Polar bears listed as endangered, while global sea ice anomaly is above averageMay 15, 2008
They finally did it. Today the polar bear was listed as an endangered species. The New York Times reports
The Center for Biological Diversity, Greenpeace and the Natural Resources Defense Council filed suit in 2005 to force a listing of the polar bear. The center, based in Arizona, has been explicit about its hopes to use this — and the earlier listing of two species of coral threatened by warming seas — as a legal cudgel to attack proposed coal-fired power plants or other new sources of carbon dioxide emissions.
The thrust of the argument that echoes around the internet and appears over and over again in the popular press is the following sequence: 1. Anthropogenic CO2 causes the planet to heat. 2. This causes more summer ice melt. 3. The longer duration of open water in the summer and fall hampers the bear’s seal hunting and breeding. 4. Bear population diminishes.
There was, in fact, a fairly rapid decrease in Arctic sea ice extent sea ice extent over the last few years. But the losses were almost entirely recovered in an unprecedented ice build-up of Arctic sea ice in the last months of 2007 and the first months of 2008
The alarmists base their argument on the studies of the bear’s habitat by the IUCN World Conservation Union. Much has been made of the IUCN’s list of the “observed or predicted trend” for the nineteen sub-populations of polar bears. Most people are not aware that only five of these nineteen populations are listed as “declining.” These sub-populations are the Southern Beaufort Sea population, Norwegian Bay population, Western Hudson population, Baffin Bay population, and Kane Basin population.
What is the condition of the sea ice for these five populations today? See for yourself in the following graphs of sea ice area.*
Figure 1. The Beaufort Sea, home of the Southern Beaufort Sea sub-population of polar bears, has had an almost exactly average seasonally adjusted sea ice extent for the last six months.
Figure 2. The Canadian Archipelago is the home of the Norwegian Bay sub-population of polar bears. This region has had an average seasonally adjusted ice extent for the last six months.
Figure 3. The Hudson Bay is the home of the Western Hudson population. The Hudson Bay seasonally adjusted sea ice extent has hovered around average for the last six months. Although it has been below average for brief periods in the last month, at the time this post is being written it is slightly above average.
Figure 4. The Baffin Bay / Newfoundland region contains the Baffin Bay and Kane subpopulations. For most of the last six months the sea ice extent has been greater than the seasonally adjusted average.
As the NYT article mentioned above made perfectly clear, this has been a battle over the alarmist’s fear of global warming, not about polar bears per se. Global warming, they worry, is going to yield an ice free Arctic, and the land bound ice in the Antarctic is on the verge of melting and flooding the coastal regions of the planet. So, how does the overall global sea ice extent look, as of today? While it has wiggled up an down about the average since satellites have been measuring it, and it stayed below average for several years, it is currently above average, as shown in figure 5, below.
Figure 5. Global sea ice area and anomaly. Click on the image to enlarge the most recent anomaly data. For the last several months the anomaly has been positive. That is, the seasonally adjusted anomaly has been greater than the 1979 to 2000 average.
My guess is that most of the alarmists are hoping and praying for a significant meltdown in the Arctic this summer. Without such a meltdown it won’t be polar bears that are endangered, but their credibility.
* Data for all figures from the University of Illinois Polar Research Group. For figures 1 through 4 of the sea ice areas and averages were digitized from the U of I graphs of sea ice areas and anomalies using 48 increments per year. Then the anomalies were subtracted from the sea ice area to give the 1979 to 2000 average. Figure 5 is from the U of I web page, with additional annotation by ClimateSanity.