Seventy-five out of seventy-seven is 97%.  The “97% of scientists” label, attached to the mission statement: “human activities are the major cause of warming”, was what almost all took away from Doran and Zimmerman’s widely reported survey.

In 2013, John Cook (and numerous co-authors), writing in Environmental Research Letters (LINK), described the results of a survey which reproduced Doran’s 97% number. They made use of a team of volunteer “citizen scientists”[3] to assess the abstracts of 11,944 papers on Climate Change topics published between 1991 and 2011. The stated aim was to determine the percentage of papers that supported the supposed consensus view of Climate Change, a view defined as “humans are causing Global Warming”. The simple words: “are causing” were carefully chosen (see footnote 4). To most people these words would imply (as intended) a sole, or at the very least, majority cause, but they are sufficiently ambiguous for that meaning to be deniable.

Cook & Co were more explicit and unambiguous on the purpose of their survey, stating that: “The public perception of a scientific consensus on AGW is a necessary element in public support for climate policy”.  Not just a search for truth then, but a search for a weapon to be used to advance a social agenda. And behold! -they came up with a figure of 97.1% [5] – a mighty weapon indeed for the Climate Warriors.

Wow!  Citizen scientists!  12,000 peer-reviewed papers! Overwhelming consensus!  97.1% of scientists agree! Human beings are causing dangerous climate change! Proof!

The 97% figure was subsequently much quoted in climate polemics by politicians, journalists and bloggers. A take-home gift for the self-styled “fact’ checkers which today infest all forms of media (see my blog post here). I would be surprised if any of these people ever actually read the detail of the Cook and Co paper: most likely only the accompanying media release and even that filtered second-hand through the lens of a MSM science reporter. The nod towards humility expressed by Naomi Oreskes ten years before was conspicuously lacking.

And It Worked!

And so the ripples of the narrative spread outwards, from press release to journalist to activist blog to Twittersphere: losing on its way- like Chinese whispers – almost all trace of original meaning, until it finally reached the Politicians in the form of processed nuggets of falsehood bearing the imprimatur: “scientists say”.

On May 16, 2013, President Barack Obama tweeted to his 31.5 million followers: 

“97% of scientists agree that climate change is real, man-made and dangerous”. 

On 19th May, 2014, US Secretary of State John Kerry (now President Biden’s Special Envoy on Climate), in a speech to students at Boston College said:

“And let there be no doubt in anybody’s mind that the science is absolutely certain…97 percent of climate scientists have confirmed that climate change is happening, and that human activity is responsible…(climate) will change dramatically for the worse.”

 On 30 November 2015, then UK Prime Minister David Cameron, in a widely broadcast speech to that year’s UN Climate Conference in Paris (COP 21), declared that:

“97% of scientists the world over have said the climate change is urgent and man-made and must be addressed”.

Are the leaders of great democracies really so stupid and easily fooled? Maybe. Maybe not. But one thing is certain – they think you are.

The Pushback

But by 2015, David Legates and several co-authors had already published, in the journal Science and Education, a devastating critique of the Cook paper (LINK). After re-analyzing Cook’s own supporting data, the Legates team showed that, of the 11,944 scientific papers examined by the Cook team, only 41 explicitly stated or even implied an agreement with the statement that humans were responsible for the greater part of present-day climate change. 41 out of 11,944 is  0.3%.

Legates Sumary John Cook data2015 re-analysis by David Legates and his co-authors of raw data taken from the Cook et al 2013 paper.

It takes some degree of chutzpa, aided by the corrupt state of current climate science, to escalate a figure of 0.3% to 97% and then get it published in a peer-reviewed journal. How did Cook and his mates manage this? By assessing the 11,944 abstracts, not on whether they explicitly supported a majority role for humans in causing present day Climate Change, but on lesser criteria, such as: do the author(s) agree that global temperatures are rising? do the author(s) agree that that CO2 has a positive forcing effect on global temperatures? is carbon sequestration important for mitigating Climate Change?  Then, when the number of ticks on these criteria had added up to whatever number was considered to be sufficiently overwhelming, they publish and obfuscate, knowing that no one who matters will ever read the detail of the paper anyway. It was the same pea-and-thimble trick (show, then hide, then switch) previously employed by Oreskes, Doran and Zimmerman.

Since the Legates et al paper, numerous other critiques have been published which comprehensively, and I believe convincingly, debunk the Oreskes, Doran and Cook research. Here are just two, of contrasting style, by Australian geologist Emeritus Professor Ian Plimer (LINK) and by Climate Change Economist at the Vriej Universiteit (Netherlands) and University of East Anglia, Professor Richard Tol (LINK)

My Opinion

The consensus figures of Oreskes, Doran and Cook were an input to, rather than an output of, their survey designs. In the case of John Cook, there can be absolutely no doubt about that conclusion, as his own private emails demonstrate (4).

But why these absurdly precise figures of 97% – 97.1 %?

The researchers were aware that, had they come up with a figure of 100% consensus, nobody would have believed them. If they had only reached, say, 93%, then they would not have met the accepted criteria of 95% for statistical significance (or p=0.05: the infamous “wee pee”). Ninety seven percent was therefore “just right” – the Goldilocks number.

The ninety seven percent solution on how to diminish and dismiss the doubters.

With their finding that only 3% of climate scientists disagreed with the alarmist position, the outlier could be characterized as that handful of deranged crackpots who inevitably get included in even the best of survey designs. Easily dismissed. Mere statistical noise. If, however, the number of sceptical scientists is around 30% (and I suspect the number is much higher, but the figure will suffice for this hypothetical), then these scientists outside the lager could not be so easily demonised and cancelled, and their arguments would have to be taken more seriously.

Last Word

But don’t take my word for it. I have provided the references and links, read the papers for yourself. Make your own judgement.



[1]  A full list of scientists skeptical of the current Catastrophic Anthropogenic Global Warming meme would run to tens of thousands. Here is a very small subset of them chosen for their outstanding qualifications and expertise in the various disciplines of Climate Change Science. In no particular order…

 John Christie, Professor of Atmospheric Science and Director of Earth Systems Science at the University of Alabama, Huntsville; Richard Lindtzen, former Alfred P Sloan Professor of Meteorology at Massachusetts Institute of Technology; Willi Soon, Researcher at the Solar and Stellar Physics Division at the Harvard-Smithsonian Centre for Astrophysics; Sallie Baulinas, former Researcher  at the Harvard-Smithsonian Centre for Astrophysics; William Happer, Cyrus Fogg Brackett Professor of Physics, Princeton University; the late Freeman Dyson, Professor Emeritus Physics at Princeton University; Intergovernmental Panel on Climate Change (IPCC), TAR, 2001: “The climate system is a coupled non-linear chaotic system therefore the long-term prediction of future climate states is not possible”; William M Briggs, atmospheric physicist and statistician, Adjunct Professor at Cornell University; Judith Curry, atmospheric physicist, former Chair of the School of Earth and Atmospheric Sciences at Georgia Institute of Technology; Ian Plimer, Professor Emeritus of Earth Sciences at the University of Melbourne; the late Professor Robert M Carter, marine sedimentologist, former Head of Earth Sciences at James Cook University (harassed into early retirement); Peter Ridd, former Professor of Marine Geophysics at James Cook University (sacked for his scientific opinions); Nir Shaviv,  Professor of Physics at the University of Jerusalem; Professor Habibullo Abdussamatov, physicist,  Head of space research, Pulkovo Observatory, St Petersburg; William Nordhaus, Economist and Nobel Laureate (2018); Professor Leif Svaalbard, astro-phyicist, Universities of Stanford and Copenhagen; Kary Mullis, Nobel Laureate in Chemistry (1993); Robert Lauchlin, Professor of Applied Physics, Stanford University, Nobel Laureate (1998); Richard Tol, Professor of the Economics of Climate Change at Vriej Universiteit, Amsterdam and Lead Author for IPCC 5TH Assessment Report; Ryan Maue, Chief Scientist at NASA’s National Oceanic and Atmospheric Administration; Professor Nicola Scafetta, physicist, Department of Earth Sciences, Environment & Resources, University of Naples, Federico II; Pat Michaels, Research Professor of Environmental Sciences at University of Virginia; Steve Koonin, physicist, former Chief  of Department Energy under Barrack Obama; Ross McKittrick, Professor of Economics at the University of Guelph, Canada; Garth Paltridge, atmospheric physicist and former Chief Research Scientist at Australia’s CSIRO. Professor Roy Spencer, meteorologist, former Senior Scientist for Climate Studies at NASA’s Marshal Space Flight Centre, winner (along with John Christie) of NASA’s Exceptional Scientific Achievement Award, currently Principal Research Scientist at University of Alabama (Huntsville). 

[2] I am surprised the number was so low, but I guess that Economic Geologists can spot a push-poll when they see one and responded appropriately. That is, where they responded at all, and not a part of the 69% who consigned the on-line survey to trash.

[3] The assessors were hardly neutral. They were recruited from readers of John Cook’s website ( – a site devoted to promoting climate alarmism and notable for a near-total lack of scepticism on CC orthodoxy.

(4) In 2012, while instructing his volunteer assessors, John Cook revealed his strategy. In a private email to one of them, released through an anonymous hack of his website, he wrote : “Okay, so we have ruled out a definition of AGW being “any amount of human influence”. We’re basically going with Ari’s porno approach (I probably should stop calling it that) which is AGW = “humans are causing global warming” eg – no specific quantification which is the only way we can do it considering the breadth of the papers we’re surveying.” (Ari Jokimaki was one of Cook’s assessors).

[5] The extra 0.1% was a nice touch, creating an air of scientific and quantitative rigour.


Oreskes, N, 2004: Beyond the ivory tower: the scientific consensus on climate change. Science 306  (5702), p1686. Doi.10.1126/science.1103618

Doran, P & Zimmerman, M.K, 2009: Examining the scientific consensus on climate change. Eos, Transactions of the American Geophysical Union, 90(3) p22-23.

Cook, J and co-authors, 2013: Quantifying the consensus on anthropogenic global warming. Environmental Research Letters. 8(7pp)


Legates, D and co-authors, 2015: Climate consensus and misinformation -a rejoinder. Science and Education

Plimer, I, 2019: Ninety seven percent of scientists agree on nothing. Op-ed in The Australian 17 January, 2019

Tol, R, 2016: Comment on quantifying the consensus. Environmental Research Letters



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