A new study warns that polar bears in Canada’s Hudson Bay could face local extinction by the middle of this century if global temperatures rise more than 2 degrees Celsius above pre-industrial levels. The research, published in the journal Communications Earth & Environment, found that the number of days without sea ice in the region has been increasing, forcing polar bears to spend more time on land without access to their primary food source: seals. Julienne Stroeve, the study’s lead author and an Arctic climate scientist from the University of Manitoba, said that the bears in southern Hudson Bay, where winter ice takes longer to return, would likely be the first to disappear.
“Those bears are unlikely to survive in that region and could disappear by the middle of this century,” Stroeve told AFP. She added that the collapse of the western Hudson Bay bear population would probably follow. Under the 2015 Paris Agreement, nations pledged to limit global warming to well below 2C and to strive for a safer 1.5C cap to avoid the worst effects of climate change.
However, global temperatures have already risen by 1.2C compared to the pre-industrial era, and current trends suggest a rise of up to 2.9C by 2100. The study found that with 2C of warming, southern Hudson Bay would be ice-free for more than 180 days, exceeding the “hard limit” of what polar bears can endure. The threshold would be breached in western Hudson Bay at between 2.2C and 2.6C of warming.
Hudson Bay polar bear survival threat
“It might start getting too long, then they won’t be able to survive,” Stroeve said. Longer ice-free periods are already affecting polar bear breeding and making their local extinction appear inevitable.
Other research has shown that Hudson Bay’s bears are trying to adapt by finding alternative food sources on land, but these cannot match the caloric value of their primary marine diet. Southern Hudson Bay is now experiencing ice-free conditions earlier than usual, with some areas already clear—a phenomenon that typically would not begin until early July. “This is the earliest breakout of ice we’ve ever seen,” Stroeve said.
“That doesn’t spell good news for the bears.”
The findings suggest that Hudson Bay’s polar bears can be seen as indicators for the future of other polar bear populations across the Arctic. “It sort of gives us a wake-up call. This is starting to be the fate of these bears,” Stroeve cautioned.
The study underscores the urgent need for global action on climate change to preserve polar bear populations and their habitats. Without significant efforts to reduce greenhouse gas emissions and limit global warming, these iconic Arctic animals could face a bleak future.
