The End May be Near

"I feel that we're getting uncomfortably close to [the] threshold," says leading marine scientist John Church, of Australia's CSIRO Marine and Atmospheric Research . This grim analysis is the result of studies by leading scientists of the latest data on rising sea levels and melting ice sheets in the polar regions.

In February, the Intergovernmental Panel on Climate Change (IPCC) projected sea level gains of 18-59 centimeters this century from temperature rises of 1.8-4.0 Celsius. Current observations "are in the very upper edge of the projections," according to Church.

Once this upper projection is passed, says Church, parts of the Antarctic and Greenland would approach a point of virtually irreversible melting that would produce sea level rises of meters. Currently, the Antarctic Peninsula is warming faster than anywhere else on Earth, and glaciers are in massive retreat.

Australian scientist John Hunter, meanwhile, who has focused on historical sea level information, says that to keep the sea water out, communities would need to begin raising sea walls.

"There's lots of places where you can't do that and where you'll have to put up with actual flooding," he said. About 100 million people around the world live within a meter of the present-day sea level, according to CSIRO Marine Research senior principal research scientist Steve Rintoul. "Those 100 million people will need to go somewhere." End: Story Text

"You can't just say we'll just put sea walls," Hunter says.