Of Warming Continue
In The Arctic
By Randolph Schmid
20 November, 2006
The Associated Press
Signs of warming continue in
the Arctic with a decline in sea ice, an increase in shrubs growing
on the tundra and rising concerns about the Greenland ice sheet.
"There have been regional
warming periods before. Now we're seeing Arctic-wide changes,"
James Overland, an oceanographer at the Pacific Marine Environmental
Laboratory in Seattle, said Thursday.
For the past five years,
it was at least 1.8 degrees Fahrenheit above average over the Arctic
over the entire year, he said.
The new "State of the
Arctic" analysis, released by the National Oceanic and Atmospheric
Administration, also reports an increase in northward movement of warmer
water through the Bering Strait in 2001-2004. This may have contributed
to a continuing reduction of sea ice.
During that time, there were
record lows in sea ice coverage in the region, Overland said. This year
there was more normal coverage in the Bering area but a record low on
the Atlantic side of the Arctic.
In the past when such a shift
occurred, there would have been no net loss of ice overall, just a change
in where there was a smaller amount. Now, however, there is both the
shift and an overall net loss of ice, he said.
Indeed, the report said Arctic
sea ice coverage this past March was the lowest in winter since measurements
by satellite began in the early 1970s.
Jacqueline A. Richter-Menge
of the Cold Regions Research and Engineering Laboratory in Hanover,
N.H., said the sea ice decline is now being observed in both winter
The study was designed to
assess the overall impact of climate change in the Arctic and will be
updated annually. It was compiled by researchers from the United States,
Canada France, Germany, Poland, Norway, Sweden and Russia, she said.
In addition, 2007 has been
designated the International Year of the Arctic, with intense scientific
study of the region planned.
There have been many changes
over the Arctic land areas, too, said Vladimir E. Romanovsky, a professor
at the geophysical institute of the University of Alaska. These include
changes in vegetation, river discharge into the Arctic Ocean, glaciers
The tundra is becoming greener
with the growth of more shrubs, he said. This development is causing
problems in some areas as herds of reindeer migrate.
At the same time, there is
some decrease in the greening of the northern forest areas, probably
due to drought. The glaciers are continuing to shrink and river discharge
into the Arctic Ocean is rising, Romanovsky said.
There has been a significant
warming of the permafrost over the past 30 years, he added.
Much of the damage to the
permafrost soil can be blamed on human construction activities and fires,
he said. In many areas, this frozen ground is close to the melting point
and soon could begin to thaw.
Overland said the changes
are affecting wildlife in the Arctic. Those in the middle levels of
the ocean, such as pollock, seem to do well; those on the surface ice
or the sea floor, such as walrus or crabs, are not coping as well.
"We're seeing a lot
of indicators of climate change in the Arctic and that may be an indicator
for change in other parts of the world," Overland said.
Most of the heating from
the sun comes to the equator and subequatorial regions, and a lot of
heat leaves by radiation from Arctic, he said.
"The temperature difference
between the Arctic and equator drives all of our weather," Overland
said. If the Arctic warms up and that difference is reduced, weather
could change, though people remain unsure about the effect.
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