Arctic Sea Ice Shrinks to Record Low
- Arctic Sea Ice Shrinks to Record Low
Published: 13:52 EST, August 17, 2007
By RANDOLPH E. SCHMID, AP Science Writer
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 center. "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 2.02 million square miles of ice in the
Arctic, falling below the Sept. 21, 2005, record minimum of 2.05 million
square miles, the agency said.
Sea ice is particularly low in the East Siberian side of the Arctic and
the Beaufort Sea north of Alaska, the center reported.
Ice in the Canadian Archipelago is also quite low. Along the Atlantic
side of the Arctic Ocean, sea ice extent is not as unusually low, but
there is still less than normal, according to the center located in
The snow and ice center is part of the Cooperative Institute for Research
in Environmental Sciences at the University of Colorado. It receives
support from NASA, the National Oceanic and Atmospheric Administration
and the National Science Foundation.
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. Exposed
to direct sun, for example, instead of reflecting 80 percent of the
sunlight, the ocean absorbs 90 percent. That causes the ocean to heat up
and raises Arctic temperatures.
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
National Snow and Ice Data Center: http://www.nsidc.org