Sea level rise predictions exaggerated...

Why am I not surprised????

Al Gore's Oscar-winning environmental documentary exaggerated the likely effects of global warming on sea levels, a new study shows.

The film, An Inconvenient Truth, suggested that the sea would rise up to 20ft "in the near future" as the ice in Greenland or Western Antarctica melts.

Other documentaries have picture Britain deluged with water, showing the House of Commons submerged.

However, while some mainstream predictions project sea levels 2 to 4 meters higher by 2100, a new study published today in Science concludes that a rise in sea level between 0.8 and 2 meters is much more likely.

While scientists agree that sea levels rose by six inches over the course of the 20th century, estimates of future rises remain hazy, mostly because there are many uncertainties, from the lack of data on what ice sheets did in the past to predict how they will react to warming, insufficient long-term satellite data to unpick the effects of natural climate change from that caused by man and a spottiness in the degree to which places such as Antarctica have warmed.

Prof Tad Pfeffer at University of Colorado in Boulder, Dr Joel Harper at University of Montana and Dr Shad O'Neel at Scripps Institute of Oceanography, La Jolla, reached these conclusions after studying the ice and water being discharged from Greenland and Antarctic ice sheets.

"We simply don't understand the physics of ice dynamics well enough to make accurate model predictions," says Dr Harper. "There are just too many uncertainties. So what we did is flip the problem on its head."

Unlike most past studies that try to add up the individual sources of ice and water discharge from the glaciers into the sea, their experiment calculated how much ice and water lost from Greenland and Antarctica that it would take for the world's seas to raise two meters.

Then they calculated how fast contributing glaciers would need to move in order to dump that much ice into the sea.

Their findings show that predictions of a two meter rise in sea level by 2100 would require significantly faster ice velocities from Greenland and Antarctica than has ever been reported before.