Why aren't climate scientists winning the argument on climate policy? It sure isn't for lack of effort.
The Intergovernmental Panel on Climate Change just published another vast pile of material, this time focused on "impacts, adaptation and vulnerability." The IPCC says that the new report's "30 chapters, supported by a number of annexes and supplementary material" were produced by a "total of 243 coordinating and lead authors and 66 review editors from 70 countries and 436 contributing authors from 54 countries." And that refers to just one of three working groups engaged in producing the IPCC's fifth assessment report.
Yet this staggering outlay of time and trouble has failed to move public opinion and public policy very far. Climate-change activists are exasperated beyond endurance by the gullibility of the people, the willful stupidity of climate-change "deniers," the cynicism of energy producers and other corporate interests, and the dithering incapacity of our democratic institutions.
Doubtless there's some truth in those complaints, but I'd give more weight to another theory. The main reason for the disconnect between the science and the public is the gross tactical incompetence of the climate-science community, as it's called, and its political champions.
Consider this latest installment of the IPCC's survey of the science. It's more carefully hedged than its predecessors - and rightly so. There are fewer specific claims about the future that the science can't fully support or that might turn out to be simply wrong. The emphasis is more on prudent actions to avoid risks, and less on precise predictions about what's coming if those actions aren't taken. That's the approach that the unsettled science of climate change dictates.
Yet look at how Secretary of State John Kerry, for instance, responded to the new publication: "Read this report and you can't deny the reality. Unless we act dramatically and quickly, science tells us our climate and our way of life are literally in jeopardy. Denial of the science is malpractice. ... The costs of inaction are catastrophic."
The new report doesn't say any of that. The science doesn't predict a catastrophe that would threaten the American way of life. The most cost-effective responses to the risks of climate change are measured and gradual, not dramatic and quick. And denying the wisdom of Kerry's call for action isn't "denial of the science" - because the science by itself can't say how much to spend on mitigation of, or adaptation to, climate change. That's a political question.
I take seriously the harms that man-made climate change might cause. Action does make sense: It's a question of insuring against risk. I'm for a gradually escalating carbon tax and for ample public support for other mitigation and adaptation efforts - including more nuclear power and research and development on cheap alternative fuels. But this cause isn't advanced by exaggerating what is known in order to scare people into action, nor by denouncing everybody who disagrees with such proposals as evil or idiotic.
The scientists themselves - some of them, at least - are partly to blame. They chose to become political advocates, no doubt out of a sincere belief that policies needed to change a lot and at once. But scientist-advocates can't expect to be seen as objective or disinterested. Once they're suspected of spinning the science or opining on questions outside their area of expertise, as political advocacy is bound to require, they lose authority. And it doesn't help when scientists who express reservations are cast out of the mainstream. You expect "you're either with us or against us" from politicians, but not from scientists.
The rules for politicians are different. They're expected to spin. It goes with the job. Still, is it too much to ask that they spin to good effect? You don't persuade the uncommitted middle of the electorate to support more deliberate action on climate change by telling them that they're too stupid to be trusted with uncertainty and that if they refuse to go along with fast dramatic action (details to follow) they're science deniers and willful destroyers of the planet.
Maybe that strategy was worth a try in the 1990s. It's had a good run, and the results speak for themselves.
Clive Crook is a Bloomberg Views columnist.