Did the PBSG game the polar bear listing process?

I was in the process of writing about something else last week when I came across a tidbit of information that, on closer examination, turned out to be part of a much bigger issue that I thought should be documented.

The story involves some machinations behind the scenes of the international Polar Bear Specialist Group, the “PBSG,” that you might find rather astonishing – and which may have implications for the various on-going battles about the polar bear’s conservation status.

A lone polar bear walking on ice [Kathy Crane (NOAA) photo].
We’ll call this a metaphor for the expulsion of Mitch Taylor from the PBSG,
after the Group switched from emphasizing unregulated over-hunting
as the primary threat to polar bears to global warming.

I was researching the history of polar bear conservation status in the international arena – that is, how, when and why (since 1965) the polar bear has been listed by the IUCN (International Union for Conservation of Nature and Natural Resources – or as it calls itself, the World Conservation Union) in its famous Red Data Book of the world’s rare and endangered animals.

It turns out that by the time of the first international meeting of polar bear biologists in 1965 – before the Polar Bear Specialist Group (PBSG) had even been formally chartered and thus, before it was associated with the IUCN – the polar bear was listed in the IUCN’s Red Book (Anonymous 1966, 68, 70) as Vulnerable.

Polar bears were down-graded from a Vulnerable rating to Lower Risk – Conservation Dependent in 1996, after the IUCN revamped its listing criteria (Derocher et al. 1998:45). It seems that by  1993, polar bear biologists had what they considered a reasonable estimate of the global population (about 21,470-28,370 (Wiig et al. 1995), more on the history of these estimates here ). And with that estimate, it appeared that polar bears no longer qualified as Vulnerable under the new IUCN criteria, as I explain below.

According to the revamped IUCN rules for 1996, there were five criteria to be evaluated in establishing whether a species is Critically Endangered, Endangered, or Vulnerable for the IUCN Red List. By the admission of the PBSG member tasked with this assessment on behalf of the Group (Øystein Wiig, Norway), the polar bear qualified for none of them (Wiig, reported in Derocher et al. 1998:45-46), which he summarizes as follows:

Criterion A. Declining population – “Overall, the number of polar bears is thought to be stable or increasing slowly, therefore Criterion A does not apply.”

Criterion B. Small distribution size – “The species has a larger distribution than 20,000 square km, therefore Criterion B does not apply.”

Criterion C. Small population size – “Based on a minimum total population of 21,000 polar bears (Wiig et al. 1995), the number of mature animals might be less than 10,000. A continuing decline does not occur, therefore, Criterion C does not apply.

Criterion D. Population very small or restricted – “The population estimate is larger than 1,000 individuals and the population has a circumpolar distribution, therefore, Criterion D does not apply.”

*Conclusion: “The polar bear does not qualify for any of the criteria of Critically Endangered, Endangered or Vulnerable and is therefore a Lower Risk taxon.” [formally, Lower Risk: Conservation Dependent]

However, this up-grade in the status of the polar bear did not appear to make the PBSG biologists very happy. You’d think these guys [and the core group were all men during this period – this situation did not change until 2009, when Elizabeth Peacock from Nunavut, Canada, joined PBSG] would have been ecstatic that the protection measures enacted in the 1970s had worked so well.

But by 2006, the polar bear had been up-graded back to Vulnerable at the  recommendation of the PBSG (Aars et al. 2006:61 and the Red List).

Curious turn of events, that. How and why did the polar bear move from being a IUCN Lower Risk* taxon in 1996 – because they were doing so well – back to a Vulnerable taxon in 2006, after only 10 years? [*in 2001, renamed Least Concern]

Good question.

It is important, in my opinion, to understand how and why this turn-about happened because there may be implications for the various on-going battles about the polar bear’s conservation status.

At the 2005 meeting of the PBSG, the authors noted (Aars et al. 2006:31) that while the polar bear did not meet any of the criteria qualifying it for listing as Vulnerable based on its current population numbers and distribution, they had discovered there was another way to get the polar bear back on the Red List of Vulnerable taxa:

“given the projected decline in sea ice, polar bears would probably meet the Population Reduction criteria [Criteria A, above] that would result in their being listed as Vulnerable. A projected or suspected population reduction of ≥ 30% that would be met within the next 10 years or three generations (up to 100 years), whichever is greater, qualifies a species as Vulnerable.”

It appears that Scott Schliebe (US Fish and Wildlife, Alaska) was the person who made the suggestion that projected [future] declines in sea ice be used as the basis for a re-evaluation of the polar bear’s IUCN status. He got the ball rolling and passed the job on to Wiig (author of the 1996 IUCN assessment) for completion (Aars et al. 2006:30).

Wiig made a presentation to the group, at their 2005 meeting, recommending a change in IUCN status to Vulnerable. However, no references to any data that he used is presented in the PBSG report on that meeting and no written transcript of the presentation is provided. [it is stated, however, that Wiig used a generation time of 15 years in his calculations, “which was calculated from the age of maturity (five years) plus half the length of the reproductive period in a complete life cycle (10 yrs, =0.5 x 20 yrs)” – this definition is important to later issues, but I won’t get into all that here].

Without further ado, the Group stated in their après-meeting press release:

“With the results of the foregoing research and related uncertainties in mind, the Group reviewed the status of polar bears using the 2001 IUCN Red List categories and criteria. The Group concluded that the IUCN Red List classification of the polar bear should be upgraded from Least Concern to Vulnerable based on the likelihood of an overall decline in size of the total population of more than 30% within the next 35 to 50 years. The principal cause of this decline is climatic warming and its consequent negative affects [sic] on the sea ice habitat of polar bears.” (Aars et al. 2006:61).

So, if I’m understanding this correctly, based on a presentation by Wiig during the 2005 meeting, the PBSG realized that polar bears could be up-graded to Vulnerable status if they used a predicted overall decline in size of the total population of more than 30% within the next 35 to 50 years based on sea ice declines due to global warming. And by the time the meeting was over, the Group had declared to the world that, indeed, an overall decline in size of the total population of more than 30% within the next 35 to 50 years was likely due to global warming.

The Group’s recommendation to up-grade the status of the polar bear to Vulnerable was apparently accepted unchallenged by the IUCN Red Book committee [well, why wouldn’t it be? – the PBSG are part of the IUCN] and it was adopted shortly thereafter, for the 2006 version of the Red List.

The Red List summary cites only two documents in justification of their decision to list the polar bear as Vulnerable: Hassol 2004 and Derocher 2004. Turns out “Hassol 2004” was written by Susan Joy Hassol, a “climate change communicator, analyst, and author known for her ability to translate science into English.” She authored the stand-alone overview report, called Impacts of a Warming Arctic, for the 2004 Arctic Doomsday Book, the Arctic Climate Impact Assessment report (ACIA 2004), a synthesis document aimed directly at policy makers. [the ACIA report was a sort of “Arctic version” of an IPCC report]

Hassol’s report contains the figure copied below* – sea ice extent from 1900 to 2003. Funny thing is, in this graph there is no distinction made between the satellite record and the data from various sources that make up the record before 1979 (i.e., 1900-1978). Doing this without saying so is bad PR, not science. [*apologies for the fuzziness, but the pdf provided disabled the “snapshot” tool that would have given a better image].

Arctic sea ice extent from 1900-2003, as depicted in Hassol 2004, pg. 25.
Notice that there is no distinction made between data from the satellite record
and the data that make up the record prior to 1979. Click to enlarge.

On top of that, it should be noted that the document Hassol was synthesizing, the Arctic Climate Impact Assessment (2004) report, contained some of the first sea ice models attempted. The ACIA report used only 19 years worth of sea ice data (1981-2000) as a baseline – not even one data point in climate terms (usually considered to be 30 years) (ACIA 2004: Chapter 6, pg. 192).

And here’s another curious fact: the “History” of polar bear status assessments, listed on the IUCN Red List online summary, copied below, omits this shift in status entirely. [found by searching “IUCN red list polar bear 2006” on Google]. The change to Lower Risk in 1996, as documented in the PBSG meeting reports and in effect for 10 long years (renamed Least Concern in 2001), has been expunged from the IUCN public record. The authors of the Red List summary – “Schliebe et al. 2008″ are listed as the assessors in this archived version – simply left those inconvenient years of the change in status out of the “Status History” altogether, as if nothing had happened:

2006 – Vulnerable (IUCN 2006)
2006 – Vulnerable
1994 – Vulnerable (Groombridge 1994)
1990 – Vulnerable (IUCN 1990)
1988 – Vulnerable (IUCN Conservation Monitoring Centre 1988)
1986 – Vulnerable (IUCN Conservation Monitoring Centre 1986)
1982 – Vulnerable (Thornback and Jenkins 1982)

[Ironically, but perhaps not so surprising, the PBSG website page dedicated to this Red List issue does include the 1996 status change].

In summarizing the above, it appears that in one brief, closed-door meeting, with only a synthesis report meant for policy makers as evidence (Hassol 2004), the PBSG got the most influential conservation group in the world [the IUCN] to accept that predicted effects of future global warming was more of a threat to polar bears than over-hunting.

Over-hunting was the reason the PBSG had been formed in the first place. By their own admission (Derocher et al. 1998:37), “a primary goal of the Agreement [signed by all Arctic nations in 1973 to protect the polar bear] was to limit the hunting of polar bears to sustainable levels.”

It appears to me that when the PBSG did not have the evidence to support listing polar bears as Vulnerable under the re-vamped IUCN criteria in 1996 (version 2.3) – because they were doing so well – the Group simply switched the primary threat from unregulated over-hunting to future global warming. Their reasons for seeming to prefer “Vulnerable” over “Least Concern” are not stated explicitly.

It also appears that no one at the time undertook the due-diligence one would reasonably expect from such a group to investigate the science behind Hassol’s glossy synthesis report. Hassol’s report for policy makers contained no references, so anyone wishing details would have had to consult the original document upon which it was based.

The fact that long-time core PBSG member Mitch Taylor eventually did check the underlying basis for the claims made – and found it wanting – is to his enduring credit as a responsible scientist. But it cost him: the Group tossed him out, as of the 2009 meeting (see details here and Nova 2009). As Derocher (outgoing chairman of the PBSG) informed Taylor by email,

“for the sake of polar bear conservation, views that run counter to human induced climate change are extremely unhelpful.
…
Nothing I heard [from the rest of the Group] had to do with your science on harvesting or your research on polar bears – it was the positions you’ve taken on global warming that brought opposition [to his inclusion as a core member of the PBSG, as of 2009].“

A pretty amazing series of events. It makes me wonder how much influence a Red Book listing of polar bears as Vulnerable (in 2006) by the IUCN had on the decision by the US Fish & Wildlife Service, in 2008, to support the petition to list polar bears as ‘threatened’ under the US Endangered Species Act (equivalent to the IUCN status of Vulnerable).

And very curious that Scott Schliebe (see here and here) was the only PBSG member who was employed by the US Fish & Wildlife Service at the time both of these listing decisions were made – and that he was the one who first suggested to the PBSG at large that the threat of global warming could be used to up-grade the conservation status of the polar bear on the IUCN Red List.

[Postscript: Schliebe retired from the US Fish & Wildlife Service in 2008, either just before or just after the change in polar bear status by the ESA was finalized]

References
Aars, J., Lunn, N. J. and Derocher, A.E. (eds.) 2006. Polar Bears: Proceedings of the 14th Working Meeting of the IUCN/SSC Polar Bear Specialist Group, 20-24 June 2005, Seattle, Washington, USA. Occasional Paper of the IUCN Species Survival Commission 32. IUCN, Gland (Switzerland) and Cambridge (UK). http://pbsg.npolar.no/en/meetings/

Anonymous. 1966. Proceedings of the First International Scientific Meeting on the Polar Bear, 6-10 September 1965 at Fairbanks, Alaska. U.S. Dept. of the Interior (Resource Publication 16) and the University of Alaska (International Conference Proceedings Series, No. 1). http://pbsg.npolar.no/en/meetings/

Anonymous. 1970. Polar Bears: Proceedings of the 2nd Working Meeting of Polar Bear Specialists, organized by IUCN at Morges, Switzerland, 2-4 February 1970. Gland, Switzerland and Cambridge UK, IUCN. http://pbsg.npolar.no/en/meetings/

Anonymous. 1968. Polar Bears: Proceedings of the 1st Working Meeting of Polar Bear Specialists, organized by IUCN at Morges, Switzerland, 29-31 January 1968. IUCN Bulletin, April/June 1968, Vol. 2, No. 7:54-56 (and reprinted in the 1970 Proceedings, pg. 89-91) http://pbsg.npolar.no/en/meetings/

Arctic Climate Impact Assessment. 2004. Cambridge University Press. Hard cover copy here http://www.cambridge.org
[published 2005]; pdf copies, including the synthesis report, available here http://www.acia.uaf.edu/ [published November 2004]

Derocher, A., Garner, G.W., Lunn, N.J., and Wiig, Ø. (eds.) 1998. Polar Bears: Proceedings of the 12th meeting of the Polar Bear Specialists Group IUCN/SSC, 3-7 February, 1997, Oslo, Norway. Gland, Switzerland and Cambridge UK, IUCN. http://pbsg.npolar.no/en/meetings/

Derocher, A. E., Lunn, N. J. and Stirling, I. 2004. Polar bears in a warming climate. Integrated Comparative Biology [sic] 44: 163-176. [should be Integrative and Comparative Biology. This paper is the print version of a 2003 conference paper and makes no reference to the not-yet-written ACIA report or any sea ice models]

Hassol, S. J. 2004. Impacts of a Warming Arctic: Arctic Climate Impact Assessment. Cambridge University Press, Cambridge, UK. http://www.acia.uaf.edu

Nova, J. 2009. Exile for Non-believers. SPPI original paper, September 2009.
http://scienceandpublicpolicy.org/originals/exile_for_non_believers.html?Itemid=0, back up pdf here: Nova_Exile_for_non_believers_2009

Schliebe, S., Wiig, Ø., Derocher, A. and Lunn, N. (IUCN SSC Polar Bear Specialist Group) 2008. Ursus maritimus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. Downloaded on 26 December 2012.