A third of the world's polar bears will disappear in next 40 years because of melting sea ice say scientists

Polar bear numbers are expected to collapse by a third in as little as 35 years as ice melts in the Arctic, a study found.

The drop in numbers will reduce the world population of the bears from around 26,000 to 17,000.

Researchers put the probability off a steep fall of around 30 per cent over the next three generations of bears at 71 per cent.

The researchers put the time frame of between 35 and 41 years.

The findings are consistent with polar bears being listed as ‘vulnerable’ on the International Union for Conservation of Nature (IUCN) red list of threatened and endangered species.

Loss of sea ice due to climate change has a direct impact on the ability of polar bears to feed and survive.

The bears need platforms of ice to reach their prey of ringed and bearded seals. Some sea ice lies over more productive hunting areas than others

Scientists have divided polar bears into 19 sub-populations, two of which have already experienced population declines due to shrinking sea ice.

Others have shown signs of ‘nutritional stress’ or are currently said to be ‘stable’ or ‘productive’, according to the study authors.

The researchers combined polar bear generational length with sea ice projections based on satellite data and computer simulation