From this article in the South Florida Sun-Sentinel.
“Whether we’re talking about a change in the number of storms or an increase in the most intense storms, the changes that are likely to come from global warming are not likely to be detectable until 50 years from now,” said Brian Soden, professor of atmospheric sciences at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science.
“There’s so much natural variability in the system, the typical year-to-year variability in hurricane activity, that the signal really doesn’t emerge from that background variability until the latter half of this century.”
“We used to think 20 years ago that in a warmer climate there would be more hurricanes,” Columbia’ Sobel said. “Then the computer models got better. Most of those started to show fewer hurricanes, not more. No one knew why. Then some of the models started to show increases with warming. So I think we’re back to where we don’t know.”