Friday, June 29, 2012

Greenland Ice Sheet Melt Nearing Critical ‘Tipping Point’

The Greenland ice sheet is poised for another record melt this year, and is approaching a "tipping point" into a new and more dangerous melt regime in which the summer melt area covers the entire land mass, according to new findings from polar researchers.

The ice sheet is the focus of scientific research because its fate has huge implications for global sea levels, which are already rising as ice sheets melt and the ocean warms, exposing coastal locations to greater damage from storm surge-related flooding.

Greenland's ice has been melting faster than many scientists expected just a decade ago, spurred by warming sea and land temperatures, changing weather patterns, and other factors. Until now, though, most of the focus has been on ice sheet dynamics — how quickly Greenland's glaciers are flowing into the sea. But the new research raises a different basis for concern.

The new findings show that the reflectivity of the Greenland ice sheet, particularly the high-elevation areas where snow typically accumulates year-round, have reached a record low since records began in 2000. This indicates that the ice sheet is absorbing more energy than normal, potentially leading to another record melt year — just two years after the 2010 record melt season. More