Global warming: Polar bears could become extinct as early as the 2030s

The future of polar bears in Hudson Bay, Canada, looks bleak: a new study warns that polar bears could become regionally extinct as early as the 2030s if global warming continues to rise and surpass critical thresholds.

Researchers from several North American and international institutions caution that a global temperature increase exceeding two degrees Celsius could have catastrophic effects on the polar bears in the southern and western Hudson Bay. The report, published in the journal Communications Earth & Environment, analyzes various warming scenarios and their impacts on sea ice, seals, and polar bears.

Ice-free days in Hudson Bay on the rise

Hudson Bay, a seasonally ice-covered marginal sea of the Arctic Ocean, is home to large populations of polar bears (Ursus maritimus). Every July, the receding sea ice forces the bears to go ashore where they rely on their fat reserves during the ice-free months until they can return to the ice in winter to continue hunting seals.

Research based on climate models, satellite data, and simulations shows that warming is significantly reducing the number of days Hudson Bay is covered by sea ice. This has dramatic implications not only for polar bears but also for ringed seals (Pusa hispida), one of their primary food sources. The diminishing sea ice cover compromises the seals’ habitat, as they build their dens in the deep snow on the ice.

The warming already caused by climate change has led to an extension of the ice-free period in Hudson Bay, resulting in a decline in polar bear populations, especially in the western Hudson Bay. This decline, which has been observable since the 1990s, is primarily due to the earlier breakup of sea ice.

Even with a moderate warming of 1.6 degrees Celsius – a threshold the world is currently nearing – polar bears in the southern Hudson Bay might not survive. With two degrees of warming, the ice-free periods in this region are expected to last between 174 and 182 days. Most ecologists believe that polar bears would not survive a fasting period of more than 180 to 200 days.

Urgent global action required

The future of polar bears and ringed seals in Hudson Bay faces significant challenges. To combat the effects of climate change and improve the survival prospects of these species, global efforts are essential. Each individual can contribute by reducing emissions and minimizing their own carbon footprint. However, crucial measures are also necessary at the national and international levels that prioritize sustainability over profit.

Although the current report primarily focuses on the impacts of climate change on polar bears and Hudson Bay, the insights gained are applicable to other parts of the world that depend on specific ecosystems. For instance, climate change also threatens the coral reefs in Florida and Australia. A poignant example of the impacts of climate change is the extinction of the Bramble Cay melomys, whose habitat, Bramble Cay, was submerged by rising sea levels between 2009 and 2011.