Just in Time for Hurricane Season

Two new studies on the hurricane-global warming relationship are just out, reported on here by the New York Times. I haven't seen the Purdue study yet. The other study, by Michael Mann and Kerry Emanuel, has already been discussed at scientific conferences and even reported on by some journalists. Mann and Emanuel suggest that contrary to previous claims about a natural "cycle" in Atlantic hurricane activity, it may be that the mid-century downturn in storms was partly the result of human-caused "global cooling" due to sulfate areosol pollution. The implication is that now that the Clean Air Act amendments have passed and aerosols are down again, carbon dioxide has become the dominant climate forcing factor, leading to global warming and, in turn, more hurricane activity. If this is correct, of course, it also means that there is no necessary endpoint in sight, no "natural cycle" that will bring about a downturn eventually--a potentially very scary conclusion. Anyway, it will be interesting to see what the scientific reaction is to this work. Meanwhile, over at Prometheus, Roger Pielke, Jr., fairly points out that there are other peer reviewed studies that have come out that provide a different take on the hurricane-GW issue, but that these studies have not been covered by the Times and aren't even mentioned in the current piece. I certainly think that the Times reporter, in providing a counterpoint (which he does anyway), could at least have mentioned this work.