Of Polar Bears and Penguins

Polar bears and, to a lesser extent, penguins were the icons of doomsayers saying both animals would soon become extinct because of global warming. However, recent evidence, actual counts and estimates, show populations of both animals are growing.

Polar Bears

The Inuit population of Canada’s Nunavut Territory say that “Scientists do a quick study one to two weeks in a helicopter, and don’t see all the polar bears. We’re getting totally different stories about the bear numbers on a daily basis from hunters and harvesters on the ground.” The Inuit say that polar bear populations within their territory is stable and on the rise. During the last ten years, the growing population has become a real problem according to the Inuits, “families enjoying outdoor activities must be on the look-out for bears. Many locals invite along other hunters for protection.” (Source).

Doomsayers assume that polar bears cannot adapt to changing conditions, but the bears have been around for a long time, perhaps as much as 600,000 years. That means they have survived several periods warmer than now. For instance, fossils evidence shows that polar bears survived the Eemian period 125,000 years ago when it was warm enough that hippos lived where London is now. (Alaska Science Forum). Within the last 11,000 years, polar bears survived the twin peaks of the Holocene Climatic Optimum which peaked at about 10,000 years ago near Alaska and between 8,500 to 5,000 years ago near Greenland. Proxy evidence shows that global temperatures were about 2.5 C warmer than now in most places and up to 7 C warmer in northern Russia.

Polar bear declines in the recent past was due in large part to over hunting which has now been controlled. The history of polar bears shows that they are highly adaptable to changing natural conditions, even conditions of very low sea ice. By the way, current Arctic sea ice extend is higher than it has been in the last five years and slightly higher than the 1979-2006 average for this time of years.

Penguins

“A new study using satellite mapping technology reveals there are twice as many emperor penguins in Antarctica than previously thought.” (ScienceDaily). “An international team of scientists describe how they used Very High Resolution satellite images to estimate the number of penguins at each colony around the coastline of Antarctica.” The survey counted 595,000 birds.

In the Falkland Islands, Gentoo penguin numbers are also increasing. “The Gentoo population now estimated to be 132,321 breeding pairs, the largest number reported since the first estimate was generated in 1933.” Also in the Falklands, Rockhopper penguins have fared less well but are recovering. The Rockhopper population which was estimated at 1.5 million in the 1930s, had been decimated in 1986 due to starvation and by an algal bloom in 2002. Now, “Rockhopper penguins, which the Falklands is estimated to be home to some 36% of the global population … now estimated to be 319,163 (18,503 breeding pairs) seemed to have recovered to the 2000 estimate…”

 

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10 comments

  1. From Jon’s own source, we can see a much different picture than the one he wishes to portray. Here are few quotes from the author of the paper Jon linked to, but that he curiously left out of his post. 

    “The warm period of the Eemian might have come at a time when the polar bear wasn’t such an ice specialist”, Talbot says.

    “We can’t predict whether the polar bear is too far out (in its evolution towards a life on ice),” she says. 

    “Though the polar bear perhaps prospered through hot times in the past, what they have in store ahead may be their greatest challenge ever.”

    “We’re going into a very similar period of time, but it’s generally thought that this is going to be warmer than (the last great warm period),” Talbot says.

    Some of Jon’s readers may have seen a recent study in ‘Science’ by Hailer, et al. A group of seven author’s from four countries contributed to the Polar Bear research. In a conversation with a reporter at the ‘Alaska Dispatch’, Hailer said  “If we continue on our current greenhouse-warming path, it will be far warmer in 50 years than at anytime in the existence of polar bears. By the latter half of this century, polar bears will be off the charts of anything they have experienced during their evolutionary history.  Ultimately, a continually warming world will have no sea-ice habitat for polar bears, and that is the rub they face.”

    But even that is not the whole picture. Although polar bears may have survived several cycles of expansion and retreat of continental ice sheets during the past 600,000 years, the authors warned that the species now faces unique modern problems that complicate its prospects — loss of habitat, conflict with people, and accumulation of industrial chemicals in the food chain that threaten bear health. 

    Rising air temperatures, thawing permafrost, rising sea levels, vegetation shifts, and increasing rainfall also have the potential to devastate animals adapted to hunting, mating, raising offspring, and denning in a frozen world.

    These “multiple human-related stressors … could magnify the impact of the current climate change, posing a novel and likely profound threat to polar bear survival,” they wrote. 

    “This study suggests that past adaptation to a changing climate may have been a slow process,” Hailer and his co-authors said in a release from Science. “Consequently, polar bears may not have enough time to adjust to these warmer conditions as they have in the past.”

    If you’re an ASSS member you can view the complete article here:

    http://www.sciencemag.org/.  (enter polar bear)

    Or if not, you can see the Hailer interview here:   

    http://www.alaskadispatch.com/article/polar-bear-dna-reveals-species-much-older-previously-thought?page=0,2

    Alaska Dispatch reporter Doug O’Harra posed this question to Steven Amstrup, a leading polar bear researcher in Alaska for the past three decades:

    “Does this new finding mean polar bears are even more vulnerable to the loss of ice habitat than we realized? Or does it suggest the opposite — that they’ve persevered through other inter-glacials and will prevail again?”

    “No doubt, some climate change deniers will suggest that an older age for polar bears means they are more resilient to warming than has been suggested. That is not true.

    1. Regardless of the date of their divergence from brown bears, it has been mostly cooler throughout their evolutionary history than it is now.  That is, most of the period of polar bear existence has been during continental glaciations rather than inter-glacials.  

    And 2. Even if they did diverge 600,000 years ago, they have only been through two periods that were noticeably warmer than the present time. These warming periods, however, did not approach the anticipated warming of this century.” 

    And they didn’t happen in conjunction with a multitude of other human induced stressors.

    Jon shows you the sea ice extant graph and wants you to look at the red line, and draw conclusions based on it. But that’s like looking at the temperature from last month and concluding that this will be the hottest year ever recorded in the U.S. A more revealing look at Arctic Sea Ice Extent can be seen here:

    Here we see a ice loss of ~1.5 million km^2 since 1979 with a dramatic downward trend line. A little different than Jon’s ‘every thing’s hunky dory in the Arctic’ scenario.

    This longer term (climate) trend tells a much different story than Jon’s conveniently cherry-picked data. For even more on Arctic Sea Ice you can visit NSIDC (National Snow and Ice Data Center) here:

    http://nsidc.org/arcticseaicenews/

    Oh, almost forgot. Those Inuit who think there’s plenty of Polar Bears out there might be somewhat biased.  Getting up to $35,000 for each bear you kill can have that effect.   JP

      1. Stabilized? Presumably, since 2007 saw the lowest extent in the entire historical record, and 2012 isn’t over; you mean the three year period of 2008 – 2010. Now let’s look at other three year periods of “stabilization”. 1981-1983, 1986-1989, 1991-1993, 1997-1999. It appears that we can find four or five periods that, by your definition were “stabilized”. We could find three or four “stabilized” four year periods. The problem for you is that these cherry-picked periods happened while the secular climate trend kept dropping dramatically. 

        You must know by now Jon, that cherry-picking short term data won’t go unchallenged. And it’s not fooling anyone.   JP

  2. John is using the “yes, but” argument.  Yes, the polar bears survived periods much warmer than now, but they might not survive anticipated warming based on speculative computer models that have questionable assumptions and a poor track record.  

    And isn’t it strange that the polar bear population is stable or increasing in spite of there being less ice?

  3. If Jon’s implication is that the new method of counting the emperor penguins somehow shows that the populations are growing or are even stable, that is not a correct analysis. The good news is that we now have a more accurate method of tracking the populations as climate change proceeds. The study should not be interpreted as showing increasing populations.

    A co-author of the study Jon cites, Phil Trathan, said this: “Current research suggests that emperor penguin colonies will be seriously affected by climate change. An accurate continent-wide census that can be easily repeated on a regular basis will help us monitor more accurately the impacts of future change on this iconic species.”. JP

    1. ScienceDaily said: 
      “A new study using satellite mapping technology reveals there are twice as many emperor penguins in Antarctica than previously thought.”  I implied nothing.  But now that you mentioned it, it seems the previous best available science greatly underestimated penguin numbers.  I wonder if that applies to polar bears too.  

      And again, the “yes, but” argument.

      1. The author of Jon’s own source material predicted that “climate change deniers”, as he called them, would use this study to suggest that Polar Bears are more “resilient to warming than has been suggested”. Jon personally saw to it that that prediction was validated.

        Is it really so difficult to understand the difference between measuring methodologies and the resulting measurements?JP

  4. As long as there are enough seals then the polar will have enough to eat. As you see that the long term ice will decrease making it harder for seals to live also. Each polar bear needs about 43 seals a year to survive. By estimations there are enough so far. What’s not good for the seals is really not good for the bears.

    http://www.polarbearsinternational.org/sites/default/files/scientists/stirling_derocher_climate_wildlife_professional_2007.pdf

    Using both field observations of hunting behaviorand size-specific metabolic requirements, Stirlingand Øritsland (1995) estimated that, on average, apolar bear requires 45 ringed seals (or ringed sealequivalents) per year to survive (larger bears wouldrequire more and smaller bears less). Hunting ofharp seals, bearded seals, and walruses wouldreduce the number of ringed seals needed but themessage is clear that large numbers of polar bearsrequire enormous numbers of ringed seals orequivalents (most species of which also require icefor pupping and molting). In crude numbers,20,000 polar bears would require about 900,000ringed seals (or ringed seal equivalents) each year,the majority of which would be pups. Although thetotal population size of ringed seals is unknown,estimates range between 5 and 7 million, makingthem one of the most abundant seal species in theworld. Like polar bears, however, they are highlyevolved to live and breed in association with sea iceso that their reproductive success and total populationsize will almost certainly decline as the sea ice disappears.

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