Coastal flooding threat worsening

Fast-melting ice from Greenland and Antarctica will lead to a much sharper rise in sea levels than previously estimated, touching off flooding that will radically alter US East Coast cities from Miami to Baltimore, according to a new study.

Climate change will cause a rise of at least onemeter in sea levels by the end of this century, according to a review of scientific data by Clean Air-Cool Planet, an environmental group that calls itself nonpartisan.

The projection is in sharp contrast to a 2007 study by the UN Intergovernmental Panel on Climate Change, which said world sea levels could increase 18-59 centimetres by 2100.

"We are on our way to radically changing what the coasts look like," said Jim White, a professor at the University of Colorado in Boulder, who worked on the study. "Norfolk could replace New Orleans as the poster child" for coastal flooding, he said.

Norfolk, Virginia, situated near the Chesapeake Bay and Atlantic Ocean, is home to the world's largest naval base.

The group said it based its conclusions on a study of ice melting by Utrecht University in The Netherlands.

The 2007 UN study linked most of its projected sea level rise to a natural expansion of water as it warms. But newer scientific data has focused more on the added impact of ice sheets sliding into oceans.

Gordon Hamilton, an associate professor at the University of Maine, said satellite data shows that Greenland is shedding ice at an accelerated rate, pushing more and more of it into the ocean.