Polar bears are facing greater risk of starvation as Arctic ice melts and they endure longer ice-free seasons, researchers said in a study published Tuesday.

With ongoing and forecasted declines in Arctic sea ice, there is a greater need to understand how polar bears use sea ice and will respond to anticipated environmental changes.

Exactly when that will happen is being influenced by humans, according to a new study, as melting polar ice alters the Earth’s rotation and changes time itself.

More than polar bears are threatened in this changing gateway to the Arctic, where warmer waters melt sea ice earlier in the year and the open ocean lingers longer.

Polar bears don’t have to worry about skipping a wash day. The sebum, or natural oil, on the mammals’ fur helps them survive the harsh Arctic weather by making it hard for ice to stick to them ...

If the ice disappeared during the summer, many creatures that rely on it would be driven to extinction, scientists warn.

For centuries, sea ice was deemed essential for polar bears to survive. Generations of the Arctic bears ventured onto the slabs of floating ice to travel long distances and prey on unsuspecting seals.