I've failed to recently because I've been working on a longer post that requires a lot of thought and interpretation. In the meantime I thought I'd let you know about a Houston Chronicle story about a scientist moderating his opinion about the connection between climate change and hurricane strength (h/t NY Times).
The hurricane expert, Kerry Emanuel of the Massachusetts Institute of Technology, unveiled a novel technique for predicting future hurricane activity this week. The new work suggests that, even in a dramatically warming world, hurricane frequency and intensity may not substantially rise during the next two centuries.
In the new paper, Emanuel and his co-authors project activity nearly two centuries hence, finding an overall drop in the number of hurricanes around the world, while the intensity of storms in some regions does rise.
For example, with Atlantic hurricanes, two of the seven model simulations Emanuel ran suggested that the overall intensity of storms would decline. Five models suggested a modest increase.
"The take-home message is that we've got a lot of work to do," Emanuel said. "There's still a lot of uncertainty in this problem. The bulk of the evidence is that hurricane power will go up, but in some places it will go down."
Honestly, the significance of Emmanuel's change of opinion and of his initial opinion seems mostly because his original paper trumpeting the connection happened to come out a few weeks before Hurricane Katrina. As a result all sorts of people including Al Gore jumped on it as evidence of the deleterious impact of human beings on our planet.
Anyway, computer simulations of climate change give no single result speaks to the their speculative nature. As we all already know about computers, they're no better than the human ignorance (or arrogance) you feed into them.
Eric Berger, "Hurricane expert reconsiders global warming's impact," Houston Chronicle (April 12, 2008).
Kerry Emanuel, Ragoth Sundararajan, and John Williams, "Hurricanes and Global Warming: Results from Downscaling IPCC AR4 Simulations," Bulletin of the American Meteorological Society 89:3 (March 2008), pp. 347–367. (abstract)