Spin doctors: Scientists debate climate change hurricane link

Do greenhouse gases help fuel hurricanes, spawning growing legions of stronger storms?

Or is this notion strictly hot air?

Friday, two of the nation's leading climate scientists traded opposing opinions during a cordial debate on global warming and hurricanes. The dueling discussion highlighted the closing day of the Florida Governor's Hurricane Conference in Fort Lauderdale.

The participants were Kerry Emanuel, a Massachusetts Institute of Technology meteorology professor who links global warming with increased Atlantic hurricanes, and Chris Landsea, a National Hurricane Center researcher who disputes this connection.

Both scientists use the same historical climate statistics and computer models — but they interpret this data in markedly different fashion.

On one side: Emanuel argues that Atlantic hurricanes are increasing in frequency and power, probably as a result of global warming. One of Time's 100 Most Influential People of 2006, his theories gained public recognition in the wake of Al Gore's An Inconvenient Truth.

"There is evidence from several independent techniques that (hurricane) power dissipation has gone up the last 25 years. Very substantially so in the Atlantic — almost a factor of three in the past 25 years," he said.

However, on a global scale, Emanuel said no such upswing in number of hurricanes is apparent. He also said that computer projections yield "mixed results" on future effects of global warming on hurricane activity.

Landsea acknowledged that greenhouse gases may be the major reason that sea-surface temperatures — the engine that drives hurricanes — have warmed during the last few decades.

But he disputed the accuracy of the historical data Emanuel used to chart some of his projected trends. Calling hurricane-monitoring techniques "unreliable, primitive and crude" for much of the past century, Landsea said the NHC did not even issue advisories for all weak, short-lived storms as late as the early 1990s.

"It's a bit of a stretch to believe that we counted them all, and we got how strong they were, and how long they lasted," he said.

Emanuel said exact historical counts are not of critical importance.

"Why should we put a weak tropical storm that lasts for 12 hours in the same bin as a Katrina?" he asked.

The global-warming hurricane debate is "one of the most contentious issues in meteorology," said Al Sandrik, a National Weather Service meteorologist in Jacksonville.

Indeed, clashing studies among hurricane researchers are bouncing back and forth like a ping-pong ball, said Stanley Goldenberg, a Miami-based research NOAA meteorologist.

Speculation aside, Landsea said he worries about America's continued migration to hurricane-prone areas, particularly Florida.

"In the next 10 years, we're going to look back on this and say, 'Well, that was an interesting climate debate about hurricanes.' But what really is important is this massive population gain we've got — our horrible vulnerability on our coastal areas," Landsea said.

"And I hope we're not going to look back in 10 years and say, 'Oh my God, why didn't we prevent what happened in Tampa, or prevent what happened in New York?' That's my big concern.

Rick Neale reports for Florida Today in Melbourne.