Polar bears' days in Alaska are numbered

Two-thirds of the world's polar bear population will be gone by 2050 -- including those in Alaska -- because of thinning Arctic sea ice from global warming, government scientists said Friday.

Only in northern Canada and northwestern Greenland were polar bears expected to survive through the end of the century, said the U.S. Geological Survey, the scientific arm of the Interior Department.

The agency projected that over the next half-century polar bears would lose 42% of the summer Arctic range they need in the Polar Basin to hunt and breed. Polar bears depend on sea ice as a platform for hunting seals, their primary food.