Are Polar Bears Really Endangered?

  • Date: 08/07/14
  • Susan Crockford, Polar Bear Science

Christina Wu at the Urban Times (July 3, 2014) recently asked this question. She came up with a surprisingly balanced argument but some predictable responses from IUCN Polar Bear Specialist Group (PBSG) biologists. As a consequence, she overlooked some critical facts that make a big difference to the answer.

Figure 1. Are polar bears really endangered? The US Fish and Wildlife Service thinks so, but only because Steven Amstrup, based on a computer model projecting sea ice out to 2050, said so (Amstrup et al. 2007). This information has been used by the Center for Biological Diversity and other NGOs, like WWF and Polar Bears International (where Amstrup is now employed), to solicit donations.

Figure 1. Predictions of polar bear population declines by 2050 are being used by the Center for Biological Diversity, WWF and Polar Bears International to solicit donations.

Wu stated that, for the populations for which we have numbers (see my discussion here), polar bear populations have been increasing overall since the 1970s. She then asked:

“So if polar bear populations are increasing, what’s all the fuss about?”

She went to PBSG biologists for answers. She talked to Elizabeth (Lily) Peacock, now a medical student, and Geoff York, who is employed full time for the World Wildlife Fund (WWF). Apparently, they did not correct her conclusion that polar bear numbers are currently increasing but brought up their concerns about the future instead.

Wu quoted Peacock as saying:

“Some populations appear to be doing OK now, but what’s frightening is what might happen in the very near future.”

Frightening” is a pretty loaded word for a scientist to use. And notice the “might” – rain might be predicted two weeks from now but that doesn’t mean it’s guaranteed to rain.

Regarding the models used to predict the future for polar bears,remember that Steven Amstrup, who is now a full time spokesperson forPolar Bears International [Save our sea ice], was the only polar bear expert consulted about how polar bears might respond to the sea ice changes generated by climate models. As I’ve pointed out previously (here and here), Amstrup appears to have been wrong, at least as far as his predictions on polar bear responses to declines in summer sea ice (July-September) are concerned.

Wu then repeats some so-called “facts” about Western Hudson Bay bears we’ve heard time and again from biologists:

“The number of cubs observed in Hudson Bay is significantly lower than what it used to be, and while older bears are fat enough to survive a few lean years, younger bears are weaker. These low numbers undermine the idea that increasing numbers of bears are the result of overall population growth.”

I expect, like most people, Wu does not realize that none of this information is published – the results of the research upon which these statements are based are not available for anyone to look at.

These data are critical evidence in support of the claim that polar bears are already being harmed by sea ice declines attributed to anthropogenic global warming – they are the most widely cited claims. Yet, the biologists responsible for the research haven’t bothered to get it published, even in preliminary form (see previous posts here and here). Why not? The logical conclusion is that the data actually don’t support their claims, but until we see the reports, no one will know for sure. [...]

So, are polar bears really threatened with extinction? All the evidence says they are not in any trouble right now: the classification of polar bears as ‘threatened with extinction’ is based completely on predictions made by computer models about what might happen by 2050. However, the results of recent polar bear research have disproved, or called into question, many of the assumptions used to make those models work. That leads me to conclude that polar bears are not endangered.

Full post