Climate change could mean the near-extinction of polar bears by the end of the century, a new study has warned.

Scientists said in a report published in Nature Climate Change on Monday that the gradual disappearance of their habitat due to shrinking sea ice is cutting short the time bears have for hunting seals.

Steven Amstrup chief scientist of Polar Bears International who came up with the study told AFP that bears face an ever longer fasting period before the ice refreezes and they can head back out to feed.

The carnivores, which live in Arctic regions where temperatures can drop as low as -40°C in winter, can fast for months, especially during the summer when ice melts every year.

The time period without ice is lasting longer and longer with global warming. Unable to find an food source to seals, more and more hungry bears are venturing from their usual territories closer to areas.

According to current trends, polar bears in 12 of 13 subpopulations analysed will have been decimated within 80 years by the galloping pace of change in the Arctic, which is warming twice as fast as the planet as a whole, the study found

There was not enough data for six others to make a judgement on their fates.

Lead author Peter Molnar, a professor at the University of Toronto said by estimating how thin and how fat polar bears can be, and modelling their energy use, we were able to calculate the number of days that polar bears can fast before cub and adult survival rates begin to decline.

Females are worst-affected by the phenomenon as they go into their dens in autumn ready to give birth in mid-winter and emerge in the spring with their cubs, according to the study.

They must then catch enough seals to store enough fat and produce enough milk to feed their cubs throughout their summer fast,” said Amstrup.

He added by 2100 new births will be severely compromised or impossible everywhere except perhaps in the Queen Elizabeth Island subpopulation in Canada’s Arctic Archipelago.

The scenario in the study predicts the average surface temperature of the earth rising 3.3°C above the preindustrial benchmark — 1°C of warming so far has caused heatwaves and droughts among other such natural events.

Scientists paint a bleak picture if we continue down the same path and even if we could cap global warming at 2.4°C, which is 0.5°C above goals mentioned in the Paris Agreement.

Amstrup said the only way to save them is to protect their habitat by halting global warming,

If somehow, sea ice could be maintained even as temperatures increase, polar bears might be fine.

The problem is that their habitat is literally melting.

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