Thursday, October 18, 2007

Artic Winds Will Change The World

A new wind circulation pattern is blowing more warm air towards the North Pole than in the 20th Century, scientists found. Shrubs are now growing in tundra areas while caribou herds are dwindling in Canada and parts of Alaska.

NOAA - Artic Report Card 2007
The first update of a report tracking the state of the Arctic indicates that some changes in that region are larger and occurring faster than those previously predicted by climate models, while other indicators show some stabilizing. The “Report Card” was issued today by an international team of scientists, including a NOAA lead author. “The Arctic is an extraordinarily interconnected region, so what happens in the Arctic doesn’t stay in the Arctic,” said Richard Spinrad, NOAA assistant administrator for oceanic and atmospheric research. “There will be significant environmental effects throughout the globe resulting from changes in the Arctic. This annual update provides key information to decision makers and the scientific community on changes that are taking place in the Arctic now.”

An international team of research scientists created a peer-reviewed website, Arctic Report Card, which tracks multiple changes in the Arctic environment. Relative to amounts of Arctic sea ice in the 1980s, the region lost almost 40 percent of the summertime sea ice in the central Arctic in 2007. While the continued loss of summertime sea ice is the most dramatic example, changes are also seen in the atmosphere, on land, in the ocean, and in location and abundance of Arctic species.

“The purpose of the Report Card is to provide a concise, scientifically credible and accessible source of information on recent changes in the Arctic,” says Jacqueline Richter-Menge, the chief editor of the project, from the US Army Cold Regions Research and Engineering Laboratory.

A lead author, James Overland, a scientist at NOAA’s Pacific Marine Environmental Laboratory in Seattle, Wash., has identified a wind circulation pattern blowing more warm air towards the North Pole, compared to the circulation patterns in the 20th century. The fate of the Greenland ice sheet represents large uncertainty. “Recent ice loss is about the same as in the early 20th century, but one cannot exclude a potentially faster response, as mechanisms remain incompletely understood,” wrote the team headed by Edward Hanna of the University of Sheffield, United Kingdom.
Not all indicators show extreme events, and some signals are mixed. For instance, North Pole ocean temperatures are returning to 1990s values, but currents are relatively warm around the edges of the Arctic Ocean.

Permafrost temperatures are stabilizing in both North America and Eurasia, but permafrost melt remains a serious problem. Shrubs are moving northward into tundra areas, but causes for treeline movements are difficult to assess because forest management practices are as influential as climate change. Changes in Arctic animal populations show mixed tendencies over decades. Many caribou and reindeer herds have declined (some up to 80 percent relative to their peaks), while Arctic goose populations have generally expanded.

“The Report Card brings together cutting edge information on changes in Arctic systems,” says Mike Gill, Circumpolar Biodiversity Monitoring Program Secretariat in Canada, and a report card co-editor. “The Report Card reinforces that natural systems in the Arctic continue to undergo significant change, with climate change likely playing an increasing role - emphasizing the need for ongoing and enhanced monitoring.”