Here is a bit of historical perspective for rational readers trying to make sense of the doom-mongering of others that current sea ice conditions spell trouble for polar bears, given that the winter maximum extent for 2017 reached a new seasonal low (keeping in mind that NSIDC does not publish error bars for these measurements, which helps elevate such pronouncements to “news”).
Ice extent (courtesy NSIDC’s MASIE) at 25 March (Day 84) is below for 2017, 2011 and 2006, almost 3 weeks after the winter maximum was declared at 7 March for 2017, 9 March for 2011, and 12 March for 2006. Extent at the maximum for 2006 was estimated at 14.68 mkm2, 14.42 mkm2 for 2017, and 14.67 mkm2 in 2011 (what tiny differences make headlines these days).
Remember: there are no polar bears in the Sea of Okhotsk or in the Baltic Sea (marked with an * below) yet ice in those regions is included in the Arctic totals used to determine maximum seasonal extent. Much (and sometimes, all) of the “Arctic” variation in extent at this time of year is accounted for by variation in Sea of Okhotsk and Baltic Sea coverage.
Bottom line: total winter ice extent for the Arctic ≠ winter polar bear habitat and neither have changed much in a decade.
See close up of the above graphic below.
It’s just an observation but NSIDC Masie ice charts show 14.7 mkm2 of sea ice for 2017 at 19 February (Day 50) but only 14.3 mkm2 for 2006 (see them copied below).
In contrast, the NSIDC interactive graph shows almost the opposite: 14.3 mkm2 for 2017 and 14.4 mkm2 for 2006 (but with both below 2 standard deviations of average).
Oddly, activist organization Polar Bears International recently updated their website and now suggest there is still time to save polar bears and sea ice – even though the IUCN Red List documented more polar bears alive in 2015 than at any time in the last 50 years, despite the recent decline of summer sea ice – and even more bizarrely, call for a public uprising.
Polar Bears International (with three polar bear scientists on staff and other as active advisors) suggest that people who love polar bears should march the streets on Earth Day with scientists to demand (as concerned and engaged citizens) that world leaders take them seriously.
Wow. I’ve been a career scientist for more than 40 years and I have to say, this is the oddest phenomenon I’ve encountered being advanced in the name of science. To me, it shows how disconnected these people are from what science is meant to be and what scientists are meant to do. Not just the polar bear scientists but the others like them that are behind this proposed march.
I recommend this blog post by Willis Eschenbach – an excerpt below.
Posted in Advocacy, Population, Sea ice habitat
Tagged climate, Earth Day, Eschenbach, facts, habitat, March, polar bear, protest, save our sea ice, save the polar bear, sea ice
Sea ice charts for 18 January from NSIDC Masie show exactly as much sea ice in 2017 as there was back in 2006 – 13.4 mkm2.
According to NSIDC daily sea ice interactive graph, there was ever so slightly more ice on 31 Dec 2016 than on that date in 2010. However, the corresponding ice maps show just how differently that ice was distributed.
Recall that in 2010, there was no huge die-off of polar bears attributed to reduced amounts of sea ice in the fall (or to reduced ice in summer, for that matter) because there was no catastrophic die-off at all.
Arctic sea ice tied 2007 for extent at the September minimum less than 3 weeks ago but with the refreeze proceeding much faster than 2007, seals will soon be returning to the ice edge and polar bears will be back to feeding like they did in 2010.
Sea ice extent less than 5.0 mkm2 lasted less than 6 weeks (23 August – 28 September), according to NSIDC.
Posted in Conservation Status
Tagged Barents Sea, Chukchi Sea, extent, feeding, freeze-up, habitat, Hudson Bay freeze-up, hunting, ice-free, polar bear, sea ice, seals, September ice minimum
There is slightly less ice this year in Hudson Bay than last year but it is hugging tight against the western shore, which means polar bears in Western and Southern Hudson Bay will be able to stay out on the ice (if they want to) until August.
The latest weekly ice graph from the Canadian Ice Service (for 9 July) below shows average ice coverage this year (and more than there was in 1976 and 1977):
[By the way, the IUCN Polar Bear Specialist Group website is still “under construction” allowing them to avoid mentioning the less-than-dire conclusions contained in the 2015 IUCN Red List assessment]
More ice maps below, comparing previous years.