Environmental Engineering Reference
In-Depth Information
One of the main papers behind the 97 percent claim is authored by John Cook, who runs the popular
Web site SkepticalScience.com, a virtual encyclopedia of arguments trying to defend predictions of cata-
strophic climate change from all challenges.
Here is Cook's summary of his paper: “Cook et al. (2013) found that over 97 percent [of papers he sur-
veyed] endorsed the view that the Earth is warming up and human emissions of greenhouse gases are the
main cause.”
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This is a fairly clear statement—97 percent of the papers surveyed endorsed the view that man-made
greenhouse gases were the main cause—
main
in common usage meaning more than 50 percent.
But even a quick scan of the paper reveals that this is not the case.
Cook is able to demonstrate only that a relative handful endorse “the view that the Earth is warming
up and human emissions of greenhouse gases are the main cause.” Cook calls this “explicit endorsement
with quantification” (quantification meaning 50 percent or more). The problem is, only a small percentage
of the papers fall into this category; Cook does not say what percentage, but when the study was publicly
challenged by economist David Friedman, one observer calculated that only
1.6 percent
explicitly stated
that man-made greenhouse gases caused at least 50 percent of global warming.
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Where did most of the 97 percent come from, then? Cook had created a category called “explicit en-
dorsement without quantification”—that is, papers in which the author, by Cook's admission, did not say
whether 1 percent or 50 percent or 100 percent of the warming was caused by man.
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He had also created a
category called “implicit endorsement,” for papers that imply (but don't say) that there is some man-made
global warming and don't quantify it.
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In other words, he created two categories that he labeled as endors-
ing a view that they most certainly didn't.
The 97percent claim isadeliberate misrepresentation designed tointimidate the public—and numerous
scientists whose papers were classified by Cook protested:
• “Cook survey included 10 of my 122 eligible papers. 5/10 were rated incorrectly. 4/5 were rated as
endorse rather than neutral.”
—Dr. Richard Tol
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• “That is not an accurate representation of my paper . . .”
—Dr. Craig Idso
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• “Nope . . . it is not an accurate representation.”
—Dr. Nir Shaviv
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• “Cook et al. (2013) is based on a strawman argument . . .”
—Dr. Nicola Scafetta
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Think about how many times you hear that 97 percent or some similar figure thrown around. It's based
on crude manipulation propagated by people whose ideological agenda it serves. It is a license to intimid-
ate.
CLIMATE ETHICS
