Tag Archives: survival

10 fallacies about Arctic sea ice & polar bear survival: teachers & parents take note

Summer sea ice loss is finally ramping up: first year is disappearing, as it has done every year since ice came to the Arctic millions of years ago. But critical misconceptions, fallacies, and disinformation abound regarding Arctic sea ice and polar bear survival. Ahead of Arctic Sea Ice Day (15 July), here are 10 fallacies that teachers and parents especially need to know about.

Polar_Bear_Summer_2 FINAL (2)

The cartoon above was done by Josh: you can drop off the price of a beer (or more) for his efforts here.

As always, please contact me if you would like to examine any of the references included in this post. These references are what make my efforts different from the activist organization Polar Bears International. PBI virtually never provide references within the content it provides, including material it presents as ‘educational’. Links to previous posts of mine that provide expanded explanations, images, and additional references are provided.

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Polar bear habitat update for early spring shows no influence of a CO2 control knob

The primary feeding period for polar bears is rapidly drawing to a close in much of the Arctic, although it may continue for another few weeks in the farthest north. Mating is pretty much over as well, which means the polar bears’ need for abundant sea ice is declining even more rapidly than the ice does itself at this time of year.

Walking bear shutterstock_329214941_web size

Despite the fact that CO2 levels have now reached 415 ppm (see tweet below), sea ice is still pretty much as it was in 2006 when CO2 was about 385 ppm. In other words, the state of sea ice at this time of year – just over 12 million kilometres squared in 2006 and in 2019 – shows no correlation with rising CO2 levels. There is also not a hint of imminent catastrophe for polar bears anywhere within their range, despite the hand-wringing messages from conservation fear-mongers and their polar bear specialist supporters.

As I’ve argued previously (with references), sea ice is a seasonal requirement for polar bears, not a year-round necessity (Crockford 2019).

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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

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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At the winter maximum, still about the same polar bear habitat this year as 2006

There is no evidence that slightly less winter sea ice than the average since 1979 has had any negative impact on polar bear health or survival: the difference is simply not biologically meaningful to Arctic animals.

PB_male on ice_Regehr USFWS_March 2010_labeled

Polar bear on winter sea ice around the yearly maximum in the Beaufort Sea, 2010 (March 21).

NASA’s 23 March 2018 announcement regarding the Arctic sea ice maximum this year:

“Sea ice in the Arctic grew to its annual maximum extent last week, and joined 2015, 2016 and 2017 as the four lowest maximum extents on record, according to scientists at the NASA-supported National Snow and Ice Data Center (NSIDC) and NASA.”

Except, what they don’t tell you is that 2006 had almost the same extent as 2018 and 2006 wasn’t far behind according to the official, averaged data presented at NSIDC’s Arctic Sea Ice News & Analysis:

Arctic sea ice Maximum 10 lowest extents_NSIDC 23 March 2018

Current conditions at the winter maximum (at 17 March 2018, from NSIDC Masie, extent measured at 14.7 mkm2, using software able to discern more ice than used for the figures in Table 1), shown below: Continue reading

Amstrup & colleages can’t refute my critique of their 2007 polar bear survival model, Part 2

Polar bear specialists Andrew Derocher and Steven Amstrup recently spent inordinate energy trying to refute the opinion piece I’d written for the Financial Post in celebration of International Polar Bear Day last month, ignoring my fully referenced State of the Polar Bear Report for 2017 that was released the same day (Crockford 2018) and the scientific manuscript I’d posted last year at PeerJ Preprints (Crockford 2017).

polar_bear_USFWS_fat Chukchi Sea bear

Their responses use misdirection and strawman arguments to make points. Such an approach would not work with the scientific community in a public review of my paper at PeerJ, but it’s perfect spin for the self-proclaimed “fact-checking” organization called Climate Feedback. The result is a wildly ineffective rebuttal of my scientific conclusion that Amstrup’s 2007 polar bear survival model has failed miserably.

This is Part 2 of my expose, see Part 1 here.
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Coffee house discussion about polar bear science & conservation in Toronto on Tuesday

In conjunction with the launch of my State of the Polar Bear Report in Toronto next week, Benny Peiser (from the Global Warming Policy Foundation) and I will be participating in a coffee house discussion about polar bear conservation and survival issues on the evening of Tuesday, 27 February 2018 at 8:30 pm.

If you’re in town, come and celebrate International Polar Bear Day with a frank discussion about polar bear science.

Grounds for Thought at GreenBeanery_Feb 27 2018

I am very much looking forward to meeting the public at this evening discussion and to chat with media representatives and colleagues at the press luncheon in the early afternoon. Journalist/opinion writer Terry Corcoran recently billed the luncheon as part of a Polar Bear Battle since conservation organization Polar Bears International (where biologist Steven Amstrup, co-author of the Harvey et al. Bioscience paper and developer of the failed 2007 polar bear survival model, is employed as chief scientist) is holding a gala fundraiser dinner the same night, just a block away.

In addition to Benny Peiser from GWPF, a number of familiar names will be at the State of the Polar Bear launch and press luncheon, including Terry Corcoran,  Larry Soloman, Joe Oliver and Conrad Black (all journalist/opinion writers at the Financial Post and/or National Post), journalist/writer Donna Laframboise who blogs at No Frakking Consensus, as well as science colleagues Chris Essex, Ross McKitrick, and Steve McIntyre of Climate Audit fame. Details below.

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