John Behrendt, APS President, writes:

In May, the polar bear was grudgingly designated as a threatened species by the U. S. Government under the Endangered Species Act, because of summer shrinking of Arctic sea ice. As the New York Times pointed out on May 18, this is a victory for conservationists and Interior Department scientists. Dirk Kempthorne, Secretary of Interior, said that the decision was driven by overwhelming scientific evidence that “sea ice is vital to polar bears’ survival,” and “all available scientific models show that the rapid loss of ice will continue.”

The bears use sea ice as a platform to hunt seals and as a pathway to the Arctic coasts where they den. The New York Times story pointed out that “the science on polar bears in a warming climate is nuanced. ... Over all, scientists agree that rising temperatures will reduce Arctic ice and stress polar bears, which prefer seals they hunt on the floes. But few foresee the species vanishing entirely for a century and likely longer.” Nonetheless, the polar bear is one of the “charismatic megafauna” and as such has captured the imagination and concern of the public. This is no doubt one of the reasons the decision to list the bear under the Endangered Species Act was so bitterly fought by and within the Administration and by the petroleum industry. Although there are roughly 190,000 walruses in the Arctic, researchers have little doubt that the figure is on a downward slide as the polar ice retreats, according to a New York Times article on May 20. “The ice is melting three weeks earlier in the spring and re-forming a month later in the fall,” according to researcher Carlton Ray of the University of Virginia.

At the “New Generation of Polar Researchers (NGPR)" symposium in May, David Carlson, director of the International Program Office for the International Polar Year (IPY), showed April 24 satellite images of the Arctic Ocean (about the maximum sea ice cover for the 2007-2008 winter) and indicated the very limited thickness of new ice after the record low ice extent of the 2007 summer. Carlson pointed out that there is a several years’ supply of warm water in the north Atlantic, which will only result in further shrinkage of sea ice in as it circulates into the Arctic Ocean in the coming summers.

Sea surface temperatures over the Chukchi and East Siberian seas have increased markedly since the year 2000. Recently, scientists from the University of Colorado raised the question, “Could the summer of 2007 be remembered as the first year of a rapid shift to a seasonally ice free Arctic Ocean?”, which might be realized as early as 2030 (Strove et al. 2008, EOS Transactions of the American Geophysical Union, v. 89, 2, p. 13-14). They stated in their January report, that the large summer heat gains in 2007 are likely to be expressed as thinner than normal ice at the start of the 2008 melt season,” (as has since been observed) “and further speculated that “a seasonally ice-free Arctic Ocean might be realized as early as 2030.”

Amy Breen reported at the NGPR Symposium, that there were 40% more shrubs in the Arctic tundra than in 1947. At the other end of the earth, Michael Willis reported, also at NGPR, after making refined corrections based on precise GPS measurements, more than 50% greater ice mass loss from the West Antarctic Ice Sheet than had been previously calculated from the GRACE Satellite over the past several years.

The effects of human caused increase in CO2 and other greenhouse gasses are becoming ever more apparent, particularly in the Polar Regions. As Susan Solomon (co-chair of IPCC Working group I) and Martin Manning pointed out in a March editorial in Science, “the IPCC assessments of climate change science, impacts, and mitigation address one of the most far-reaching and complex challenges that society has ever faced.” We in the American Polar Society are well placed to observe these changes and speak our concerns to the public, where appropriate. Seek out the small active groups in your local areas, who are concerned about climate change and its effects. Some of us (e.g. … Kenneth Toovak Sr. and I) are old enough to have seen significant changes in the polar regions in our lifetimes. We are in for an exciting ride!