Study has new take on jump in storms

Ever since Hurricane Katrina in 2005, hurricanes have often been seen as a symbol of global warming's wrath. Many climate change specialists have tied the rise of hurricanes in recent years to global warming and hotter waters that fuel them.

Another group of specialists, those who study hurricanes and who are more often skeptical about global warming, say there is no link. They attribute the recent increase to a natural, multidecade cycle.

What makes this study different is Knutson, a meteorologist with the National Oceanic and Atmospheric Administration's fluid dynamics lab in Princeton, N.J.

He has warned about the harmful effects of climate change and has even complained in the past about being censored by the Bush administration on past studies on the dangers of global warming.

He said his new study, based on a computer model, argues "against the notion that we've already seen a really dramatic increase in Atlantic hurricane activity resulting from greenhouse warming."

The study, published online yesterday in the journal Nature Geoscience, predicts that by the end of the century, the number of hurricanes in the Atlantic will fall by 18 percent.

The number of hurricanes making landfall in the United States and its neighbors - anywhere west of Puerto Rico - will drop by 30 percent because of wind factors.

The biggest storms - those with winds of more than 110 miles per hour - would decrease in frequency by 8 percent. Tropical storms, those with winds between 39 and 73 miles per hour, would decrease by 27 percent.

It's not all good news from Knutson's study, however. His computer model also forecasts that hurricanes and tropical storms will be wetter and fiercer. Rainfall within 30 miles of a hurricane should jump by 37 percent, and wind strength should increase by about 2 percent, Knutson's study says.

And Knutson said this study significantly underestimates the increase in wind strength. Some other scientists criticized his computer model.

MIT hurricane meteorologist Kerry Emanuel, while praising Knutson as a scientist, called his conclusion "demonstrably wrong" based on a computer model that doesn't look properly at storms.