As a photographer Paul Nicklen and filmmakers of the conservation group SeaLegacy Arrived on the Baffin Islands in late summer, they encountered a heart-wrenching sight: a starved polar bear on its deathbed.

Nicklen is no stranger to bears, the biologist and wildlife photographer has seen over 3000 bears in the wild since growing up in the far north of Canada. But the emaciated polar bear seen in the video Nicklen posted to social media on December 5 was one of the worst sights he has ever seen. "We stood there crying and filming with tears on our cheeks," he said. The video shows a polar bear clinging to life, its white hair limp covering its thin, bony body. The bear drags one of its hind legs behind it, probably due to muscle wasting. In search of food, the polar bear slowly rummages through a nearby trash can used seasonally by Inuit fishermen. He finds nothing and falls back on the ground in resignation.

In the days that Nicklen released the footage, he was asked why he didn't intervene. "Of course that's what came to mind," Nicklen said. "But it's not like I'm walking around with a tranquilizer gun or 400 pounds of seal meat. And even if he did,' said Nicklen, it would only have prolonged the bear's misery. In addition, feeding wild polar bears is illegal in Canada. The wildlife photographer says he filmed the bear's slow, agonizing death because he didn't want it to die in vain. "When scientists say bears are going extinct, I want people to see what it looks like. Bears will starve," Nicklen said, "and this is what a starved bear looks like."

By telling the story of the polar bear, Nicklen hopes to get a bigger message across about the deadly consequences of global warming. Polar bears have long been ignorant mascots of the effects of climate change. As animals that only live in arctic regions, they are often the first to feel the effects of warming and rising sea levels. The big bears mainly feed on seals on the sea ice. During the summer months, it is not uncommon for polar bears to live months without eating while waiting for the arctic ice to solidify. In 2002, the World Wildlife Fund report predicted that climate change could ultimately endanger or cause polar bears to become extinct. Even then, the report found that polar bears used to move from ice to land and stayed longer on land, making the bear fasting season unhealthy. At the end of summer, most of the bears examined by the World Wildlife Fund showed signs of hunger.

Heartbreaking video shows starving polar bears in the ice-free Arctic

Fifteen years later, the icy polar bear hunting grounds are in even worse shape. The national snow and ice data center, which tracks sea ice cover annually, has consistently seen record lows in its reporting on sea ice - a decline that is only likely to get worse. One recently in the magazine Biosciences published study examined how climate research is often falsely discredited. The study found that climate deniers are able to downplay the threat of climate change by discrediting the polar bear threat. A study carried out last year by the European Geoscience Union and this year from US Geological Survey was released, but confirms that melting sea ice continues to be an existential threat to polar bears.