Misplaced eco-anxiety that kids have about polar bears starts with activist biologists like Steven Amstrup, spokesperson for an organization devoted to raising climate change alarm – and media outlets like The Guardian who help them spread fears unsupported by scientific evidence.
Fat healthy polar bear male at Kaktovik, Alaska in the Southern Beaufort Sea, September 2019, Ed Boudreau photo, with permission.
You can’t get much more over the top than these statements from Amstrup today but read carefully: it’s either opinion or factual aspects of polar bear life (“we know that the bears aren’t feeding”) made to sound like new, terrifying developments that can be blamed on climate change.
From The Guardian (29 September 2019), “We know they aren’t feeding’: fears for polar bears over shrinking Arctic ice” [my bold]:
“In 2015, the group reported that the polar bear population in the Beaufort Sea had declined by 40% over the previous decade. “We can only anticipate that those declines have continued,” Amstrup said.
The loss of sea ice this year was so pronounced early in the season that tagging crews from the US Geological Survey (USGS) concluded that the sea ice offshore in the western arctic was too thin and unstable to be able to conduct their studies – the first time the team have pulled their studies because of safety issues.”
…“Amstrup said funding cutbacks and the fact that biologists cannot get out and study the bears means it may never be able to collect the necessary data to assess “just how bad this year was”.
Instead, Amstrup says this bad ice year and record warm summer are symbols of what the future will bring. Bad years like this will be increasingly frequent and the bad years will be increasingly worse – as long as we allow CO2 levels to continue to rise.
“We know that as greenhouse gas concentrations continue to rise it’s going to be warmer and we’re going to have less and less sea ice until polar bears disappear,” he said.”
Amstrup has been crying wolf since 2007: the predictions of polar bear catastrophe were all based on his opinion (that’s how the model was constructed) that this species would not be able to cope with 42% less summer sea ice than they had in 1980 (Amstrup et al. 2007; Crockford 2017, 2019; Durner et al. 2009).
However, the evidence collected by his colleagues has proven him wrong again and again but he hasn’t changed his tune. Polar bears in the Chukchi Sea (the “western arctic”) have been thriving despite the dramatic decline in sea ice there – and so have the seals they depend upon for food (Crawford et al. 2015; Regehr et al. 2018; Rode and Regehr 2010; Rode et al. 2013, 2014, 2018). Barents Sea bears have been thriving despite an even greater loss of summer ice (Aars 208; Aars et al. 2017).
Amstrup suggests that polar bear numbers in the Southern Beaufort this year can only have declined further than the dip calculated for the 2001-2010 period. Not so: it is entirely possible – and eminently plausible – that numbers have increased. That’s because bear numbers declined due to thick ice conditions in spring between 2004 and 2007 that were as bad as they had been in 1974-1976, not because of reduced summer ice since 2007 (Crockford 2017, 2018, 2019; Stirling 2002; Stirling et al. 2008; York et al. 2016).
Southern Beaufort polar bear populations have a long history of declines and recoveries (Stirling 2002) and all the photos of polar bears out of Alaska for the last several years have shown fat healthy bears – two are shown here. Where are the dozens of starving bears that would supposedly be the harbingers of a declining population since 2010? Amstrup does not produce evidence of them.
Fat healthy bear family at the Kaktovik bone pile, 20 April 2016
In addition, the idea that it’s significant that scientists can’t get out on the ice to study polar bears because the ice is “too thin” is bogus. For polar bear studies, sea ice needs to be thick enough to support the weight of a helicopter, research gear and 3-4 people without exceeding the risk threshold for insurance purposes (see photo below). That’s much thicker ice than is necessary to support the weight of a polar bear. Too thin for scientists is not too thin for polar bear survival.
“We know they aren’t feeding” Surprise, surprise! Actually, it’s known that well-fed polar bears are able to survive at least 5 months without food and most bears eat little over the summer whether they hang out on shore or stay on the sea ice (Stirling and Øritsland 1995).
Summer sea ice levels since 2007 have not been getting worse and worse: after an abrupt decline in 2007, September ice coverage has varied between about 3-5 mkm2. This year was not worse than 2012 – which did not, by the way, trigger a polar bear catastrophe – but Amstrup tries to make it sound like 2019 was especially horrific.
Amstrup says “we know” that rising CO2 is going to cause sea ice to continue to decline until polar bears “disappear” but that’s simply not true: it’s his opinion that polar bears will disappear. Moreover, he says “sea ice” when he means summer sea ice, which is deliberately misleading: in fact, no sea ice model predicts that sea ice in winter and spring will decline significantly, let alone disappear completely (Stroeve et al. 2007; Overland and Wang 2013; Perovich et al. 2018; Wang and Overland 2012, 2015).
The truth is, Amstrup has a vested interest in advancing polar bear catastrophe: as I explain in my new book, The Polar Bear Catastrophe That Never Happened (Crockford 2019), he considers his 2007 prediction that summer sea ice decline would decimate polar bear numbers to be a career legacy. He cannot bear to admit he was wrong (no pun intended) . That’s highly unscientific. Yet the media assists him in passing his unfounded eco-anxiety about polar bears on to naïve young children and gullible adults without a word about the current healthy status of the bears.
See this post from 2015, with references: If summer ice was critical for S. Beaufort polar bears, 2012 would have decimated them
And this one, also from 2015, with references: Polar bears out on the sea ice eat few seals in summer and early fall
See this post from earlier this month, with references: Western Hudson Bay polar bears in great shape after five good sea ice seasons
And finally, see this important summary post from July this year, with references: 10 fallacies about Arctic sea ice and polar bear survival: teachers & parents take note
References
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).
Aars, J., Marques,T.A, Lone, K., Anderson, M., Wiig, Ø., Fløystad, I.M.B., Hagen, S.B. and Buckland, S.T. 2017. The number and distribution of polar bears in the western Barents Sea. Polar Research 36:1. 1374125. doi:10.1080/17518369.2017.1374125
Amstrup, S.C., Marcot, B.G. & Douglas, D.C. 2007. Forecasting the rangewide status of polar bears at selected times in the 21st century. US Geological Survey. Reston, VA. Pdf here
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. 2018. State of the Polar Bear Report 2017. Global Warming Policy Foundation Report #29. London. pdf.
Crockford, S.J. 2019. The Polar Bear Catastrophe That Never Happened. Global Warming Policy Foundation, London. Available in paperback and ebook formats.
Durner, G.M., Douglas, D.C., Nielson, R.M., Amstrup, S.C., McDonald, T.L., et al. 2009. Predicting 21st-century polar bear habitat distribution from global climate models. Ecology Monographs 79: 25–58.
Overland, J.E. and Wang, M. 2013. When will the summer Arctic be nearly sea ice free? Geophysical Research Letters 40: 2097-2101.
Perovich, D., Meier, W., Tschudi, M.,Farrell, S., Hendricks, S., Gerland, S., Haas, C., Krumpen, T., Polashenski, C., Ricker, R. and Webster, M. 2018. Sea ice. Arctic Report Card 2018, NOAA. https://www.arctic.noaa.gov/Report-Card/Report-Card-2018
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
Rode, K. and Regehr, E.V. 2010. Polar bear research in the Chukchi and Bering Seas: A synopsis of 2010 field work. Unpublished report to the US Fish and Wildlife Service, Department of the Interior, Anchorage. pdf here.
Rode, K.D., Douglas, D., Durner, G., Derocher, A.E., Thiemann, G.W., and Budge, S. 2013. Variation in the response of an Arctic top predator experiencing habitat loss: feeding and reproductive ecology of two polar bear populations. Oral presentation by Karyn Rode, 28th Lowell Wakefield Fisheries Symposium, March 26-29. Anchorage, AK.
Rode, K.D., Regehr, E.V., Douglas, D., Durner, G., Derocher, A.E., Thiemann, G.W., and Budge, S. 2014. Variation in the response of an Arctic top predator experiencing habitat loss: feeding and reproductive ecology of two polar bear populations. Global Change Biology 20(1):76-88. http://onlinelibrary.wiley.com/doi/10.1111/gcb.12339/abstract
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
Stirling, I. 2002. Polar bears and seals in the eastern Beaufort Sea and Amundsen Gulf: a synthesis of population trends and ecological relationships over three decades. Arctic 55 (Suppl. 1):59-76. http://arctic.synergiesprairies.ca/arctic/index.php/arctic/issue/view/42
Stirling, I. and Øritsland, N. A. 1995. Relationships between estimates of ringed seal (Phoca hispida) and polar bear (Ursus maritimus) populations in the Canadian Arctic. Canadian Journal of Fisheries and Aquatic Sciences 52: 2594 – 2612. http://www.nrcresearchpress.com/doi/abs/10.1139/f95-849#.VNep0y5v_gU
Stirling, I., Richardson, E., Thiemann, G.W. and Derocher, A.E. 2008. Unusual predation attempts of polar bears on ringed seals in the southern Beaufort Sea: possible significance of changing spring ice conditions. Arctic 61:14-22. http://arctic.synergiesprairies.ca/arctic/index.php/arctic/article/view/3/3
Stroeve, J., Holland, M.M., Meier, W., Scambos, T. and Serreze, M. 2007. Arctic sea ice decline: Faster than forecast. Geophysical Research Letters 34:L09501. https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2007GL029703
Wang, M. and Overland, J. E. 2012. A sea ice free summer Arctic within 30 years: An update from CMIP5 models. Geophysical Research Letters 39: L18501. doi:10.1029/2012GL052868
Wang, M. and Overland, J.E. 2015. Projected future duration of the sea-ice-free season in the Alaskan Arctic. Progress in Oceanography 136:50-59.
York, J., Dowsley, M, Cornwell, A., Kuc, M. and Taylor, M. 2016. Demographic and traditional knowledge perspectives on the current status of Canadian polar bear subpopulations. Ecology and Evolution 6(9):2897-2924. DOI: 10.1002/ece3.2030
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