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

Subscribe to Geographical!

geo line break v3

Free eBooks - Geographical Newsletter

Sign up for our weekly newsletter today and get a FREE eBook collection!

geo line break v3

University of Winchester

geo line break v3

EDUCATION PARTNERS

Aberystwyth University University of Greenwich The University of Derby

TRAVEL PARTNERS

Ponant

Silversea

Travel the Unknown

DOSSIERS

Like longer reads? Try our in-depth dossiers that provide a comprehensive view of each topic

  • Natural Capital: Putting a price on nature
    Natural capital is a way to quantify the value of the world that nature provides for us – the air, soils, water, even recreational activity. Advocat...
    The human game – tackling football’s ‘slave trade’
    Few would argue with football’s position as the world’s number one sport. But as Mark Rowe discovers, this global popularity is masking a sinister...
    Essential oil?
    Palm oil is omnipresent in global consumption. But in many circles it is considered the scourge of the natural world, for the deforestation and habita...
    London: a walk in the park
    In the 2016 London Mayoral election, the city’s natural environment was high on the agenda. Geographical asks: does the capital have a green future,...
    The Money Trail
    Remittance payments are a fundamental, yet often overlooked, part of the global economy. But the impact on nations receiving the money isn’t just a ...

MORE DOSSIERS

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

A new system of robotic aerial vehicles is revolutionising the…

Wildlife

Technology used in creating safe urban environments is now being…

Climate

Brazil’s shift to the right of the political spectrum could…

Wildlife

Laura Cole travels to Orkney to find out why numbers…

Wildlife

The unprecedented frequency of winter tick epidemics have resulted in…

Oceans

Ocean debris, mostly composed of plastic, reaches remote Atlantic islands…

Geophoto

With motion detectors becoming ever more sophisticated, and clearer, crisper…

Nature

Natural capital is a way to quantify the value of…

Tectonics

The reason for the unusual location of Mount St Helens…

Climate

Most plants thicken their leaves in response to higher carbon…

Climate

Not just the preserve of flatulent cows, methane is causing…

Climate

As the United States’ Supreme Court delays a landmark climate…

Geophoto

Of Britain's 15 national parks, the New Forest is probably…

Energy

The Treasury has announced that it is considering imposing a…

Tectonics

Major earthquakes are triggering seismic activity half the world away

Climate

Marco Magrini finds that a warming world also means a…

Wildlife

Unchecked tourism is potentially reducing the number of cheetah cubs that…

Oceans

A relocated military base in Okinawa, Japan will cause ‘irreversible’…

Climate

The ongoing recovery of the planet’s ozone layer is being…

Oceans

The Ocean Cleanup has launched System 001, a floating barrier…