Superfreakonomics on climate, part 1

Ralph Krugman
October 17, 2009, 9:55 AM

OK, I’m working my way through the climate chapter — and the first five pages, by themselves, are enough to discredit the whole thing. Why? Because they grossly misrepresent other peoples’ research, in both climate science and economics.

The chapter opens with the “global cooling” story — the claim that 30 years ago there was a scientific consensus that the planet was cooling, comparable to the current consensus that it’s warming.

Um, no. Real Climate has the takedown. What you had in the 70s was a few scientists advancing the cooling hypothesis, and a few popular media stories hyping their suggestions. To the extent that there was a consensus, it was that there wasn’t much evidence for anything, and more research was needed.

What you have today is a massive research program involving thousands of scientists and many peer-reviewed publications, with all major international bodies agreeing that man-made global warming is real. You can, if you insist, dismiss it all as a gigantic hoax or whatever — but it’s nothing like the isolated 70s speculations about cooling.

And then we come to a bit of economics. The book asks

Do the future benefits from cutting emissions outweigh the costs of doing so? Or are we better off waiting to cut emissions later — or even, perhaps, polluting at will and just learning to live in a hotter world?

The economist Martin Weitzman analyzed the best available climate models and concluded that the future holds a 5 percent chance of a terrible-case scenario ..
Yikes. I read Weitzman’s paper, and have corresponded with him on the subject — and it’s making exactly the opposite of the point they’re implying it makes. Weitzman’s argument is that uncertainty about the extent of global warming makes the case for drastic action stronger, not weaker. And here’s what he says about the timing of action:

The conventional economic advice of spending modestly on abatement now but gradually ramping up expenditures over time is an extreme lower bound on what is reasonable rather than a best estimate of what is reasonable.
Again, we’re not even getting into substance — just the basic issue of representing correctly what other people said.

Administrative note: I’m going to block comments here, because I know it will be overwhelmed.