Ten good reasons not to worry about polar bears
Some activists are calling 2013 the Year of the Polar Bear. Here are 10 good reasons not to worry so much
6. Polar bears need spring and early summer ice (March through June) for gorging on young, fat seals and documented declines in sea ice have rarely impinged on that critical feeding period (except for a few isolated years in Hudson Bay, see point 4, above).
A new study suggests that while some Western Hudson Bay bears will likely perish if the ice-free period extends to six months (from its current four-to-four+), many will survive because of their exceptional fat storage abilities.
7. There is no plausible evidence that regulated subsistence hunting is causing polar bear numbers to decline, despite suspicions harbored by the Polar Bearcialist Group.
8. Global temperatures have not risen in a statistically significant way in the last 16 years (see Figure 2) – a standstill not predicted by climate models and a phenomenon even the chairman of the IPCC has acknowledged – which suggests that the record sea ice lows of the last few years are probably not primarily due to CO2-caused increases in global temperatures.
Such changes in Arctic sea ice appear to be normal habitat variations that polar bears have survived before (see point 9, below) and are likely due to natural processes we do not yet fully understand.
Figure 1. LEFT – There has not been any statistically significant increase in global temperatures over the last 16 years (1997-2013), even though CO2 levels have continued to rise (Graph modified by David Evans, using Hadley UK Met Office data (HadCRUT4). RIGHT– Sea ice extent in September (the yearly minimum) has declined quite a bit since 1997 – although nowhere near zero – while global temperatures have barely changed overall (Graph from NSIDC).
9. Survival of polar bears over a hundred thousand years (at least) of highly variable sea ice coverage indicates that those biologists who portend a doomed future for the polar bear have grossly underestimated its ability to survive vastly different conditions than those that existed in the late 1970s when Ian Stirling began his polar bear research.
Sea ice has varied – countless dozens of times – over the short term (decades-long climate oscillations) and the long term (glacial-to-interglacial cycles of thousands of years). Over the last 100,000 years, there have been periods of much less ice than today, but also much, much more.
Polar bear population numbers probably fluctuated up and down in conjunction with some of these sea ice changes but the polar bear as a species survived – and so did all of the Arctic seal species it depends on for food. Such survival indicates that these Arctic species, in an evolutionary sense, are very well-adapted to their highlyvariable habitat.
10. Polar bears today are well distributed throughout their available territory, which is a recognized characteristic of a healthy species.
These are all good reasons to feel good about the current status of the polar bear. It is plain to see that these ice-dwelling bears are not currently threatened with extinction due to declining sea ice, despite the hue and cry from activist scientists and environmental organisations. Indeed, because the polar bear is doing so well, those who would like to see polar bears listed as ‘threatened’ depend entirely upon dramatic declines in sea ice prophesied to occur decades from now to make their case.
Dr Susan Crockford is an evolutionary biologist and an expert on polar bear evolution. She has been working for 35 years in archaeozoology, paleozoology and forensic zoology and is an adjunct professor at the University of Victoria, British Columbia, Canada. This is an abridged version of a report by The Global Warming Policy Foundation. See the full report here.
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