Polar bears still on thin ice, but cutting greenhouse gases now can avert extinction

Dec 15, 2010
A female polar bear walks in the tidal area along Canada’s Hudson Bay in autumn 2010, waiting for ice to form. Credit: Steven C. Amstrup, Polar Bears International

Polar bears were added to the threatened species list nearly three years ago as their icy habitat showed steady, precipitous decline because of a warming climate. But it appears the Arctic icons aren't necessarily doomed after all.

Scientists from several institutions, including the U.S. Geological Survey and the University of Washington, have found that if humans reduce greenhouse gas emissions significantly in the next decade or two, enough Arctic ice is likely to remain intact during late summer and early autumn for to survive.

"What we projected in 2007 was based solely on the business-as-usual greenhouse gas scenario," said Steven Amstrup, an emeritus researcher with the U.S. Geological Survey and the senior scientist with the Montana-based conservation organization Polar Bears International. "That was a pretty dire outlook, but it didn't consider the possibility of greenhouse gas mitigation."

That study projected that only about one-third of the world's 22,000 polar bears might be left by mid-century if the dramatic Arctic ice decline continued, and that eventually they could disappear completely. The work led to the 2008 listing of polar bears as a threatened species.

The new research, published in the Dec. 16 issue of Nature, is based in part on modeling proposed by Cecilia Bitz, a UW associate professor of atmospheric sciences. It indicates there is no "tipping point" that would result in unstoppable loss of summer sea ice when greenhouse gas-driven warming rose above a certain threshold.

"Our research offers a very promising, hopeful message, but it's also an incentive for mitigating ," Bitz said.

Amstrup is the lead author of the Nature paper. Besides Bitz, co-authors are Eric DeWeaver of the National Science Foundation, David Douglas and George Durner of the USGS Alaska Science Center, Bruce Marcot of the U.S. Forest Service in Oregon and David Bailey of the National Center for Atmospheric Research in Colorado.

Because the scientists were looking specifically to see if there is a tipping point beyond which seasonal Arctic ice could not recover, they used a general circulation model with a sea-ice component particularly sensitive to rising temperatures, with major parts of it designed by Bitz.

"We didn't necessarily need to compare with other models since we were using one that is extremely sensitive in the Arctic, which allowed us to make a more conservative statement about the potential to slow the loss of sea ice," she said.

Previous work by Bitz and others showed that unchecked temperature increases, along with natural environmental volatility, could result in the loss of vast areas of in less than a decade. It also showed that with continued business-as-usual greenhouse gas emissions the ice did not recover after such rapid ice losses, and it largely disappeared altogether in following decades.

Two male polar bears playfully spar near Hudson Bay, where sea ice melts in the summer and then reforms in the autumn. The bears need the ice in late summer and fall to be able to reach their prey, primarily seals. Credit: Steven C. Amstrup, Polar Bears International

However, the new Nature study indicates that if greenhouse gas emissions were reduced substantially in the near future, rapid ice losses would be followed by substantial retention of the remaining ice through this century, as well as partial recovery of the ice that disappeared during the rapid ice loss.

Polar bears depend on sea ice for access to ringed and bearded seals, their primary food source. During seasons when they can't reach sea ice, the bears mostly go without food and can lose about 2 pounds a day. The periods when they don't have ice access have increased and are expected to continue increasing with the current level of greenhouse gas emissions.

As part of the current study, the potential sea-ice outlook generated by the general circulation model, as well as many features of polar bear life history, were placed into a network model, which can, for example, examine the relationship between polar bears and their environment. Those results indicated that increased retention of sea-ice habitat because of greenhouse gas mitigation would allow polar bears to survive in greater numbers throughout this century, and in more areas of the Arctic, than would happen with no mitigation.

Amstrup divided the Arctic into four separate ecoregions according to the nature of ice typically found there, and the 2007 study showed a very high likelihood that polar bears would become extinct in two of those regions given current trends in .

"There's still a fairly high probability in both of those regions that polar bears could disappear," Amstrup said. "But with mitigation and aggressive management of hunting and other direct bear-human interactions, the probability of extinction would now be lower than the probability that polar bear numbers will simply be reduced.

"With mitigation, conditions for polar bears might even improve in the other two ecoregions. The benefit of mitigation to polar bears is substantial."

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User comments : 36

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danlgarmstrong
2.3 / 5 (7) Dec 15, 2010
Give it up - we are not going to cut carbon emmissions in time to avert the melting of the artic. Want to save the polar bears? Start them up in the Antartic. Might wipe out a few other species doing that but, well, I LIKE polar bears.
Titto
1.7 / 5 (22) Dec 15, 2010
PLEASE THIS IS A RESPECTED SITE! DO NOT PUT BULL SH!T ON HERE!! WE KNOW AGW IS A SCAM AND DON'T YOU GUYS FOLLOW THE SOLARCYCLE24 THEN? HUH??
SIBERIAN TYPE TEMPERATURES IN BRITAIN, WATCH THE WINTER NOW AND YOU STILL PUT ABSOLUTE CRAP LIKE THIS ON THE WEBSITE. I AM DISSAPOINTED REALLY!!!!THE NORTH POLE HAS INCREASED BY MILLIONS OF SQUARE KM ALREADY. OPEN YOU EYES MAN!!!!
gmurphy
3.8 / 5 (16) Dec 15, 2010
Keep your tinfoil hat on tight Titto!
danlgarmstrong
5 / 5 (6) Dec 15, 2010
This from the National Snow and Ice Data Center:
http://nsidc.org/...aicenews

Arctic sea ice extent averaged over November 2010 was 9.89 million square kilometers (3.82 million square miles). This is the second-lowest November ice extent recorded over the period of satellite observations from 1979 to 2010, 50,000 square kilometers (19,300 square miles) above the previous record low of 9.84 million square kilometers (3.80 million square miles) set in 2006.

Ice extent was unusually low in both the Atlantic and Pacific sectors of the Arctic and in Hudson Bay. Typically by the end of November, nearly half of Hudson Bay has iced over. But on November 30, only 17% of the bay was covered by sea ice. Compared to the 1979 to 2000 average, the ice extent was 12.4% below average for the Arctic as a whole.
Yellowdart
2.5 / 5 (13) Dec 15, 2010
Frankly, I think Polar Bear exctinction may in fact be due to Coca Cola exploitation...

A few greedy polar bears have sold out their brethen...

In response, I no longer drink Coke.
ArtflDgr
1.9 / 5 (18) Dec 15, 2010
personally i am tired that they take messages down if the censors dont agree with relevance. i mean commisars of the ministry of "truth".

polar bear numbers are increasing

the sad thing is that these people are ruining the reputation of science itself. lets see them get grants from the public till when the public has no confidence in them! you want how much? to do what?

IF your such a genius, then finding it yourself from your own efforts should be a breeze!!!! after all if the economy is so unfair and its so easy, then why bother us poor people?

Yellowdart
1.7 / 5 (17) Dec 15, 2010
The part thats iffy about this, is that it is entirely based upon loss of sea ice. Even assuming their PB counts are accurate, PB's dont need sea ice...they just need food. They go to the water to find fish and seal. They dont hunt on multi-year ice.

Frankly, they may do better, having more food options.

Since the sea ice isnt gone tomorrow, they will have plenty of time to adjust and reproduce anyway.

The population has more than tripled since hunting was ended.
http://www.examin...cals-say
ChiRaven
2.5 / 5 (8) Dec 15, 2010
My problem is with the science here. The premature presentation of results that did not take the alternatives into account, and the seemingly arrogant concept that they don't NEED to make any comparisons with other models because theirs is SO good (in spite of the obvious shortcomings of their earlier models) does not seem to be something that would exactly instill confidence in their current work. Unfortunately, so very much of the work in this field seems to be based on alarmist presentations based on hasty work (Himalayan glaciers, anyone?) that has to be modified later when other facts are included that SHOULD have been considered to begin with.
Howhot
2.8 / 5 (9) Dec 15, 2010
There is a big problem here. It has to do with all of these people that are Anti-Global-Warming deniers. Anyone of you AGW deniers want to volunteer how much you are being paid to post here. The science is frightening and yet these AGWd'S deny, misdirect, and obfuscate every fact that is presented to the public. So sure; listen to those clowns if you want; but thats not going to help when in 10 years, it really will be "Record Breaking" hot as crap summers all over, methane is released from the great bogs of the North, and civilization implodes in a "Soylent Green" moment. I raise my a pleasant finger to the AGWD's. May your children have hell.
Alphakronik
2.5 / 5 (8) Dec 16, 2010
There is a big problem here. It has to do with all of these people that are Anti-Global-Warming deniers. Anyone of you AGW deniers want to volunteer how much you are being paid to post here. The science is frightening and yet these AGWd'S deny, misdirect, and obfuscate every fact that is presented to the public. So sure; listen to those clowns if you want; but thats not going to help when in 10 years, it really will be "Record Breaking" hot as crap summers all over, methane is released from the great bogs of the North, and civilization implodes in a "Soylent Green" moment. I raise my a pleasant finger to the AGWD's. May your children have hell.


You do realize those are the same things we've been told for 30 years, yet none of it has yet to come to fruition. If 8 of the 9 models used to predict climate change do not account for green plants using C02, please explain to me how the predictions can be anywhere close to accurate. Go ahead, I'll wait.

Howhot
3 / 5 (8) Dec 16, 2010
And so all you would like to endure is heat, drought, and soggy icy winters. I guess the money you are paid doesn't hurt. You disgust me. So where am I wrong? You have seen the movie "Soylent Green"? If so what do you think about humanity and the possibly of drought induced food shortages caused by your CO2 addiction. You POS.
Howhot
2.8 / 5 (9) Dec 16, 2010
@Alphakronik: It's getting hotter and hotter, but AGWDs like you will not look at a graph that smacks you in the face with the TRUTH about where the environment is at. You POS. So do you even care about anyone? Seriously I want to know.
EdMoore
2.3 / 5 (9) Dec 16, 2010
When the global warming scam artists explain how historic ice ages advanced and retreated WITHOUT man's influence, then they could say that their computational models are even correct.

Until then, their "science" is little more than Al Gore's latest example of continuing lies, deception, junk science and United Nations-style command economics.
Claudius
1.4 / 5 (11) Dec 16, 2010
From ScienceDaliy:

"In fact, the polar bear populations have been increasing rapidly in recent decades due to hunting restrictions."

"After careful examination, my co-authors and I were unable to find any references to works providing evidence that the forecasting methods used in the reports had been previously validated. In essence, they give no scientific basis for deciding one way or the other about the polar bear.”
ArtflDgr
1.7 / 5 (6) Dec 16, 2010
Anyone of you AGW deniers want to volunteer how much you are being paid to post here.

sure...
nothing...
unlike lysenkoist's...
danlgarmstrong
4 / 5 (2) Dec 16, 2010
The climate is warming and we will need to deal with the consequences. Whether it is man made or not is irrelevant. Drought, Storms and the migration of whole populations will happen and need to be planned for.

Even if CO2 is the cause of the problem, I do not see us being able to cut back global emissions if left up to the government. It is too political. The one hope here is the coorporations cutting back by themselves. This may be possible, but I believe more likely is that CO2 emissions will keep increasing for many decades.

So, given that climate change IS happening - how do we deal with its effects?

Gustav
2.3 / 5 (6) Dec 16, 2010
Polar bears aren't threatened for starters. They have proliferated in recent years. They are being seen all around the Hudson Bay, which was not the case only 20 years ago. CO2 in the present-day concentrations has negligible effect on the Earth's atmosphere and temperatures, so the call for CO2 reduction, which would severely handicap our economies and well-being, to save polar bears, which don't need saving, is complete nonsense.
Dug
1.6 / 5 (7) Dec 16, 2010
As if this warming period is vastly different from others the planet has experienced in the past. New polar bear studies are showing that the bears adapt to life on land just fine. The planet has had CO2 multiple times higher than it does today and life carried on. The expectation that many life forms aren't always in some kind of change adaptation process isn't either logical or borne out by the planets history. Frankly greenhouse warming should be very low in our lists of priorities. Noting that the 95% of the human food supply is dependent on petroleum based fertilizers and petroleum transportation fuels and that 85% of the human food supply is dependent on phosphate fertilizers that are non-renewable and estimated to run out in the next 50 years - anthropic global warming seems to be a self-limiting problem.
danlgarmstrong
2 / 5 (2) Dec 16, 2010
Frankly greenhouse warming should be very low in our lists of priorities.

Stopping 'anthropic global warming' I agree is probably impossible. Again I ask - What plans are being made to deal with its effects?

Noting that the 95% of the human food supply is dependent on petroleum based fertilizers and petroleum transportation fuels and that 85% of the human food supply is dependent on phosphate fertilizers that are non-renewable and estimated to run out in the next 50 years - anthropic global warming seems to be a self-limiting problem.

Rereading that it seems that you are even more pessimistic than me! You seem to expect that the problem will fix itself by massive die offs of the human race through starvation. IMHO - not the best solution.
3432682
1.5 / 5 (12) Dec 16, 2010
The warming has been small. The effects have been beneficial. Skeptics are not paid, the AGW crowd is paid billions per year by government. Polar bears are more numerous than ever. Temperatures were warmer for 80% of the last 10,000 years; how did the polar bears cope with that? None of the dire consequences of the AGW crowd have come true. Temperatures are cooling slightly now. Why should we spend trillions, and restrict booming human prosperity and health in order to solve a non-problem? AGW is a religion.
Shootist
1.7 / 5 (11) Dec 16, 2010
Give it up - we are not going to cut carbon emmissions in time to avert the melting of the artic.


The Arctic has melted before and will melt again.

"The Polar Bears will be fine". - Freeman Dyson.

http://www.nytime...n-t.html
Howhot
2 / 5 (4) Dec 17, 2010
@3432682 and you other mis-directed screed;
This Man-made-global-warming issue that the AGWd's like to belittle has HUGE implications for everyone. As long as you deny the science; you are doomed to mediocrity; and science doesn't just bend to a AGWd's whim. You just think it.

Think of polar bears, you AGW-deniers! (scum)
Howhot
1.5 / 5 (4) Dec 17, 2010
@3432682 again;
You said; "the AGW crowd is paid billions per year by government". You do realize how much work the "AGW crowd" has done to inform you and warn you ("we the people") that Global Warming do to CO2 is going to cause a lot of pain an suffering if action is not taken to stop it. But we are not going to stop are we GWSift7, 3432682 and the dick from NASA? And we will die.
Shootist
1.5 / 5 (8) Dec 18, 2010
I quote an Authoritative Source, and one of the greatest scientific minds of our time, and get rated 1. I love it.

To repeat; "The Polar Bears will be fine". - Freeman Dyson.

http://www.nytime...tml?_r=1

thermodynamics
5 / 5 (1) Dec 18, 2010
Shootist: Dyson is one of the great minds still alive. You are absolutely correct. However, that does not mean he is correct. From the article you quote, Dyson says: “I don’t think of myself predicting things,” he says. “I’m expressing possibilities. Things that could happen." What that goes back to is that he has also in the past said we would be moving by jet pack by now (energetically unfavorable). He did not predict high cost power, he expected power to be nearly free by now through fusion energy production. In the same article they say: "...he imagines the furniture and art that people will “grow” for themselves, the pet dinosaurs they will “grow” for their children, along with an idiosyncratic menagerie of genetically engineered cousins of the carbon-eating tree: termites to consume derelict automobiles, a potato capable of flourishing on the dry red surfaces of Mars, a collision-avoiding car..." Continued
thermodynamics
5 / 5 (1) Dec 18, 2010
Continued: I agree with the collision-avoiding car but I don't buy the automobile eating termites. The point is that Dyson did make the comment: "the polar bears will be fine..." But that was clearly his speculation. He is a visionary, but like most prolific visionaries he is sometimes provably wrong. That does not diminish his prodigious accomplishments. What it does say is that the polar bears might not be alright. In fact, it appears they are having problems (as you have seen documented in other references). They are losing weight, having less surviving young, and are being forced out of their normal foraging range. The population is much larger than in the 1950s, but only because hunting has been banned on them in almost every part of the world (except for indigenous peoples with allocations for social reasons). To quote Dyson without putting it in context is purposefully misleading people.
Shootist
1.6 / 5 (7) Dec 18, 2010
He knows models, and modeling, as well as anyone on the planet. He knows, better than all of us, that when the pushers of AGE predict temperatures to an accuracy of .1C, they are nuts. It isn't possible that their models have anywhere near this level of accuracy.

The pushers of AGW say the planet has warmed 1C in the past 100 years. How do they know this? Certainly it is nigh impossible to generate an average daily temperature, for the entire planet, within 1 degree C accuracy.

I do not disagree that the planet has warmed. The Hudson River froze solid enough during the Revolution that Washington had cannon dragged across. I also know that the planet was warmer in AD 1000 than it is now. Cattle farms in Greenland. Vineyards in Scotland.

I look at these models and realize that no valid statistics have been applied. Which is pretty much what Prof. Dyson said.

"The Polar Bears will be fine." - Freeman Dyson
Shootist
1 / 5 (6) Dec 18, 2010
He knows models, and modeling, as well as anyone on the planet. He knows, better than all of us, that when the pushers of AGE predict temperatures to an accuracy of .1C, they are nuts. It isn't possible that their models have anywhere near this level of accuracy.

The pushers of AGW say the planet has warmed 1C in the past 100 years. How do they know this? Certainly it is nigh impossible to generate an average daily temperature, for the entire planet, within 1 degree C accuracy.

I do not disagree that the planet has warmed. The Hudson River froze solid enough during the Revolution that Washington had cannon dragged across. I also know that the planet was warmer in AD 1000 than it is now. Cattle farms in Greenland. Vineyards in Scotland.

I look at these models and realize that no valid statistics have been applied. Which is pretty much what Prof. Dyson said.

"The Polar Bears will be fine." - Freeman Dyson


correction: AGW, not AGE. hangs head in shame ...
whitefang
5 / 5 (2) Dec 19, 2010
'Anti Global Warming deniers.' Isn't that a double-negative?
braindead
5 / 5 (2) Dec 19, 2010
PLEASE THIS IS A RESPECTED SITE! DO NOT PUT BULL SH!T ON HERE!! WE KNOW AGW IS A SCAM AND DON'T YOU GUYS FOLLOW THE SOLARCYCLE24 THEN? HUH??
SIBERIAN TYPE TEMPERATURES IN BRITAIN, WATCH THE WINTER NOW AND YOU STILL PUT ABSOLUTE CRAP LIKE THIS ON THE WEBSITE. I AM DISSAPOINTED REALLY!!!!THE NORTH POLE HAS INCREASED BY MILLIONS OF SQUARE KM ALREADY. OPEN YOU EYES MAN!!!!


NO need to SHOUT? Can you explain how the North Pole, which is a geographic point, increases in area?
_nigmatic10
1.7 / 5 (6) Dec 20, 2010
People really seem to be under the illusion stopping any and all man made activity will stop the global climate warming trend. It really won't. The earth will get warmer, and the earth will get cooler, and while everyones focused on that, the environmental poisoning will continue unchecked.
GSwift7
1.3 / 5 (7) Dec 20, 2010
The recent flurry of AGW stories in the science and environmental news had me puzzled, until just the other day. I was not aware that a big vote was about to happen in CA over a State cap and trade law. Now it makes sense. They have been hammering on all the issues that voters in CA are most sensitive about, in an all-out effort to get that cap and trade law passed.

Anybody know who provides the funding in support of cap and trade laws? Hint: you can look it up on Google. It's mostly financial players and fund management companies but also people like Enron (who were among the biggest backers of Kyoto, according to what I've read). Always follow the money. The money tells the truest story of all, and I'm NOT talking about the pennies they throw on the ground for researchers.

If you think the people who stand to make billions on this CA cap and trade law have been completely honest, then you have way too much faith in your fellow man.
GSwift7
1.6 / 5 (7) Dec 20, 2010
It's up to you to decide who is telling the truth and who is lying to you. Life is a million shades of grey. I doubt very much that it's as black and white as some people would like to color the argument over pro and anti AGW. I think it's blatantly lazy to fully buy into the arguments of either side 100%. Both sides are lying to you. It's just a question of when and how much each side is lying.

When I see stories that use words like forever and always in a scientific context, that sets off an alarm bell. I also always read cautiously when 'scientists' urge drastic and/or hasty responses to dire situations. Sometimes it doesn't take much effort to find faulty claims or exaggerations.

Here's a hint for people that aren't used to reading about scientific findings: Not every new study leads to an earthshaking conclusion about the fate of mankind. When you start seeing predictions of global catastrophy, beware who is tell you that.
newsreader
2.3 / 5 (3) Dec 20, 2010
Twenty years from now, polar bears will be known as the canaries in the global warming tunnel.
Skeptic_Heretic
5 / 5 (1) Dec 20, 2010
I quote an Authoritative Source, and one of the greatest scientific minds of our time, and get rated 1. I love it.

To repeat; "The Polar Bears will be fine". - Freeman Dyson.

http://www.nytime...tml?_r=1

The reason why you get downranked is because you're quote mining.

Here's a few more Dyson gems for you.
We live on a shrinking and vulnerable planet which our lack of foresight is rapidly turning into a slum.

We cannot hope to either understand or to manage the carbon in the atmosphere unless we understand and manage the trees and the soil too.

If one believes, as I do, that ESP exists but is scientifically untestable, one must believe that the scope of science is limited.

I don't so much practice science anymore as it is.


These are all Dyson quotes, all of which give different looks at the issue. To pick one and use it as often as you do shows lack of depth in understanding his points.
ryggesogn2
1.4 / 5 (10) Dec 20, 2010
Would the same AGWites be trying to save the dinosaurs or mammoths or saber tooth tigers or the ground sloth or ....from climate change if they could?