Apparently, in their haste to produce an even more controversial followup to the first book, the authors of Freakonomics get the facts colossally wrong (from the New Yorker):
Given their emphasis on cold, hard numbers, it’s noteworthy that Levitt and Dubner ignore what are, by now, whole libraries’ worth of data on global warming. Indeed, just about everything they have to say on the topic is, factually speaking, wrong. Among the many matters they misrepresent are: the significance of carbon emissions as a climate-forcing agent, the mechanics of climate modeling, the temperature record of the past decade, and the climate history of the past several hundred thousand years. Raymond T. Pierrehumbert is a climatologist who, like Levitt, teaches at the University of Chicago. In a particularly scathing critique, he composed an open letter to Levitt, which he posted on the blog RealClimate.
“The problem wasn’t necessarily that you talked to the wrong experts or talked to too few of them,” he observes. “The problem was that you failed to do the most elementary thinking.” Pierrehumbert carefully dissects one of the arguments that Levitt and Dubner seem to subscribe to—that solar cells, because they are dark, actually contribute to global warming—and shows it to be fallacious. “Really simple arithmetic, which you could not be bothered to do, would have been enough to tell you,” he writes, that this claim “is complete and utter nonsense.”