Posted on February 19, 2021 | Comments Offon Fact: polar bears are thriving despite sea ice loss according to the scientific literature
Is Facebook now an expert on polar bear conservation status? Apparently they have decreed themselves the last word for online content. There is a plan afoot to label anything that says polar bears are not being harmed by recent sea ice declines as ‘disinformation’ – but on whose authority? Thanks to Josh for the cartoon below.
A new section of the Climate Science Information Center, launching alongside the labelling trial, debunks common myths such as the false claim that polar bear populations are not suffering due to global heating, or the widespread belief that excess carbon emissions help plant life. Facebook is working with climate communication experts from around the world, including at the University of Cambridge, to produce the content.
Ah, they’re consulting ‘climate communication experts‘! Those experts surely must be up on all the latest papers and not trusting the word of obviously biased conservations organizations like the WWF or PBI whose real reason for existence is the generation of as much money in donations as possible?
The peer reviewed literature supports the claim that polar bears are currently thriving despite recent ice declines – especially in the Chukchi and Barents Seas – regardless of what computer model predictions say about what might happen in the future. This is a fact, not a ‘myth’. See my paper from 2017 and my 2019 book for most of the citations (Crockford 2017, 2019) and others in the reference list below. Check them out yourself before you believe Facebook. Ask me for any paper you’d like to see via the ‘contact me’ form and I’ll send it along. Also, look for my State of the Polar Bear Report 2020 next week.
The polar bear has two features that mark it as a thriving species: it’s as wide-spread across the Arctic as it was hundreds of years ago and there has not been a sustained, statistically significant decline in numbers in any of the 19 official subpopulations. Modest declines in abundance for Western and Southern Hudson Bay documented in 2016 were not statistically significant and have almost certainly been reversed since then.
That’s because the last four years have been especially good for Hudson Bay bears: in 2020, most Western Hudson Bay bears left for the newly-formed ice as early in the autumn as they did in the 1980s – for the fourth year in a row – and sea ice breakup in spring was also like the 1980s for the second year in a row. Southern Hudson Bay bears experienced virtually identical conditions. The number of bear problems in Churchill, Manitoba, which self-identifies as the ‘Polar Bear Capital of the World’, were the lowest in years.
Bears that came ashore in mid-to-late August and left in November would have spent only three months on land – about one month less than most bears did in the 1980s and two months less than bears did in the early 2000s (Castro de la Guardia et al 2017). The last four years at least have been very similar – so it’s no wonder none of this information has been made available in the peer-reviewed literature.
It’s not just these Canadian bears that have been thriving: virtually all polar bears across the Arctic have been in excellent condition in recent years. Photos of fat bears are the ‘new normal’. They’ve had an abundance of fat seal pups to eat in the spring due in large part to increased primary productivity. According to NOAA scientists, summer growth of plankton in the Arctic has increased since 2002 because of longer ice-free periods, especially in the Russian Arctic, the Barents Sea and Hudson Bay. Due to especially low ice levels in 2020, plankton blooms hit records highs in August (see photo below). More abundant plankton benefits the entire Arctic food chain: more fish means fatter seal pups and well-fed polar bears. This goes a long way towards explaining why polar bears doing so well in areas like the Chukchi and Barents Seas where profound summer sea ice losses have occurred in recent years.
However, none of these recent facts were taken into account for the 2020 computer model that predicted the near-extinction of the species by 2100 and minimal cub survival for Southern Hudson Bay bears before 2030. This pessimistic model’s primary assumption was that historical data from Western Hudson Bay polar bears could be used as a proxy to predict how all other bear populations across the Arctic would respond to various predicted declines in summer ice coverage. Unfortunately, the model also depended upon the scientifically discredited and implausible ‘worst case’ climate scenario (‘RCP8.5’) to arrive at its dystopian vision of future sea ice conditions.
As a consequence, this new prediction of polar bear extinction is even less worthy of serious consideration than the failed prediction polar bear specialists developed in 2007. We now know that polar bears have generally benefitted from much less summer sea ice than was available in the 1980s and rather than declining continuously, September sea ice levels have been rather stable since 2007 (see graph below, from US NSIDC).
Sadly, the facts indicating that polar bears are thriving across the Arctic are routinely pushed aside in favour of an ominous prophetic narrative because it supports the ‘climate change emergency’ rhetoric. ‘Trust the science’ is meaningless if model outputs based on faulty assumptions are considered evidence and if scientists display obvious biases, as the IUCN Polar Bear Specialist Group does when it ignores a massive increase in population numbers that was not statistically significant, as they did for Barents Sea bears, but adopts the new number if it’s not statistically significant but shows a slight decline as they did for Western Hudson Bay.
This is why I do what I do – someone needs to keep the public abreast of recent literature and on-the-ground developments that don’t conform to the climate emergency narrative and to call out false statements made by polar bear specialists with an agenda. There is currently no climate emergency for polar bears, despite what computer models suggest might happen decades from now.
Aars, J. 2018. Population changes in polar bears: protected, but quickly losing habitat. Fram Forum Newsletter 2018. Fram Centre, Tromso. Download pdf here (32 mb).
Atwood, T.C., Bromaghin, J.F., Patil, V.P., Durner, G.M., Douglas, D.C., and Simac, K.S., 2020. Analyses on subpopulation abundance and annual number of maternal dens for the U.S. Fish and Wildlife Service on polar bears (Ursus maritimus) in the southern Beaufort Sea, Alaska: U.S. Geological Survey Open-File Report 2020-1087. https://doi.org/10.3133/ofr20201087. pdf here.
Castro de la Guardia, L., Myers, P.G., Derocher, A.E., Lunn, N.J., Terwisscha van Scheltinga, A.D. 2017. Sea ice cycle in western Hudson Bay, Canada, from a polar bear perspective. Marine Ecology Progress Series 564: 225–233. http://www.int-res.com/abstracts/meps/v564/p225-233/
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Crawford, J.A., Quakenbush, L.T. and Citta, J.J. 2015. A comparison of ringed and bearded seal diet, condition and productivity between historical (1975–1984) and recent (2003–2012) periods in the Alaskan Bering and Chukchi seas. Progress in Oceanography 136:133-150.
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 19 January 2017. Doi: 10.7287/peerj.preprints.2737v1 Open access. https://peerj.com/preprints/2737/
Crockford, S.J. 2019. The Polar Bear Catastrophe That Never Happened. Global Warming Policy Foundation, London. Available in paperback and ebook formats. Crockford, S.J. 2020. State of the Polar Bear Report 2019. Global Warming Policy Foundation Report 39, London. pdf here.
Dyck, M., Regehr, E.V. and Ware, J.V. 2020. Assessment of Abundance for the Gulf of Boothia Polar Bear Subpopulation Using Genetic Mark-Recapture. Final Report, Government of Nunavut, Department of Environment, Iglulik. 12 June 2020. Pdf here.
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MacCracken, J.G., Beatty, W.S., Garlich-Miller, J.L., Kissling, M.L and Snyder, J.A. 2017. Final Species Status Assessment for the Pacific Walrus (Odobenus rosmarus divergens), May 2017 (Version 1.0). US Fish & Wildlife Service, Anchorage, AK. Pdf here (8.6 mb).
Perovich, D., Meier, W., Tschudi, M., Hendricks, S., Petty, A.A., Divine, D., Farrell, S., Gerland, S., Haas, C., Kaleschke, L., Pavlova, O., Ricker, R., Tian-Kunze, X., Webster, M. and Wood, K. 2020. Sea ice. 2020 Arctic Report Card, NOAA. https://arctic.noaa.gov/Report-Card/Report-Card-2020/ArtMID/7975/ArticleID/891/Sea-Ice Pdf of entire Arctic Report Card here (12mb).
Regehr, E.V., Hostetter, N.J., Wilson, R.R., Rode, K.D., St. Martin, M., Converse, S.J. 2018. Integrated population modeling provides the first empirical estimates of vital rates and abundance for polar bears in the Chukchi Sea. Scientific Reports 8 (1) DOI: 10.1038/s41598-018-34824-7 https://www.nature.com/articles/s41598-018-34824-7
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Rode, K. D., R. R. Wilson, D. C. Douglas, V. Muhlenbruch, T.C. Atwood, E. V. Regehr, E.S. Richardson, N.W. Pilfold, A.E. Derocher, G.M Durner, I. Stirling, S.C. Amstrup, M. S. Martin, A.M. Pagano, and K. Simac. 2018. Spring fasting behavior in a marine apex predator provides an index of ecosystem productivity. Global Change Biology http://onlinelibrary.wiley.com/doi/10.1111/gcb.13933/full