Survey: By 2050 only one third of world's polar bears left

Only a third of the world’s polar bears may be left within 50 years because of thinning sea ice from global warming in the Arctic, the US Geological Survey said.

The agency forecasts that, during that time, polar bears will also lose 42% of the Arctic range they need to live in during summer in the Polar Basin where they need to hunt and breed.

USGS director Mark Myers said the findings from US and Canadian scientists were based on six months of new studies, during which the health of three polar bear groups and their dependency on Arctic sea ice were examined using “new and traditional models”.

They were made public to help guide Interior Secretary Dirk Kempthorne’s decision, expected in January, on his agency’s proposal to add the polar bear to the government’s endangered species list.

Last December, Mr Kempthorne proposed designating as a “threatened” species deserving of federal protection under the Endangered Species Act, because of melting Arctic sea ice from global warming. That category is second to “endangered” on the government’s list of species believed most likely to become extinct.

Polar bears depend on sea ice as a platform for hunting seals, which is their primary food. But the sea ice is decreasing throughout their Arctic range due to climate change, the USGS said.

A separate organisation, the World Conservation Union, based in Gland, Switzerland, has estimated that the polar bear population in the Arctic is about 20,000 to 25,000, put at risk by melting sea ice, pollution, hunting, development and even tourism.