Our directory of things of interest

University Directory

Polar bear populations to decrease 30 per cent by 2050

Polar bear populations to decrease 30 per cent by 2050 outdoorsman
06 Jan
2017
The toll, as a response to melting sea ice, would result in 8,600 less individuals from an estimated population of 26,000

An extensive study by the US Fish and Wildlife Service has predicted that in the next 35 to 41 years, polar bear populations across the Arctic could reduce by almost a third.

Such a toll has a 71 per cent likelihood of occurring, the study states, a prediction determined by averaging three possible scenarios of polar bear reactions to melting sea ice. Three were needed because polar bears are divided into 19 subpopulations across the region and are not all reacting to ice melt in the same way. Some subpopulations have shown declines, some show nutritional stress while others have been observed as being either productive or simply stable.

‘The data used in our study were obtained from long-term research programs on polar bears across their range,’ explains Kristin Laidre, a principal scientist at the Polar Science Center, University of Washington who contributed to the report. One of the three scenarios projected a proportional decline of bears with sea ice. The other two projected losses out of already observed changes to 11 of the 19 subpopulations. ‘Finally, we also used satellite data from NASA to look at the sea ice trends in each subpopulation,’ she says.

Polar bears use platforms of sea ice to hunt for seals. Because they hunt little else, reductions in sea ice can seriously impact their nutrition and the survival rate of cubs. The satellite data revealed that ice cover has declined in all 19 of these subpopulation ranges over the last 35 years. ‘Anthropogenic climate change is the primary threat to the species because, over the long-term, global temperatures will increase and Arctic sea ice will decrease as long as atmospheric greenhouse gas concentrations continue to rise,’ the report states.

It concludes that its results are consistent with the polar bear having an IUCN listing of ‘vulnerable’.


For more great content like this, sign up below for our FREE weekly newsletter. The best of Geographical in your inbox, every Friday afternoon!

 
 
 

Related items

NEVER MISS A STORY - Follow Geographical on Social

Want to stay up to date with breaking Geographical stories? Join the thousands following us on Twitter, Facebook and Instagram and stay informed about the world.

More articles in NATURE...

Wildlife

Invasive species are considered one of the greatest threats to…

Nature

Professor Steve Fletcher, director of the Global Plastics Policy Centre…

Wildlife

The international conservation agreement CITES is nearly half a century old.…

Wildlife

With Scotland’s salmon under threat, environmental groups are planting trees…

Oceans

As coastal development continues to grow, research begins to reveal the…

Wildlife

Research into rhesus macaques on a remote island finds that survivors of…

Climate

 The release of the latest IPCC report suggests it's 'now…

Wildlife

A new technique to collect animal DNA from thin air could…

Wildlife

As animal species decline, plants that rely on them to…

Nature

Calls to make ecocide a crime are gaining ground

Wildlife

In South Africa, a new wave of poaching has taken…

Tectonics

A volcanologist unpicks the devastating eruption of Hunga Tonga-Hunga Ha’apai

Oceans

Some areas of the ocean are richer in microplastics than…

Oceans

The ocean floor is home to rich deposits of metals…

Climate

The industry will only keep growing. Could algae help to…

Nature

A monumental effort is underway to map the world’s fungal…

Geophoto

In his project Black Dots, Nicholas JR White set out upon the…

Wildlife

China’s Amur tiger population is recovering, reflecting the country’s changing…

Climate

Scientists are pushing back against the notion that the food…

Geophoto

Xavi Bou's artistic visions of flight beguile the eye