Daily Archives: April 3, 2014

Amstrup grasps at straws to defend his polar-bears-are-doomed computer model

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.”

Polar bear cubs in den wikipedia

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 [In the same ADN article, geneticist Charlotte Lindqvist, offered an outdated argument against future polar bear survival that I’ll deal with later]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):

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