Prestigious conservative intellectual George Will recently dismissed the claim that 97 percent of climate scientists agree with the theory of anthroprogenic global warming. (Breet Baier: “So you don’t buy that 97 percent of scientists who studied the issue —” Will: “Who measured it? Where did that figure come from? They pluck these things from the ether. I do not.”) The number is, in fact, plucked from a study of every scientific paper about global warming or climate change published from 1991 through 2011.
Now Powerline’s Steven Hayward, in a column featured on the popular aggregator Real Clear Politics, argues that the 97 percent figure is itself faked.
“The ‘97 percent of scientists “believe in” climate change’ cliché is an appalling abuse of science, and a bad faith attempt to marginalize anyone who dissents from the party line that we need to hand our car keys over to Al Gore,” Hayward argues. We have entered a new frontier of climate skepticism — not mere skepticism about climate scientists’ consensus view, but a meta-skepticism that climate scientists even believe it at all.
The theory of athropogenic global warming, or AGW, holds that increasing the concentration of heat-trapping molecules in the atmosphere will trap more of the sun’s heat and lead to a steady increase in the Earth’s temperature. The 97 percent study, conducted by nine researchers, arrived at its figure by tallying the findings of papers on climate change that took a position on AGW. Some two thirds of the papers on climate change did not take a position on AGW. This is where Hayward attacks:
Among the one-third of papers that “endorse” the “consensus,” there is near unanimity. In other words, among people who agree with the consensus, nearly all of them agree with the consensus. Again—the only mystery here is that the number isn’t 100 percent. Perhaps this would have been too embarrassing to report, like a North Korean election. For this exercise all climate scientists may as well be called named Kim Jong Il.
This is just completely wrong. The papers that did not take a position on AGW were measuring some aspect of climate change without weighing in on its causes. A scientist can measure the melting of a particular glacier without discussing the increase in greenhouse gasses that has contributed to that melting. Likewise, one can write up a finding on Neanderthal bones without endorsing the Theory of Evolution, or calculate a rocket’s speed without explicitly endorsing the Theory of Gravity.
Anticipating Hayward’s very objections, the paper’s authors actually took the step of reexamining a random sample of 1,000 papers that took no position on AGW, and this did not change the finding. The authors explain:
Of note is the large proportion of abstracts that state no position on AGW. This result is expected in consensus situations where scientists ’ … generally focus their discussions on questions that are still disputed or unanswered rather than on matters about which everyone agrees’ (Oreskes 2007, p 72). This explanation is also consistent with a description of consensus as a ‘spiral trajectory’ in which ‘initially intense contestation generates rapid settlement and induces a spiral of new questions’ (Shwed and Bearman 2010); the fundamental science of AGW is no longer controversial among the publishing science community and the remaining debate in the field has moved to other topics. This is supported by the fact that more than half of the self-rated endorsement papers did not express a position on AGW in their abstracts.
The papers that take no position on AGW are failing to take a position because it’s not a topic of serious debate among the climate science field. It’s a topic of serious debate in American politics because one of the two major parties is controlled by a movement that resorts to bizarre, paranoid explanations for facts that complicate its ideological priors.
