After reading this BBC article on modeling the “tipping point” of polar bear populations, it seemed this photo summed it up well, especially since modeling was substituted in lieu of “nearly non-existent data”. I wonder how the bears survived the Roman Warm Period, or the Medieval Warm Period?
From the BBC: Polar bears face ‘tipping point’
By Matt Walker
Editor, Earth News
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.
Educated guesses
Until now, most studies measuring polar bear survival have relied on a method called “mark and recapture”.
We may not see any substantial effect on polar bear reproduction and survival until some threshold is passed. At that point reproduction and survival will decline dramatically and very rapidly
Peter Molnar University of Alberta, Edmonton, Canada
This involves repeatedly catching polar bears in a population over several years, which is cost and time-intensive.
Because of that, the information scientists have gathered on polar bear populations varies greatly: for example, datasets span up to four decades in the best studied populations in Western Hudson Bay and Southern Beaufort Sea, but are almost non-existent for bears in some parts of Russia.
Even more difficult is measuring how survival and reproduction might change under future climatic conditions.
“Some populations are expected to go extinct with climate warming, while others are expected to persist, albeit at a reduced population size,” says Dr Peter Molnar of the University of Alberta, Edmonton, Canada.
However, these projections are essentially educated guesses, based on experts judging or extrapolating how current population trends might continue as the climate changes.
“So we’ve looked at the underlying mechanisms of polar bear ecology to assist our understanding of what will happen in a warming world,” Dr Molnar told the BBC.
Fasting and mating
Dr Molnar, Professor Andrew Derocher and colleagues from the University of Alberta and York University, Toronto focused on the physiology, behaviour and ecology of polar bears, and how these might change as temperatures increase.
“We developed a model for the mating ecology of polar bears. The model estimates how many females in a population will be able to find a mate during the mating season, and thus get impregnated.”
Male polar bears find females by wandering the ice, sniffing bear tracks they come across. If the tracks have been made by a female in mating condition, the male follows the tracks to her.
The researchers modelled how this behaviour would change as warming temperatures fragment sea ice.
They also modelled the impact on the bears’ survival.
Southern populations of polar bears fast in summer, forced ashore as the sea ice melts.
As these ice-free seasons lengthen, fewer bears are expected to have enough fat and protein stores to survive the fast.
By developing a physiological model that estimates how fast a bear uses up its fat and protein stores, the researchers could estimate how long it takes a bear to die of starvation.
“In both cases, the expected changes in reproduction and survival were non-linear,” explains Dr Molnar.
“That is, as the climate warms, we may not see any substantial effect on polar bear reproduction and survival for a while, up until some threshold is passed, at which point reproduction and survival will decline dramatically and very rapidly.”
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Read the entire story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/earth/hi/earth_news/newsid_8700000/8700472.stm
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insted of telling us thay should go and tell the bears all about what is going to happen too them ,the one having a crap first
[snip, sorry just a bit OTT]
In my experience, a polar bear will eat just about anything that stands still long enough for the bear to get its mouth around – they don’t just eat seals. There’s a reason that Churchill, MB has a problem with bears, and it’s not because they’re throwing seals out with the rest of the garbage.
It seems likely to me that, if the ice did disappear for longer periods, the bears would simply find other food sources, such as the tourists flocking to the north in ever-greater numbers to see the “disappearing” polar bears.
It will get hot in the Arctic, right after it finishes being incredibly cold.
I wonder what the coming ice age will do to polar bear populations.
Since polar bears are nothing but brown bears who moved north, about 250,000 years bp, for less crowded conditions, I assume, they will be fine. If not, we can just breed new ones and teach them to hunt seals.
Everything that is, was not always so. Nature adjusts and evolves. Bears have legs, fish have fins, birds have wings. All make good use of their mobility.
On one hand they say, ‘ the science is settled, no need for more studies’, on the other, there’s apparently a continuous stream of new studys expounded and promoted by the AGW media.
Don’t often hear an AGWer standing by their ‘science is settled, no need for more studies’ principle when the study concludes in favour of AGW.
That Dr. Mitchell Taylor isn’t saying the same is enough for me. I’ll take the PhD with serious field experience and connections throughout the breadth of the Inuit community over the one who has actually been there less times than he has attended WWF functions but prefers playing on campus with models. I’m going to guess real data is too rigid.
TA
May 25, 2010 at 11:22 am
“How long have polar bears been around? Have they made it through other warming periods?”
About 250,000 years, though some studies put it at about 500,000. They are basically a sub-species of Brown Bear. And yes, they have made it through warm periods just fine.
Perhaps what they should be modeling instead is the tipping point for CAGW/CC ideology, or perhaps of the BBC itself.
The polar bear in the photo clearly demonstrates the value of such “studies”.
BTW, how does it taste polar bear’s meat?….just thinking
I bet the polar bear has changed the albedo by much more by what he left behind in the picture than our portion of CO2 we emit. Either it is very painful or the bear us just laughing in the face of AGWarmers…
Garbage in, brown stuff out!
I always thought the scientific process meant you had to have something which was measurable. All this “tipping point” based on “computer models” isn’t science, it’s guesswork. But hey… at least it’s worse than we thought, right?
How does things like this even get published?
“Until now, most studies measuring polar bear survival have relied on a method called “mark and recapture”.”
When the real world observations fail to deliver alarm the models surely will.
Modelling male bears in search of female bears… omg.
As if those animals walk randomly over the North Pole. I’m not a biologist, but I think that any male bear that feels the need will find a willing female bear and vice versa. Ice or no ice.
Can someone please try to explain how anyone who receives the results of a study like this happily draws his wallet and asks for more bear manure?
Polar Bears, the only animal known to hunt man.
If they run out of fish and seals, perhaps we’ll be next.
I think Al Gore should setup and man an observation post to verify the Polar Bear’s ability to hunt man.
After all, nothing ventured, nothing gained.
Report: “The status of the polar bear in a vulnerable Arctic – WWF Norway, March 2008”
A non-peer-reviewed report, which translates to “an opinion piece” according to East-Anglia-climate-scientist-slang.
But anyway. Here is the condensed wisdom of the report:
The polar bear count is as follows: 5 groups are expanding in numbers, 5 groups are decreasing, and for the others, there is not enough data.
And further: for the next ten years, it is estimated that five of the populations have a high or very high risk of decrease, while six have a low or very low risk, and for a further eight populations, there is not enough data.
(Meaning that everything is OK.)
But: (!!): Biggest risk to the population according to WWF? Global warming.
Well, according to WWF global warming has been going on for decades, especially in the Arctic, and one of the posterboys for the warming has been the polar bear, lost and scrambling to hold on to a small piece of iceberg.
And even here – on their own turf – using their own most highlighted example, they can not, even in their own non-peer-reviewed-opinion-piece, produce even the fainest case or evidence for even the most miniscule decrease in the number of polar bears??
It is a travesty.
What they totally DISMISS is that the genetic make-up of a polar bears came from brown bears 150k years ago. That genetic information is still in there but just suppressed and waiting to be re-ignited by a change of climate conditions back to the way they were. Polar bears DO occasionally mate with grizzly bears too BTW and that behavior may be further enhanced by a warmer climate with grizzlies able to spread further north in warmer conditions and polar bears coming further south looking for food.
Another thing they dismiss is how hearty a species has to be in order to just exist at the poles in the first place. Some species in the tropics are so fragile that only a couple degrees change threatens them. Polar bears are the opposite and have endured comparatively WILD extremes scraping out a living at such high latitude – they have already proven themselves to be an extremely DURABLE species.
More warmth generally means more plants = more food = equals easier living conditions which all tells me to trust these alarmist global warming tales as much as I trust that Greenland will melt or Himalayan glaciers will be gone in a few years.
I think they should model the BBC’s pension fonds tipping point.
Because it will arrive sooner than they think.
OK…. if it is polar bear reproduction that’s the issue, surely it makes more sense to introduce couples counselling, marital aids, or seminars on ‘how to track the bear of your dreams on land instead of ice’, than to bring western civilization to its knees with some wacky cap&trade or carbon tax regimen.
stevengoddard says: May 25, 2010 at 11:48 am It will get hot in the Arctic, right after it finishes being incredibly cold.
Yes, the reality of a lot of the north pole is that the ice holding down the tundra is holding down all that trapped missing ERB heat. Once it erupts, there’s no stopping it and the arctic will just boil away.
Polar bears have survived a lot longer than us humans on this planet.
Oh boy, that’s horrible, it’s worst than we thought!
If you think this article is not based on data, what would you think about this one published on Nature:
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo877.html
I can’t read no more than the abstract but it really looks promising!
I’ve just spent 15 minutes trying to find out how many PBs there are at the moment.
Almost all the places I looked at agree that in the 1950s there were about 5,000 world-wide, and that now there are 20,000 to 25,000.
So even if the population tumbles back to 5,000, PBs should survive.
If the same scenario was repeated with warmists instead of PBs, would this mean that some warmists would survive no matter what happened?
Which nightmare is worse?
A polar bear was shot and killed in Fort Yukon, Alaska in March 2008. It was eating lynx carcasses near the city dump. Fort Yukon sits about 250 miles south of the Arctic Ocean. Somehow I don’t think that they will have any problem finding anything to eat should the ice go out.
Every now and then you get a report of a polar bear – grizzly hybrid being shot. Last one was in April in Canada. The last report I can find prior to that was in 2006. Both were around the Canadian Arctic. Don’t know if this hybrid breeds true, as it difficult to ask the bears. They are not all that good conversationalists and tend to stay cranky.