The whole article is an eye opener, but the last few paragraphs should
really make some people open their brains.

Arctic ice: it's melting
Scientists say wintertime loss of polar ice is growing along with a
continuing summertime pattern and is strong evidence of global warming
Jane Kay, Chronicle Environment Writer

Thursday, September 14, 2006


Printable Version
Email This Article




The vast expanses of ice floating in the Arctic Sea are melting in
winter as well as in the summer, likely because of global warming, NASA
scientists said Thursday.

"This is the strongest evidence yet of global warming in the Arctic,''
said Josefino Comiso, a research scientist at NASA's Goddard Space
Flight Center in Greenbelt, Md.

And if the ice continued to melt at the current rate, Comiso said, it
could have profound effects on all life in the Arctic and other
consequences around the world.

Particularly hard hit would be the polar bears, which live on the ice,
he said. Sea ice also provides oxygen-rich cold water needed for the
growth of phytoplankton. A decline in the number of the tiny plants
could have a cascading effect on the food supply of fish and
crustaceans, seals and the other marine mammals.

The size of this summer's Arctic ice won't be known for a few weeks
because it usually reaches its smallest size the third week of
September. Last year, scientists found that polar ice an area twice the
size of Texas has melted since NASA started compiling satellite data 27
years ago. Scientists said there could be no ice left in the Arctic in
the summer by the end of the century.

Until 2005, the wintertime sea ice -- which is thick and multilayered
-- has been relatively stable. In the summer, the ice is thinner, more
mobile and melts at the edges every spring before freezing up again in
the autumn.

In the last two winters -- 2005 and 2006 -- the size of the sea ice was
6 percent smaller than average, the data show. The sea ice in the
Northern Hemisphere covers nearly 10 million square miles in the
winter. The melting -- most of it occurring in the eastern Arctic near
the North Pole -- correlates with a rise the ocean's surface water
temperature.

The melting period is growing by 15 days each decade, meaning less time
for ice to grow back, experts said.

When Comiso saw the decline of winter sea ice in 2005, he said, "it was
only one year, and I didn't think it was so serious.''

However, based on NASA data, his computer simulations and two years of
melting ice, "this has a very large chance of continuing," he said.

Already a greater number of polar bears have been showing up in Inuit
communities in the Arctic, apparently searching for food, said NASA
researcher Claire Parkinson.

The bears use the sea ice toseals and other marine mammals. "When the
ice retreats, they have to come on the land. Normally, when they're on
the land, they're not eating,'' she said.

The bears come on land more often now, she said, because they're
probably hungrier and afraid of being stranded on a retreating floe,
she said.

Parkinson and Ian Stirling, a biologist in the Canadian Wildlife
Service, published a study in the journal Arctic this month showing
that the polar bear population is shrinking, even though there have
been more sightings. Instead, the Hudson Bay population has declined
from 1,200 bears in 1989 to 950 bears in 2004, and the weight of adult
females has dropped. None of the 18 other populations in the Arctic has
grown, either, she said.

It's not impossible that the sea ice could recover in coming years,
Parkinson said.

"The possibility is there that the Arctic will recover, but that is not
as likely as that it will continue to decrease,'' she said.

The U.S. Fish and Wildlife Service is considering listing the polar
bear as a threatened species under the Endangered Species Act and is
conducting studies in the North Slope of Alaska and elsewhere in the
Arctic.

The loss of Arctic sea ice has global effects, scientists say.

Sea ice is made of frozen ocean water, and when it melts, it doesn't
raise the ocean's level as do melting glaciers and ice sheets. But less
sea ice means a smaller area of ice to reflect radiation away from
Earth, and the dark, open water absorbs heat. Both phenomena could
accelerate the world's warming, scientists say.

"We're seeing an overall pattern of global warming,'' said Mark
Serreze, senior research scientist at the National Snow and Ice Data
Center in Boulder, Colo., which joined NASA scientists at a telephone
news conference Wednesday.

Ice core borings in Antarctica have produced a record of historic
carbon dioxide concentrations over the last 600,000 years. The borings
show the levels of carbon dioxide, a greenhouse gas, are at their
highest ever because of the burning of fossil fuels, Serreze said.

Serreze said he was surprised to see a new lake, or polynya, the size
of Maryland, opening up in the sea ice north of the Beaufort Sea.

In 20 years of looking at sea ice, he has never seen anything like it.

"If you asked me five years ago if it was human activity (causing
global warming) versus natural variability, I was a fence-sitter,''
Serreze said.

"The magnitude of the changes is starting to rise above the noise of
natural variability. There is a continuing trend. What we see in the
Arctic is part of a much larger picture. We hate to say, 'We told you
so.' But we told you so.''