Only ‘aggressive’ cuts to carbon emissions can save polar bears from extinction, study says

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Melting sea ice could “jeopardise” the survival of most of the Arctic’s polar bear population by 2100, a new study claims.

Researchers from the University of Toronto in Canada said a loss of sea ice caused by global warming will force them on to land, where they must rely on fat reserves due to a lack of food.

The study, published in Nature Climate Change, said “aggressive” cuts to greenhouse gas emissions are now needed to save the polar bears, which rely on sea ice to reach their prey, from extinction.

Researchers used modelling to determine a polar bear’s energy requirements while fasting and the thresholds that would limit survival, along with a model to predict the future number of ice-free days.

This was then used to estimate when the survival thresholds would be surpassed for 13 Arctic sub-populations, representing 80% of all polar bears.

Summer weather July 25th 2018
A polar bear (Danny Lawson/PA)

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Study author Peter Molnar and his colleagues found that, under a high greenhouse gas emissions scenario, the bears’ survival would be “unlikely” over much of the Arctic due to reduced sea ice.

However, under a “moderate emissions scenario”, more sub-populations could survive this century.

“Ultimately, aggressive greenhouse gas emissions mitigation will be required to save polar bears from extinction,” the study said.

Researchers found that cubs would be most at risk from fasting, while solitary adult females would be the least affected.

It also found that survival thresholds may have already been reached in several polar bear sub-populations.

The authors said their study was limited by the use of a single “earth systems model” – used to determine how sea ice will be affected – and because of uncertainties and variations in bear behaviour and energy usage among sub-populations.

“Our model captures demographic trends observed during 1979 to 2016, showing that recruitment and survival impact thresholds may already have been exceeded in some (polar bear) sub-populations,” the authors said.

“It also suggests that, with high greenhouse gas emissions, steeply declining reproduction and survival will jeopardise the persistence of all but a few high-Arctic sub-populations by 2100.”

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  • Show Comments
    1. This is pure speculation. We were told for years that polar bears were threatened with extinction because of “global warming/anthropogenic climate change”. In reality, the bears were thriving. Their numbers are higher than ever. So why this wild speculation now? Could it be to bolster the ruinous “Green New Deal” that is about to be foisted on us and which is essentially about saving the global banking and finance system under the smokescreen of environmentalism.

    2. I thought the Arctic sea Ice went in 1980, or was it 1990, 2000, 2012, 2015 or pick a year, these bullshiting twats should loose a limb every time they get it wrong to stop them scaring my kids, and yes there are more polar bears now than ever due to the restrictions on hunting not me cycling to work, that’s why they are moving south. I dispair with people who can’t be arsed to check this stuff out. Otherwise a very good website.

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