Photo: Mike Segar

WASHINGTON - Sea levels on the United States' mid-Atlantic coast are rising faster than the global average because of global warming, threatening the future of coastal communities, the Environmental Protection Agency said on Friday.

Coastal waters from New York to North Carolina have crept up by an average of 2.4 to 4.4 millimeters (0.09 to 0.17 inches) a year, compared with an average global increase of 1.7 millimeters (0.07 inches) a year, the EPA said in a report.

As a result, sea levels along the East Coast rose about a foot over the past century, the EPA's report, commissioned by the Climate Change Science Program, said.

The EPA focused on the mid-Atlantic region because it "will likely see the greatest impacts due to rising waters, coastal storms, and a high concentration of population along the coastline," the agency said.

Higher sea levels threaten to erode beaches and drastically change the habitats of species in the area, often at a pace too fast for species to adapt and survive, the EPA said.

Communities in the area are at greater risk of flooding as a "higher sea level provides an elevated base for storm surges to build upon and diminishes the rate at which low-lying areas drain," the report found.

Floods will probably cause more damage in the future as higher sea levels gradually erode and wash away dunes, beaches and wetlands that serve as a protective barrier. Consequently, homes and businesses would be closer to the water's edge.

Rising sea levels have implications beyond the mid-Atlantic region, the report said.

Ports challenged by rising waters could slow the transport of goods across the country, and disappearing beaches could hurt resorts and affect tourism revenue, the EPA said, damaging an already fragile U.S. economy.

"Movement to the coast and development continues, despite the growing vulnerability to coastal hazards," the EPA said.

Scientists have said the rate sea levels are rising has accelerated. By the end of the century, global sea levels could be seven to 23 inches higher, the Intergovernmental Panel on Climate Change has predicted.

Federal, state and local governments should step in now to prepare for the rising seas, said the EPA along with the National Oceanic and Atmospheric Administration and the U.S. Geological Survey, who contributed to the report.

Governments should protect residents through policies that preserve public beaches and coastal ecosystems and encourage retrofits of buildings to make them higher, the agencies said.

Engineering rules for coastal areas used today are based on current sea levels and will not suffice in the future, the report said.

Flood insurance rates also could be tweaked to accommodate risk from rising sea levels, the report said.

(Editing by Marguerita Choy)

© Thomson Reuters 2009 All rights reserved