Tag Archives: sea ice loss

What about the polar bears? Disconnect between predictions and observations

With all the talk this week about future climate – the global warming imagined by IPCC crystal ball models, that is – the focus for many is rightly on the gulf between predictions and observations that have taken place so far. This follows on reminders a few weeks ago of the many failed predictions that we would have seen an “ice-free Arctic” by now.

[by “ice-free” they mean “nearly ice-free,” or “when ice coverage is less than 1 million square kilometers, or about 386,000 square miles.”]

But what about the polar bears? Is there a similar disconnect between predictions and observations for polar bear survival? Yes, indeed.

Many Arctic biologists insist that polar bears are not just threatened by future global warming and a “melting ice cap.” They contend polar bears are already being harmed by declines in summer sea ice coverage, or will be shortly.

The problem is, the results of scientific studies show otherwise. Virtually all of the evidence generated by polar bear researchers shows that polar bears are not being harmed by declines in summer sea ice, and in some cases, they are doing very well indeed. In other words, they are not responding as expected.

A few weeks ago, I summarized these studies, which reveal that:

Less summer ice ≠ few bears (evidence from Davis Strait; S. Hudson Bay; Barents Sea; S. Beaufort; W. Hudson Bay).

Less summer ice ≠ “skinnier” bears (evidence from Chukchi Sea; S. Hudson Bay).

“Skinnier” bears ≠ fewer bears (evidence from S. Hudson Bay; S. Beaufort; Davis Strait).

Less summer ice ≠  lower cub survival (evidence from S. Hudson Bay; Chukchi Sea).

Less summer ice ≠ more cannibalism & hybridization

Have a look if you missed it (August 18, 2013, with pdf copies to download), “Polar bears have not been harmed by sea ice declines in summer – the evidence.”

[Update Sunday Sept 29 2013: these two stories (on the temperature pause and polar bears thriving (in which I get a mention), just out in the Mail on Sunday (UK)]

Mail on Sunday_Temp pause and polar bears_Sept 29 2013

How and why great news about Chukchi polar bears has been suppressed

A new peer-reviewed report (Rode et al. 2014 [in print] 2013, accepted), released last month (announced here), documents the fact that polar bears in the Chukchi Sea are doing better than virtually any other population studied, despite significant losses in summer sea ice over the last two decades – even though the Polar Bear Specialist Group (PBSG) said this population was declining (Obbard et al. 2010).

Rode and Regehr 2010_Chukchi_report2010_Fig1_triplets_labelled

Rather than this good news being shouted far and wide, what we’ve seen so far is a mere whisper. The strategy for suppressing the information appears to have several parts: make it hard to find; don’t actively publicize it; down-play the spectacularly good nature of the news; minimize how wrong they were; keep the focus on the future.

Something similar happened with the newly-published paper on Davis Strait bears (Peacock et al. 2013, discussed here and here) but the news there wasn’t quite so shockingly different from expected. The suppression of good news stands in marked contrast to anything with a hint of bad news, which gets reported around the world — for example, Andrew Derocher and colleagues and their prepare now to save polar bears” policy paper in February, 2013.

US Fish & Wildlife biologist Eric Regehr, co-investigator of the Chukchi study and co-author of the newly-published report, wrote an announcement about the paper. It wasn’t a real press release, since it was not actually sent to media outlets. It was a statement, with a brief summary of the paper, posted on a regional US Fish & Wildlife website, with no mention of lead author Karyn Rode. Not surprisingly, lack of active promotion = no media coverage.

The posted announcement also down-played how well the Chukchi bears are doing. In fact, the news documented in the paper is much better than any of them let on: Chukchi polar bears are doing better than virtually all other populations studied.

But Regehr also had to do some damage control to counter the evidence this paper contains of how wrong they had all been — not only about the Chukchi population today but about their predictions for polar bears in the future.

After all, the computer models used to predict a dire future for polar bears combined the Chukchi Sea with the Southern Beaufort, as having similar ice habitats (“ice ecoregions”). The published paper and Regehr’s statement now say these two regions are very different and that polar bear response to loss of sea ice is “complex” rather than a simple matter of less summer ice = harm to polar bears. Regehr goes on to say that polar bear scientists expected this would happen. I call total BS on this one, which I explain in full later (with a map).

Finally, Regehr’s statement emphasizes that good news for 1 subpopulation out of 19 today should not be celebrated because the overall future for polar bears — prophesied by computerized crystal balls — is bleak. Focus on the future, they say. Did they forget that for years they’ve been telling us that polar bears are already being harmed and that this foreshadows what’s to come? Now we have the results of yet another peer-reviewed study showing bears not being harmed by declines in summer ice (see the full list here).

So, in the end, all of this double-talk and contradiction is not just about suppressing this particular paper. There’s much more at stake.

The Rode et al. Chukchi paper is strong evidence that their predictions of a grim future for polar bears – based on theoretical responses to summer sea ice declines that should already be apparent – have been refuted by their own studies. It’s no wonder they want to keep the media away from this story.

Details below.  [Update September 11, 2013: another news outlet picks up the story, see Point 2 below]

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Biologists spreading misinformation: hybridization with grizzlies not due to polar bears moving inland

A paper published last week in the journal Science, written by a team of biologists and atmospheric scientists, expounds on a possible dire future for a range of Arctic animals. It’s called, “Ecological consequences of sea-ice decline” and surprisingly, polar bears are discussed only briefly.

However, with the inclusion of one short sentence, the paper manages to perpetuate misinformation on grizzly/polar bear hybridization that first appeared in a commentary essay three years ago in Nature  (Kelly et al. 2010)1. The Post et al. 2013 missive contains this astonishing statement (repeated by a Canadian Press news report):

Hybridization between polar bears and grizzly bears may be the result of increasing inland presence of polar bears as a result of a prolonged ice-free season.

Lead author of the paper, Professor of Biology Eric Post, is quoted extensively in the press release issued by his employer (Penn State University, pdf here). In it, Post re-states the above sentence in simpler terms, removing any doubt of its intended interpretation:

“… polar and grizzly bears already have been observed to have hybridized because polar bears now are spending more time on land, where they have contact with grizzlies.

Both statements are patently false. All recent hybridization events documented (2006-2013) occurred because a few male grizzlies traveled over the sea ice into polar bear territory and found themselves a polar bear female to impregnate (see news items here and here, Fig. 1 below). These events did not occur on land during the ice-free season (which is late summer/early fall), but on the sea ice in spring (March-May).

Grizzlies have been documented wandering over the sea ice of the western Arctic since at least 1885 (Doupe et al. 2007; Fig. 2, below) and the presence in this region of hybrid grizzly/polar bear offspring is not an indicator of declining summer sea ice, whether due to global warming or natural causes, or some combination thereof.

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