Posted onNovember 14, 2023|Comments Off on Walrus and polar bear population size changes in the N. Atlantic over the last 20k years
This is a lesson in how to assess the potential worth of scientific papers. One of two similar Arctic evolution studies got media attention, at least in Canada — about the polar bears, of course — but in my opinion the walrus research conclusions are much better supported, less biased by climate change rhetoric, and lack the hubris present in the polar bear paper.
Both studies use similar sample sizes for the regions they had in common (North Atlantic) and used computer models to determine genetic diversity and population size changes since the LGM. However, the tone of the walrus paper was less emotionally-charged and the caveats of the work were appropriately stated. In my opinion, papers like the polar bear example contribute to eroding the public’s trust in science.
The last Ice Age peaked between about 27,000 and 19,000 years ago. At this time the Arctic was buried under kilometers of glacial ice sheets, and so marine mammals were pushed southwards to areas of ice floes and more open water. Walrus survived in some areas of the Atlantic located further to the south, and as soon as climates warmed again, the ice edge retreated and walrus populations pushed quickly northwards again. This combination of warming and climate-driven dispersal led to local walrus populations becoming more genetically differentiated. Walrus study, Lund University press release 27 September 2023
Posted onSeptember 6, 2020|Comments Off on Sceptical covid-19 research and sceptical polar bear science: is there a difference?
This essay about medical researchers having trouble getting their papers published because the results don’t support the official pandemic narrative has disturbing parallels with my experience trying to inject some balance into the official polar bear conservation narrative.1 Especially poignant is the mention of models built on assumptions sold as ‘facts’ that fail once data (i.e. evidence) become available – which of course is the entire point of my latest book, The Polar Bear Catastrophe That Never Happened.
Posted onAugust 9, 2020|Comments Off on Many W Hudson Bay polar bears still offshore at 7 August despite apparent low ice levels
Contrary to all expert expectations, five female polar bears (45%) out of eleven that had tracking collars attached last year were still out on the sea ice that’s lingering along the western shore of Hudson Bay as of 7 August. And if five collared bears are out there, then there are almost certainly many more without collars doing the same thing. This pattern of bears staying out on the ice long after the so-called ‘critical threshold’ of 50% concentration has passed has been going on since at least 2015 and many bears on tracking maps in July and August appear to be on ice that doesn’t exist.
There are two explanations for this pattern and both are likely true: 1) much more ice actually exists on Hudson Bay than satellites can detect and 2) polar bear experts are wrong that Western Hudson Bay polar bears head to land soon after sea ice concentration drops below 50%. Models that predict a catastrophic future for Western Hudson Bay polar bears (Castro de la Guardia et al. 2013; Molnar et al. 2020) assume that ice coverage of less than 50% in summer greatly reduces polar bear survival. However, if polar bears do not always head to land when sea ice drops below 50% then the models cannot possibly describe their future accurately. In other words, depending on the discredited ‘worst case’ RCP8.5 climate scenario for the most recent polar bear survival model that extrapolates from Western Hudson Bay bear data to many other subpopulations, as I discussed previously, may not be its only fault.