Sea levels rising faster than expected: scientists

COPENHAGEN (Reuters) - The U.N.’s climate change panel may be severely underestimating the sea-level rise caused by global warming, climate scientists said on Monday, calling for swift cuts in greenhouse emissions.

“The sea-level rise may well exceed one meter (3.28 feet) by 2100 if we continue on our path of increasing emissions,” said Stefan Rahmstorf, professor at the Potsdam Institute for Climate Impact Research. “Even for a low emission scenario, the best estimate is about one meter.”

Rahmstorf spoke at the International Scientific Congress on Climate Change in Copenhagen.

The U.N.’s Intergovernmental Panel on Climate Change in 2007 predicted global warming would cause sea levels to rise by between 18 cm and 59 cm (7 inches and 23 inches) this century.

The IPCC said at the time the estimate could not accurately take into account factors such as the melting of ice sheets in Greenland and Antarctica. Many scientists criticized the number as too conservative.

“The ice loss in Greenland shows an acceleration during the last decade,” said veteran Greenland researcher Konrad Steffen, director of the Cooperative Institute for Research in Environmental Sciences at the University of Colorado, Boulder.

“The upper range of sea-level rise by 2100 might be above one meter or more on a global average, with large regional differences depending where the source of ice loss occurs,” he said.

John Church, a researcher at the Center for Australian Weather and Climate Research in Hobart, said rising oceans will lead to more frequent devastating floods in coastal areas.

The faster humans limit carbon dioxide emissions, the greater the chance to avoid the most extreme scenarios, he said.

“We could pass a threshold during the 21st century that can commit the world to meters of sea-level rise,” he said. “Short-term emission goals are critical.”

Early reductions of emissions are much more effective than actions later in the century, the scientists said.

“With stiff reductions in 2050 you can end the temperature curve (rise) quite quickly, but there’s not much you can do to the sea-level rise anymore,” Rahmstorf said. “We are setting in motion processes that will lead to sea levels rising for centuries to come.”