Oddly, it seems some people expect polar bears to sit around and suffer (or die) when local conditions deteriorate, rather than move elsewhere.
While there are perhaps a few places where moving is not really an option over the short term, over the long term (more than one season) polar bears are free to shift to another locale if ice conditions change (either too much ice or too little).
An announcement by the WWF last week (10 April) caught my eye, as it talked about bears moving from one area to another because of changing ice conditions — as if this was surprising, extraordinary and newsworthy. That said, at least they weren’t suggesting the bears are all going to die because of declining ice, which is a huge improvement.
See what you think of this part of the press release (below), in the context of what we know about the movement of bears between regions:
Posted in Conservation Status, Life History, Sea ice habitat
Tagged adaptation, AMO, Amstrup, Barents Sea, dens, Franz Josef Land, Kara Sea, Mauritzen, polar bear, polar bear resilience, pregnant females, satellite radio collars, spring ice conditions, Svalbard, WWF
Polar bear activist Steven Amstrup made an astonishing statement in an interview earlier this week — he insisted that the current rate of warming in the Arctic is greater than anything polar bears have lived through before. He also said that optimistic comments on the future of polar bears made by geneticist Matt Cronin a few weeks ago were “incautious” and “misleading.”
Previously, I described how a new paper by Cronin and colleagues confirmed that genetic evidence indicates polar bears have been around long enough to have survived several past Interglacial periods that were warmer than today (and therefore, would have had virtually no summer ice). Cronin, not unreasonably, had some critical things to say about computer modeled predictions that polar bears could not survive in an Arctic without summer sea ice.
On Monday, the Anchorage Daily News gave Amstrup a forum to rebuke Cronin for his comments. A similar story was also carried by the Washington Post. [In the same ADN article, geneticist Charlotte Lindqvist, offered an outdated argument against future polar bear survival that I’ll deal with later]
Today, I’ll address Amstrup’s ridiculous assertion that the current rate of warming, attributed by him primarily to human activities rather than natural variation, is something polar bears have never experienced in their evolutionary history (a period of more than 400,000 years!).
Let’s start with the offending portion of the news item (published March 31, 2014):
Posted in Advocacy, Evolution, History
Tagged Amstrup, Anchorage Daily News, Cronin, Eemian, future, global warming, Holocene, interglacial, Lindqvist, misleading, models, past warming trends, polar bear, polar bear resilience, rate of warming