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Polar bears unlikely to survive if global warming isn't reversed: US report
Jul 13, 2015

According to a U.S. government report, About a third of the world’s polar bears could be in imminent danger from greenhouse gas emissions in as soon as a decade, U.S. Geological Survey said scientific models don’t bode well for polar bear populations across the world. Greenhouse gases are blamed for the climate warming that’s reducing polar bears' summer sea ice habitat. Scientists saw no rebound in population in the projections that stretched to the year 2100.

The scientific models attempted to predict the effects on polar bear populations under two scenarios — one in which greenhouse gas emissions stabilised, and the other in which they continued unabated.

Under either scenario, the bears in the Alaska, Russia and Norway group with an estimated population of about 8,500 would start to be affected in either 2025 or 2030, Polar bears use sea ice for feeding, mating and giving birth. When the ice retreats in the summer, polar bears are forced to the land. A study found the land-based food would not help it adapt to the loss of sea ice. USGS didn’t predict specific number declines and instead projected whether a population would see a decrease.

Polar bears in Canada and Greenland also could see dramatic population drops by 2050. Bears in the high Canadian Arctic fared the best in the two scientific models. They saw a “greatly decreased” population only under the worst-case scenario.

The polar bear (or Ursinus Maritimus), the largest member of the Ursidae (bear) family, is also the largest terrestrial land carnivore and is found largely within the Arctic Circle encompassing the Arctic Ocean, its surrounding seas and land masses.  this area belongs to five nations: Denmark (which administers Greenland), Norway (which administers the Svalbard archipelago), Canada, the United States (of which Alaska is a part) and Russia.

Polar bears depend on sea ice

Polar bears are found throughout the circumpolar Arctic...

  • along or near coasts

  • on islands

  • and most importantly, on sea ice.

Why is sea ice important?

Polar bears spend much of their time on the annual arctic sea ice. It provides a platform for them to hunt, live, breed, and in some cases create maternal dens. Sea ice is more than a simple platform: it is an entire ecosystem inhabited by plankton and micro-organisms, which support a rich food chain that nourishes seals, that in turn become prey for polar bears. It is the very foundation and defining characteristic of the arctic marine ecosystem.

Why is the polar bear so important?

  • Polar bears help us gain an understanding of what is happening throughout the Arctic, as a polar bear at risk may signal something is wrong elsewhere in the arctic marine ecosystem.

  • Large carnivores - those that are at the apex  or top of the food chain - are particularly sensitive indicators of the health of an ecosystem.


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