Saturday, March 29, 2008

As sea water rises, the toll to Florida is logged

St. Petersburg Times (Florida): Global warming is boosting the sea level along Florida's gulf coast and already causing profound environmental changes, scientists say….

"People have a hard time accepting that this is happening here," said University of Florida professor Jack Putz, who has led a Levy County research effort since 1992. Seeing the dying palms, he said, "brings a global problem right into our own backyard."

What is happening is not just a minor botanical alteration in a few isolated places. The scientists studying the phenomenon see it as a harbinger for major changes in the state's geography — submerging islands and turning swamps into open bays. Those changes alone can create a serious economic impact on businesses such as fishing.

The rising sea generally has crept up so slowly that it has been barely noticeable. In the Tampa Bay area, for instance, "we've actually seen an increase of about an inch a decade" since measurements began in the 1940s, said Holly Greening, executive director of the Tampa Bay Estuary Program. Now, the rate at which the sea level is rising appears to be picking up speed.

It's often difficult to detect along urban coastlines because seawalls and renourished beaches can obscure or blunt the impact, said Mike Savarese, a Florida Gulf Coast University marine science professor. But the changes wrought by higher seas are more obvious in wilderness areas such as state and national parks. In those natural areas, "we're seeing some real indications of a change out there," Savarese said.

….Florida is a good place to study the rising sea level because its a coastal state where seas have risen and fallen for tens of thousands of years. That enables scientists to see what happened in the past and compare it to what's occurring now.

...How long will it take before sea level rise begins to cause major changes? If you ask Harold Wanless, chairman of the University of Miami's geological sciences department who studies how the coastlines of South Florida have evolved over the past 4,000 years, he will give you one answer.

Wanless believes the rate will continue increasing until it surpasses 3 feet by the end of this century, and could even reach 5 feet. That "basically takes all of our barrier islands and makes them close to unlivable," he said.

But Wanless' predictions surpass what scientists from the U.S. Geological Survey have found so far in their studies from around the nation's coastline.

…The scientific uncertainty has left public officials unsure how to deal with the problem. "I don't think that anybody's really pinned down numbers that make sense yet," said Ed Chesney, Clearwater's environmental manager. "You're talking eight inches or eight feet . . . The jury's still out on that timetable.''...

NASA image of Florida, Wikimedia Commons

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