Emily Chan
Within the next few decades, the polar bears in Canada’s Hudson Bay are projected to disappear altogether as global temperatures continue to rise. If we don’t try to slow down the effects of global warming, we’ll never see these animals again.
In a new study, researchers predicted when the sea ice in the Hudson Bay would be too thin for polar bears to survive on by examining the latest climate models from the Intergovernmental Panel on Climate Change.
They found that the southern population of polar bears in Hudson Bay would die off if global temperatures increased between 1.6 and 2.1 degrees Celsius. If they climb up to between 2.2 and 2.6 degrees Celsius, the western population will vanish as well.
A thick layer of ice forms on top of Hudson Bay every fall, which helps the bears hunt for seals. The ice melts in the spring, which is when the bears return to land. They rely on their fat stores for survival until the ice forms again.
However, as the world grows warmer, the formation of sea ice is delayed in the fall and melting earlier in the spring.
This means that polar bears must fast for longer. If these lengthy ice-free periods continue, the polar bears will be unable to reproduce and will eventually starve to death. It is estimated that the southern population of bears in Hudson Bay could disappear as soon as the 2030s.
The ice also needs to be thick enough to support the weight of the bears. Polar bears can weigh up to 1,300 pounds. They often dash across the ice to catch seals.
Scientists believe that sea ice must be just under four inches thick in order to hold the weight of the creatures. Others say that the ice should be thicker than that.
“I can’t land a helicopter on that ice,” Andrew Derocher, a professor of biological sciences at the University of Alberta, said. “It needs to be about twice that thick for polar bears to be really using it.”
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