The
first study to combine computer models of rising temperatures with records
of the ancient climate has indicated that sea levels could rise by up to 20ft
(6m) by 2100, placing millions of people at risk.
The threat comes from melting ice sheets in Greenland and Antarctica, which
scientists behind the research now believe are on track to release vast volumes
of water significantly more quickly than older models have predicted. Their
analysis of events between 129,000 and 116,000 years ago, when the Arctic last
warmed to temperatures forecast for 2100, shows that there could be large rises
in sea level.