Monday, 10 September 2012

Declining Arctic Sea Ice

by Richard Farmer |

That declining ice. The big Arctic melt goes on. The National Snow and Ice Data center in the United States reported overnight that following the new record low recorded on August 26, Arctic sea ice extent continued to drop and is now below 4.00 million square kilometers (1.54 million square miles). Compared to September conditions in the 1980s and 1990s, this represents a 45% reduction in the area of the Arctic covered by sea ice. At least one more week likely remains in the melt season.

Professor Peter Wadhams has told BBC Newsnight that the loss of Arctic ice is effectively doubling mankind's contribution to global warming. White ice reflects more sunlight than open water, acting like a parasol, Prof Wadhams explained. Melting of white Arctic ice, currently at its lowest level in recent history, is causing more absorption.

Prof Wadhams calculates that this increased absorption of the sun's rays is "the equivalent of about 20 years of additional CO2 being added by man". He predicts that the Arctic ice cap is "heading for oblivion". In 1980, the Arctic ice in summer made up some 2% of the Earth's surface. But since then the ice has roughly halved in area, and the volume of ice has dropped to just a quarter of what it was.