If the goals of the Paris Agreement are missed, these polar bears could become extinct
Polar bears in Southern Hudson Bay could become extinct as early as the 2030s as the sea ice that helps them hunt thins, a new study suggests.
“We know that loss of Arctic sea ice would be catastrophic for polar bears, so this could be The first sub-population disappeared.” Earth & Environment Communications.
Last month, the eastern half of Hudson Bay, the world’s most studied polar bear habitat, not frozen a month earlier than usual.
Polar bears are accustomed to ice-free seasons lasting about four months when they rely on their blubber reserves until the ice improves and they can hunt blubber seals from the ice floes. But the presence of sea ice does not guarantee that bears will be able to hunt; it needs to be thick enough to support them.
While previous research looked at sea ice coverage to determine the species’ ability to survive, Dr. Stroeve and her colleagues used climate models from the Intergovernmental Panel on Climate Change. most recent report to predict when the remaining ice is too thin for bears to hunt successfully.
While there is no consensus on the amount of ice needed to support an adult male polar bear, the study relied on field research to determine a baseline of about 10 centimeters, or just under 4 inches.
Polar bears excel at making do with minimal resources when encountering ice. They crawl. They swayed on their bellies. They stretch their limbs as far apart as possible, spreading their mass evenly across the ice. Sometimes they still fall through. That’s usually not a problem for bears, which are strong swimmers, but it’s a bigger problem if they hunt seals. Breaking through the ice is like an alarm going off, alerting the seal to the presence of a predator.
Polar bears need thick ice for the sprints they often need to catch seals, said Geoffrey York, senior director of research and policy at Polar Bears International and co-author of the study. Sea ice has a high salt content and is more flexible and elastic than glassy freshwater ice. But other experts said 10 centimeters pushed it.
“We’re always trying to find a metric to use,” said Andrew Derocher, a professor of biological sciences at the University of Alberta. “But 10 cm is quite thin. I can’t land the helicopter on that ice. It needs to be twice as thick for polar bears to actually use it.”
Elisabeth Kruger, a World Wildlife Fund manager focusing on the Arctic, said the modeling was less severe than it might have been. “It was actually quite difficult,” she said.
The current ice-free season is about a month longer than what polar bears are used to. From research that when the ice-free period lasts up to six monthsEven the healthiest Hudson Bay bears, generally healthy adult males, will struggle to survive.
Polar bears are considered an indicator species, meaning they predict the health and viability of the broader Arctic ecosystem. The simultaneous loss of sea ice along with the decline in snow cover significantly affects their preferred diet of ringed seals, which have difficulty keeping seal pups alive in the nest. spawn if the snow level drops below 32 cm.
Last year, global temperatures temporarily hit a plateau 1.5 degrees Celsius compared to pre-industrial times. Under the Paris climate accord, countries agreed to try to limit global warming to that level or below to prevent the worst effects of global warming. Although rising temperatures are not permanent, Dr. Stroeve and other scientists say polar bears in this region cannot survive if temperatures exceed 2.1 degrees Celsius above pre-industrial standards. Karma.
Today, there are approx half of the polar bears in Western Hudson Bay as of 1987.
“Our best analysis is that we will still have polar bears until the end of the century,” Dr. Derocher said, referring to the 19 sub-populations living across the Arctic. “But that’s very unlikely in Hudson Bay.”
Hudson Bay bears are unlikely to move from their habitat, even when conditions become difficult. At some point, First Nations and Inuit communities may have to change their traditional polar bear harvesting practices simply to preserve bear populations. Towns may have to figure out how to prevent bears from foraging for human food during difficult times to minimize human-bear conflicts. Longer-term possibilities might include distributing kibble from polar bears, but Dr. Derocher says it’s impossible to maintain a subpopulation that way forever.
“Aside from addressing greenhouse gas emissions, there are no viable actions for long-term population management,” said Dr. Derocher.
