Sea Level Studies: US Coasts Even More Vulnerable Than Previously Thought

Article excerpt

South Florida, southern Louisiana, and the Carolinas top the list of states with the most land to lose if sea level rises 1 meter, according to a pair of new studies.

Cities and hamlets along America's popular coastlines are more vulnerable to rising sea levels than previously estimated, according to a pair of new studies.

The studies find up to 32 percent more coastal real estate vulnerable to a 1 meter rise in sea level, while the population exposed to rising water goes up by 87 percent.

The numbers vary markedly by region, with south Florida, southern Louisiana, and the Carolinas topping the list of states with the most land to lose. Populations would be most heavily affected in Florida, Louisiana, California, New York, and New Jersey, the studies find.

Since the 1880s, sea levels have risen an average of 8 inches as global warming has taken hold. During this century, levels are expected to rise by as much as 1 to 2 meters, depending on how much additional carbon dioxide humans pump into the atmosphere from burning fossil fuels and from land-use changes. The figure could be higher still, some researchers argue, if ice sheets atop Greenland and West Antarctica lose ice faster than currently anticipated.

Overall, 3.7 million people live at or below the 1-meter level, the studies find. Florida alone hosts an estimated $30 billion worth of taxable property along its vulnerable southeast coast, hinting at the enormous cost if global warming drives sea levels to conditions projected by the end of the century.

Between now and the end of the century, sea-level increases that fall considerably below 1 to 2 meters still pose interim threats, the studies hold. Between now and 2030, the likelihood of experiencing a once-in-a-century coastal flood will have more than doubled for at least two-thirds of the locations the studies cover. More than half of the locations could expect to see the likelihood of a once-per-century coastal flood triple.

"The risks are imminent and serious," said Ben Strauss, a scientist with Climate Central and the lead author of one of two related papers appearing in the journal Environmental Research Letters, in a prepared statement.

Researchers from the University of Arizona and the National Oceanic and Atmospheric Administration also participated in the studies. …