Maybe Clark or one of the other mets could address this....

On Morning Edition today, there was a piece on global warming and hurricanes where the experts appearing stated that the variations due to the multi-decadal signal were more significant than global warming. They also stated that large scale hurricane environment depends on contrast between ocean temps and upper atmosphere temps and that it wasn't clear that global warming affected the temperature contrast. They did hypothesize that if global warming triggered enough polar ice cap melt to shut down the Gulf Stream that tropical ocean temps would increase enough to have an impact on hurricanes, but that was a possible future condition, not a present condition. The gist, as I understood it, was that there is not evidence to attribute the heightened activity to global warming. And I say this as someone who believes that global warming is a genuine problem and would like to see restrictions on carbon emissions.