You can’t figure out what’s going on with status updates from the IUCN Polar Bear Specialist Group (PBSG) without deconstructing the spin and the 2013 update is no exception. Here’s my travel guide, with a map, to the good news.
I’ve finally had a chance to go through all of the details provided with the 2013 PBSG status table (pdf here). It’s just about all good news, once you wade through the spin. Numbers aside, out of the 13 populations for which some kind of data exist, five populations are now classified by the PBSG as ‘stable’ (two more than 2009), one is still increasing, and three have been upgraded from ‘declining’ to ‘data deficient’ (I explain below why this is a promotion).
That leaves four that are still considered ‘declining’- two of those judgments are based primarily on concerns of overhunting, and one is based on a statistically insignificant decline that may not be valid and is being re-assessed (and really should have been upgraded to ‘data deficient’). That leaves only one population – Western Hudson Bay – where PBSG biologists tenaciously blame global warming for all changes to polar bear biology, and even then, the data supporting that conclusion is still not available.
Posted in Advocacy, Conservation Status, Population, Sea ice habitat
Tagged conservation, good news, IUCN Polar Bear Specialist Group, PBSG, polar bear, polar bear spin, population estimates, status, unpublished data, update
“The Arctic” is a bit hard to define. While the Arctic Circle works as a good boundary for some purposes and the 100C isotherm for July for others, neither work for polar bears because several subpopulations live well south of these limits (Fig. 1).
In the east, Western Hudson Bay, Southern Hudson Bay and Davis Strait are all located well south of the Arctic Circle and the first two (and half of Davis Strait) are beyond the 100C July isotherm as well. In the western Arctic, the Chukchi Sea subpopulation is within the 100C July isotherm but at least half of its bears reside south of the Arctic Circle (Fig. 1) in the Bering Sea (see previous post here).
Unique amongst all of these is Southern Hudson Bay – all of its polar bears make maternity dens and/or spend the summer south of 600N.
Southern Hudson Bay (SH) bears live in the Canadian provinces of Ontario, while Western Hudson Bay (WH) bears reside in Manitoba and Nunavut. The two groups mix over the winter but appear to spend the summer/fall in their respective regions (Stirling et al. 2004). [See previous posts on Western Hudson Bay bears here, here, and here]
“Further south” in the Arctic usually means warmer, with open water present more weeks every summer, sea ice for fewer weeks over the winter. So, shouldn’t the bears of Southern Hudson Bay be already suffering more harm from global warming than virtually all other subpopulations, including those in Western Hudson Bay?
After all, Western Hudson Bay bears appear to have experienced a statistically significant decline in numbers, among other effects (Regehr et al. 2007; Stirling and Derocher 2012) — surely Southern Hudson Bay bears are doing worse?
You’d think so, but they aren’t.
Figure 1. Boundary limits for “the Arctic” (top map) such as the Arctic Circle (dashed line) or the 100C isotherm for July (solid red line) would not include several polar bear subpopulations that live south of these.
Posted in Conservation Status, Population, Sea ice habitat
Tagged Arctic Circle, Chukchi Sea, Davis Strait, Derocher, Hudson Bay, Hudson Bay breakup, James Bay, July isotherm, Ontario, Polar Bear Specialist Group, population size, Southern Hudson Bay, Stirling, unpublished data, western hudson bay
Benny Peiser over at the Global Warming Policy Foundation has just posted an essay by well-known author Matt Ridley (including “The Rational Optimist”), entitled “We should be listening to Susan Crockford” which is included as a foreword to a pdf of my earlier post, “Ten good reasons not to worry about polar bears.”
This stand-alone pdf is especially suitable for sharing with friends and policy makers.
I encourage you to have a look.
Back in October, I wrote about US Fish & Wildlife biologist Eric Regehr comments about a recent survey of Chukchi Sea polar bears, the results of which are still not published. Since then, I’ve been able to track down a bit of information.
This project appears to have run for five years, from 2008 to 2011. The work was confined to the eastern (US) portion of the Chukchi, see maps below (Polar Bear News 2010; Rode and Regehr 2010). Researchers were doing mark-recapture work with helicopters, putting radio collars on some females and radio ear tags on a few males. They worked primarily in March and April (mating season for polar bears), operating entirely on the offshore sea ice – working, I might add, on bears that technically speaking do not exist, since the official population estimate for this region is “zero” (they are not included in the global estimate of 20,000-25,000, see pdf here,, discussed here).
Figure 1. Chukchi Sea – getting you oriented. Note the location of Kotzebue Sound, northeast of the Bering Strait. Map from Wikipedia.
In 2012, US Fish & Wildlife biologist Eric Regehr told reporter Jill Burke at Alaska Dispatch that they found the bears were “reproducing well and maintaining good body condition.” I’ve finally found some details regarding what he meant by that statement (although no final reports or peer-reviewed papers are out, see footnote below).
Polar bear biologists Ian Stirling and Andrew Derocher continue to insist that western Hudson Bay (WHB) polar bears are already showing negative effects of reduced sea ice due to global warming. In their 2012 summary paper (Stirling and Derocher 2012), they updated someone else’s graph of global sea ice (to 2011) but used a graph for Hudson Bay (HB) ice breakup dates that ended in 2007. However, we know from other evidence that at least one of those years (2009) would have required extending the scale of the breakup date graph upwards and flattened the slope of the trend line. Updating the HB breakup date graph would not have supported Stirling and Derocher’s premise that polar bears in WHB are starving due to increasingly earlier sea ice breakup, so they simply left the data out (see Fig. 1).
In other fields, this is called fraud.
Is it fraud here? You decide.
I’ve expressed my outrage about this before (here and here), because we know from news reports that in 2009, breakup of Hudson Bay sea ice was unusually late: the Port of Churchill (in WHB) did not open for ship traffic until Aug. 12, a full three weeks later than average (July 21) – and the latest opening of the Port since records began in 1974.
I try not to keep thinking of Stirling and Derocher’s unscientific behaviour but was reminded of it again on Monday (March 4) when I attended a lecture at the University of Victoria given by paleoclimatologist Michael Mann. To my disbelief, Mann tried to argue that global temperatures predicted by NASA scientist James Hansen in 1988 have “closely resembled” actual temperatures since then – by presenting a graph of actual temperatures (observations) that ended in 2005, despite the fact that recent temperatures have not risen at the rate depicted in his graph (see previous post, #8). He did say, as an aside, that “you could argue that if the data were extended out to the present, the line might more closely resemble scenario C [a flat line]” but then continued with his story that observations were matching the ever-rising-temperatures of Hansen’s scenario B (see Figure 2 below).
For both parties – Stirling/Derocher and Mann – the recent data points left off their graphs did not fit their narrative: sea ice in Hudson Bay is not on a steady, precipitous decline and global temperatures have not continued to rise as predicted by Hansen in 1988. The graphs look like science, but they are not.
This article from yesterday about sea ice in the Bering Sea is priceless: while we are still being told that below average ice coverage (common 10-20 years ago) is a sign of global warming that means the end of polar bears sometime in the future, it turns out that too much ice is bad, less ice is friendlier and lots of ice is hopefully something that we’ll never see again.
From the article:
After a 2012 Bering Sea snow crab season that saw unusually severe sea ice inhibit fishermen’s efforts to catch almost 89 million pounds of the shellfish, 2013 is shaping up to be much friendlier.
According to Kathleen Cole, a forecaster with the National Weather Service ice desk, this winter was unlikely to match 2012, even before it began. Despite some recent rumors of encroaching ice into the Bering Sea fishery, the situation is better than last year, she said.
“We’re just not going to have a year like last year. It’s going to be, by no means, that bad,” she said. “Last year was something that we’d never seen before, and hopefully something that we’ll never see again.”
Sea ice is still well above average in the Bering Sea this year – as it has been for 7 of the last 10 years. See the ice extent map from NSIDC from yesterday below and my previous post from December 2012: Now that Bering Sea ice cover is high again, variability is normal (note that polar bears of the Bering Sea are considered part of the “Chukchi Sea” subpopulation, which we know practically nothing about, see previous post here). Continue reading