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What rising sea levels could mean for coastal areas

Researchers have created simulations of what could happen to coastal regions as sea levels rise because of global warming. Images: If sea levels climb a meter

If sea levels rise a meter, the streets of Miami could end up underwater while New Orleans could become part of the Gulf of Mexico. But those aren't the only areas that will be in trouble, if two researchers from the University of Arizona are correct.

Jonathan Overpeck, director of the Environmental Studies Laboratory in the department of geosciences, and senior research specialist Jeremy Weiss have mapped simulations of what could occur to coastal communities worldwide as sea levels begin to rise because of global warming. The simulations show what coastal regions look like now and what could happen if sea levels climb by 1 meter. The researchers also created prognostications for less likely scenarios, rises of 2 to 6 meters.

"Using digital elevation models (DEMs) available through the United States Geological Survey, we calculated coastal areas susceptible to sea level rise based solely on elevation and adjacency to the sea for regions around the globe," the two wrote on their Web site.

Some degree of sea level rise is inevitable over the coming decades. Last week, the Intergovernmental Panel on Climate Change issued a report stating that sea levels could rise from 7 to 23 inches by 2100 because of rising temperatures. A 23-inch rise would be about 0.6 meters, or nearly 2 feet. That's enough to cause trouble in low-lying places like New Orleans and Bangladesh, but most coastal borders worldwide would have far less trouble.

"By 2100, it is probable safe to say that three meters is an upper-end estimate. Two feet is more likely," said Overpeck in an e-mail.

Other scientists, however, have predicted that sea levels could rise 10 feet or more by 2100 because of accelerated melting of the polar ice caps.

In the simulations, red and pink mark areas susceptible to flooding. At three meters, much of the Netherlands is reclaimed by the sea while Trieste, Italy, looks swampy. Irian Jaya, the half of New Guinea controlled by Indonesia, loses large hunks of real estate.

Throughout all of the simulations, however, Australia remains relatively untouched.