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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Models, models, everywhere but nary a fact in sight!
In the end, have they no shame?
Oh man… That’s cold….
Its all a matter of a distorted anthropomorphic perspective. If there was a magazine called “Fish Stocks Review” there would be cheering from the rooftops that millions of future generations of fish would go on to survive and multiply on account of not being eaten by polar bears. Plentiful healthy cheap fish for all to eat. Good news for humans!
Instead we get brain-dead conniving academic alarmism. “Its all worse than we thought! Quick! Send more grant money!”
how is it the only studies that show polar bears are gonna die, plants will cause AGW, sea levels will rise, we’re all gonna die etc etc etc are computer modelled? what happened to good old lets have a look ats whats actually happenning?
So the woods is not the only place a bear takes a dump.
Look it’s Al Gore!
1 they have no real world facts to present 2 polar bears have been around for a long time and obviously survived much longer and higher warming trends 3 the (researchers) need the money
Stupid is as Stupid Does!!!!
“How does one STOP stupid?”
Well it’s about time they stopped doing actual research on polar bears. Have you seen those things? They’re freaking HUGE! and dangerous! It’s much better to do all the work from your computer than to risk evisceration.
I have to think we’re not really serious about calling polar bears threatened while we’re still issuing hunting permits.
One concrete number in the article: the southern population of male polar bears in western hudson bay would be cut in half if the ice-free season increased from 4 months to 6 months. That doesn’t seem much like extinction.
Oh wait. How much global warming would be necessary to extend the ice-free season that much? Significantly more than the worst-case IPCC scenarios?
Anyone who played with population simulations back in the 70s/80s when chaos theory was first being developed, and our ‘toy’ computers were ‘highest tech’, knows that if the programming uses non-linear equations, you will get technically chaotic results.
This is an artifact of the programming and equations, not necessarily a reflection of actuality. It is possible that polar bear populations levels vs. rising temperatures are correctly be represented by non-linear equations…..but, considering their long term survival through known historic warm periods, it is unlikely.
If environment changes, these animals will adapt, they will not sit idly by and starve themselves out of existance. This species has been around for countless millenia and have adapted to changes. Evolution demands that they survive, the breeding, hunting patterns will alter to assure survival. The real threat is to climate researchers whose liveihoods and life styles are dependant on perpetuating climate hysteria
How long have polar bears been around? Have they made it through other warming periods?
Willie Soon has done an interview in which he describes his polar bear research. He contends that the optimum Arctic temperature for polar bears is warmer than it has been over the past few hundred years. Warmer temperatures increase the food supply for polar bears by increasing the Arctic fish population. Soon cites circumstantial evidence that during the medieval warm period polar bear numbers were greater than today’s. However, if it got so warm that all Arctic ice melted that obviously would be bad for the bears. Soon’s description of his polar bear research is about halfway through this long but wonderful interview with him and David Legates:
http://www.itsrainmakingtime.com/_recent/climate_part2.html
Since CO2 is arguably not causing warming in the Arctic or anywhere else and there is evidence that the Arctic warming of recent years was induced naturally and is about to reverse it would seem that Molnar, et. al.’s research is just another example of pointless government-funded climate change research. For a reference on predicted naturally-driven Arctic cooling see:
http://icecap.us/images/uploads/AARI_PREDICTS_ARCTIC_COOLING.pdf
So, what happens to the polar bear population 25 years from now when the warm fasting season is REDUCED to 3.5 months instead of the current 4 months due to a cyclical cold-snap predicted by nearly every weather model which will persist for at least 30 years?
Will the polar bear population boom, or will they die out since it is simply too damn cold to… ummm…uhh… “adequately perform”… yeah, that sounds like a good euphemism for it…
The article presupposes that the Arctic ice is disappearing. It is not disappearing.
Ergo, this article is worth less than the bear’s deposit in the heading photgraph.
Dr. Molnar states that an increase in the summer fast season will affect bear populations. Probably true. Dr. Molnar uses a 50% increase in the fast season, from the current 4 months, to 6 months.
But, I am certain that he has not measured the melt season, but only modeled it.
According to data from the Cryosphere Today, the arctic melt season is essentially unchanged over the satellite record. The melt is starting slightly early, but so is the freeze also slightly early.
If the melt season is unchanged, then the bear fast season will also be unchanged.
http://pielkeclimatesci.wordpress.com/2009/09/09/temporal-trends-in-arctic-and-antarctic-sea-ice-maximum-and-minimum-areal-extents/
http://pielkeclimatesci.wordpress.com/2008/12/04/are-there-long-term-trends-in-the-start-of-freeze-up-and-melt-of-arctic-sea-ice/
Note that Pielke Sr’s charts in the latter reference are not available. They are referenced to his old site, before his switch to WordPress.
I see the problem of the Polar Bear tipping point quite clearly. The bears should obviously widen their stance to increase stability and avoid reaching the tipping point where presumably, tipping too far backward would soil his fur.
Polar Bear in Summer
“Southern populations of polar bears fast in summer, forced ashore as the sea ice melts.”
WT? Molnar is a well known moonbat. Now he is shown to be an out-right liar.
First off, the whole concept of regional populations is idiotic with a species where individuals regularly travel 100 of kilometers.
Second, many southern populations are only there because of the food supplied by people and their trash. Now that people are being more careful with their trash, the bears are moving. That is why those two so-called sub-populations are declining.
Third, Polar Bears act very much like Brown Bears (which is what they are) during the summer.
Fourth, I am so pissed off, I think I’ll stop writing. BTW, This is the field that I wanted to pursue growing up, but the marxist indoctrination drove me away, GRRRRRR!
Funny my models show that at the current rate of BS modelers will be extinct by 2012.
This rings alot like the article from Purdue a few weeks back that came up with the wet bulb temperature for humans. The writer never questions how fantastically outrageous the scenario put forward is – the computer model said it will be really bad if this scenario happens!! Never mind that no data shows that it is happening or will happen.
The press should be smart enough to provide a little perspective; maybe analyze what is being presented a little. They are making fools of themselves.
So basically the original piece says that if things were different, they wouldn’t be the same. Well, that is an interesting concept.
The only way to stop that for happening is feeding them with AGWRs.
“[But] eventually mortality will dramatically increase when a certain threshold is passed; for example, while starvation mortality is currently negligible”
If the arctic melts anywhere near the predictions made by climate scientists, Al Gore and all his friends will run to the arctic to point out the crisis, providing much needed food for the polar bears.
Sometimes one has to admire the efficient methods of solving problems that nature has.
[snip – sorry, just a bit OTT]