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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Anyone who reads just a little bit into the life of polar bears comes away with the understanding that they live on land, their dens are on land, they hibernate on land, and they hunt for food offshore – near land.
Unlike the plethora of misinformation that spews forth from the media and alarmists, polar bears do not spend all day treading water or perched on small blocks of ice. And those pictures of polar bears atop swiss-cheese looking ice bergs are bergs that flipped as they melt, leaving the bears stranded as the bergs rolled over. Man does not cause berg flipping, nature does.
The last significant polar bear study shows polar bear numbers have doubled in the last few decades. Some of the 21 populations have increased, some have decreased, some have not changed. The populations that increased were those in areas where temperatures increased! There is no polar bear population in the Arctic Ocean; only the 21 populations that surround it. The polar bears are not endangered. They are not in trouble. Only shoddy science and dogma keeps attempting to promote the image of polar bear extinction. Nothing could be further from the truth.
That one must be for Chantal Kreviasuk, the Canadian Climate Change Expert… singer who always defends polar bears in the Globe and Mail…
What if hunting was banned completely how would that mess up their Nintendo computer model? Did they punch in for pollution caused by persistent organic pollutants (POPs) and its effects on reproduction rates? Oil spills, shipping?
Sordnay says:
May 25, 2010 at 12:42 pm
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!
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This is the retroactive guilt article. Humans are now supposed to have caused the last Ice age by making Mammoths et al extinct.
DirkH says:
May 25, 2010 at 12:57 pm
If somebody has some grant money left i can make a computer model that shows a tipping point for the human population if we don’t do some measure X (to be defined). You know, like the Club Of Rome’s Limits To Growth, only more dramatic. Just tell me the year you need the tipping point in and the extent of the population decline you want. I think i’ll use something like infectious diseases, spread of drug addiction or maybe pollution induced infertility as the mechanism, but i’m open to suggestions.
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As I recall that “computer model” was published in Analog – Science fact/Science fiction in the late sixties or early seventies. The article proved it was statistically impossible for humans to produce a fertilized egg.
It is a classic example of how to lie with statistics using actual facts in a very scientific sounding publication. It should be required reading for all students about to graduate or adults about to vote.
Chuck L says:
May 25, 2010 at 1:36 pm
Is polar bear tipping like cow tipping?
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No, Cow tipping is a heck of a lot safer unless the farmer has a shotgun…..
I think modeling is a cool thing. Let’s input AGW believers as the outcome, with increased use of the term “tipping point” as the trended variable. By GEORGE! It works! We have a decreasing catastrophic trend in AGW believers!
Tipping point in, tipping point out. I like this.
Some people seem to expect a static environment. Any organism existing at the edge of its range will be the most vulnerable to changes. The bears adapted to a harsh environment and surely could find a way to survive in a milder one if the models are accurate.
Gail Combs
May 25, 2010 at 5:38 pm
Maybe those Polar Bear experts should be funded to find out exactly were that tipping point is by direct observation.
According to studies of beaches on the north Greenland shore, the Arctic was ice free for perhaps a thousand years during the Holocene maximum some 6,000 years ago. Since polar bears survived that one would have to surmise the tipping point is a long ways off if it comes at all.
I object to the photo you posted. Very poor humor.
Maybe some polar bears should be moved to Rwanda, where cold weather killed 4 gorillas.
Perhaps this image is more appropriate?
http://current.com/1cgma4c
The extended article states that canada is home to about 2/3 of the polar bar population. With 7,000 polar bears in Russia, 7,000 in Greenland, 3,000 on the North Cape and 1,500 (?) in Alaska I believe the count is about 33,500 world-wide leaving Canada with not quite half the population.
I just finished a polar bear population model that shows conclusively that polar bears don’t die off when the global temperature rises. I only made a single assumption: that polar bears turn into jackelopes when the average global temperature rises. Since data relevant to this phenomenon is nearly non-existent you must believe this model.
Don’t forget the eggplant that ate Chicago. (The whole planet’s doomed.)
“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.”
Did they take into account that Polar bears are unlikely to die of starvation while
there are other Polar bears around? They’re cannibals!
Here a while back, crocks and manatees were complainin about the cold waters in Florida. Might the polar bears find it to their liking?
Heck, they put wolves into Wallowa County again and they seem to LOVE it there! Very adaptable creatures you know. Left their wild side at the roadside tootsweet and are feasting on bovine calves inbetween having lots of pups.
I have a hunch the polar bears, if forced to move, would find something better to eat and easier to catch, and would enjoy the rather more comfortable mating environment of a sunnier climate. One little known attribute of animals. Sometimes when they move to a new habitat, they INCREASE in numbers, finding their new digs much better than their old surroundings. Seems likely that polar bears would be of this group.
Rent seeking biologists who specialise in studying a certain Arctic based mammalian species?
I am curious as to how you would factor in “survival instincts” into a computer model? If you link the original article, there is a picture of a male polar bear. I think that the caption was written by a sly skeptic with a sense of ha ha. It reads ” here is a male in prime condition”. Nice little dig there, as the bear looks about as far from extinction as a bear can look.
I think polar bears suffer from lead disease
DL;
I didn’t say Buffalo eat humans, they just chase them and kill them if they catch them.
Lots of humans to that to other species as well.
Hmm…
I think a steaming pile of poley bear poo is sure-fire evidentiary proof that AGW is the real deal and everything/everyone is tipping over.
Afterall, anything that steams must be hot right ?
So there you have it. The poley bears have tipped over too.
Heck, I think we should write that observation up and have one of the peer-reviewed journals publish it.
(Oh don’t worry about having to add in any of that sciencey-type stuff like physics or some such… It’s a guaranteed publish because all we have to do is use the words “AGW”, “proof of global warming”, and “unprecidented” all in the same sentence in order to get a passing grade.)
RichieP: May 25, 2010 at 3:03 pm
Readers of French will enjoy this little quiz from Greenpeace France – tests to see if you’re suffering from the disease of climatoscepticism and offers to cure you.
Judging from the comments, the disease of climatoscepticism is more widespread than Green Peas figured — lots of “Where’s your proof of what you claim?” types.
What a silly paper. It assumes that the bears will starve in conditions that other bears thrive in. It assumes no natural selection. Even the creationists believe in natural selection. It assumes we wont/ can’t farm the polar bear. Farming should be easy and profitable.
Step 1. Shoot one polar bear that’s making trouble near an Arctic town.
Step 2. Sell the pelt to the legal market for $6000-$8000. Sell the Meat to the inuit for over $80.
Step 3. Go to Calgary and buy 30 tons of rendered tallow at about $30-50 dollars a ton. Buy 5 tons of offal. Often free but assume $50 all up. Throw in $100 of fish oil. Mince and mix well, freeze.
Step 4. Ship north at up to $10 to 100 a ton. $350-$3500
Step 5. Place your 50kg lumps of polar bear feed and run, FAST! Make sure your feeding stations are at least 150 miles from town to keep the bears away from the school kiddies. Make sure your the only person with hunting rights in that area.
Step 6. Bank the profit. $1500+50+100+3500=5150 $6000-5150=$850 ~ 14% Using the upper price for the pelt and lower prices for the feed. $8000 – 1350=$6650 ~83%
Step 7. Buy ammo and repeat next year. Don’t shoot your stud polar bear or best breeding females.
An additional step would be to buy 400 tons of tropical hay. Plant species that are not frost hardy, ship north and distribute in heaps. These enhance the bio-productivity of the area without adding feral plants. Bears eat voles.
Hunt the Arctic fox to keep them in balance.
Select your bears for retained wild hunting skill and traits. I.e. Shoot the lazy ones.
The four things you don’t do are: fencing the bears, caging the bears, taming the bears, let the government ban hunting to save the bears.
I’m an Aussy If I can figure it out, so could a Canadian. eh.