A giant glacier is seen making its way to the waters of
Croaker Bay on Devon Island in this file photo. (AP
Photo/The Canadian Press, Jonathan Hayward, File)
Arctic sea ice is melting so fast most of it could be
gone in 30 years.
A new analysis of changing conditions in the region, using
complex computer models of weather and climate, says
conditions that had been forecast by the end of the century
could occur much sooner.
A change in the amount of ice is important because the white
surface reflects sunlight back into space. When ice is
replaced by dark ocean water that sunlight can be absorbed,
warming the water and increasing the warming of the planet.
The finding adds to concern about climate change caused by
human activities such as burning fossil fuels, a problem that
has begun receiving more attention in the Obama
administration and is part of the G20 discussions under way
in London.
"Due to the recent loss of sea ice, the 2005-2008 autumn
central Arctic surface air temperatures were greater than
5degC above" what would be expected, the new study reports.
That amount of temperature increase had been expected by the
year 2070.
The new report by Muyin Wang of the Joint Institute for the
Study of Atmosphere and Ocean and James E. Overland of the
National Oceanic and Atmospheric Administration's Pacific
Marine Environmental Laboratory, appears in Friday's edition
of the journal Geophysical Research Letters.
They expect the area covered by summer sea ice to decline
from about 2.8 million square miles (7.25 million sq km)
normally to 620,000 square miles within 30 years.
Last year's summer minimum was 1.8 million square miles in
September, second lowest only to 2007 which had a minimum of
1.65 million square miles, according to the National Snow and
Ice Data Center.
The Center said Arctic sea ice reached its winter maximum for
this year at 5.8 million square miles on Feb. 28. That was
278,000 square miles below the 1979-2000 average making it
the fifth lowest on record. The six lowest maximums since
1979 have all occurred in the last six years.
Overland and Wang combined sea-ice observations with six
complex computer models used by the Intergovernmental Panel
on Climate Change to reach their conclusions. Combining
several computer models helps avoid uncertainties caused by
natural variability.
Much of the remaining ice would be north of Canada and
Greenland, with much less between Alaska and Russia in the
Pacific Arctic.
"The Arctic is often called the Earth's refrigerator because
the sea ice helps cool the planet by reflecting the sun's
radiation back into space," Wang said in a statement.
"With less ice, the sun's warmth is instead absorbed by the
open water, contributing to warmer temperatures in the water
and the air."
The study was supported by the NOAA Climate Change Program
Office, the Institute for the Study of the Ocean and
Atmosphere and the US Department of Energy.
