‘No extinctions’: Polar bears survived periods when the Arctic had no ice

  • Polar bear trio

Former Vice President Al Gore shocked Americans in “An Inconvenient Truth” when he said polar bears were drowning because global warming was melting Arctic sea ice, but now a new study shows that polar bears did just fine even when there was no ice covering the Arctic.

Scientists with the U.S. Geological Daily Caller  New FoundationSurvey (USGS) and the University of Alaska, Fairbanks released a study claiming the “stratigraphic record of the last 1.5 [million years] indicates that no marine species’ extinction events occurred despite major climate oscillations,” including periods where the Arctic was completely ice-free in summertime.

“Some species thought to be dependent on summer sea ice (e.g., polar bears) survived through these periods,” write Thomas Cronin of the USGS and Matthew Cronin of the University of Alaska in their new study.

“In the case of summer sea-ice-free interglacial periods, the presence of winter sea ice habitat, polar bears’ ability to fast during summer, seals ability to use land areas in the absence of sea ice, and the availability of new prey species shifting ranges into the Arctic may have allowed survival during warm periods,” Cronin and Cronin write.

The scientists found that contrary to claims made by Gore in his 2006 film, polar bears have adapted to past warm periods. This is in line with Cronin’s work which has found that polar bears have been a genetically-distinct species long enough to have survived past periods where the Arctic had little to no ice.

The new study not only finds polar bears survived ice-free periods in the Arctic, but there’s no evidence of any other marine species going extinct over the last 1.5 million years. That even goes for walruses, which have made news lately for massive beachings in the Arctic some say are being driven by global warming.

What’s most interesting is that they also claim species were likely worse off during periods when the Arctic and neighboring continents were covered by massive ice sheets.

“In contrast, during glacial periods the much smaller Arctic Ocean and much of the adjacent continents were covered with massive ice sheets, thick ice shelves, and sea ice making large regions virtually uninhabitable to most species that inhabit today’s Arctic,” the scientists write.

For years, environmentalists and scientists held up the polar bear as the poster child of global warming. According to activists, polar bears would be harmed by less Arctic sea ice because they would have nowhere to rest while hunting for food in the summer.

“That’s not good for creatures like polar bears who depend on the ice,” Gore says in “An Inconvenient Truth” as ominous music plays in the background, adding that a new study found “polar bears that have actually drowned swimming long distances, up to 60 miles, to find the ice.”

Fears about global warming’s impact on polar bears even spurred the U.S. Fish and Wildlife Service to list the bear as “threatened” under the Endangered Species Act in 2008 — the first species to be listed over possibly being harmed in the future from global warming.

Not only does genetic evidence suggest bears survived ice-free periods in the past, but polar bear populations have boomed despite shrinking Arctic sea ice coverage.

For example, sea ice extent during April — polar bears generally stalk seals in Spring — has been decreasing 2.4 percent per decade since 1979, all while polar bear populations have boomed and there are significantly more polar bears today than there were 40 years ago.

A shrinking Arctic doesn’t seem to be harming polar bears like Gore warned in his film. In fact, veteran zoologist Susan Crockford argues that thick spring ice is a bigger problem for polar bears than sparse summer ice.

“Thick spring ice near shore drives seals to give birth elsewhere because they cannot maintain their breathing holes in the ice,” Crockford writes on her blog. “This leaves mothers emerging from onshore dens with newborn cubs with nothing to eat at a time when they desperately need food: cubs die quickly, mothers more slowly.”

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This article originally appeared at the Daily Caller and appears here by permission.

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About the Author: Michael Bastasch

Michael Bastasch writes on energy, climate and the environment for the Daily Caller.