From Polar Bear Science
Posted on February 24, 2021 |
The ‘State of the Polar Bear Report 2020’ is now available. Forget hand-wringing about what might happen fifty years from now – celebrate the fabulous news that polar bears had yet another good year.
Press release from the Global Warming Policy Forum:
Download the report here.
Crockford, S.J. 2021. The State of the Polar Bear Report 2020. Global Warming Policy Foundation Report 48, London.
London, 27 February: A prominent Canadian zoologist says that Facebook’s information is gravely out of date and 2020 was another good year for polar bears.
In the State of the Polar Bear Report 2020, published by the Global Warming Policy Foundation (GWPF) on International Polar Bear Day, zoologist Dr. Susan Crockford explains that while the climate change narrative insists that polar bear populations are declining due to reduced sea ice, the scientific literature doesn’t support such a conclusion.
Crockford clarifies that the IUCN’s 2015 Red List assessment for polar bears, which Facebook uses as an authority for ‘fact checking’, is seriously out of date. New and compelling evidence shows bears that in regions with profound summer ice loss are doing well.
Included in that evidence are survey results for 8 of the 19 polar bear subpopulations, only two of which showed insignificant declines after very modest ice loss. The rest were either stable or increasing, and some despite major reductions in sea ice. As a result, the global population size is now almost 30,000 – up from about 26,000 in 2015.
Dr. Crockford points out that in 2020, even though summer sea ice declined to the second lowest levels since 1979, there were no reports of widespread starvation of bears, acts of cannibalism, or drowning deaths that might suggest bears were having trouble surviving the ice-free season.
As Crockford’s report reveals, plankton growth – the critical health measure of marine life in the Arctic – reached record highs in August 2020. More plankton (‘primary productivity’) due to less summer ice means more fodder for the entire food chain, including polar bears. This explains why bears are thriving in areas such as the Barents Sea, which have seen reduced levels of sea ice.
Dr. Crockford notes that, ironically, polar bears in Western Hudson Bay experienced excellent ice conditions for the fourth year in a row in 2020. Bears were fat and healthy when they arrived on shore for the summer. Some spent as little as three months on shore – about one month less time than most bears did in the 1980s and two months less than bears did in the 1990s and 2000s.
Dr. Crockford explains that polar bears are more flexible in their habitat requirements than experts assumed and less summer ice has so far been beneficial rather than detrimental.
“Polar bears continue to be described as ‘canaries in the coal mine’ for the effects of human-caused climate change, but the evidence shows they are far from being a highly-sensitive indicator species. It’s not a myth: 2020 appears to have been another good year for polar bears.”
- Results of three new polar bear population surveys were published in 2020 and all were found to be either stable or increasing.
- Southern Beaufort polar bear numbers were found to have been stable since 2010, not reduced as assumed and the official estimate remains about 907.
- M’Clintock Channel polar bear numbers more than doubled from 284 in 2000 to 716 in 2016, due to reduced hunting and improved habitat quality (less multiyear ice).
- Gulf of Boothia numbers were found to be stable, with an estimate of 1525 bears in 2017; body condition increased between study periods and thus showed ‘good potential for growth’.
- At present, the official IUCN Red List global population estimate, completed in 2015, is 22,000-31,000 (average about 26,000) but surveys conducted since then, including those made public in 2020, would raise that average to almost 30,000. There has been no sustained statistically significant decline in any subpopulation.
- Reports on surveys in Viscount Melville (completed 2016) and Davis Strait (completed 2018) have not yet been published; completion of an East Greenland survey is expected in 2022.
- In 2020, Russian authorities announced the first-ever aerial surveys of all four polar bear subpopulations (Chukchi, Laptev, Kara, and Barents Seas), to be undertaken between 2021 and 2023.
- Contrary to expectations, a new study has shown that polar bear females in the Svalbard area of the Barents Sea were in better condition (i.e. fatter) in 2015 than they had been in the 1990s and early 2000s, despite contending with the greatest decline in sea ice habitat of all Arctic regions.
- Primary productivity in the Arctic has increased since 2002 because of longer ice-free periods (especially in the Laptev, East Siberian, Kara, and Chukchi Seas but also in the Barents Sea and Hudson Bay), but hit records highs in 2020; more fodder for the entire Arctic food chain explains why polar bears, ringed and bearded seals, and walrus are thriving despite profound sea ice loss.
- In 2020, contrary to expectations, freeze-up of sea ice on Western Hudson Bay came as early in the autumn as it did in the 1980s (for the fourth year in a row) and sea-ice breakup in spring was also like the 1980s; polar bears onshore were in excellent condition. These conditions came despite summer sea-ice extent across the entire Arctic being the second lowest since 1979. Data collected since 2004 on weights of female polar bears in Western Hudson Bay have still not been published; instead, polar bear specialists have transformed standard body condition data collected 1985–2018 into a new metric for population health they call ‘energetics’, which cannot be compared with previous studies. Meanwhile, they continue to cite decades-old raw data from previous studies to support statements that lack of sea ice is causing declines in body condition of adult females, cub survival, and population size.
- Contrary to expectations, in Western Hudson Bay, many polar bears remained on the deteriorating sea ice much longer than usual in summer, and stayed ashore longer in fall after official freeze-up thresholds had been reached, calling into question the assumed relationship between sea-ice coverage and polar bear behaviour and health. Some bears that left the ice in late August and then returned before late November would have spent only three months onshore – about one month less time than typical in the 1980s, and two months less than in the 1990s and 2000s.
- There were few problem polar bear reports in 2020, except for one fatal polar bear attack in August, in a campground near Longyearbyen, Svalbard. Ryrkaypiy, Chukotka, which in 2019 was besieged by more than 50 bears that had congregated to feed on walrus carcasses nearby, avoided a similar problem in 2020 by posting guards around the town. The town of Churchill saw the lowest number of problems bears in years.
- In 2020, virtually all polar bear research was halted across the Arctic for the entire year due to restrictions on travel and efforts to isolate vulnerable northern communities from Covid-19.
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