Hudson Bay has been oddly slow to freeze this year, which has led to a predictable bit of hand-wringing from certain biologists reiterating prophesies of polar bear population collapse. However, since 2009, the last time that freeze-up was anywhere near this late was 2016. In other words, far from this years’ late freeze-up being a picture of ‘the new normal,’ conditions in 2021 are actually unusual compared to the last twelve years.

Moreover, considering that 2021 fall ice formation for the Arctic in general is well ahead of 2016 (and every year since, except 2018), it’s hard to see why human-caused global warming caused by ever-increasing CO2 emissions explains the slow freeze-up of Hudson Bay. Timing of Hudson Bay freeze-up has always been highly variable from one year to the next (Castro de la Guardia et al. 2017: Fig. 3, copied below). The average freeze-up date in the 1980s was 16 November ± 5 days, while from 2005-2015 this had shifted about a week to 24 November ± 8 days (Castro de la Guardia et al. 2017:230). This year freeze-up was later than usual but last year and the three years before that the ice froze as early as it did in the 1980s. Cue the zombie apocalypse.

UPDATE 11 December 2021: see chart below from Andrew Derocher on the position of tagged WH bears at 10 December.