Sea levels globally are very unlikely to rise by more than 2m (7ft) this century, scientists conclude.

Major increases would have to be fuelled by a faster flow of glaciers on the Greenland or Antarctic ice sheets. But writing in the journal Science, a US team concludes that a rise of 2m would need glaciers to reach speeds that are "physically untenable".

However, even increases substantially less than 2m would cause major issues for many societies, they say. "Even a sea level rise of 20cm (8in) in a century will have quite dramatic implications," said Shad O'Neel from the US Geological Survey (USGS).

"Woe betide any government that thinks a 2m rise in sea level isn't something to take notice of" said Dr David Vaughan of the British Antarctic Survey. "

This work is in no way meant to undermine the seriousness of climate change, and sea level rise is something we're going to have to deal with," he told BBC News.

Al Gore's documentary An Inconvenient Truth received some criticism for implying that a rise of 20ft (6m) was possible in the near future, although it did not give a definite timeframe. By contrast, this latest research tallies broadly with the conclusions of other groups that have examined the question using different approaches.