The video is tough to watch: A crew from the conservation group Sea Legacy came across a starving polar bear in Canada's Baffin Islands that clearly didn't have long to live. "We stood there crying—filming with tears rolling down our cheeks," photographer Paul Nicklen tells National Geographic. As Live Science notes, it's impossible to say conclusively what is behind the death of any individual bear, but Nicklen says the answer is obvious in this case: climate change. Melting sea ice has made it difficult for the bears to gain access to a staple of their diet, seals. In the video, shot in late summer, the rail-thin bear is seen rummaging through a trash can. "When scientists say bears are going extinct, I want people to realize what it looks like," says Nicklen. "This is what a starving bear looks like."
In its coverage of the video, the Guardian cites a 2015 study from the International Union for the Conservation of Nature citing rising temperatures as the No. 1 threat facing the global population of 26,000 polar bears. The study documents an increasing number of ice-free days in Arctic regions and suggests that the bear population could drop 30% by 2050 and eventually reach a tipping point after which extinction is inevitable. So why didn't Nicklen and the crew help this particular bear? It would have been a futile effort that would only have prolonged the bear's agony, he says. Plus, feeding bears is illegal in Canada. In any event, it's "not like I walk around with a tranquilizer gun or 400 pounds of seal meat." (Read more polar bears stories.)