Scientists Disagree On Link Between Storms, Warming

Studies supporting a link between global warming and storm intensity keep coming. The latest will be published this week by Florida State University geography professor James B. Elsner in the journal Geophysical Research Letters. Elsner found that average air temperatures during hurricane season predict the Atlantic Ocean's surface temperatures, not vice versa, which he said means it is "much more likely the atmosphere is warming the ocean" and helping create more severe storms.

And Judith A. Curry, of Georgia Tech's School of Earth and Atmospheric Sciences, who co-authored a paper last year suggesting that rising sea temperatures have been accompanied by more intense hurricanes, has challenged Landsea's critique. She said Landsea and like-minded researchers have not "done the hard work" to reanalyze the entire historic hurricane database to determine whether it really is skewed. She does not go as far as Elsner, however, saying his paper identifies "an interesting statistical relationship" but does not physically explain how warmer air might be heating the Atlantic.

Curry's work, in turn, has been challenged by Phil Klotzbach, a research associate at Colorado State University, who published a paper in May suggesting that, since 1986, there has been no global trend in hurricane intensity. Klotzbach's paper, in Geophysical Research Letters, looked at a 20-year period rather than the 35-year period Curry and others examined, which explains how he reached different conclusions.

"At this point, we haven't seen any significant correlation" between hurricanes and climate change, he said.

MIT professor Kerry Emmanuel -- who helped spark the debate with a paper in the journal Nature a year ago suggesting that warmer sea surface temperatures had spawned more destructive storms -- has made an effort to correct for measurement biases in his studies.

He is still criticized by researchers such as Landsea, but Emmanuel responded in an interview that the bias in the underlying data "isn't very large." He added that he and other researchers in Europe have found such a strong link between warming sea surface temperatures and more intense hurricanes that, "You literally have to argue that the correlation is an accident. That to me is improbable."

Curry noted that the hurricane question has focused Americans on global warming far more than other climate-related developments, such as melting glaciers in Greenland. "Katrina was sort of the 9/11 of global warming," she said in an interview. "It was a lot more real and immediate. It had more of a real socioeconomic impact in the way the melting of glaciers doesn't."

Many environmental groups have seized on the public's concern, arguing that 2005's brutal hurricane season highlights the dangers of global warming. The advocacy group Environmental Defense has a new Web site devoted to "Hurricanes and Climate Change," including "11 Facts That Will Blow You Away."

Meanwhile, William Hooke, who directs the American Meteorological Society's policy program, said that whatever the answer turns out to be, "We ought not to lose sight of the fact that we're doing a poor job of protecting ourselves against the hurricanes we have now."