By Chris Landsea: New Hurricane Science
Today a new paper by Gabe Vecchi and Brian Soden has been published:
Vecchi G. A., B. J. Soden (2007), Increased tropical Atlantic wind shear in model projections of global warming, Geophys. Res. Lett., 34, L08702, doi:10.1029/2006GL028905. (PDF)
My reading of the paper by Vecchi and Soden is that this is a very important contribution to the understanding of how global warming is affecting hurricane activity. The study thoroughly examines how the wind shear and other parameters that can alter the number and intensity of hurricanes because of manmade global warming. What they found - surprisingly - is that in the Atlantic that the wind shear should increase significantly over a large portion of where hurricanes occur - making it more difficult for hurricanes to form and grow. This was identified in all of the 18 global climate models they examined. (Perhaps it's not that surprising given that Knutson/Tuleya 2004 showed some of the same signal for the more reliable models back then. Now the signal is in ALL of the CGCMs.) Even the MPI changes in the Atlantic appear mixed, due to the smaller SST increases there (with more uniform upper trop temp changes) compared with the rest of the global tropics/subtropics.
One implication to me is that this further provides evidence that the busy period we've seen in the Atlantic hurricanes since 1995 is due to natural cycles, rather than manmade causes. We've seen a big reduction in wind shear in the last thirteen hurricane seasons, which is OPPOSITE to the signal that Vecchi and Soden have linked to manmade global warming changes. Another implication is that this paper reconfirms earlier work that suggests that global warming will cause very small changes to Atlantic hurricanes, even several decades from now.[emphasis added]
Note that the predicted result of global warming should be fewer hurricanes, not more of them. It also looks like we would expect, on average, less intense hurricanes as well. The extremely active hurricanes seasons we have been experiencing in the Atlantic basin actually argue against their being any noticeable effect on tropical storms by warming.
In one sense none of this is new, but this signal has now been identified in every single major hurricane model used today. It is safe to say that folks like Gore are using "catastrophe scenarios" that contradict the state of the science today.
Oh consensus, we hardly knew ye!
Gore is a charlatan.
Let's see how folks are reacting to this study.
Kerry Emanuel, a hurricane expert at the Massachusetts Institute of Technology [whose previous work is directly contradicted by these findings-ed.] , said he thinks storms' sensitivity to wind shear may be overestimated.
Emanuel, who was not involved in this research, said he published a study last year that calculated that increasing the potential intensity of a storm via warming by 10% increases hurricane power by 65%, whereas increasing shear by 10% decreases hurricane power by only 12%. [As ALL hurricane models are accounted for in this new study, one can only assume that either A) Emanuel's work is shoddy, or B) Deliberately misleading. Based on what I've read of Emanuel's "work" I'm leaning towards "B" being more likely.]
On the other hand, Christopher W. Landsea of NOAA's National Hurricane Center, called Vecchi's study "a very important contribution to the understanding of how global warming is affecting hurricane activity."
Landsea, who was not part of the research, said he believes it "provides evidence that the busy period we've seen in the Atlantic hurricanes since 1995 is due to natural cycles, rather than manmade causes."
The research was funded by NOAA and NASA.
Actually, the complete discounting of this new study by Emanuel without even a HINT that he should investigate the matter more fully, simply confirms the lack of scientific principle at play here. Emanuel has spoken the "gospel" and he doesn't want to hear from the "unbelievers."