Posted onSeptember 20, 2020|Comments Off on Potential impact of the second-lowest sea ice minimum since 1979 on polar bear survival
The annual summer sea ice minimum in the Arctic has been reached and while the precise extent has not yet been officially determined, it’s clear this will be the ‘second lowest’ minimum (after 2012) since 1979. However, as there is no evidence that polar bears were harmed by the 2012 ‘lowest’ summer sea ice this year’s ‘second-lowest’ is unlikely to have any negative effect.
In this summary of how polar bears have been doing since the the lowest sea ice minimum in 2012, I show that contrary to all predictions, polar bears have been thriving despite reduced summer ice in the Barents, Chukchi and Southern Beaufort Seas, and because of unexpectedly short ice-free seasons in Hudson Bay and less multiyear ice in the Canadian Arctic Archipelago.
UPDATE 21 September (10:20 PT): NSIDC has just announced the Arctic sea ice extent minimum (preliminary) for 2020 at 3.74 mkm2 reached on 15 September. See full report here.
Posted onMay 13, 2019|Comments Off on Polar bear habitat update for early spring shows no influence of a CO2 control knob
The primary feeding period for polar bears is rapidly drawing to a close in much of the Arctic, although it may continue for another few weeks in the farthest north. Mating is pretty much over as well, which means the polar bears’ need for abundant sea ice is declining even more rapidly than the ice does itself at this time of year.
Despite the fact that CO2 levels have now reached 415 ppm (see tweet below), sea ice is still pretty much as it was in 2006 when CO2 was about 385 ppm. In other words, the state of sea ice at this time of year – just over 12 million kilometres squared in 2006 and in 2019 – shows no correlation with rising CO2 levels. There is also not a hint of imminent catastrophe for polar bears anywhere within their range, despite the hand-wringing messages from conservation fear-mongers and their polar bear specialist supporters.
Posted onMay 20, 2018|Comments Off on IUCN polar bear specialists reject IPCC- supported forecasts of sea ice based on CO2
In case you missed it — or missed the significance of it — polar bear specialist Mitch Taylor correctly pointed out in his recent essay (a response to the New York Timesarticle that appeared Tuesday (10 April) about the Harvey et al. (2018) BioScience paper) that the IUCN Polar Bear Specialist Group have given up using computer models of future sea ice extent based on rising CO2 levels supported by the IPCC.
Their latest assessment (Regehr et al. 2016) does not link polar bear survival models to climate modeled forecasts of Arctic sea ice decline but rather to an assumption that declines already documented will continue in linear fashion over this century.
This means that CO2 emissions blamed on human fossil fuel use is no longer directly tied to the predicted future decline of polar bear numbers: IUCN polar bear specialists simply assume that sea ice will continue to decline in a linear fashion with no cause attributed to that decline except the broad assumption that anthropogenic climate change is to blame for Arctic sea ice declines since 1979.
No wonder former USGS polar bear biologist Steve Amstrup never refers to this IUCN PBSG study: he and the organization that now employs him, Polar Bears International, are still firmly wedded to the concept that CO2 is the sea ice control knob.
Posted onMay 15, 2018|Comments Off on Polar bear habitat update mid-May: little change since 1989 despite CO2 increase
Sea ice habitat for polar bears has not become progressively worse each year during their season of critical feeding and mating, as some scaremongers often imply. It’s true that absolute extent of Arctic ice is lower this spring than it was in 1979. However, according to NSIDC Masie figures, polar bear habitat at mid-May registers about 12 million km2, just as it did in 2006 (although it is distributed a little differently); other data show spring extent has changed little since a major decline occurred in 1989, despite ever-rising CO2 levels.
In other words, there has been virtually no change in sea ice cover over the last 12 years, despite the fact that atmospheric CO2 has now surpassed 410 parts per million, a considerable and steady increase over levels in 2006 which were about 380 ppm (see below, from the Scripps Oceanographic Laboratory, included in the Washington Post story 3 May 2018):
Posted onApril 15, 2018|Comments Off on Polar bear specialist Mitch Taylor on accountability in polar bear science
Polar bear specialist Mitch Taylor emailed me and others his response to the New York Timesarticle that appeared Tuesday (10 April) about the Harvey et al. (2018) BioScience paper attacking my scientific integrity. Here it is in full, with his permission, and my comments. Don’t miss the footnote!
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