Unchecked climate change could render Hudson Bay polar bears extinct by 2030s, report warns

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This article was published 13/06/2024 (512 days ago), so information in it may no longer be current.

Polar bears in Hudson Bay could be extinct as early as the 2030s if temperature agreements set out in the Paris Climate Accord are not met quickly, as per a new report co-authored by University of Manitoba researchers.

A report, titled “Ice-free period too long for Southern and Western Hudson Bay polar bear populations if global warming exceeds 1.6 to 2.6C,” which was written by researchers from various universities and organizations around the globe, warns a localized extinction of polar bears in northern Manitoba could occur between the 2030s and 2060s.

The report analyzed various climate-warming scenarios if greenhouse gas emissions continue and the globe surpasses the 2 C warming limit as set out in the Paris Agreement, an international treaty on climate change that was adopted in 2015. While research found that parts of the Hudson Bay habitat could be maintained if we’re able to keep warming under 2 C, we’re not hitting that mark today, co-author Alex Crawford said.

“2.6 degrees of warming, that’s above the Paris Climate Accord, but it is worth saying that is less warming then we’re currently on pace for,” said Crawford, an assistant professor in the department of environment and geography.

“We are currently at a trajectory with the amount of emissions that we are putting up into the atmosphere that we will exceed that this century.”

The study looked at sea-ice thickness to determine polar bear survival. Ice that’s too thin to support the animal’s weight for hunting, mating and denning threatens the population.

While research has long warned about the effect of warming temperatures on polar bear populations, the new report uses modelling to determine how much warming would make Hudson Bay no longer habitable for polar bears. It also improves on previous models.

“If we didn’t do the corrections on these models, the projections would look worse,” Crawford said. “We’ve taken a lot of pains to make sure we’re not being alarmist in any of the work that we’re doing here — and even with those efforts, the future does still look very precarious.”

Crawford hopes the detailed research will better inform politicians and policymakers about climate change and polar bear conservation.

“Humans have a lot of agency here,” he said.

“If we were to make policy decisions that would reduce the amount of greenhouse gases we are emitting into the atmosphere, then we have a chance at preserving the Hudson Bay polar bear population.”

While analyses of the data is constantly improving, the discussion is nothing new for John Gunter, the head of tour operator Frontiers North Adventures, who said his company has been managing against troubling reports for two decades.

“As a company, we’re trying to reduce our dependence on polar bears,” he said. “We’re trying to sort of preserve our core business of polar bears and stimulate growth in other areas, including summer beluga whales and winter northern lights.”

The Winnipeg company sells tours to Churchill to see the polar bears in its iconic buggies.

It has been looking at how it can reduce its own emissions, including converting its fleet to electric power. It’s also exploring how to best compost food waste in the sub Arctic.

“We just look at our own business and we figure out what we can do to hold up our end of the bargain for these bears,” he said.

Hudson Bay bruins are the most well-studied polar bear population in the world, having been in scientists’ radar for decades. The area is home to two of the world’s 19 polar bear subpopulations.

Polar Bears International, a conservation non-profit that monitors polar bear activity, has headquarters in Churchill and Bozeman, Mont.

“Churchill itself is a fairly small town, but they really have outsized importance. They are global players in the polar bear world because they’re home to this very important population that has this extensive research history,” said John Whiteman, the organization’s chief research scientist, who is a biology professor at Old Dominion University in Virginia.

While their research has long-term implications for climate change, it’s also of more immediate concern to the residents of Churchill, who have to be on guard for hungry bears wandering into town to search for food.

“Separate from the more long-term climate change concerns, there’s also the more day-to-day concerns that are really important of (asking) how do you live with polar bears?” he said.

Researchers tracking ‘pizzly,’ ‘grolar’ bears

Researchers are exploring another possible side-effect of warming temperatures on bears: they are tracking the rare appearance of “pizzly bears” and “grolar bears” — hybrids of polar and grizzly bears — through a tracking chip developed by a team that includes a U of M researcher.

Ruth Rivkin, a post-doctoral research fellow who works with the U of M, Polar Bears Int., and the San Diego Zoo Wildlife Alliance, studies polar bears and their response to climate change. She analyzed 370 polar bears and 440 grizzly bear samples across Canada, Alaska and Greenland and found there were only eight hybrids bears who were already known to researchers.

“We were interested in trying to understand how often hybridization happens. We knew of these eight hybrid (bears) that existed, and so we wanted to see if this was kind of a unique case between a small number of bears or if it was more widespread,” Rivkin said Thursday.

Researchers have found grizzly bears and polar bears interact more frequently nowadays. Warming temperatures mean they’ve been able to find food and resources on the sea ice in winter, which is when polar bears typically mate.

nicole.buffie@freepress.mb.ca

malak.abas@freepress.mb.ca