SCOTT SIMON, HOST:
A devastating National Geographic video has been making its way around the world - a polar bear, gaunt and weak from starvation, pawing through garbage at an abandoned fishing camp on Baffin Island. The bear seems so exhausted from hunger it can barely stand. The filmmakers believe the bear was just hours from death. The bear and the video have called renewed attention to climate change and the decline of sea ice that polar bears need to hunt and find food. Steven Amstrup is chief scientist for the conservation group Polar Bears International, and he joins us now.
Thanks so much for being with us.
STEVEN AMSTRUP: Thank you for having me.
SIMON: Must have been hard for you to see this video.
AMSTRUP: It's really heartbreaking for anybody. And for somebody like me, who's spent most of my adult life studying polar bears, it really is a difficult image to watch.
SIMON: As I don't have to tell you, Mr. Amstrup, there were people who took to the Web to say - what do we really know about this bear and the circumstances? From your point of view, what do we know about the plight of this bear?
AMSTRUP: Well, I think, this particular bear, we don't know much. But I'd like to give you a little bit of background that I think many people don't understand. Polar bears eat principally two species of seals, and they can only catch those seals from the surface of the sea ice. Throughout the Arctic, the land foods, the terrestrial foods, are insufficient to feed polar bears. So we can think of the sea ice kind of as the polar bear's giant dinner plate. And it's got these seals laying out there like giant fat pills, and that's what the polar bears have specialized on.
And we also know that there's a linear relationship between global mean temperature and sea ice extent. So the warmer it gets, the less sea ice we have. If we allow the world to continue to warm, we'll have less and less ice that the polar bears depend on. Now, for this particular bear I think that there's kind of two take-home messages. One is, given the background that I just gave you, we know that longer periods of sea ice absence from areas like Baffin Bay will result in more and more bears that are food-deprived and result in a condition like the image that we've seen here.
SIMON: There are people have said, well, you know, we don't really know. Maybe the bear was sick for other reasons.
AMSTRUP: Absolutely. And that was the next point I was going to make is that we know very little about this bear. We know that the bear is malnourished to the point of starvation. I think that the photographers are correct that this bear was probably in its last hours of life. But polar bears have very few natural enemies. You know, humans have hunted them for millennia, and occasionally wolves can kill the young. But for the most part, when polar bears die naturally - and they do, otherwise, the world would be covered with polar bears - typically, it's because of lack of the ability to get food. And so they starve. And so this bear could have had a broken jaw or could have had other injuries that prevented it from being an effective hunter. Maybe it was just unlucky in catching food before the ice went away.
SIMON: So as far as you're concerned, this video could be a kind of wake-up call for people?
AMSTRUP: Exactly, yeah. We can't say for sure what caused the problem that this bear is experiencing. But we do know that, ultimately, if we don't stop the warming of the world, more and more bears will be experiencing this fate. And, ultimately, they'll all be gone.
SIMON: Steven Amstrup is chief scientist for Polar Bears International.
Thanks so much for being with us.
AMSTRUP: Thank you, Scott.
(SOUNDBITE OF MUSIC)
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.