Economist David Friedman has an excellent posting on the politics of global warming. (You can also read this in today's Financial Post.)
After reviewing the science behind the issue, Friedman concludes that "global warming is probably real, is probably but not certainly anthropogenic, is probably not going to have large effects on size and frequency of hurricanes and is probably not going to have large effects on sea level. It is a real problem but not, on current evidence, an impending catastrophe."
So why all the doom and gloom pronouncements from people like Al Gore.
Because, says Friedman, "Environmentalism in general and global warming in particular provide new arguments for expanded government power, new taxes, and the like. That does not mean, of course, that those arguments are wrong, but it does mean that there are a lot of people who have an incentive to support them whether wrong or right."
In other words, he says "Global warming provides arguments for things that a lot of people, mostly left of center, want to do anyway—shift lifestyles away from automobiles towards mass transit, reduce consumption of depletable resources, and the like. Environmentalism is in part a real argument, in part a religion, in part an aesthetic; the second and third parts make people too willing to accept the first."