How Is the Arctic Like the Wicked Witch of the West?*

It wouldn’t be early autumn without the annual “Arctic report card,” which tracks recent changes at the top of the planet. Produced by the National Oceanic and Atmospheric Administration, part of the U.S. Commerce Department, this year’s report card documents a continued decrease in the extent of summer sea ice, which experts call “a dramatic illustration of the pronounced impact increased global temperatures are having on the Arctic regions.” The scientists also found autumn temperatures  “a record 5º C above normal, due to the major loss of sea ice in recent years which allows more solar heating of the ocean. Winter and springtime temperatures remain relatively warm over the entire Arctic, in contrast to the 20th century and consistent with an emerging global warming influence.” Sea-ice retreat is associated with warmer temps because dark, liquid water absorbs more solar energy than white ice does; that warming of the ocean affects land and atmosphere temps as well as marine life, and reduces the amount of winter sea ice that lasts into the following summer.

These drastic changes in the physical world have, not surprisingly, had an impact on the biological world. The scientists report that the retreat of sea ice has already led to poorer health “and reduced survival of polar bears in western Hudson Bay. . . . With the record summer sea ice retreats of 2007 and 2008, walruses, in some regions of the Arctic, were forced to haul out along shores in unusually large numbers, triggering increases in trampling deaths . . . Recent estimates of wild caribou and reindeer indicate that these populations may be entering a period of declining numbers.”

In this year’s report card, three of the six areas (atmosphere, sea ice, and Greenland) are coded red, meaning the changes are strongly attributed to warming. Biology, ocean and land changes are coded yellow, meaning they may partly, or also, reflect natural variations. Last year’s report card had two red areas (atmosphere and sea ice) and four yellow.

Of course, as we all know, climate change has nothing to do with human activities, as Sarah Palin told an interviewer in August (“I'm not one, though, who would attribute [climate change] to being man-made."). Phew.

*"I'm melting, I'm melting . . . "