How are polar bears doing 15 years after the IUCN declared them “Critically Endangered”? – Watts up with that?

Reposted by Polar Bear Science

Posted on May 10, 2021 |

Earlier this month marked the 15th anniversary of the day the IUCN declared polar bears critically endangered due to climate change. This is the first time such a designation has been given. It was based on the opinion of polar bear specialists, who examined the vague information available at the time and decided that the bears could have serious problems 45 years from now. This decision changed the way the IUCN assessed species risk and created mass confusion for the general public, who mistakenly believed that polar bear numbers had already declined significantly.

The Polar Bear Specialist Group was founded in 1968 as a unit of the International Union for Conservation of Nature (IUCN), which had just drawn up a “Red List” of threatened and endangered species. The PBSG negotiated the 1973 International Treaty to Protect Polar Bears from Unregulated Hunting, a very real threat to which they have been exposed for decades.

Polar bears were first classified as “Endangered” by the IUCN in 1982 – a category that corresponds to “threatened” in the US. They stayed in this category until 1996 when it became clear that polar bear numbers had rebounded significantly. Due to the population decline, polar bears’ status changed to “lower risk” in 1996 (now known as “least concern”) and stayed there for 10 years: polar bears were rescued.

The PBSG members were clearly not pleased that polar bears were no longer classified as “endangered” (this is evident from their meeting reports). Therefore, in 2005, they recommended to the IUCN to re-qualify polar bears as “endangered” due to population declines. It is expected that the modeled sea ice loss will result from expectations of global warming (see below, from the ACIA 2005 report). Although this assessment merely reflected the opinion of PBSG members about what might happen in the future, it was accepted by the IUCN in 2006 as if backed up by detailed scientific analysis (Aars et al. 2006; Crockford 2017, 2019 ).

Without a bit of irony, on May 1, 2006, the IUCN reported two known animals among 530 that were added to the Endangered Species List that year: the polar bear, based on the opinion of scientists informed by climate models that their numbers would decrease by more than 30% in the next 45 years and the hippopotamus, based on an actual decrease of more than 95% in the Congo. Both should be classified as “vulnerable” – one based on facts of catastrophic local decline and the other based on prophecy.

The use of “future threats” based on climate models to explain an endangered species had never been done before, by the IUCN or by others. Here are some of the stories from that eventful time:

Dependence on fossil fuels is driving polar bears to extinction, says WWF-Canada (WWF, May 4, 2006).

Polar bears are given the status of “endangered” on the world list of endangered species (CBC, May 1, 2006).

Polar bears sink deeper into danger (NATURE News, May 2, 2006)

One reason for the PBSG’s decision to include polar bears in the “endangered” category was undoubtedly the knowledge that in early 2005 three activist environmental groups (Center for Biodiversity, Greenpeace and Defense Council for Natural Resources) had submitted a petition to list polar bears according to threatened by the US Endangered Species Act (ESA). Later that year, the groups sued the US government for failing to address their concerns within the timeframe required by ESA rules.

Now that they knew it was possible, American biologists from the US Geological Survey (USGS) used the IUCN Future Threats strategy in 2007 to support the prediction that polar bears would be critically endangered within three generations of polar bears, or 45 years due to the predicted sea ice loss (Amstrup et al. 2007). This time they made a model to support their opinions, but it was a certain type of model that could treat opinions as if they were facts (a “Bayesian” model). I’ve shown that their prediction (that 2/3 of the world’s polar bears would disappear if the sea ice fell by about 40% and stayed there for 10 years – which wasn’t expected before 2050, but instead happened in 2007) failed spectacularly Fashion (Crockford 2017, 2019; Crockford and Spirit 2018).

In 2015, the IUCN commissioned another assessment, this time not only calling for the use of a mathematical model to predict future declines, but also the use of facts instead of opinions: a Bayesian model would not be acceptable. The official estimate of the world population used by the IUCN in 2015 was 22,000 to 31,000 (or an average of 26,000). The worst thing they could predict for the future was that by 2050 there was a 70% probability that the population would decline by 30% or more (Wiig et al. 2015; Regehr et al. 2016). They did not acknowledge that a 30% decrease would not even be statistically significant for most modern populations (Crockford 2020: 15). Additionally, they underestimated the fact that they simply assumed that sea ice would continue to decline linearly in summer: in fact, no sea ice models were used for the climate.

Fat Svalbard polar bears.

Now, in 2021, polar bear numbers are the highest in 60 years. Recent poll results would bring the global average to around 30,000 (Crockford 2021): a little down from 26,000, but not by any significant amount. However, a plausible argument can be made that this number is likely much higher – possibly up to 58,000 (Crockford 2017, 2019, 2020: 3).

Polar Bear Red List status in 2006 provided employment for biologists and increased donations to conservation organizations, but nothing for the bears that the 1973 international treaty had not done. Protection from overhunting was what the bears needed: most populations are still recovering from the wanton slaughter that began more than a century ago.

In other words, I don’t see any positive impact on the bears if they are listed by the IUCN: they were already well protected by national laws and international treaties that were signed before 2006. Concerns about future polar bear survival have always been predicted with low sea ice levels in the future, but even after 15 years of moderately low summer sea ice (about 40% less than 1979), we have not yet seen species-wide impacts that are clearly attributable to climate change.

In the last 15 years we have learned that polar bears only need sea ice until about mid-May or mid-June (depending on latitude) and in late autumn (November) until winter. As long as there is ice at these times, the bears will be fine. The idea that summer sea ice is essential for the survival of polar bears was considered wrong at an early stage by polar bear specialists.

As I explained in my book The Polar Bear Disaster That Never Happened, if polar bears really needed as much summer ice as IUCN biologists assumed in 2006, there would be fewer than 10,000 bears left – and it just didn’t happen.

Climate change is unlikely to affect polar bears’ future unless there is much less ice by mid-May, which given current conditions, is unlikely to happen any time soon (see below):

References

Aars, J., Lunn, NJ and Derocher, AE (Eds.) 2006. Polar Bears: Report on the 14th IUCN / SSC Working Group on Polar Bears from June 20-24, 2005 in Seattle, Washington, USA. IUCN Species Survival Commission Occasional Paper 32nd IUCN, Gland (Switzerland) and Cambridge (UK). http://pbsg.npolar.no/en/meetings/

ACIA 2005. Arctic Climate Impact Assessment: Scientific Report. Cambridge University Press. See the graphics package with sea ice projections here.

Amstrup, SC, Marcot, BG & Douglas, DC 2007. Predicting the far-reaching status of polar bears at selected times in the 21st century. US geological survey. Reston, VA. Pdf here

Crockford, SJ 2017. Testing the hypothesis that routine sea ice cover of 3-5 mkm2 leads to a decrease in the population size of polar bears (Ursus maritimus) by more than 30%. PeerJ Preprints January 19, 2017. Doi: 10.7287 / peerj.preprints.2737v1 Open Access. https://peerj.com/preprints/2737/

Crockford, SJ 2019. The polar bear disaster that never happened. Global Warming Policy Foundation, London. Available in paperback and e-book formats.

Crockford, SJ 2020. Polar Bear Condition Report 2019. Global Warming Policy Foundation Report 39, London. pdf here.

Crockford, SJ 2021. Polar Bear Condition Report 2020. Global Warming Policy Foundation Report 48, London. pdf here.

Crockford, SJ and Spirit, V. 2018. Conservation fiasco. Range Magazine, Winter 2017/2018, pg. 26-27. Pdf here.

Regehr, EV, Laidre, KL, Akçakaya, HR, Amstrup, SC, Atwood, TC, Lunn, NJ, Obbard, M., Stern, H., Thiemann, GW & Wiig, Ø. 2016. Conservation status of polar bears (Ursus maritimus) in terms of projected sea ice decline. Biology Letters 12: 20160556. http://rsbl.royalsocietypublishing.org/content/12/12/20160556 Additional data here.

Wiig, Ø., Amstrup, S., Atwood, T., Laidre, K., Lunn, N., Obbard, M., et al. 2015. Ursus maritimus. The IUCN 2015 Red List of Threatened Species: e.T22823A14871490. Available at http://www.iucnredlist.org/details/22823/0 [accessed Nov. 28, 2015]. See the insert for population figures.

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