Arctic polar bears "face near-extinction within decades" warn scientists - BBC News

Arctic polar bears are facing near extinction by the end of the century if the sea ice they depend on continues to disappear. That's the stark warning from a new study looking at the long-term future of the bears as greenhouse gas emissions contribute to the melting of the bears' frozen hunting grounds. Our science correspondent Victoria Gill has the story. They are the poster species for climate change. Predators that depend on a fragile transient hunting ground, the Arctic sea ice. And this study has shown that polar bears' survival is tied to that ice. The scientists used models based on satellite data to forecast sea ice decline in the Arctic over the coming decades. That enabled them to predict a future tipping point to create a timeline for when the frozen hunting season will be too short for the bears to fatten up before the summer. At the current rate of warming, the researchers say all but a few polar bear populations will collapse before 2100. With less fat they're entering a fasting season that's longer than it used to be. So is that now unavoidable? Are we already on that trajectory to just lose polar bears? The trajectory that we're on now is not a good one. But if society gets its act together globally, we can halt global warming in time to save polar bears. And if we do, we'll benefit the rest of life on earth, including ourselves. The consequences of climate change are already playing out in the Arctic landscape. And this new timeline, the researchers say, is a stark reminder that the survival of an entire species is at stake. Victoria Gill, BBC News.