Not surprisingly, in the wake of Tropical Cyclone Larry Australians are beginning to chatter about possible links between global warming and hurricanes. And in at least one venue (The Age), the discussion has taken an interesting turn. Specifically, it appears that CSIRO, Australia's national scientific research organization, is expecting that the country will indeed have to deal with stronger cyclones due to global warming in the future. But here's the catch--based upon its own modeling studies, CSIRO is also expecting to see less storms in total. CSIRO's models aren't the only ones that come up this way. A modeling result out of Japan, which I highlighted a while back, found the following:
A comparison of the experiments suggests that the tropical cyclone frequency in the warm-climate experiment is globally reduced by about 30% (but increased in the North Atlantic) compared to the present day-climate experiment. Furthermore, the number of intense tropical cyclones increases.
This is of course just splendid if you're living in Florida. For most of the world (according to this study), global warming giveth stronger storms but it also taketh away in terms of the total number of storms. But for the Atlantic, it's projected to be a double whammy, giveth and giveth. To be sure, these are all modeling results, the Gospel according to supercomputer, so they must be taken with a grain of salt (as is true of any future projections). They're a little bit better than mere ungrounded speculation, but also considerably less solid than fact. Still, the results shouldn't be ignored. Indeed, based upon my initial reporting, I've found that there's at least a potential logic behind the notion that GW might cause stronger storms but also less frequent ones. If I can get it right, the thinking seems to run like this: Global warming is heating up the oceans, and from a heat transport perspective, one strong hurricane can expel considerably more heat up into the atmosphere than several weaker ones. So in terms of cooling the oceans and transporting heat away from the tropics, more strong storms and fewer total storms makes a kind of sense. Granted, the truth is that scientists really don't know enough to say one way or another what's going to happen with the issue of tropical cyclone frequency. It remains a big mystery. At this point, scientists don't even understand why it is that there are about 80 tropical cyclones globally per year, as opposed to 8, as opposed to 800. Once they come to terms with this problem, hopefully they'll also have a better sense of how global warming will affect the total number of storms in different ocean basins. In the meantime, we in the U.S. can only hope--hope--that that Japanese modeling result is wrong....
P.S.: Posted a comment to Real Climate to seek reaction to this post. Any comments will be noted here.