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...

Oceans

Many scientists believe that jellyfish numbers are increasing, pointing to…

Geophoto

Prepare to be inspired, startled and filled with awe in…

Climate

Excessive use of nitrogen-based fertilisers is contributing to numerous environmental…

Energy

A group of scientists from Edinburgh University has come up…

Geophoto

​This year’s winning environmental photographs show the impacts of the…

Wildlife

A WWF report has revealed that global forest vertebrate populations…

Climate

Yesterday saw one of the biggest public protest movements in…

Climate

On the eve of millions of world citizens going on…

Wildlife

Around 75 million birds are kept as pets in Indonesia,…

Wildlife

Migratory animals are actively adjusting their traditions to cope with…

Climate

How many trees can you plant in a day?

Polar

New analysis of NASA data has led to the discovery…

Climate

Naomi Klein is back and calling for a new world…

Geophoto

The move away from film has meant more pictures being…

Oceans

As the ocean looks set to get busier due to…

Climate

A report details how tropical storms are fuelling the rise…

Wildlife

After years of trials, talks, tweaks and test runs, EarthRanger…

Climate

Nationalism might gain political points in certain parts of the…

Geophoto

With guaranteed sunshine, bright blue skies and not a hint…

Oceans

A review of coral-saving methods is helping communities decide which…