Arctic sea ice shrinks to lowest area on record
Last Updated: Friday, August 17, 2007 | 4:43 PM ET
The Associated Press
There was less sea ice in the Arctic on Friday than ever before on
record, and the melting is continuing, the U.S. National Snow and Ice
Data Center reported.
"Today is a historic day," said Mark Serreze, a senior research
scientist at the centre. "This is the least sea ice we've ever seen in
the satellite record and we have another month left to go in the melt
season this year."
Satellite measurements showed 5.2 million square kilometres of ice in
the Arctic, falling below the Sept. 21, 2005, record minimum of 5.3
million square kilometres, the agency said.
Sea ice is particularly low in the East Siberian side of the Arctic
and the Beaufort Sea north of Alaska, the centre said. Ice in the
Canadian archipelago is also quite low, it said.
Along the Atlantic side of the Arctic Ocean, the amount of sea ice is
not as unusually low, but there is still less than normal, according
to the centre, located in Boulder, Colo.
The snow and ice centre is part of the Co-operative Institute for
Research in Environmental Sciences at the University of Colorado. It
receives support from NASA, the U.S. National Oceanic and Atmospheric
Administration and the National Science Foundation.
Continue Article
Scientists began monitoring the extent of Arctic sea ice in the 1970s
when satellite images became available.
The polar regions have long been of concern to climate specialists
studying global warming because those regions are expected to feel the
impact of climate change sooner and to a greater extent than other areas.
Sea ice in the Arctic helps keep those regions cool by reflecting
sunlight that might be absorbed by darker land or ocean surfaces.
Arctic snow and ice reflect 80 per cent of the sunlight they receive,
compared with only 10 per cent by open ocean water. That, in turn,
causes the ocean to heat up and raises Arctic temperatures.
'Very strong evidence' of greenhouse warming
Unusually clear sky conditions have prevailed in the Arctic in June
and July, promoting more sunshine at the time when the sun is highest
in the sky over the region. The centre said this led to an unusually
high amount of solar energy being absorbed by the Arctic ice surface,
accelerating the melting process. Fairly strong winds also brought in
some warm air from the south.
But, Serreze said in a telephone interview, while some natural
variability is involved in the melting, "we simply can't explain
everything through natural processes."
"It is very strong evidence that we are starting to see an effect of
greenhouse warming," he said.
The puzzling thing, he said, is that the melting is actually occurring
faster than computer climate models have predicted.
Several years ago he would have predicted a complete melt of Arctic
sea ice in summer would occur by the year 2070 to 2100, Serreze said.
But at the rates now occurring, a complete melt could happen by 2030,
he said Friday.
There will still be ice in winter, he said, but it could be gone in
summer.
© The Canadian Press, 2007
CP
-Ross Mayhew.
posted to ClimateConcern
Comments (0)
You don't have permission to comment on this page.