Is Global Warming Killing the Polar
Bears?
By JIM CARLTON
Staff Reporter of THE WALL STREET JOURNAL
December 14, 2005; Page B1
It may be the latest evidence of global warming: Polar bears are
drowning.
Scientists for the first time have documented multiple deaths of
polar bears off Alaska, where they likely drowned after swimming
long distances in the ocean amid the melting of the Arctic ice
shelf. The bears spend most of their time hunting and raising their
young on ice floes.
In a quarter-century of aerial surveys of the Alaskan coastline
before 2004, researchers from the U.S. Minerals Management Service
said they typically spotted a lone polar bear swimming in the ocean
far from ice about once every two years. Polar-bear drownings were
so rare that they have never been documented in the surveys.
But in September 2004, when the polar ice cap had retreated a
record 160 miles north of the northern coast of Alaska, researchers
counted 10 polar bears swimming as far as 60 miles offshore. Polar
bears can swim long distances but have evolved to mainly swim
between sheets of ice, scientists say.
The researchers returned to the vicinity a few days after a fierce
storm and found four dead bears floating in the water.
"Extrapolation of survey data suggests that on the order of 40
bears may have been swimming and that many of those probably
drowned as a result of rough seas caused by high winds," the
researchers say in a report set to be released today.
While the government researchers won't speculate on why a climate
change is taking place in the Arctic, environmentalists unconnected
to the survey say U.S. policies emphasizing oil and gas development
are exacerbating global warming, which is accelerating the melting
of the ice. "For anyone who has wondered how global warming and
reduced sea ice will affect polar bears, the answer is simple --
they die," said Richard Steiner, a marine-biology professor at the
University of Alaska.
The environmental group Greenpeace began airing a 30-second
commercial yesterday in New York, Los Angeles, Atlanta and other
cities showing an animated adult polar bear and a cub on a cracking
ice floe. The two bears, nowhere near land, slip underneath the
water. "Polar bears may soon be extinct because of global warming,"
the voice-over states. It ends with "Global Warming: It's the Real
Thing," a takeoff of a Coca-Cola Co. commercial featuring polar
bears.
Some experts say that climate change may indeed be shrinking the
ice pack, but they dispute that emissions are the main culprit or
that significantly cutting greenhouse gases would really make a
difference. "Whether humans are responsible for some, most, or all
of the current warming trend in the Arctic, there is no proposal on
the table that would actually prevent continued warming or reverse
present trends," said Sterling Burnett, a senior fellow at the
National Center for Policy Analysis, a nongovernment organization
based in Dallas. "The question is how to adapt to future changes in
climate, regardless of the direction or the cause."
In addition to documenting polar-bear deaths, the Minerals
Management Service researchers, Chuck Monnett, Jeffrey Gleason and
Lisa Rotterman, also found a striking shift in the bears' habits.
From 1979 to 1991, 87% of the bears spotted were found mostly on
sea ice. From 1992 to 2004, the percentage dropped to 33%. Most of
the remaining bears have been found either in the ocean or on
beaches, congregating around carcasses of whales butchered by
hunters. In the past, polar bears were rarely seen at such kill
sites, because they spent their time hunting their favorite meal --
seals -- on sea ice.
Marine experts consider the findings -- to be presented at a
marine-mammal conference this week in San Diego -- an ominous sign.
Some have warned for years that a rapid thawing of the Arctic from
global warming could endanger species like the polar bear. Already,
a warmer Alaska over the past half-century has been linked to
increased erosion of rivers and streams, insect infestations and
the undermining of pipelines and roads as the permafrost
thaws.
Alarmed by the swift changes, the Alaska Inter-Tribal Council, a
consortium of the state's tribes, earlier this month passed a
resolution urging that the U.S. government enact a mandatory
program to reduce global warming.
Some scientists predict polar bears could become extinct within the
next century because they have adapted over the millennia to only
hunting on ice. If they try to swim in disappearing ice conditions
to catch seals, more are likely to tire and drown, scientists say.
Polar bears that stay onshore aren't adapted to hunting land
animals like caribou, which are preyed upon by more-aggressive
grizzly bears. Polar bears also require more fat intake than most
food on land offers them, experts say.
"As the sea ice goes, that will direct to a very great extent what
happens to polar bears," said Steven Amstrup, a polar-bear
specialist with the U.S. Geological Survey in Anchorage,
Alaska.
Another study set to be released at the marine-mammal conference
shows what might happen to the Alaskan polar bears over time.
Researchers from the USGS, the University of Wyoming and the
Canadian Wildlife Service found that the population of polar bears
in Canada's western Hudson Bay -- near the southernmost habitat for
the bears in the world -- fell to 935 in 2004 from 1,194 in 1987, a
22% drop. Researchers said the decline -- the first recorded for
these bears -- came in tandem with an extension by nearly a full
month in the time it takes for Hudson Bay to ice over after the
summer.
"Our findings may foreshadow how more northerly populations will
respond to projected warming in the Arctic ecosystem," wrote Mr.
Amstrup, a co-author of the report.
Previous studies by the U.S. and Canadian governments support a
link between the decline in sea ice in the Arctic and the ways
polar bears try to adapt to their surroundings. For example,
researchers say polar bears in the Beaufort Sea off Alaska and
Canada used to spend most of their lives jumping from ice floe to
ice floe in pursuit of seals. Only pregnant bears would
occasionally wander onto the mainland, in search of a den.
But weekly aerial surveys by the U.S. Fish and Wildlife Service
show that, over the past five years, an unusually large number of
bears have congregated along the beaches. Between the coastal town
of Barrow, Alaska and the Canadian border, about 300 miles east,
researchers counted as many as 200 bears on land, said Scott
Schliebe, director of the Fish and Wildlife's polar-bear project.
Many bears could be seen gathered around whale carcasses near
villages like Kaktovik, which lies in the Arctic National Wildlife
Refuge where the Bush administration is pushing for drilling.
Scientists measured the distances from where the bears were
gathered to the nearest ice sheets at sea and found this
correlation: The farther the ice was from shore, the larger the
number of bears were found on land.
Scientists estimate there are 20,000 to 25,000 polar bears
world-wide, including about 2,000 that frequent the Beaufort Sea
off Alaska. The latest population study by federal officials, in
1997, suggested the Alaskan bear population wasn't endangered. An
update is expected by the end of next year.
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Poor Polar Bears. 