Will polar bears go extinct by 2030? — Part I
Human-caused global warming is poised to wipe out polar bears. The normally staid U.S. Geological Survey — studying whether the bear should be listed as a threatened species under the Endangered Species Act — concluded grimly last Friday:
That’s right — this grim prediction is optimistic, a best-case scenario. In the next post, I’ll examine why polar bears are likely to go extinct by 2030 if not 2020. But first I need to dispense with a myth that polar bears are doing well — a myth propagated by some commenters on this blog and people like Bjørn Lomborg in his new book, Cool It: The Skeptical Environmentalist’s Guide to Global Warming.
As an aside, Amazon.com amazingly invited, of all people, Michael Crichton, the seriously confused global warming Denier, to be the book’s guest reviewer – perhaps Amazon.com should change its name to Deforestation.com. In his effusive review, Crichton repeats the myth:
Lomborg is only interested in real problems, and he has no patience with media fear-mongering; he begins by dispatching the myth of the endangered polar bears, showing that this Disneyesque cartoon has no relevance to the real world where polar bear populations are in fact increasing. Lomborg considers the issue in detail, citing sources from Al Gore to the World Wildlife Fund, then demonstrating that polar bear populations have actually increased five fold since the 1960s.
Uhh, no. First off, if the Bush Administration’s USGS says the polar bear is facing devastation from global warming, you can safely say the claim has more credibility than anything Lomborg or Crichton write.
Second, global warming can temporarily boost polar bear populations. The 2004 study, “Polar Bears in a Warming Climate” in Integrative and Comparative Biology, explains:
In the short term, climatic warming may improve bear and seal habitats in higher latitudes over continental shelves if currently thick multiyear ice is replaced by annual ice with more leads, making it more suitable for seals.
Third, global warming can temporarily make it appear as if polar bear populations have increased. The 2006 study, “Possible Effects of Climate Warming on Selected Populations of Polar Bears (Ursus maritimus) in the Canadian Arctic,” in Arctic, notes that for four of five polar bear popluations in the Canadian Arctic
… residents of coastal settlements have reported seeing more polar bears and having more problem bear encounters during the open-water season, particularly in the fall. In those areas, the increased numbers of sightings have been interpreted as indicative of an increase in population size, with the result that quotas for Inuit hunters were increased. However, in Western Hudson Bay, the decline in population size, condition, and survival of young as a consequence of earlier breakup of the sea ice brought about by climate warming have all been well documented (Stirling et al., 1999; Gagnon and Gough, 2005; Regehr et al., 2005; I. Stirling and N.J. Lunn, unpub. data [references in paper]). In Baffin Bay, the available data suggest that the population is being overharvested, so the reason for seeing more polar bears is unlikely to be an increase in population size.
What is the reason for seeing more polar bears, then?
… the sea ice is breaking up at progressively earlier dates, so that bears must fast for longer periods during the open-water season. Thus, at least part of the explanation for the appearance of more bears near coastal communities and hunting camps is likely that they are searching for alternative food sources in years when their stored body fat depots may be depleted before freeze-up, when they can return to the sea ice to hunt seals again.
So, no, there does not appear to be any evidence of a real or sustainable increase in polar bear population.
Fourth, some polar bear populations are clearly declining or on the verge of declining — not just in the Western Hudson Bay case noted above, but also in the Southern Beaufort Sea. A 2006 USGS study found an apparent decline in polar bears. The study also saw “declines in cub survival and physical stature” — the same trend that preceded “a significant decline in population size” in western Hudson Bay, Canada.
But what about the claim “polar bear populations have actually increased five fold since the 1960s” and perhaps even risen slightly over the past two decades? This claim is well debunked by Dr. Andrew Derocher, Chair of the IUCN (World Conservation Union) SSC (Species Survival Commission) Polar Bear Specialist Group, which I will reprint at length here because this myth has gained new credibility thanks to Lumborg’s book:
The bottom line here is that it is an apples and oranges issue. The early estimates of polar bear abundance are a guess–there is no data at all for the 1950-60s. Nothing but guesses. We are sure the populations were being negatively affected by excess harvest (e.g., aircraft hunting, ship hunting, self-killing guns, traps, and no harvest limits). The harvest levels were huge and growing. The resulting low numbers of bears were due only to excess harvest but, again, it was simply a guess as to the number of bears.
After the signing of the International Agreement on Polar Bears in the 1970s, harvests were controlled and the numbers increased–there is no argument from anyone on this point. Some populations recovered very slowly (e.g., Barents Sea took almost 30 years) but some recovered faster. Some likely never were depressed by hunting that much, but the harvest levels remained too high and the populations subsequently declined. M’Clintock Channel is a good example. The population is currently down by over 60% of historic levels due only to overharvesting. Some populations recovered as harvests were controlled, but have since declined due to climate-related effects (e.g., Western Hudson Bay). In Western Hudson Bay, previously sustainable harvests cannot be maintained as the reproductive and survival rates have declined due to changes in the sea ice.
At this point, we lack quantitative data for an overall assessment of trend in Canada or Nunavut as a whole. There is, however, very strong evidence for a decline in Western Hudson Bay and the Southern Beaufort Sea based on quantitative studies. More recently, scientists working in the Southern Hudson Bay have reported a major decline in the condition of polar bears. A decline in condition was the precursor to the population decline in Western Hudson Bay. There is clear suggestion of a population decline due to over-harvest in Baffin Bay, Kane Basin and possibly Norwegian Bay.
The point is that you cannot simply summarize the status of polar bears–the information lies in the individual populations. You cannot put the various time periods together into a simplistic overview. Sea ice is declining but again, it is not declining the same everywhere. Some small areas of multi-year ice may improve habitat for polar bears. This latter point, however, does not mean that the habitat in all areas will improve and the predictions are very clear that the primary habitat of polar bears is at risk.
Dr. Derocher ends bluntly:
… no habitat, no seals; no seals, no bears. This never was an issue of polar bears alone. The only effective conservation approach is to protect the habitat and this is an issue of climate change. You can distort the issue any way you so desire. At the end of the day, the sea ice is disappearing. Take away the habitat and the species follows shortly thereafter (or before).
Comparing declines caused by harvest followed by recovery from harvest controls to declines from loss of habitat and climate warming are apples and oranges. Ignorant people write ignorant things.
The polar bear is at grave risk of extinction. Just when that extinction might come I will address in Part II.
September 10th, 2007 at 9:47 am
I will never understand how deniers of all stripes reconcile their beliefs with the real world and keep their heads from exploding. The atmosphere is warming? No it’s not! The cheap oil is running out and production is about ti peak? No! There’s an infinite amount of oil if we just let the free market go after it! Polar bears are threatened because their habitat is disappearing? No! They’ll somehow live and thrive without a habitat!
Oy.
September 11th, 2007 at 7:07 pm
Lou, your response is typical of the brainwashed AGW believers. Do some research about oil before spouting your bullshit. Suggest you start with “Shell Colorado oil shale” and progress from there.
Given that Polar Bears have survived other times of warm climate (with no or little sea ice) without going extinct, how do these scientists come to the conclusion that they will go extinct in the next 30 years?
September 11th, 2007 at 8:45 pm
Mobius — you are very wrong.
The Arctic has not been ice free for at least a million years.
“According to both fossil and DNA evidence, the polar bear diverged from the brown bear roughly 200 thousand years ago; fossils show that between 10 and 20 thousand years ago the polar bear’s molar teeth changed significantly from those of the brown bear.”
http://en.wikipedia.org/wiki/Polar_bear
Please, keep this civil. I will delete comments with profanity.
September 17th, 2007 at 9:26 pm
Lou Grinzo’s response reminds me of what i heard in elementary school 40 years - yes 40 years ago. Same exact crap 40 years later. Overpopulation - oil is running out - nuclear holocaust is just around the corner - global starvation and disease. Give me a break. Come on, isn’t anyone original anymore? I call it “disaster recycling”
Lou, you might understand the deniers - like me - if you spent a little time researching the facts. I have been a scientist for 25 years. I have done the analysis and I - like most - yes most scientists - have determined that “man-made” global warming is nothing but political hype and people like you who do not take the time to research the data are suckers. Go ahead purchase all the carbon credits your budget can handle but don’t try to make me contribute.
Lou, global mean temperature? Use your common sense and think about that concept for just a minute. How does one accurately measure the temperature of a planet the size of the Earth over the last 100 years? What about the instrument’s error? It’s calibration? Has the calibration of every instrument been maintained over the last 100 years? Has the environment around the instrument changed over the last 100 years? Is their more concrete? buildings? people? heat exhausts from compressors near the instrument? when was the temperature taken? during shaded times? times of rain? windy days? What about time of day and day of year? Have these instruments been measured at the same time of the day on the same day of the year over the last 100 years? Have measuring instruments been added and if so, where? in cold areas? in warm areas? The Earth is has an EXTREMELY large surface area. How much surface area do the instruments cover? I can go on and on but one quickly sees that “global mean temperature” measurement is no more accurate then averaging the New York City telephone book. The average telephone number in New York is useless. Our measurement of the change in the Earth’s mean temperature over the last 100 years is useless because it is overrun with inconsistencies; thereby, resulting in huge errors. Common sense dictates this. Americans have lots of common sense but it seems that they have turned it off. I equate “man-made”global warming to reports that Elvis is alive.
September 17th, 2007 at 9:56 pm
Joe,
Correct. There is no room for profanity.
Sir, you are wrong about man-made global warming regardless of the speculated future of the polar bear and to quote wikipedia as if it is the standard of fact is amazing. The other day, while in the checkout line in the grocery store, I read an article in the World News that said that JFK was alive and residing in a special section of the White House.
I see scare tactics here sir. Please state facts not speculation. Gore and the NOAA told us that 2006 would result in the worst hurricane season on record. 2007 is resulting in only a small number of hurricanes. Pathetic experts. IPCC told use years ago that sea levels would rise 20-plus feet over the next 50-100 years. In February 2007, those sea level rises were less then a foot. IPCC put the “hockey stick” temperature plot in their report that was later showed to be wrong. NASA stated that 1998 was the hottest year on record until an error was found and now 1934 was the hottest year. Computer models used for the latest IPCC report discussing the “horrible” effects of man-made global warming conveniently focus only on the last 30 years of temperatures - it ignores the cooling cycle from 1940-1970 -guess this is for maximum negative effect. This emission shows that the “computer models” are bias. Let’s discuss how many scientists supported the IPCC conclusions that man is responsible for global warming vice the number of scientists who simply submitted their data for IPPC report?
November 1st, 2007 at 8:38 pm
i may be yong but i think there is sutch thing as global warming. but it may not be as bad as everyone exagerates.
November 1st, 2007 at 8:39 pm
P.S. eevee is a pokemon
serch it on google images
November 1st, 2007 at 8:40 pm
P.S. eevee is a pokemon. serch it on google images
November 1st, 2007 at 8:41 pm
WHY WONT MY LAST @ COMMENTS SHOW UP!!!! >:0
November 1st, 2007 at 8:41 pm
sorry never mind my last comment…
November 1st, 2007 at 8:43 pm
to the person that made this site: sorry for all the stupid comments
January 28th, 2008 at 3:33 pm
I read the ice caps on Mars are melting and Uranus is hotter now than when Voyager flew by it in 1987.
Who was burning fossil fuels when the last Ice Age ended 10,00 years ago and the sea level rose 250 feet? Atlanteans?
Isn’t a “changing environment” the driving force behind evolution? The fact the earth does change is the very reason it is a living planet and not a dead one like Mars or Venus. There are vast geological and biological cycles that take place over millions of years that are essential to recycle the essential elements of life. The payoff is that the must change for this to hapen.
How do you work out the “carvbon footprint” of a volcano/
How many people are making a very comfortable living writing reports, doing reasearch, etc into this subject?
February 1st, 2008 at 9:58 am
You are very correct. Read the latest ipcc report. And the UN is very conservative, with all those developing nations that do not want to be told there is a problem.
Polar bears are drowning, an extremely painful way to go. Polar bears are starving. It is all extremely sad and horrifying, really, and i hope we all learn how to stop this.
Step one might be to admit it exists.
February 1st, 2008 at 9:59 am
Read the latest ipcc report. And the UN is very conservative, with all those developing nations that do not want to be told there is a problem. And Dr. Derocher is a very respected and somewhat conservative scientist, as well.
Polar bears are drowning, an extremely painful way to go. Polar bears are starving. It is all extremely sad and horrifying, really, and i hope we all learn how to stop this.
Step one might be to admit it exists.
I never posted on here before so i could not have said this.
February 5th, 2008 at 4:31 pm
ok i love the PB and i dont want to see it go
i agree with David D.
March 26th, 2008 at 11:30 am
POLAR BEARS
April 9th, 2008 at 2:00 pm
I wanna STOP GLOBAL WARMING NOW!!! AND SAVE THESE POLAR BEARS!!!
April 28th, 2008 at 7:12 pm
I love Polar Bears and I don’t want to see them be endangered.l Just wish that global warming will stop before it gets more worse than ever.I wish there was a way to stop it .CAN YOU HELP ME STOP THIS.
April 28th, 2008 at 7:15 pm
Ohh and I did not say that your comments were a waiting moderatoin
May 1st, 2008 at 1:51 pm
Wht polar, she was my f, my pal, my darling, my hope, my everything,
But, now, she’s NONE, GONE 4ever.
May 8th, 2008 at 9:52 am
diz iz agreat website n i like it i think is mad cool
that ppl are letting other people kno that polar bearsz are gonna die in 2030
but were trying 2 get other people 2 help the invironment
…….
for real
May 9th, 2008 at 1:22 pm
lol
May 12th, 2008 at 1:21 pm
this is gay