Geology

Faster-moving sea ice forces polar bears to use more energy

Rapid global warming has sped up the movement of sea ice off Alaska's coasts, and already at-risk polar bears are paying a price, a new U.S. study says.

Most sea ice moves throughout the year and the iconic white bears are on a perpetual walk to stay within their preferred habitat, said U.S. Geological Survey research ecologist George Durner, lead author of the study.

He compares it to living on a treadmill that has picked up speed because ice is thinner, more brittle and moving faster because of wind and ocean currents.

"Increased sea ice drift rates likely exacerbate the physiological stress due to reduced foraging opportunity already experienced by many...

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