15 years after ESA listing as ‘threatened’ due to sea ice loss polar bears are abundant & thriving
Dr. Susan Crockford: "Polar bear turned out to be more flexible and resilient than predicted and many subpopulations are better off than before. Davis Strait and Chukchi Sea bears are doing very well: Barents Sea bears in particular are thriving despite by far the most sea ice loss of any Arctic region...polar bears are no closer to extinction than they were 15 years ago, according to the results of field studies. There is no existential emergency for polar bears or any other Arctic sea mammals due to declining summer sea ice, despite continued messages of doom from remorseless experts."
Dr. Susan Crockford
Experts who used the American Endangered Species Act (ESA) to list polar bears as ‘threatened’ in May 2008 were mistaken: sea ice authorities got their predictions wrong about future ice extent and polar bear specialists erroneously declared that two-thirds of polar bears would disappear if summer sea ice declines continued unabated.
By 2007, there was even less summer sea ice than computer models of the day had predicted (Stroeve et al. 2007, see red line on graph below) and in 2012, it dropped to just above 3 mkm2.
Updated sea ice predictions published in 2014 by the Stroeve team (see below) went to the other extreme, using totally implausible RCP 8.5 scenarios to predict a virtually ice-free Arctic (< 1 mkm2 ice extent) before 2040, which seem just as likely to be just as wrong as their 2007 attempt (Hausfather and Peters 2020; Pielke and Ritchie 2021; Stroeve et al. 2007, 2014; Swart et al. 2015).
In fact, for 12 years out of the last 15, summer ice extent has been below 5.0 mkm2 (often well below), which polar bear experts had not anticipated would happen until at least 2050 (Amstrup et al. 2006).
In 2012, NOAA sea ice experts summarized this sea ice loss as “reduced by nearly 50%” since 1979:
Despite this dramatic decline in sea ice, polar bears are still abundant and thriving because polar bear specialists got it wrong about the bears’ need for this habitat in summer (Crockford 2017, 2019; Crockford and Geist 2018). Polar bear turned out to be more flexible and resilient than predicted and many subpopulations are better off than before. Davis Strait and Chukchi Sea bears are doing very well: Barents Sea bears in particular are thriving despite by far the most sea ice loss of any Arctic region (e.g. Conn et al. 2021; Frey et al. 2022; Haavik 2022; Lippold et al. 2019; Peacock et al. 2013; Regehr et al. 2018; Rode et al. 2014, 2018, 2021, 2022).
This was not what had been predicted when the bears were listed as ‘threatened’ in 2008.
Conclusion: Despite the Arctic warming four times as fast as the rest of the world with rising CO2 levels and almost 50% less summer ice than there was in 1979, polar bears are no closer to extinction than they were 15 years ago, according to the results of field studies. There is no existential emergency for polar bears or any other Arctic sea mammals due to declining summer sea ice, despite continued messages of doom from remorseless experts.
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Conn, P.B., Chernook, V.I., Moreland, E.E., et al. 2021. Aerial survey estimates of polar bears and their tracks in the Chukchi Sea. PLoS ONE 16(5): e0251130. https://doi.org/10.1371/journal.pone.0251130
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. and Geist, V. 2018. Conservation Fiasco. Range Magazine, Winter 2017/2018, pg. 26-27. Pdf here.
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