- The Bogus 97% “Consensus” Argument on Climate Change
by One of the popular rhetorical moves in the climate change debate is for advocates of aggressive government intervention to claim that “97% of scientists” agree with their position, and so therefore any critics must be unscientific “deniers.”
Now these claims have been dubious from the start; people like David Friedman have demonstrated that the “97% consensus” assertion became a talking point only through a biased procedure that mischaracterized how journal articles were rated, and thereby inflating the estimate.
But beyond that, a review in The New Republic of a book critical of mainstream economics uses the exact same degree of consensus in order to cast aspersions on the science of economics. In other words, when it comes to the nearly unanimous rejection of rent control or tariffs among professional economists, at least some progressive leftists conclude that there must be group-think involved. The one consistent thread in both cases—that of the climate scientists and that of the economists—is that The New Republic takes the side that will expand the scope of government power, a central tenet since its birth by Herbert Croly a century ago.
The Dubious “97% Consensus” Claim Regarding Climate Science
Back in 2014, David Friedman worked through the original paper that kicked off the “97% consensus” talking point. What the original authors, Cook et al., actually found in their 2013 paper was that 97.1% of the relevant articles agreed that humans contribute to global warming. But notice that that is not at all the same thing as saying that humans are the main contributors to observed global warming (since the Industrial Revolution).
This is a huge distinction. For example, I co-authored a Cato study with climate scientists Pat Michaels and Chip Knappenberger, in which we strongly opposed a U.S. carbon tax. Yet both Michaels and Knappenberger would be climate scientists who were part of the “97% consensus” according to Cook et al. That is, Michaels and Knappenberger both agree that, other things equal, human activity that emits carbon dioxide will make the world warmer than it otherwise would be. That observation by itself does not mean there is a crisis nor does it justify a large carbon tax.