MIT/Penn State Study - Link Beween Warming, Hurricane Frequency - AFP

Human induced climate change, rather than naturally occurring ocean cycles, may be responsible for the recent increases in frequency and strength of North Atlantic hurricanes, according to Penn State and Massachusetts Institute of Technology researchers.
"Anthropogenic factors are likely responsible for long-term trends in tropical Atlantic warmth and tropical cyclone activity," the researchers report in an upcoming issue of the American Geophysical Society's EOS.

Michael E. Mann, associate professor of meteorology and geosciences, Penn State, and Kerry A. Emanuel, professor of atmospheric sciences, MIT, looked at the record of global sea surface temperatures, hurricane frequency, aerosol impacts and the so-called Atlantic Multidecadal Oscillation (AMO) Ð an ocean cycle similar, but weaker and less frequent than the El Nino/La Nina cycle.

Although others have suggested that the AMO, a cycle of from 50 to 70 years, is the significant contributing factor to the increase in number and strength of hurricanes, their statistical analysis and modeling indicate that it is only the tropical Atlantic sea surface temperature that is responsible, tempered by the cooling effects of some lower atmospheric pollutants.

"We only have a good record of hurricanes and sea surface temperature for a little more than the last 100 years," says Mann, who is also director of Penn State's Earth System Science Center. "This means we have only observed about one and a half to two cycles of the AMO. Peer-reviewed research does suggest that the signal exists, but it is difficult to estimate the period and magnitude of the oscillation directly from observations."

EDIT

http://www.terradaily.com/reports/Climate_Change_Responsible_For_Increased_Hurricanes.html

That's too bad.