„Record sea-ice melt a warning sign“: top German Arctic researchers

09/19/2012 - This summer’s record low of Arctic sea-ice is a warning sign, some of Germany’s leading ice researchers stated in a joint press conference in Hamburg today. Never before since the beginning of satellite observations – and very probably even since 1500 years or more – the sea-ice cover shrunk to such small area. “The record melt measured some weeks ago has thus been exceeded significantly again, leaving the 2012 record 23 percent below the previous record just five years before,” said Anders Levermann of the Potsdam Institute for Climate Impact Research.
„Record sea-ice melt a warning sign“: top German Arctic researchers
Current sea-ice extent in the Arctic. Image: Cryosphere today (http://arctic.atmos.uiuc.edu/cryosphere/)

When the white sea-ice cover shrinks, less solar energy is reflected back into space – which in turn actually accelerates global warming, the dominant factor for the historic melt. „This vicious circle has impacts on the whole planet as well as regionally, contributing for instance to to the melting of the Greenland ice sheet that stores a potential for long-term sea-level rise of several meters,” said Levermann  who is a lead-author of the sea-level-change chapter in the upcoming assessment report of the Intergovernmental Panel on Climate Change (IPCC).

Peter Lemke of the Alfred Wegener Institute for Polar and Marine Research pointed out that the Arctic sea-ice, though far away, actually matters for Europe. The sea-ice melt for instance might disturb global oceanic circulation patterns as well as atmospheric circulation patterns. Lars Kaleschke of the Universitiy of Hamburg highlighted that not just the surface area covered by ice is reduced but also the thickness. In fact, the overall volume of the ice around the North Pole has shrunk by roughly three quarters. Dirk Notz of the Max Planck Institute for Meteorology said that Arctic summer sea-ice might disappear almost completely by the middle of our century already.


Weblink to additional information at the University of Hamburg

Weblink to a background paper by the German ice researchers
(only available in German)