from TreeHugger.com
by Stephen Messenger - Science / Climate Change
Greenland is home to one of the world's largest and most vital sources of land-based ice cover, long considered at a heightened risk from the melting effects of global warming -- but a new report is revealing that the threat of melt off may be even more alarming.
According to a new report published in Nature Climate Change, the breaking-point for Greenland's ice is a bit closer at hand. Scientists say that even a relatively minor increase in global temps of 1.6 degrees Celsius may render the ice sheet melt off 'irreversible'. It was previously estimated that this grim reality would only come about with a rise of 3.1 degrees.
To make matters worse, reaching this breaking point may not be far off.
"We might already be approaching the critical threshold,” says the report's lead-author Alexander Robinson, via Bloomberg. “The more we exceed the threshold, the faster it melts."
Using computer modeling, Robinson and his team from determined just how long it would take for Greenland's ice to melt completely at various raises in temperature averages. With an increase around 2 degrees, the region's 660 thousands square miles of ice cover would melt in about 50 thousand years; if temperatures spiked 8 degrees, that process could take just 2,000 years. And, say researchers, once gone the ice would not return.
"Our study shows that under certain conditions the melting of the Greenland ice sheet becomes irreversible. This supports the notion that the icesheet is a tipping element in the Earth system," says Andrey Ganopolski, from Germany's Potsdam Institute for Climate Impact Research. "If the global temperature significantly overshoots the threshold for a long time, the ice will continue melting and not regrow - even if the climate would, after many thousand years, return to its pre-industrial state."
In the event that Greenland's ice were to melt, ocean levels would rise around 23 feet, significantly altering coastlines throughout the globe.
