Polar bears and climate change


in Canada, Economics, Politics, Science, The environment

Tristan's friend Nell in a beret

From the media coverage, it seems that attitudes at Canada’s recent polar bear summit clustered around two positions: that climate change is a profound threat to the species, and that the species has been doing well in recent times. While a lot of the coverage is focused on supposedly different kinds of knowledge, I am not sure if there is much factual disagreement here. The issue isn’t the current size of the polar bear population, or how it compares with the size a few decades ago. The issue is whether a major threat to the species exists and can be anticipated, as well as how polar bear populations ought to be managed in the next while.

One quote from Harry Flaherty, chair of the Nunavut Wildlife Management Board, seems rather telling:

[Researchers and environmental groups] are using the polar bear as a tool, a tool to fight climate change. They shouldn’t do that. The polar bear will survive. It has been surviving for thousands of years.

This sits uneasily beside the knowledge that atmospheric concentrations of carbon dioxide are already higher than they have been in more than 650,000 years and they are on track to become much higher still. In short, because of climate change, the experience of the last few thousand years may not be very useful for projecting the characteristics of the time ahead. This is especially true in the Arctic, given how the rate of climatic change there is so much higher than elsewhere.

On the matter of polar bear hunting, the appropriate course of action is less clear. Hunting in a way that does not, in and of itself, threaten polar bear populations might be considered sustainable. At the same time, it might be viewed as just another stress on a population that will be severely threatened by climate change. Given the amount of climate change already locked into the planetary system, it does seem quite plausible that the polar ice will be gone in the summertime well before 2100 and that all of Greenland may melt over the course of hundreds or thousands or years. I don’t know whether polar bears would be able to survive in such circumstances. If not, the issue of how many of them are to be hunted in the next few decades isn’t terribly important. It seems a bit like making an effort to ration food on the Titanic.

If we want to save polar bears, we will need to make an extremely aggressive effort to stabilize climate. Meeting the UNFCCC criterion of “avoiding dangerous anthropogenic interference in the climate system” would not be enough, since polar bears are likely to be deeply threatened by a level of overall change that doesn’t meet most people’s interpretations of that standard.

{ 20 comments… read them below or add one }

. January 19, 2009 at 11:34 am

Canada: Climate change measures won’t help polar bears
Source: Copyright 2009, Canwest News Service

“There’s nothing Canada can do on its own to fight climate change that will improve the plight of the polar bear, Environment Minister Jim Prentice told reporters Friday.”

Canada: Science clashes with Inuit tradition as experts meet to decide fate of polar bear
Source: Copyright 2009, Canadian Press

Canada’s polar bears are not teetering on the brink of extinction and don’t need the alarmist rhetoric coming from some of the world’s biologists, some Inuit experts said Friday at a one-day summit to discuss the fate of the arctic mammals.

While scientists warned vanishing sea ice and over-hunting means two-thirds of the iconic predators could be gone within 50 years, the people who have shared “a personal relationship” with polar bears for thousands of years say the threat is exaggerated.”

Magictofu January 19, 2009 at 1:28 pm

I am glad to see some common sense on this issue. Past polar bear population trends are not linked to the current threat. Also, the number of polar bear encounters per years (read traditional knowledge) seems like a very bad proxy to estimate the polar bear population particularly if starved bears tend to roam around villages and other inhabited places in order to find some sustenance or because they are stranded on land because of the disapearance of the ice-sheet.

That being said, could we assume that a careful hunt aimed at reducing the number of bears (particularly the weaker ones or those that roam around inhabited places for food) just below the ratio of the estimated population decline associated with climate change could be appropriate?

Milan January 19, 2009 at 1:41 pm

I think the sensible position is the following:

Managing polar bear hunting is necessary but not sufficient to protect the polar bear species. While preventing unsustainable hunting is necessary, it is only through aggressive climate change policies that we can maintain a high likelihood that the species will survive. Indeed, stopping climate change at a level compatible with polar bear survival may be far more difficult and costly than stopping it at a level compatible with reasonable human prosperity.

Note that ‘prosperity’ here refers more to being able to maintain agriculture and avoid runaway climate change impacts, rather than continued fossil fuel-powered economic growth.

R.K. January 19, 2009 at 3:13 pm

The choice seems to be: would you prefer to have your polar bears drowned or shot?

R.K. January 19, 2009 at 3:18 pm

Personally, I find it amazing that any human being out there wants to kill polar bears or, for that matter, lions and tigers.

It’s such a stupid caveman mentality it makes me sick. What does it prove when you kill a rare, powerful, and beautiful animal with a gun? If anything, that you have no real appreciation for nature. It also shows that you have way to many personal lackings to compensate for.

. January 19, 2009 at 3:31 pm

Nature Reports Climate Change
Published online: 18 December 2008 | doi:10.1038/climate.2008.141

Bad news for bears

Olive Heffernan

“Seth Cherry of the University of Alberta, Canada, and colleagues located polar bears by helicopter and anesthetized them using a dart gun before taking blood samples to determine their serum urea to serum creatinine (U/C) ratios. U/C values, which are low when bears are in a physiological fasting state, were obtained for 436 individuals during April and May of 1985–1986 and 2005–2006. Of the bears sampled by Cherry’s team, the numbers fasting were 9.6 per cent in 1985 and 10.5 per cent in 1986, increasing to 21.4 per cent in 2005 and 29.3 per cent in 2006. Polar bears from all sex, age and reproductive classes were more likely to be found fasting in 2005-2006 than in 1985–1986. During all years of the study, adult males involved in breeding comprised a high proportion of the bears with low U/C levels.”

Anon January 19, 2009 at 7:08 pm

In most countries, environment ministers worry about pollution and wildlife.

In Canada, they announce that the government will be funding natural gas pipelines.

Milan January 19, 2009 at 7:57 pm

[Unrelated to the comments above] Here is the website of Nell Chitty, the young woman in the photo above.

Milan January 19, 2009 at 7:59 pm


I too find it astonishing that people want to shoot polar bears. It is definitely a dumb macho thing to do. That being said, I can also see why communities that have hunting as a major economic activity want to have people continue doing it.


That is certainly discordant – especially since the project has not yet had its social and environmental impacts assessed.

Sarah January 19, 2009 at 9:14 pm

RK – nicely put! In terms of the suffering of each animal then if the marksmen are competent then I suspect it is preferable to shoot them. That would also benefit the local communities in the short term, whereas if the bears drown then they lose out forever (aside from the dubious benefit of not fearing predation by bears) & there’s no ecological gain. My sense would be that we should let the hunting continue at a reasonable (i.e. lowish) level & work on trying to slow down climate change. So saying, there’s an argument that we should all focus on bigger issues and stop arguing about bears: see http://vimeo.com/user432587 .

Anon January 19, 2009 at 9:26 pm

More likely than not, polar bears are doomed.

Arguably, the best thing that can happen in relation to them is for the government to declare them ‘Doomed due to climate change.’ It would focus a bit more attention on not dooming other species.

. March 19, 2009 at 4:00 pm

Canada responds to melting sea ice

Canadian Press

March 19, 2009 at 11:47 AM EDT

Canada is conceding that a treaty on polar bears signed 35 years ago is now forcing it into action on climate change.

All five countries that signed the treaty have ended talks in Norway with an agreement that melting sea ice is now the biggest single threat to the long-term survival of the bears. The agreement calls for an urgent and effective response to address climate change.

. March 20, 2009 at 10:22 am

Canada not holding back on polar bear protection: Prentice

By Juliet O’Neill, Canwest News ServiceMarch 19, 2009

Environment Minister Jim Prentice dismissed an allegation Thursday that Canada was reluctant to sign a declaration with four other countries that climate change is “the most important long-term threat” to polar bears.

But the minister also acknowledged he believes the jury’s still out on whether the ultimate impact of global warming on polar bears will be bad or good.

“I don’t think anyone disagrees the whole process of climate change has implications for polar bears,” Prentice told the Winnipeg Free Press. “What those implications are is still under scientific investigation. It could be positive, it could be negative.”

R.K. March 20, 2009 at 10:25 am

What a tool! Of course the complete transformation of their habitat and the loss of the sea ice they require to hunt will be negative. That’s exactly what the scientists meant when they said that climate change was the greatest threat to the bears.

R.K. March 20, 2009 at 10:30 am

According to the International Union for Conservation of Nature:

“Polar bears exhibit low reproductive rates with long generational spans. These factors make facultative adaptation by polar bears to significantly reduced ice coverage scenarios unlikely. Polar bears did adapt to warmer climate periods of the past. Due to their long generation time and the current greater speed of global warming, it seems unlikely that polar bear will be able to adapt to the current warming trend in the Arctic. If climatic trends continue polar bears may become extirpated from most of their range within 100 years.”

And the US geological survey:

“Polar bear populations in the Polar Basin Divergent and Seasonal Ice ecoregions will most likely be extirpated by mid century. Approximately 2/3
of the world’s current polar bear population resides in the combined area of these two ecoregions.

Polar bear populations in the Archipelago Ecoregion appear likely to persist through the middle of the century. Some modeling scenarios suggest persistence of polar bears in this ecoregion toward the end of the century. The number of bears in this ecoregion will likely be less than at present due to the reduced amount of habitat and other factors.

Polar bears in the Polar Basin Convergent Ecoregion may persist through mid-century, but they most probably will be extirpated at and beyond year 75.

Because recently observed declines in sea ice extent continue to outpace most GCM projections, more extensive sea ice seems an increasingly unlikely future. Yet, to qualitatively alter outcomes projected by our models and head off the projected loss of 2/3 of the world’s current polar bears, future sea ice would have to be far more extensive than is projected by even conservative General Circulation Models.”

Milan March 20, 2009 at 1:30 pm

It’s a pretty shocking thing to say. It also demonstrates how we must apply critical thinking whenever politicians make claims about scientific facts and debates.

. May 8, 2009 at 10:13 pm

Species Act Won’t Be Used to Force Lower Emissions

By David A. Fahrenthold
Washington Post Staff Writer
Saturday, May 9, 2009

The federal bureaucracy that safeguards endangered species isn’t equipped to tackle climate change, Interior Department officials said yesterday — declining to protect Alaskan polar bears by cracking down on polluters in the Lower 48.

The decision, announced yesterday by Interior Secretary Ken Salazar, was the Obama administration’s first word on an emerging environmental question.

The 35-year-old Endangered Species Act was designed to save animals from close-by threats such as hunting, trapping and logging. But, now that U.S. species from mountainsides to tropical seas are threatened by climate change, can it be used to fight a global problem?

Salazar, upholding a decision made in the last months of the Bush administration, said no.

“The Endangered Species Act is not the appropriate tool for us to deal with what is a global issue,” Salazar said in a conference call with reporters. Instead, he said, the administration will push Congress to enact legislation setting national caps on greenhouse gases.

. May 11, 2009 at 10:15 am

Obama Sides with Bush on Polar Bears and Climate
By Edward Humes

The Obama administration announced today that it is embracing a last-minute “midnight rule” created by President Bush that eviscerates protections for the imperiled polar bear.

This rule, celebrated by Alaska Governor Sarah Palin and now adopted by Obama, bars the government from using the polar bear’s protected status to regulate greenhouse gas emissions as an extinction threat if those emissions originate outside the animal’s Arctic habitat. It is known as the “4(d) rule” after the section of the Endangered Species Act that it amends.

However, as the official listing of the polar bear acknowledged, it is exactly those remote emissions — and the climate change they cause — that are destroying the polar bear’s sea-ice habitat, driving the creatures into extinction. The rule not only violates the intent of the Endangered Species Act, environmentalists have argued, but also dooms the polar bear as a wild species.

“We must do all we can to help the polar bear recover, recognizing that the greatest threat to the polar bear is the melting of Arctic sea ice caused by climate change,” Salazar said. “However, the Endangered Species Act is not the proper mechanism for controlling our nation’s carbon emissions.”

This was the same argument the Bush administration employed, asserting that it would be wrong to use the Endangered Species Act as a “back door” method of regulating greenhouse gas pollution. But environmentalists have argued that the broad intent of the Endangered Species Act unequivocally requires a response to all human-caused extinction threats, including global warming. They’ve advocated that the powerful law should be viewed as a valuable tool and opportunity to tackle the climate crisis.

. May 26, 2010 at 9:52 am

Polar bears face ‘tipping point’ due to climate change

Climate change will trigger a dramatic and sudden decline in the number of polar bears, a new study has concluded.

The research is the first to directly model how changing climate will affect polar bear reproduction and survival.

Based on what is known of polar bear physiology, behaviour and ecology, it predicts pregnancy rates will fall and fewer bears will survive fasting during longer ice-free seasons.

These changes will happen suddenly as bears pass a ‘tipping point’.

Details of the research are published in the journal Biological Conservation.

. November 30, 2010 at 8:46 pm

Biologists report more bad news for polar bears

Will polar bears survive in a warmer world? UCLA life scientists present new evidence that their numbers are likely to dwindle. As polar bears lose habitat due to global warming, these biologists say, they will be forced southward in search of alternative sources of food, where they will increasingly come into competition with grizzly bears.

To test how this competition might unfold, the UCLA biologists constructed three-dimensional computer models of the skulls of polar bears and grizzly bears — a subspecies of brown bears — and simulated the process of biting. The models enabled them to compare the two species in terms of how hard they can bite and how strong their skulls are.

“What we found was striking,” said Graham Slater, a National Science Foundation–funded UCLA postdoctoral scholar in ecology and evolutionary biology and lead author of the research. “The polar bear and brown bear can bite equally hard, but the polar bear’s skull is a much weaker structure.”

The implication is that polar bears are likely to lose out in competition for food to grizzlies as warmer temperatures bring them into the same environments, because grizzlies’ stronger skulls are better suited to a plant-rich diet, said Slater and Blaire Van Valkenburgh, UCLA professor of ecology and evolutionary biology and senior author of the research.

“The result for polar bears may be lower weight, smaller and fewer litters, less reproductive success, fewer that would survive to adulthood, and dwindling populations,” Van Valkenburgh said. “Then you can get into an extinction vortex, where a small population becomes even smaller in a downward spiral to extinction.

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