Tag Archives: decline

It’s back: Bering Sea polar bear habitat has recovered from a low earlier this month

Fancy that! After a load of handwringing earlier this month, mobile pack ice in the Bering Sea has returned. Just like ice in the Barents Sea, Bering Sea ice is highly variable (Brown et al. 2011): it moves with winds and currents, so a ‘decline’ during the winter usually indicates redistribution, not melting.

Polar_bear Bering Sea 2007 USFWS lg

Polar bear on Bering Sea ice 2007 USFWS

According to researcher Rick Thoman from the University of Alaska Fairbanks, quoted by the Canadian Press:

“Wind blew ice to Russian beaches in the west and to the south side of Norton Sound south of Nome but left open water all the way to Chukchi Sea north of the Bering Strait.”

Polar bears that venture into the Bering Sea are part of the Chukchi Sea subpopulation, which is known to be thriving (Crockford 2019; AC SWG 2018; Regehr et al. 2018; Rode and Regehr 2010; Rode et al. 2013, 2014, 2015, 2018).

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Before National Geographic apologized for hyping the starving polar bear video they exploited it to promote a message of doom

Back in early February this year, National Geographic used their “this is what climate change looks like” video to promote a newly-published polar bear study and endorse conservation activist Steven Amstrup’s debunked and abandoned prediction of polar bear catastrophe due to global warming. Even with this revelation, the starving polar bear video fiasco is not yet over.

Baffin Island starving pb headline_GlobalNews_8 Dec 2017

Polar Bears Really Are Starving Because of Global Warming, Study Shows (National Geographic, 1 February 2018).

The initial focus of the February 2018 National Geographic article was a study published that week by Anthony Pagano and colleagues (Pagano et al. 2018; Whiteman 2018), suggesting that a few polar bears in the Southern Beaufort Sea were not getting enough to eat in early spring from 2014-2016 (with no reference to sea ice conditions; see my critique of that study here).

Then, Steven Amstrup, spokesman for activist organization Polar Bears International, is quoted as saying (my bold):

“If these results hold up [from Pagano’s study], then it shows that the loss of sea ice may have a bigger impact on the bears than previously thought, said Amstrup, a former USGS polar bear expert. Amstrup’s own 2010 study projected that continued decline in sea ice would reduce the global population of bears by two thirds, to less than 10,000 by 2050.

Seriously, no one except Amstrup and his Polar Bears International fanbase are citing his outlandish 2010 prediction, which is just a rehash of his 2007 USGS internal report and its 2008 journal version (Amstrup 2007, 2008, 2010). Amstrup’s prediction is not only a failure (Crockford 2017, 2018; Crockford and Geist 2018) but it’s been abandoned by his colleagues for vaguer or more moderate predictions of population decline (e.g. Atwood et al. 2015, 2016; Regehr et al. 2016).

National Geographic has now apologized for saying that the emaciated bear in the SeaLegacy video they so heavily promoted was “what climate change looks like” (and replaced the caption with “this is what starvation looks like,” even though there is no evidence the bear was starving from lack of food rather than from severe illness).

But the damage is done. By endorsing the discredited polar bear survival predictions of Amstrup along with the video, National Geographic degraded itself even further in the eyes of rational and informed readers. I’ll have more to say on the SeaLegacy video exploited by National Geographic and its message that starving polar bears are victims of climate change in a subsequent post: we haven’t yet reached the end of this debacle.

References

Amstrup, S.C., Marcot, B.G. & Douglas, D.C. 2007. Forecasting the rangewide status of polar bears at selected times in the 21st century. US Geological Survey. Reston, VA. Pdf here

Amstrup, S.C., Marcot, B.G., Douglas, D.C. 2008. A Bayesian network modeling approach to forecasting the 21st century worldwide status of polar bears. Pgs. 213-268 in Arctic Sea Ice Decline: Observations, Projections, Mechanisms, and Implications, E.T. DeWeaver, C.M. Bitz, and L.B. Tremblay (eds.). Geophysical Monograph 180. American Geophysical Union, Washington, D.C. http://onlinelibrary.wiley.com/doi/10.1029/180GM14/summary and http://alaska.usgs.gov/science/biology/polar_bears/pubs.html

Atwood, T.C., Marcot, B.G., Douglas,D.C., Amstrup, S.C., Rode, K.D., Durner, G.M. and Bromaghin, J.F. 2015. Evaluating and ranking threats to the long-term persistence of polar bears. USGS Open-File Report 2014–1254. Pdf here.

Atwood, T.C., Marcot, B.G., Douglas, D.C., Amstrup, S.C., Rode, K.D., Durner, G.M. et al. 2016. Forecasting the relative influence of environmental and anthropogenic stressors on polar bears. Ecosphere, 7(6), e01370.

Crockford, S.J. 2017. Testing the hypothesis that routine sea ice coverage of 3-5 mkm2 results in a greater than 30% decline in population size of polar bears (Ursus maritimus). PeerJ Preprints 2 March 2017. Doi: 10.7287/peerj.preprints.2737v3 Open access. https://doi.org/10.7287/peerj.preprints.2737v3

Crockford, S.J. 2018. State of the Polar Bear Report 2017. Global Warming Policy Foundation Report #29. London. pdf here.

Crockford, S.J. and Geist, V. 2018. Conservation Fiasco. Range Magazine, Winter 2017/2018, pg. 26-27. Pdf here.

Pagano, A.M., Durner, G.M., Rode, K.D., Atwood, T.C., Atkinson, S.N., Peacock, E., Costa, D.P., Owen, M.A. and Williams, T.M. 2018. High-energy, high-fat lifestyle challenges an Arctic apex predator, the polar bear. Science 359 (6375): 568 DOI: 10.1126/science.aan8677

Whiteman, J.P. 2018. Out of balance in the Arctic. Science 359 (6375):514-515. http://science.sciencemag.org/content/359/6375/514

Hansen’s 1988 climate change testimony was the answer to Stirling’s polar bear problem

Last week’s media coverage made me realize that James Hansen’s testimony to a US Senate committee in 1988 provided well-timed answer to a vexatious problem facing polar bear biologist Ian Stirling. Thirty years ago, Stirling was struggling to understand why polar bear productivity in Western Hudson Bay had dropped.  He was ripe for the suggestion from Hansen (and his follow-up paper) that human-caused global warming could be the explanation. An interview with Stirling and colleague Andrew Derocher published in 2016 helps connect the dots.DA-IS-measuring_Ian Stirling

Many bears were in poor condition in the fall of 1983 (Calvert et al. 1986:19, 24; Ramsay and Stirling 1988). In general, the 1980s saw weights of bears decline and cub mortality increase, with a marked increase in the loss of whole litters over what had been documented in the 1960s and 1970s (Derocher and Stirling 1992, 1995).

Until Hansen and climate change came along,  density-dependent effects (such as the number of bears out-pacing food supply) were seen as the most likely explanation. But sea ice decline blamed on human-caused global warming was suddenly a new possibility that Stirling soon embraced (Stirling and Derocher 1993). By the late 1990s, sea ice coverage on Hudson Bay had indeed declined but the correlation with polar bear productivity produced a weak trend that was not statistically significant (Stirling et al. 1999).

The 1999 Stirling paper did not provide scientific evidence to explain the 1980s decline in productivity as much as it presented a novel scapegoat to blame when a more plausible explanation could not be made.

Bottom line: Global warming could not have been the proximate cause of the productivity changes in WH polar bears documented during the 1980s but Stirling spent the next two and a half decades vigorously pushing climate change as the cause of all polar bear ills. Continue reading

Hudson Bay ice update: more thick first year ice habitat for polar bears in 2018 than 2004

Despite pronouncements from one polar bear specialist that “ice in Hudson Bay is in rapid retreat” a look back in time shows that there is more thick first year ice over the Bay this year for the week of the summer solstice than there was in 2004 – and much less open water than 1998.

Lunn et al 2016 EA cover image WH bear

Below, 2018, June 18 (the week of the summer solstice):

Hudson Bay weekly stage of development 2018 June 18

Compare the above to the same week coverage chart for 2004, below:
Hudson Bay weekly stage of development 2004_June 21

Ice coverage for some other recent years are shown below compared to 1998, the year the ice breakup pattern on Hudson Bay changed. Speed and melt sequences vary according to the amount of thick first year ice present, discussed previously here.

PS. If you’re wearing white today, flaunt it! Tell your friends and colleagues that you’re celebrating the success of polar bears despite such low summer sea ice since 2007 that 2/3 of them were predicted to disappear.
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Svalbard polar bear data 2016 through 2018 shows no impact of low ice years

Last week, the Norwegian Polar Institute updated their online data collected for the Svalbard area to include 2017 and 2018 — fall sea ice data and spring polar bear data. Older data for comparison go back to 1993 for polar bears and 1979 for sea ice, showing little to no impact of the reduced ice present since 2016 in late spring through fall.

Svalbard polar bear_NP015991-isbjorn-JA

Here’s what the introduction says, in part [my bold]:

“…The polar bear habitat is changing rapidly, and the Polar Basin could be ice-free in summer within a few years. Gaining access to preferred denning areas and their favourite prey, ringed seals, depends on good sea ice conditions at the right time and place. The population probably increased considerably during the years after hunting was banned in 1973, and new knowledge indicates that the population hasn’t been reduced the last 10-15 years, in spite of a large reduction in available sea ice in the same period.”

See Aars et al. 2017 for details on the 2015 Svalbard polar bear population count, keeping in mind that the subpopulation region is called “Barents Sea” for a reason: only a few hundred individuals currently stick close to Svalbard year round while most Barents Sea bears inhabit the pack ice around Franz Josef Land to the east (Aars et al. 2009; Crockford 2017, 2018).
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IUCN polar bear specialists reject IPCC- supported forecasts of sea ice based on CO2

In case you missed it — or missed the significance of it — polar bear specialist Mitch Taylor correctly pointed out in his recent essay (a response to the New York Times article that appeared Tuesday (10 April) about the Harvey et al. (2018) BioScience paper) that the IUCN Polar Bear Specialist Group have given up using computer models of future sea ice extent based on rising CO2 levels supported by the IPCC.

Polar_Bear_male_Regehr photo_March 21 2010_labeled

Their latest assessment (Regehr et al. 2016) does not link polar bear survival models to climate modeled forecasts of Arctic sea ice decline but rather to an assumption that declines already documented will continue in linear fashion over this century.

This means that CO2 emissions blamed on human fossil fuel use is no longer directly tied to the predicted future decline of polar bear numbers: IUCN polar bear specialists simply assume that sea ice will continue to decline in a linear fashion with no cause attributed to that decline except the broad assumption that anthropogenic climate change is to blame for Arctic sea ice declines since 1979.

No wonder former USGS polar bear biologist Steve Amstrup never refers to this IUCN PBSG study: he and the organization that now employs him, Polar Bears International, are still firmly wedded to the concept that CO2 is the sea ice control knob.

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My Financial Post op-ed: Polar bears keep thriving even as global warming alarmists keep pretending they’re dying

One powerful polar bear fact is slowly rising above the message of looming catastrophe repeated endlessly by the media: More than 15,000 polar bears have not disappeared since 2005. Although the extent of the summer sea ice after 2006 dropped abruptly to levels not expected until 2050, the predicted 67-per-cent decline in polar bear numbers simply didn’t happen. Rather, global polar bear numbers have been stable or slightly improved.

lying-bear-shutterstock_244419640_cropped_web-size.jpg

The polar bear’s resilience should have meant the end of its use as a cherished icon of global warming doom, but it didn’t. The alarmism is not going away without a struggle. Continue reading