Here's another reference (from National Geographic) that probably says
about the same thing:

". . .a new study in the journal Nature found that hurricanes and
typhoons have become stronger and longer-lasting over the past 30
years. These upswings correlate with a rise in sea surface
temperatures.

The duration and strength of hurricanes have increased by about 50
percent over the last three decades, according to study author Kerry
Emanuel, a professor of atmospheric science at the Massachusetts
Institute of Technology in Cambridge."

http://news.nationalgeographic.com/n...0804_hurricane...