New research says that unless drastic action is taken to reduce the amount of greenhouse gases being pumped into the atmosphere, ice melting from Antarctica will drive global sea levels higher, and faster than anticipated.  The more accurate model projects a 1.14 meter rise by 2100 - just from Antarctic melting.

The study was produced by Robert DeConto of the University of Massachusetts Amherst and Penn State University's David Pollard, and is published in the journal Nature.  Their modeling data is more accurate because it is the first to anticipate the impacts of all phases of ice melting. 

Previous studies focused only on warmer waters melting the ice shelves from below.  But ice melt does not occur in a linear fashion as temperatures increase - there are a number of processes involved.  The DeConto-Pollard study incorporates more types of melting, including: the effect of surface melt-water; rain trickling down from above; fracturing supporting ice which hastens its slide to the sea.  The new data doubles the expected sea rise.

"Sea level has risen a lot - 10 to 20 meters - in warm periods in the past, and our ice sheet models couldn't make the Antarctic ice sheet retreat enough to explain that," said Professor Pollard.  "We were looking for new mechanisms that could make the ice more vulnerable to climate warming to explain past sea level rise," he added.

Major ice sheet loss could occur as soon as 2050.  Total sea level rise from Antarctica could total more than 13 meters by 2500.  Now, add ice melt from Greenland, Siberia, Canada, and the Arctic Circle - and you can envision what sort of danger is coming for low lying islands and coastal communities.

"Frankly, I hope we're wrong about this," said Professor DeConto. 

Unfortunately, they probably aren't.  Colleagues participating in the peer review have nothing but praise for DeConto's and Pollard's innovative modeling.