Polar bears in good shape, Inuvialuit hunters say in study
Polar bears in good shape, Inuvialuit hunters say in studyTraditional knowledge has always shown there are more bears out there than scientists estimate, Pokiak told CBC News: “That’s part of the traditional knowledge we wanted to collect.” The study, published by the Wildlife Management Advisory Council, came from interviews with 75 hunters in all six Inuvialuit communities over a three-year period. It found traditional knowledge holders in the region say the bears are healthy and their population is stable.
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Polar bears and melting ice: three facts that shouldn’t surprise you
If I was invited by USA TODAY to discuss how climate change is affecting polar bears now – summed up in three talking points – this is what I’d say. I’d use some meaningful images rather than cute pictures of cuddly bear cubs and I’d provide links to my work with references and details to back up my answers.
Compare my responses to those supplied by Steve Amstrup in his capacity as spokesperson for Polar Bears International (“Save our sea ice!”) to Jolie Lee at USA TODAY last week, who’s word is expected to be taken as gospel.
1. Disappearing population
Not disappearing – predicted to disappear, which is a different thing altogether.
In fact, biologists at the IUCN Polar Bear Specialist Group estimate that there must be more than 20,000-25,000 bears in the world, a number that hasn’t changed since 2001.
I say “more than 20,000-25,000” because a few large areas exist where polar bears live but have never been studied or counted, so the global estimate does not include those bears. Polar bears are also well distributed across available Arctic habitats, an accepted mark of a species in good health. [See more here, here, and here]
The computer-models that predicted two-thirds of the worlds polar bears will be gone by 2050 were based on assumptions made by Steve Amstrup regarding how polar bears will respond to predicted declines in sea ice. However, studies conducted since then have shown that many of these assumptions are wrong. It follows then, that the predictions of population decline cannot possibly be correct. [See more here, here, and here]
In addition, the two populations that appeared at one point to be declining due to summer sea ice loss (Western Hudson Bay, WHB and Southern Beaufort, SB) — triggering the 2008 ‘threatened with extinction’ classification in the USA — had serious issues with their population estimates. It now seems polar bears simply move around a bit as ice conditions change at the local level, which is what we would expect them to do. [See more here, here,and here]
Polar bears do most of their feeding on the ice during the spring and early summer (February to June) and the extent of ice in those seasons has declined very little over the last 35 years (see below).[More here]
Sea ice extent graphs for …
NBC: Polar Bears Like ‘Passengers on the Titanic’ Because of Global Warming – Polar Bear Expert Ridicules Claims
Polar Bear Expert: ‘The annual minimum reached in late summer has little impact on polar bear health and survival. What matters most to polar bears is the presence of ample ice in spring and early summer (March-June), which is their critical feeding period’
What polar bear habitat could look like in another 5-6 weeks
According to the National Snow and Ice Data Center (NSIDC, Sept. 20 report), the annual sea ice minimum extent was reached on Sept. 13, 2013.
At 5.10 million square kilometers, this year’s low was a whopping 1.69 million square kilometers above the minimum extent for 2012 (which was the lowest since 1979) and well within two standard deviations of the 19979-2010 average. (Two standard deviations: “Measurements that fall far outside of the two standard deviation range or consistently fall outside that range suggest that something unusual is occurring that can’t be explained by normal processes”).
The minimum extent for 2013 is virtually indistinguishable from the minimum for 2009, which was 5.13 million square kilometers. The ice was distributed a bit differently in 2009 – more in the east and less in the west — than it was this year (see Fig. 1 below).
Figure 1. I used JAXA to plot the date the 2013 minimum was reached (September 13, 5.10 million square kilometers, white) with an overlay (purple) for the same date back in 2009 (September 13, 2009, 5.13 million square kilometers), when that year’s minimum was reached. Areas of overlap are pink.
You’ll know from previous discussions here that the annual minimum reached in late summer has little impact on polar bear health and survival (see excellent summary of the evidence for that here). What matters most to polar bears is the presence of ample ice in spring and early summer (March-June), which is their critical feeding period.
But after the fast that many polar bears endure over the height of the summer, they are eager to get back onto the ice and resume hunting. When in the fall does that become possible?
I wondered what the similarity in extent for 2013 and 2009 might tell us about polar bear habitat development over the next month or so.
In other words, what might polar bears this year expect in the way of sea ice development by say, the end of October? When might they be able to start hunting?
So I used the JAXA (Japan Aerospace Exploration Agency) “Sea ice monitor” feature, which I used to generate Fig. 1 (which maps sea ice concentration for any date you choose back to 2002, see here), to plot the date the 2013 minimum was reached (September 13) with an …
So, now we have at least two reports in the peer-reviewed literature that state flat out that the presumed negative effects of declining sea ice on a population’s size are indistinguishable from a population that is as large as it can get.
Hard to believe, isn’t it? Rather than being proven victims of Arctic sea ice in a “death spiral” due to global warming, when they finally present the data, biologists have to admit that they cannot actually tell the difference between a polar bear population that is so large that it can no longer increase and one that is suffering a population decline because of reduced sea ice.…