Global warming cause of intense hurricanes?

Robert Bazell Chief science and health correspondent • Profile • E-mail

NEW YORK - In recorded history, two storms as powerful as Hurricanes Rita and Katrina have never hit the United States in one season. A coincidence, perhaps, but scientists say ocean temperature could be big factor.

“If you think of a hurricane like a car,” explains NASA’s Dr. David Adamec, “there are a lot of parts that keep it going, but the sea surface temperature and the heat that is provided by the ocean, that is the gasoline that fuels it.”

In the Gulf of Mexico, there is a lot of fuel right now.

To measure sea temperature, researchers use buoys that transmit readings directly, as well as remote sensing satellites. Those readings have found record temperatures in the gulf and Atlantic Ocean this year.

“The sun was having an easy time reaching the sea surface and just warmed up the water,” says Adamec, “and just made it ripe for a lot of strong intense hurricanes this year.”

The big question is will the trend continue in future years?

Scientists say one season, even like this one, cannot indicate anything about climate change. But those same measurements show that in the past 50 years the oceans have gotten one degree warmer. That may not sound like much, but the experts say it is a lot of energy.

Indeed, recent studies show that, worldwide, the number of Category 4 and 5 hurricanes has doubled with that one degree change and that’s a source of worry.

Slide show   Warning signs Click to view images tied to global warming more photos

“At the moment we’ve only warmed up one,” says Dr. Stephen Schnieder, a climatologist at Stanford’s Institute for International Studies. “What happens when we warm up three or five degrees — which is projected in the next several decades to the end of the century?”

It’s global warming that many experts say results partly from humans releasing greenhouse gases — possibly creating even more violent storms in the future.

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