Katrina and global warming

One of the most irritating aspects of the Katrina disaster is the moralistic outrage that greets any attempt to point out that there may be a connection with global warming — a phenomenon about which the Bushites are in denial. How nice to see, then, a forthright New Yorker piece on the subject by Elizabeth Kolbert. Sample:

Though hurricanes are, in their details, extremely complicated, basically they all draw their energy from the same source: the warm surface waters of the ocean. This is why they form only in the tropics, and during the season when sea surface temperatures are highest. It follows that if sea surface temperatures increase — as they have been doing — then the amount of energy available to hurricanes will grow. In general, climate scientists predict that climbing CO2 levels will lead to an increase in the intensity of hurricanes, though not in hurricane frequency. (This increase will be superimposed on any natural cycles of hurricane activity.) Meanwhile, as sea levels rise—water expands as it warms — storm surges, like the one that breached the levees in New Orleans, will inevitably become more dangerous. In a paper published in Nature just a few weeks before Katrina struck, a researcher at the Massachusetts Institute of Technology reported that wind-speed measurements made by planes flying through tropical storms showed that the “potential destructiveness” of such storms had “increased markedly” since the nineteen-seventies, right in line with rising sea surface temperatures.