Tag Archives: Stirling

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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Archive of 2007 USGS reports supporting 2008 ESA listing for the polar bear

The administrative reports used in 2007 to support the decision to list polar bears as ‘threatened’ under the US Endangered Species Act (ESA) in 2008 disappeared from the US Geological Survey website several years ago. I have archived them here in pdf format to make them easy to find for anyone wishing to access the accuracy of the models, data, and assumptions made in 2007.

Amstrup w triplet_Prudhoe Bay 2005_USGS_sm

Steven Amstrup in 2005, then lead USGS polar bear biologist, with triplet cubs, Prudhoe Bay, AK.

This is a housekeeping post meant for future reference. I’ve included citations for the relevant sea ice projection papers used in the models presented in the 2007 documents and a few other related reports from the same time period. Continue reading

Two technical critiques of the Harvey et al. polar bear Bioscience attack paper

Not much time for blogging, but two technical critiques  of the Harvey et al. paper have recently been posted, which you might like to read at your leisure. I will update this post when I can if more critiques appear plus I’ve provided a list of previous posts (my and others) on this issue.

Polar Bears, Inadequate data and Statistical Lipstick (18 Decemeber 2018, RomanM writing at ClimateAudit)

McIntyre guest blog on Harvey paper photo led_RomanM 18 Dec 2017

Polar bear attack paper invalidated by non-independent analysis” (Cross posted 14 December 2017 at ClimateScepticism from the blog of Shub Nuggarath, 12 December 2017).

UPDATE 19 December 2017: Richard Tol has posted a draft of his critique, which was itself updated 20 December “Lipstick on a bear” in which he concludes:

“In sum, Harvey et al. (2017) play a statistical game of smoke and mirrors. They validate their data, collected by an unclear process, by comparing it to data of unknown provenance. They artificially inflate the dimensionality of their data only to reduce that dimensionality using a principal component analysis. They pretend their results are two dimensional where there is only one dimension. They suggest that there are many nuanced positions where there are only a few stark ones – at least, in their data. On a topic as complex as this, there are of course many nuanced positions; the jitter applied conceals the poor quality of Harvey’s data. They show that these is disagreement on the vulnerability of polar bears to climate change, but offer no new evidence who is right or wrong – apart from a fallacious argument from authority, with a “majority view” taken from an unrepresentative sample. Once the substandard statistical application to poor data is removed, what remains is a not-so-veiled attempt at a colleague’s reputation.”

UPDATED 20 December 2017: Lead author of the Bioscience attack paper Jeff Harvey talked to an Amsterdam newspaper about the backlash to the paper, original Dutch and English translation here.

Fig 3 Sea ice prediction vs reality 2012

Predicted sea ice changes (based on 2004 data) at 2020, 2050, and 2080 that were used in 2007 to predict a 66% decline in global polar bear numbers vs. an example of the sea ice extent reality experienced since 2007 (shown is 2012). See Crockford 2017 for details.

Read a short summary of the paper that Harvey et al. don’t want you to know about here:

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

The paper they don’t want you to read is here:

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

The paper being criticized (Harvey et al. 2017, in press: “Internet blogs, polar bears, and climate-change denial by proxy”, Bioscience, open access) is available here.  There is a supplementary data file available here and the data for the principal component analysis is available here  and (h/t to R. Tol), the R code is available here

More on this after Christmas but for now a list of previous blog posts of mine and others is provided below. Continue reading

Polar bears refused to die as predicted and this is how the propheseers respond

The polar bear experts who predicted tens of thousands of polar bears would be dead by now (given the ice conditions since 2007) have found my well-documented criticisms of their failed prophesies have caused them to lose face and credibility with the public.

Fig 3 Sea ice prediction vs reality 2012

Predicted sea ice changes (based on 2004 data) at 2020, 2050, and 2080 that were used in 2007 to predict a 67% decline in global polar bear numbers vs. an example of the sea ice extent reality experienced since 2007 (shown is 2012). See Crockford 2017 for details.

Although the gullible media still pretends to believe the doomsday stories offered by these researchers, the polar bear has fallen as a useful icon for those trying to sell a looming global warming catastrophe to the public.

Here’s what happened: I published my professional criticisms on the failed predictions of the polar bear conservation community in a professional online scientific preprint journal to which any colleague can make a comment, write a review, or ask a question (Crockford 2017). Since its publication in February 2017, not one of the people whose work is referred to in my paper bothered to counter my arguments or write a review.

They ignored me, perhaps hoping the veracity of my arguments would not have to be addressed. But it has not turned out that way. Now, too late, they have chosen a personal attack in the journal BioScience (Harvey et al. 2018 in press).

UPDATE 30 November 2017: See a detailed criticism of this nasty paper here and a shorter one below.

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Why is polar bear conservation such a contentious issue?

Are polar bears in decline or not? Who is to blame for the fact that there is no clear answer about how polar bears are doing? Apparently, everyone except polar bear specialists are at fault for the way polar bear issues have been handled in recent years (including me), at least according to one northern journalist.

UpHere Magazine_July 2016 cover cropped

Back in February, I wrote a rather critical review of an exclusive interview with polar bear researcher Ian Stirling that was published in the February issue of UpHere Magazine called, He speaks for the polar bears – with this lede under the title:

“No fear-mongering. No exaggeration. For Ian Stirling, it’s purely about the science.”

I said “Yeah, well – judge for yourself,” and pointed out some rather critical inaccuracies and obfuscations in Stirling’s answers that I backed up with references.

Well, the editor of that magazine, Tim Edwards, emailed me a few days later and said:

“...we wanted to try to clarify the issues and just talk hard science, no rhetoric. Lo and behold, we’re learning that even his opinion is by no means universally agreed-upon. So thank you for your criticism.”

In May, I was contacted by UpHere writer Dan Campbell, who spoke to me several times before writing this month’s article (15 July 2016), Lost in the numbers: The polar bear is getting more attention than ever, but that may be harming the animal more than helping. Have a look and decide if it clarifies any of the polar bear issues for you. Continue reading

Climate Hustle knows: Ten dire predictions that have failed as global polar bear population hits 22-31k

[Reposted today from earlier this year in support of the 2 May release of the intentionally funny documentary, Climate Hustle (across the US and a few Canadian locations) because host Marc Morano knows that polar bear numbers have not declined as people have been led to believe, see the trailer below]

Climate Hustle_May 2 2016

Grim predictions of the imminent demise of polar bears – their “harsh prophetic reality” as it’s been called – have been touted since at least 2001. But such depressing prophesies have so widely missed the mark they can now be said to have failed.

While polar bears may be negatively affected by declines in sea ice sometime in the future, so far there is no convincing evidence that any unnatural harm has come to them. Indeed, global population size (described by officials as a “tentative guess“) appears to have grown slightly over this time, as the maximum estimated number was 28,370 in 1993 (Wiig and colleagues 1995; range 21,470-28,370) but rose to 31,000 in 2015 (Wiig and colleagues 2015, pdf here of 2015 IUCN Red List assessment; range 22,000-31,000).

Here are the failed predictions (in no particular order, references at the end):
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Polar bear biologists imply “summer sea ice” and “sea ice” are synonymous

According to sea ice experts, winter sea ice habitat for polar bears is not expected to decline at all by 2050 and the critical spring sea ice that polar bears need for gorging on young seals and for mating is not predicted to change much (Durner et al. 2007, 2009), which is why computer modelled predictions about the dire future for polar bears only assessed the potential future effects of declining summer sea ice (e.g. Amstrup et al. 2007; Stirling and Derocher 2012). Note spring is April-June.

Female with cubs Beaufort_USFWS credit 2007 w label_sm

See if that fact is clear in the interview responses by out-spoken polar bear biologists that has just been published in the polar bear portion (“Beyond the polar bear”) of this year’s University of Alberta magazine spring climate change feature. If you can get past the “canaries in the coal mine” opener…
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