I have a piece up on Slate today on the scientific debate over global warming and hurricanes, in which I try to get down in the trenches a bit with the scientists studying the issue and see where our collective knowledge stands, where they agree and disagree.
A big question of the moment is, can you attribute Katrina, and other big storms of 2005 (and the ones we're likely to see over the next few years, this year's quietude notwithstanding) to global warming? If so, it's the best case of a direct and immediate impact on Americans from global climate change. A thousand-plus dead, hundreds of thousands homeless - that's serious.
Alas, the answers are not (yet, anyway) clear-cut. But they aren't especially comforting, either.
In a nutshell: There's been a drumbeat of studies over the past year that strongly suggest that the warming atmosphere is also heating up the oceans, and this in turn is pumping up the size of large hurricanes, both in the Atlantic and around the globe. These studies are like the pieces of a big, complex puzzle, still being assembled, and it looks rather scary.
But there's a loose-knit group of scientists that has devoted a lot of time to knocking down those studies, trying to disassemble the puzzle. They're meteorologists, used to short-term predictions, well-versed in statistics and history. They just don't see it, and they've been picking away at the sometimes-incomplete databases and sweeping assumptions their colleagues are using to try to demonstrate a link.
What everyone agrees on, though, is that we're in an era of big storms, and there's a lot more development - homes, businesses, entire cities - in the path of hurricanes than there was during the last big hurricane upswing that ended around 1969. Even the skeptics agree global warming should have some (more marginal) effect on the strength of storms. So, we're going to see more Katrinas. The only question is whether it'll be bad or really bad. Anyone think we're ready?
John McQuaid is the co-author of Path of Destruction: The Devastation of New Orleans and the Coming Age of Superstorms.