It’s the world’s largest land carnivore, a fearsome beast weighing over half a tonne, a survivor in one of the most hostile environments on the planet, and yet it is cute enough to be depicted as a cuddly toy. The polar bear (Ursus maritimus) is an iconic animal, all the more so now that it has become a symbol of the threats of climate change: in an increasingly warmer world, those who depend on ice stand to lose. But is the polar bear on the brink of extinction?
An image of a polar bear sleeping on a small iceberg won the People’s Choice Award in the Wildlife Photographer of the Year competition in 2023. The photograph by British photographer Nima Sarikhani, entitled Ice Bed, taken in the Norwegian archipelago of Svalbard, shows a young male polar bear taking a nap on a small iceberg after carving out a hollow for himself with his claws. Although the image does not show the bear in danger, it has once again served as a wake-up call about the risk facing the species, joining previous images of starving bears, although again with no direct link to the effects of climate change.
A successful species living on the edge
From our human perspective, polar bears survive on the edge. From nature’s point of view, it’s a highly successful species that has adapted to a niche where it has no direct rival on the water. Of the eight species of bears that survive today, the polar bear is most closely related to the brown bear, with which it can breed. The two branches diverged hundreds of thousands of years ago, or perhaps a million, and the polar bear found its home on the Arctic ice.
Today, their status varies between subpopulations: of the nine for which there is sufficient data, three are in decline, particularly the southernmost Canadian ones. Despite this, according to the WWF, “polar bears are among the few large carnivores that are still found in roughly their original habitat and range—and in some places, in roughly their natural numbers.”
The threat of climate change
But it is undeniable that, with the Arctic being the region most affected by warming, and threatened by interests seeking to exploit its resources by taking advantage of the melting ice, the polar bear is at risk. A 2023 study found that the current impact of climate change on polar bears has already been far greater than the natural variation in conditions over the past 4,000 years. What are the prospects for this species?
According to the UN’s Intergovernmental Panel on Climate Change (IPCC) report on the cryosphere, warming of 2°C or less—the upper limit set by the 2015 Paris Agreement—will be a severe blow to the polar bear, with researchers predicting the complete disappearance of Arctic summer ice over the next century. More specifically, studies have shown that as the ice retreats, bears will be forced to travel greater distances and swim further to find food, consuming more energy and increasing the risk to their cubs.
A 2023 study reveals that when floating ice melts in summer, bears are forced to spend months on land without access to their primary prey, seals, causing them to lose a kilo of weight per day and threatening them with starvation. This also reduces milk production in the mothers, which is harmful to the survival of their pups. The study’s first author, Louise Archer of the University of Toronto, says that “impaired lactation has likely played a role in the recent decline of several polar bear populations.” Lack of food also causes bears to scavenge on garbage, where they can eat products that poison them—for example, they are attracted to the smell of antifreeze fluid—or plastics that kill them, as well as leading to an increase in attacks on humans.
A bleak future
Overall, the future for polar bears is bleak. In 2020, the first predictive study concluded that “with high greenhouse gas emissions, steeply declining reproduction and survival will jeopardize the persistence of all but a few high-Arctic subpopulations by 2100.” According to study co-author Steven Amstrup of Polar Bears International, “moderate emissions reductions may prolong global persistence, but are not likely to prevent the extirpation of several populations, emphasizing the urgency of more ambitious emissions cuts.” Arctic climate change expert Robert Newton of Columbia University agrees: “My best guess is that polar bears could go extinct somewhere between 2050 and 2100.”
On the positive side, at least the management of these animals is improving: stable polar bear populations in Canada have been maintained thanks to successful collaborative mechanisms between scientists and Inuit communities. Climate change will continue to be the limiting factor, but if demands for emissions reductions are met, humans may be able to help this iconic species survive.
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