Polar Bears to Start Dying Off in 10 Years, Thanks to Climate Change

Polar bears
Polar bear Giovanna, left, and her twin polar bear cubs Nela and Nobby sit in their enclosure at Munich's Hellabrunn Zoo January 14, 2015. As the world warms, the ice-free season in polar bears’ Arctic habitats grows longer and longer. Michael Dalder/Reuters

We’ve heard it before: Arctic sea ice is disappearing quite fast. And who relies on sea ice? A lot of people and other animals, not to mention the communities all over the world that would be impacted by the accompanying rise in sea level. But a study out today led by U.S. Geological Survey (USGS) biologists paints a particularly dire picture for what disappearing sea ice will do to polar bears.

If the human world doesn’t sharply cut greenhouse gas emissions soon, the authors write, the polar bear population of Alaska, Russia and Norway, which makes up one-third of the world’s population of the bears, is likely to begin plummeting by 2025, the Associated Press reports. Polar bears in Canada and Greenland will start dying off 25 years after that.

“Short of action that effectively addresses the primary cause of diminishing sea ice, it is unlikely that polar bears will be recovered,” the U.S. Fish and Wildlife Service wrote in a draft recovery plan released the same day, The New York Times reports.

As the world warms, the ice-free season in polar bears’ Arctic habitats grows longer and longer.

Adaptation options for the bears, the USGS notes, are limited: Polar bears eat seals, and seals are largely impossible to access without the ability to travel on ice. The bears also use the ice for mating and giving birth.

If emissions continue unabated, the ice-free summer season is likely to extend beyond four months starting in the second half of this century. According to the USGS models, once past the four-month mark, the damage to polar bears becomes “more pronounced.”

“[B]eing without food for 4 months or longer is likely to have adverse effects on polar bear reproduction and survival,” the USGS writes.