Dr. Susan Crockford
Hudson Bay has been strangely slow freezing this year, this has resulted in a a bit of a predictable handshake are from some biologists repeat prophesying the collapse of the polar bear population. However, since 2009, the last freeze was anywhere near the end of the year 2016. In other words, a far cry from these years, a ‘late freeze’ is a picture of a ‘thing. the new normal’, in 2021 is really different from the past twelve years.
Furthermore, considering that the fall of 2021 ice formation in the Arctic is generally before 2016 (and every year since, except for 2018), it’s hard to see why human-caused global warming caused by increasing CO2 emissions explains the slow freezing of Hudson Bay. The duration of the Hudson Bay freeze is highly variable from year to year (Castro de la Guardia et al. 2017: Figure 3, reproduced below). The average freeze date in the 1980s was 16 November ± 5 days, while from 2005-2015 this changed by about a week to 24 November ± 8 days (Castro de la Guardia et al. 2017: 230) . This year freezes later than usual but last year and three years before that the ice froze like as early as the 1980s. Signaling the zombie apocalypse.
According to an article in Guardians last week: ‘Not easy to fix’: Polar bear capital of the world turns to electric trolley to save bears (December 3rd) 2021):
“We’re not having the best sea ice formation years we’ve had. “When you do that over a long enough period of time, you can expect that your population will decrease,” said Andrew Derocher, a biology professor at the University of Alberta.
However, Derocher misinterpreted the long-term freeze data for the Western Hudson Bay. The most recently published data (Castro de la Guardia et al. 2017) unequivocally refutes his claims about Guardians. Furthermore, Derocher has not updated this information in the scientific literature since 2015 despite the annual calculation. All I could do was publicly document the phenomenon based on sea ice charts and reports from local observers.
Based on published and privately recorded sea ice data daily (Castro de la Guardia et al. 2017: Figure 3, reproduced below), there was a year or two of late glaciation (‘bad’ under Derocher’s parlance) every decade since 1979: 1981, 1994, 1998, 2009, 2010, 2016, 2021. The frequency of bad years has never been higher than twice per decade and has not increased over time. The ‘OK’ years will have bears leaving the ice in the last week of November, which happened in 2010-2015 over the last decade. 2016 ‘bad’: freezes pretty late. However, in 2017, 2018 and 2019, the bears left shore around the same time as the 1980s (in the second week of November or so), by Derocher’s standards as ‘good’ years. ‘. It was three good years in the 2010s, six good years and one bad year; for the 2020s so far, a good year and a bad year. Even the 1980s had a bad year and two good years out of the good.
In other words, the most recent full decade can most honestly be described as a combination of good and good years similar to the 1980s.
Although the 2016 freeze was late and the bears didn’t leave until the second week of December, almost all bears landed in very good condition in July, which means the extra waiting time for the ice to drop is not an issue.
Guardians The piece then stated:
It has been 156 days since most of the bears last ate. At 180 days, the famine began to occur.
The ice also melts earlier in the season, meaning bears are forced to return to land a few weeks earlier than usual and have a smaller window to hunt.
Over the past decade, the bears have lost a total of nearly 12 days of ice at the end of the season.
“We were always worried about breaking up early with a really late freeze,” said Derocher. “And that would be the worst-case scenario for polar bears.”
Consider that terrifying-sounding statement about days on shore and famine. According to Derocher and colleagues, December 3 marks 167 days ashore for WH bears, which means average day disembark when parting for all bears in 2021 is Day 170 or June 19. In the fall, all signs show some The bear left the shore on November 26 and almost all left before December 4. If we call it 168 days, that’s certainly a longer land stay than in the 1980s but no longer than in the late 1990s and early 2000s (see chart above, table C).
However, there have been no reports of bears particularly emaciated or starving this year (most summer photos show bears in good condition) or any reports of eating. cannibalism: I’m quite sure that if there was, Derocher would say so. There is a problem with the body condition of the bears when they come ashore: Conundrum of 1983 It was not early parting that year but most bears came ashore in poor condition and by mid-November many were very thin and likely struggled to make it through the winter (Ramsay and Stirling 1988). ).
The article states that “at 180 days, the famine began to occur”. This is a complete misrepresentation of the model prediction it refers to (Molnár et al. 2010). The model predicts that 9-21% of adult males will get risk starve to death on shore 180 days (6 months), increased from 3-6% in men get risk starved to death at 120 days (4 months) ashore (that was the habit of WH bears in the 1980s).
Thus, starvation is not a certain 180 days, but a possibility. So far, there has been no year that the population has been ashore for 180 days so there is no data, only predictive models. While 2003 to be close to that ‘starvation risk’ threshold, nothing in the literature says 2003 was the year adult bears starved to death: That honor came in 1983 (Ramsay and Stirling 1988).
More, Guardians The article has even more comments from Derocher:
Now the bears are showing warning signs.
The weight of pregnant polar bears has decreased over the years, as has the newborn cubs. Bears typically lose one kilogram of weight per day, they remain on the tundra instead of the ice – putting further pressure on the population.
The bear population has decreased by nearly 30% since 1987. If current trends are maintained, The bears are predicted to undergo an unsuccessful breeding by 2040, accelerating the extinction of species.
“In the end, you’ll pretty much have a population of polar bears that can’t sustain themselves and it’s just a matter of time before they’re exterminated. When? That’s the million dollar question,” said Derocher.
I pointed out recently that the claim by polar bear researcher Nick Lunn that unpublished data on the weights of WH pregnant polar bears have decreased by 15% between 1980 and 2019 is indeed true. mean 2019 bear is heavier compared to the 1990s and early 2000s. I also commented at length on this claim of a 30% drop in WH numbers since 1987, which is a deliberate misrepresentation of data (Crockford 2019, 2021; Dyck et al. 2017). Furthermore, the 2020 model mentioned by Derocher predicts WH reproductive failure in 2040 using sea ice forecast ‘business as usual’ unbelievable that should not be taken seriously by anyone (Hausfather and Peters 2020; Molnár et al. 2020).
Finally, for the hint of an impending ‘zombie’ polar bear population in West Hudson Bay, is it funny that Derocher doesn’t point out that freezing slower than usual of Hudson Bay this year is likely to favor polar bears? The slow freezing allows the bears to buy time hunting seals falling from the ice edge the extreme cold and darkness of winter make that activity extremely difficult, and almost certainly risk starving to death. No, he wouldn’t want to mention it: it would kill the zombies.
Castro de la Guardia, L., Myers, PG, Derocher, AE, Lunn, NJ, Terwisscha van Scheltinga, AD 2017. Cycle of sea ice west of Hudson Bay, Canada, from a polar bear’s perspective. Sea Ecological Progress Series 564: 225–233. http://www.int-res.com/abstracts/meps/v564/p225-233/
Crockford, SJ in 2021. Polar Bear Status Report 2020. Global Warming Policy Foundation 48, London. pdf here.
Dyck, M., Campbell, M., Lee, D., Boulanger, J. and Hedman, D. 2017. 2016 Aerial survey of polar bear populations in Western Hudson Bay. Final report, Nunavut Environment Bureau, Wildlife Research Division, Iglolik, NU. http://www.gov.nu.ca/environnement/information/wildlife-research-reports#polarbear
Hausfather, Z. and Peters, GP 2020. Emissions – misleading ‘business as usual’ story [“Stop using the worst-case scenario for climate warming as the most likely outcome — more-realistic baselines make for better policy”]. nature 577: 618-620
Molnár, PK, Derocher, AE, Thiemann, GW and Lewis, MA 2010. Predicting the viability, reproduction, and abundance of polar bears under climate change. Biological conservation 143: 1612−1622.
Molnár, PK, Bitz, CM, Holland, MM, Kay, JE, Penk, SR and Amstrup, SC 2020. The length of the fasting season places a time limit on the existence of polar bears globally. Natural climate change. https://doi.org/10.1038/s41558-020-0818-9
Ramsay, MA and Stirling, I. 1988. Biology and reproductive ecology of female polar bears (Ursus maritimus). London Zoological Journal 214:601-624. http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.1988.tb03762.x/abstract