A group of climate scientists in the United States says a United Nations panel of experts has underestimated a predicted rise in sea levels this century.
The UN panel forecast that global warming would result in a rise of between 18 and 59 centimetres.
One of the scientists who believes this is well short of the mark is James Hansen of NASA, who believes the sea level will rise several metres by the end of this century.
Dr Hansen argues that the UN panel did not take into account melting ice sheets in Greenland and Antartica.
"That’s beginning to lose mass and it is situated on bedrock which is below sea level, so it’s potentially unstable and could give a very large sea-level rise," he said.