Experts and environmentalists say the broad answer — however controversial and nuanced it may be — is to reduce the present levels of global greenhouse gas emissions in order to curb global warming. In January, federal wildlife officials issued a report that called climate change the biggest threat to the survival of the polar bear.
Polar bears depend on sea ice as a platform for hunting seals. As the planet warms, that ice cover melts earlier and earlier, limiting the amount of time polar bears have to hunt and build up their fat reserves before moving to land. As a result, they can end up skinny and in poor physical health by the end of long ice-free summers.
Biologists agree that as ice cover continues to decrease, there will be a significant drop in the polar bear population, which according to federal wildlife officials stands at about 26,000 globally. A 2015 assessment projected a reduction of over 30 percent in the number of polar bears by 2050.
“Polar bears are built for a feast-or-famine type of eating,” said Elisabeth Kruger, an arctic wildlife program officer with the World Wildlife Fund. “But when that period of fasting gets too long, it can put them on the brink.”
All of which makes the viral images of a fur-and-bones polar bear particularly striking. The bear Mr. Nicklen and his team documented was stuck on land, its muscles atrophied by continuing starvation, and apparently on the edge of death.
One would have to do “a lot of specific investigating” to determine the cause of suffering for a particular polar bear, Ms. Kruger said, but what is captured in Mr. Nicklen’s photo “is one of the ways polar bears die.”
Most of the feedback Mr. Nicklen has received on social media appears positive, if twined with sadness. (The viral video of the polar bear, he noted, has been slowed from normal speed.) But he has also received blowback from some who have complained he did not do enough to help.
“People assume you’re just coldhearted,” he said. “Of course we’re upset.” But feeding the polar bear would not only prolong its misery, he said, it would have been illegal. And “for me to take a gun up to that polar bear and kill it, now you’re looking at jail.”
This is not the first time a downtrodden polar bear has captured the hearts of humans. After all, they are “incredibly charismatic,” Ms. Kruger said, and “big, white, fluffy creatures.”
Last year, a polar bear named Pizza garnered the support of millions of people worldwide when animal welfare advocates began a campaign to move “the world’s saddest polar bear,” as he was known, from a mall in southern China, where the bear lived in a glass enclosure.
Mr. Nicklen said the polar bear he and his team found was never given a cute human name. But he said everyone on the team called it by the same phrase: “The dying polar bear.”