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Polar bears may face extinction by 2100, scientists warn

A polar bear family at Svalbard in northern Norway, 10 July, 2020

 

Polar bears may face extinction by 2100, scientists warn

 

By Patryk Krych | The World Daily | JULY 21st 2020

 

For the first time, scientists have developed a prediction for when they think polar bears may face their extinction. The prediction is based on the current curve of climate-affecting carbon emissions – the main threat to the species’ existence.

A study was recently published in Nature Climate Change, exploring the manners in which polar bear populations may be affected by two varying greenhouse gas emission scenarios. According to the study, many polar bears may begin to experience failure in reproduction capabilities by as early as the year 2040. This is thought to be the first step towards their eventual extinction.

The study further shows that even if the current emission rates are slightly lessened, the polar bears would still end up experiencing reproductive failure by 2080. At the present rate, it is predicted that by the end of the century, polar bears’ last remaining appropriate habitat will be on the Queen Elizabeth Islands, in Canada’s Arctic North.

“It’s been clear for some time that polar bears are going to suffer under climate change,” said Péter Molnár, who lead the study, and is a biologist at the University of Toronto Scarborough. “But what was not fully clear was when we would expect major declines in the survival and reproduction of polar bears that could ultimately lead to their extirpation. We didn’t know whether that would happen early or later in this century.”

Molnár and his colleagues performed the study by estimating the maximum amounts by which a polar bear could get fat and thin, and then derived the total number of days they could go without food before both the adult and cub’s survivability rates saw a decline. This estimate was developed by modelling the animals’ energy usage.

At present, there are fewer than 26,000 polar bears left in the world, scientists estimate. The current pace of climate change has severely affected ice levels in their usual hunting grounds – ice they rely on for sustenance, as they hunt fish and seals through their breathing holes. If forced to migrate over to land, they wouldn’t be able to survive, given their instinctual hunting tactics. Ice levels continue to decrease yearly.

“With something like polar bears, where you’re not going to get their habitat back, it’s not clear we’re going to try to hold on to these populations everywhere,” said Andrew Derocher, a biology professor at the University of Alberta who heads the Polar Bear Science Lab. He is unaffiliated with the study. “If we start to see a large number of bears on land dying of starvation, what kind of interventions would we get into?”

Derocher spoke on the potential issues that could arise in terms of the inevitable “increased human-bear conflict,” referring to the Arctic communities that could see more polar bears in their localities, and how not all are prepared for their increased presence. Some have programmes in place for dealing with polar bear presence – others have no such programmes. He also added that polar bear managers will have certain issues to work out, those primarily being whether to feed the bears when they inevitably start to migrate away from the melting ice, or consider relocating them back to icy areas.

“Imagine going to Churchill, Manitoba -a hub of polar bear tourism- and seeing 50 bears walking around like that [starved]. The public outcry is going to be intense and managers need to be thinking about what their policies are going to be now,” Derocher said.

Currently, polar bears are residing in various icy places, from Svalbard, Norway, to Hudson Bay in Canada, as well as the Chukchi Sea. 13 of the world’s 19 polar bear subpopulations were analysed in the study, which accounts for 80% of the species’ total population. The study found that in a scenario of unmitigated emissions, the polar bears inhabiting the Southern Hudson Bay, and the Davis Strait in Canada were all “very likely” to suffer reproductive failure by 2040.

“Even if we mitigate emissions, we are still going to see some subpopulations go extinct before the end of the century,” Molnár said. “But we would have substantially more populations persisting by the end of the century, even with reduced reproduction, compared with a business-as-usual emissions scenario.”

Steven Amstrup, chief scientist for Polar Bears International and a co-author of the study, warned that the current projections were “probably on the conservative side.”

He explained, stating that the models used for the study were in a better form than reality in terms of the bears’ body conditions, at the beginning of their fasting periods. “The impacts we project are likely to occur more rapidly than the paper suggests.”

Polar bears are unlike many other endangered species, in the sense that their natural habitats cannot be regrown or replanted. The defamation of their icy hunting grounds is a result of the entire world, and the emissions released from all around it. Saving polar bears means battling climate change. If the issue is to be properly addressed, Armstrup said, then it is most important that the public take notice, and understand its urgency.

 

By Patryk Krych | © The World Daily 2020

 

 

Categories:
Environment
Tags:
WildlifeEnvironmentArcticPolar regions