Record low May sea ice rings alarm bells for Hudson Bay polar bears

This article was written by Gloria Dickie and was published in the Globe & Mail on June 14, 2024.

A polar bear walks along the shoreline of the Hudson Bay looking for something to eat near Churchill, Man., in August, 2022.

The extent of sea ice covering Hudson Bay hit a record low for May, intensifying concern over the fate of the some 4,000 polar bears that live there, as new research adds to a growing scientific consensus that the region’s bears are on track to disappear within decades.

Three of the world’s remaining 19 polar bear populations live in and around the vast Hudson Bay, which connects to the Arctic and Atlantic oceans. The region is unique compared to the Arctic as the bay thaws out entirely in summer, forcing bears to come ashore while they wait for the ice to return. The bears do not eat during this time, as they need sea ice to hunt seals.

While the bay normally remains covered in ice in May, this year the eastern portion of Hudson Bay opened up, the National Snow and Ice Data Service said, as strong winds shifted ice westward. This led Hudson Bay to register its lowest extent of ice for May in the satellite record dating back to 1979, at 205,000 square kilometres below average.

“It’s a very unusual situation,” said polar bear biologist Andrew Derocher of the University of Alberta. “There are fewer bears in eastern Hudson Bay, but there is much less known about where they come from.”

Bears using the area, he added, probably moved out as the ice shifted this year. “But if they got stuck on the offshore islands, they’ll likely be in trouble as the ice disappeared from that area and hasn’t come back,” he said.

Mr. Derocher said the bears he observed during spring fieldwork in western Hudson Bay appeared to be in good condition, but that will not continue as climate change upends the bears’ habitat.

A study published in the journal Nature Communications Earth and Environment on Thursday highlighted the peril facing the world’s southernmost polar bear populations.

If the world were to breach the UN Paris Agreement target of limiting global warming to 1.5 degrees Celsius above preindustrial temperatures, the research suggests polar bears in western Hudson Bay and southern Hudson Bay would be in serious trouble.

Under current emissions policies, the world is on track to surpass 1.5 degrees of warming in the 2030s.

“The disappearance of the southern Hudson Bay polar bears is imminent, with western Hudson Bay not far behind,” said study lead author Julienne Stroeve of the University of Manitoba.

“If we go over the 2 C of warming, we can’t really hope that those bears will still stay there.” The western Hudson Bay polar bear population has already fallen by half since 1987.

The research, which used warming projections from 20 climate models, determined western Hudson Bay would become an unsuitable habitat for polar bears at around 2.2 degrees of warming.

Southern Hudson Bay would no longer be able to support bears at between 1.6 and 2.1 degrees of warming, as the lengthened open water period would force bears to fast beyond the point of survival.

While previous studies have made similar projections, the new research factored in sea ice thickness for the first time. Even if sea ice is present, it may not be thick enough to support the weight of an adult bear.

Past studies assessing future polar bear survival, Ms. Stroeve said, may have underestimated how long polar bears will be forced to go without hunting by around 50 days when only examining sea ice extent.

Author: Ray Nakano

Ray is a retired, third generation Japanese Canadian born and raised in Hamilton, Ontario. He resides in Toronto where he worked for the Ontario Government for 28 years. Ray was ordained by Thich Nhat Hanh in 2011 and practises in the Plum Village tradition, supporting sanghas in their mindfulness practice. Ray is very concerned about our climate crisis. He has been actively involved with the ClimateFast group (https://climatefast.ca) for the past 5 years. He works to bring awareness of our climate crisis to others and motivate them to take action. He has created the myclimatechange.home.blog website, for tracking climate-related news articles, reports, and organizations. He has created mobilizecanada.ca to focus on what you can do to address the climate crisis. He is always looking for opportunities to reach out to communities, politicians, and governments to communicate about our climate crisis and what we need to do. He says: “Our world is in dire straits. We have to bend the curve on our heat-trapping pollutants in the next few years if we hope to avoid the most serious impacts of human-caused global warming. Doing nothing is not an option. We must do everything we can to create a livable future for our children, our grandchildren, and all future generations.”