Tag Archives: increase

Global polar bear population larger than previous thought – almost 30,000

The results of three recently-released studies that were not included in the last IUCN Red List assessment add more than 2,050 bears (on average)1 to the official 2015 global polar bear estimate, a point you won’t likely hear next Monday (27 February) from most polar bear specialists, conservation organizations, their cheerleaders and corporate sponsors on International Polar Bear Day.

global-pb-population-size-graphic2_2017-feb-polarbearscience-corrected

This means the adjusted 2015 global estimate for polar bears should be about 28,500 (average), a significant increase over the official estimate of 26,500 (average) for 2015 — and an even larger increase over the 2005 estimate of about 22,500 (average)2, despite the dramatic loss of summer sea ice since 2007 that we hear about endlessly.

It is increasingly obvious that polar bears are thriving despite having lived through summer sea ice levels not predicted to occur until 2050 – levels of sea ice that experts said would wipe out 2/3 of the world’s polar bears (Amstrup et al. 2007; Crockford 2017 v3).

A result, I have been remiss to point out [updated 28 Feb. 2017 & included in revised Version 3 of Crockford 2017], that Drs. Kesten Green, Scott Armstrong and Willie Soon correctly concluded in 2008 was a likely outcome. In their 2008 paper that roundly criticized the USGS forecasting methods used to support placing polar bears on the US Endangered Species List (Armstrong et al. 2008:390), they concluded:

“Given the upward trend in polar bear numbers over the past few decades, a modest upward trend is likely to continue in the near future because the apparent cause of the trend (hunting restrictions) remains.”

So when you hear, “Save the polar bears, their future is grim” next week, remember that polar bears are thriving right now because those future predictions were flawed: summer sea ice is not critical habitat for polar bears. Instead of a vacuous “vanishing species” polar bear T-shirt from WWF, buy Polar Bear Facts and Myths for the kids in your life – and Polar Bears: Outstanding Survivors of Climate Change for your home or community library. You’ll be glad you did.

Footnotes:

1. Total for all three estimate increases is 2054, or about 2050.
Barents Sea (BS) estimated at 3749 for entire region, up 42% (1109) since 2004 estimate of 2640, based on 42% Svalbard increase determined in 2015 (Norwegian Polar Institute 2015; Crockford 2017 v2) applied across the region. This is consistent with observations in 2004 that researchers found about three times (2.87) as many bears in the Russian sector than in Svalbard (Aars et al. 2009), and the stated expectation by Norwegian biologists that the population size would continue to increase despite declines in sea ice (Fauchald et al. 2014).

Baffin Bay (BB) estimate 2,826 (95% CI = 2,059-3,593) at 2013 (SWG 2016), up 752.

Kane Basin (KB) estimate 357 (95% CI: 221 – 493) at 2013 (SWG 2016), up 193.

2. USGS polar bear biologists (Amstrup et al. 2007) used a figure of 24,500 for the global population size in 2005 to support their prediction of doom at mid-century that put polar bears on the US Endangered Species List (Crockford 2017 v2). If we use that figure instead of the average of “20,000-25,000” the increase at 2015 (with the amended data) is still a remarkable 16%.

Update 26 Feb 2017. Original image replaced, without % calculation.

Update 1 March 2017. Crockford 2017 updated, Version 3 is now the most recent available.

References

Aars, J., Marques, T.A., Buckland, S.T., Andersen, M., Belikov, S., Boltunov, A., et al. 2009. Estimating the Barents Sea polar bear subpopulation. Marine Mammal Science 25:35-52.

Amstrup, S.C.,Marcot, B.G. and Douglas,D.C. 2007. Forecasting the rangewide status of polar bears at selected times in the 21st century. Administrative Report, US Geological Survey. Reston, Virginia. 8.8 MB pdf here [may no longer be available online]

Armstrong, J.S., Green, K.C. and Soon, W. 2008. Polar bear population forecasts: A public-policy forecasting audit. Interfaces 38:382–405.

Crockford, S.J. 2017 v3. 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

Fauchald, P., Arneberg, P., Berge, J., Gerland, S., Kovacs, K.M., Reigstad, M. and Sundet, J.H. 2014. An assessment of MOSJ – the state of the marine environment around Svalbard and Jan Mayen. Norwegian Polar Institute Report Series no. 145. Available at http://www.mosj.no/en/documents/

SWG [Scientific Working Group to the Canada-Greenland Joint Commission on Polar Bear]. 2016. Re-Assessment of the Baffin Bay and Kane Basin Polar Bear Subpopulations: Final Report to the Canada-Greenland Joint Commission on Polar Bear. +636 pp. http://www.gov.nu.ca/documents-publications/349

Survey Results: Svalbard polar bear numbers increased 42% over last 11 years

Results of this fall’s Barents Sea population survey have been released by the Norwegian Polar Institute and they are phenomenal: despite several years with poor ice conditions, there are more bears now (~975) than there were in 2004 (~685) around Svalbard (a 42 30% increase) and the bears were in good condition.

Svalbard polar bear fall 2015_Aars

Oddly, in a September report right after the count, biologist Jon Aars reported them in “excellent” condition, with some of them “as fat as pigs.” I guess “good” is the same as “excellent.”

Bears in the Russian portion of the Barents Sea were not counted this year because the Russians would not allow it; the previous total count, from 2004, was 2,650 (range ~1900-3600) for the entire region.

map-BarentsSea

In the map above (courtesy the IUCN Polar Bear Specialist Group), the Svalbard archipelago is on the left (Norwegian territory) and the archipelagos of Franz Josef Land and Novaya Zemlya on the right (Russian territory).

Oddly, the comments made by lead researcher Jon Aars to a Norwegian newspaper (in English), which picked this up yesterday (“Polar bears make a comeback” ), were far more positive than those in the press release (which is likely all that western media will see).

UPDATE 24 December 2015: The new population survey number for Svalbard is actually a 42% increase over the 2004 number. Thanks to Arvid Oen, a WUWT reader, for alerting Anthony Watts to the error, and to Anthony for passing it along. Title and text fixed accordingly, apologies to any others who have picked this up. Cheers and Merry Christmas.

Continue reading