A polar bear tests the strength of sea ice in the Arctic on 13 September 2015. Photo: Mario Hoppmann / European Geosciences Union / AFP / Getty Images

By David Cox
27 February 2018
(NBC News) – For the past two decades, scientists have been monitoring the effects of a warming Arctic on the world’s polar bears — and the bears’ future has looked increasingly bleak.The latest estimates suggest that Arctic sea ice is disappearing by 14 percent a decade, drastically limiting the bears’ ability to hunt the seals on which they feed. And research on bears living on the Arctic islands of Svalbard shows that the animals are now reproducing at a rate one-fifth of that seen just 20 years ago.Given these dismal statistics, scientists now predict that the global population of polar bears could fall from 20,000 to 30,000 today to fewer than 5,000 by 2100 — and beyond that no one knows. Even if a small population of bears manage to hang on, they’re not out of the woods.“One of the problems when population levels in a species get this low is that you start to get an increased likelihood of genetic disorders due to inbreeding,” says University of Alberta biologist Andrew Derocher.Luckily for the bears and the humans who love them, Derocher and a cadre of fellow scientists are developing a complex set of strategies to save the animals. It’s an audacious plan, encompassing everything from providing extra food for the bears to turning female grizzly bears into surrogate moms for their white-coated cousins.But it may be all that stands between the bears and oblivion. […]But Amstrup warns that unless we find ways to mitigate the ongoing warming of the Arctic, the species will cease to exist in the wild even if we turn to assisted reproduction.“If human-driven climate change continues unabated, the last ice areas will ultimately disappear, and the remaining wild bears with them,” he says. “There’s no future for polar bears in an Arctic without the sea ice which enables them to hunt and form the dens where they raise their cubs. From then on, the species will only exist in zoos.” [more]

Scientists hatch bold plan to save polar bears