MITCHELL: Do 97% of the world’s scientists believe that man has caused global warming?

French President Emmanuel Macron, right, prepares to deliver a speech at the end of the One Planet Summit, at the Elysee Palace, in Paris, Monday Jan. 11, 2021. A coalition of at least 50 countries have committed to protect 30% of the planet, including land and sea, over the decade in efforts to halt species extinction and address climate change issues, during a global summit aimed at protecting the world's biodiversity. (Ludovic Marin, Pool Photo via AP)

In a previous article, I had related the story of having been put on the spot during a dinner party — challenged, actually — to deny that man-made global warming presents an existential threat to human existence. My dinner partner delivered what he believed to be the coup-de-grace by asking me how I could possibly disagree with the world’s brightest scientific minds, then stating the oft-repeated claim that “97% of the world’s scientists believe that man has caused global warming.” As I sat mute, he glanced around the table with knowing self-satisfaction.

In any conversation on the subject of anthropogenic global warming (man-made global warming, or “AGW”), proponents of the AGW hypothesis cite this supposed “97% consensus” as fact. When questioned, however, few are able to explain how this “fact” was determined. The story behind the origin of this statement demonstrates how readily people accept as fact something they either want to believe is true or feel they don’t have the background to question.

So, how was this 97% “consensus” actually determined? Shockingly, its unscientific origins are found in a 2013 article put forward by a former Australian cartoonist and web developer who subsequently obtained a PhD in the “cognitive science of climate denial.” 

I did not know such a degree existed.

The lead author, John Cook, posted the article on his website, — a website dedicated to promoting the hypothesis of man-made global warming. For those who’d like to read Cook’s article, it can still be found on the website: “Quantifying the consensus on anthropogenic global warming in the scientific literature,” John Cook et al 2013 Environ. Res. Lett. 8 024024.

Cook’s article documented his survey of some 11,944 climate abstracts from 1991 to 2011 matching the topics “global climate change” or “global warming.” This survey was conducted in an effort to determine — presumptively — the evolution of the “consensus” on man-made global warming.  

What this survey found was that 66.4% of the 11,944 abstracts in fact expressed no position whatsoever on man-made global warming. Of the remaining 33.6% that did express a position on global warming, Cook found that 97.1% of these endorsed the hypothesis that global warming is the result of human activity.

When I first read the Abstract of Cook’s article, I thought that I had misread his conclusions — they made no sense. Clearly, the survey results showed that the great majority of the 11,944 research papers on topics involving “global climate change” or “global warming” — fully 66.4% of these papers — expressed “no position” on the question of whether global warming could be the result of human activity. If this was “settled science,” how could so many scientist-authors fail to take a position one way or another on arguably the most important and urgent question in the history of climate science?

In calculating this supposed 97% scientific consensus on the “fact” of man-made global warming, Cook disregarded the 66.4% of the research papers he surveyed that expressed “no position” on that question. If these papers are properly taken into account, the percentage of scientist-authors who support the hypothesis of man-made global warming (based upon Cook’s survey) is actually 32.6% — hardly a “consensus”!

Since it appears that the Cook article was not subject to prior scientific peer review, and the authors had an obvious bias, I understand that they would try to skew the results. However, the level of intellectual dishonesty in the calculations is breathtaking. How is it that intelligent people can be fooled by such chicanery?

On May 16, 2013, one day after the Cook publication, President Obama tweeted: “Ninety-seven percent of scientists agree: #climate change is real, man-made and dangerous.” President Obama thus added a conclusion that even Cook did not reach. 

It is often said that a lie repeated often enough creates an illusion of truth.  With Obama’s presidential endorsement, Cook’s statement has been cited ever since as an established “fact”, used to mislead unquestioning people about man-made global warming, and to shame those who do dare to question the hypothesis.

In our next article, I will examine what the world’s scientists actually do believe about the hypothesis of man-made global warming.

This article is the second in a planned series by Guy K. Mitchell, Jr. Mr. Mitchell is the founder and chairman of Mitchell Industries, a diversified manufacturing company based in Birmingham, Alabama.