Geoscience Reference
In-Depth Information
reduction with a lot of annual variation.
In addition, by combining Arctic and Ant-
arctic sea ice numbers, Will was able to ob-
scure the rapid decrease in area, age, and
thickness of the Arctic sea ice. This cherry
picking of data, or focusing on particular
meaningless variations rather than the big
picture, is a common tactic among climate
skeptics.
state of Alaska opposed the designation
because it would allegedly hinder future
resource development. The state argued
that the future of the sea ice was uncer-
tain, that the models predicting ice trends
were not accurate, and that the scientific
literature on the bear was questionable.
Hunting groups opposed the designation as
well. One of the arguments of opponents
was that the polar bears were believed to
have evolved from grizzly bears perhaps
100,000 years ago. So why couldn't they
just revert to their old food sources? The
answer is that the change in ice is happen-
ing extremely fast in terms of the bears'
food supply, and whether they can adapt
quickly enough is questionable.
The polar bears are threatened because
of their seasonal dependence on floating
ice. The narwhal is threatened because it
has specialized feeding habits and a very
narrow range of habitat. The narwhal is a
medium-sized tusked whale which weighs
between 900 and 1,600 kilograms (2,000
and 3,500 pounds) and is capable of diving
as deep as 1,370 meters (4,500 feet). In the
winter the narwhal feeds on the life forms
that spend the winter beneath the pack ice;
no pack ice would mean no food.
The hooded seal spends much time away
from the ice, but for its all-important birth-
ing it requires pack ice. The pups, aban-
doned by their mother a few days after
birth, reside for several weeks on the ice be-
fore venturing into the water on their own.
Less well known is the plight of the Pa-
Disappearing arctic Sea ice
and the animals
Loss of Arctic Ocean sea ice is causing prob-
lems for ivory gulls, the Pacific walrus,
hooded seals, the narwhal whale, and po-
lar bears, each for different reasons. The
bears spend most of their lives on the ice
and depend on it for capturing ringed seals
as the seals surface at breathing holes. Five
of nineteen polar bear subspecies are said
to be in decline.
The plight of the polar bear, now classi-
fied as “threatened” by the United States
government, has been given particularly
wide publicity. It is an iconic animal, warm
and fuzzy (from a distance). Lots of teddy
bears are polar bears, but alongside a bear,
walruses or hooded seals are rather unat-
tractive, and few of them are found on de-
partment store shelves in the toy section.
The decision in 2008 to list the bears as
threatened, based as it was on global warm-
ing projections that Arctic sea ice would
soon disappear, was controversial. The
