Sea ice shrank to the smallest extent in modern history. An atmospheric “hot spot” drifted closer to Europe. Some caribou herds have crashed in an environment that grows shrubbier by the decade.
Yet permafrost, while warming in some places, appears to have cooled at some depths, and may be stablizing. North Pole marine waters seem cooler. And there sure are gobs of geese.
NOAA’s annual report card on the State of the Arctic found mixed signals, and has posted its findings on an easy to navigate web site.
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.
Climactic patters in the Arctic seem to have changed, with winter and spring temperatures above average pretty much all over, oceanographer James Overland told the Associated Press.
“This is unusual and looks like the beginning of a signal from global warming,” said Overland, with NOAA’s Pacific Marine Environmental Laboratory in Seattle. in a telephone briefing.
If you go back 100 years, it would be warm in one part of the Arctic and cold in another, Overland said. “We’re not getting that now.”
Overland was one of the lead authors on the report. The AP story, however, garbled one other detail. It reported that permafrost was “melting.” The “State of the Arctic” permafrost section says no such thing. In fact, the link states “permafrost temperatures stabilizing.”
University of Alaska Fairbanks permafrost researcher Vladimir Romanovsky has reported that while permafrost has warmed at many stations, and even flirted with the freezing point, widespread meltdown has not occurred yet. Far North Science checked in with Romanovksy last spring about his findings.
Here’s an excerpt from the report:
In 2006, there was practically no change to the mean annual temperatures at the permafrost surface if compared to 2005 … Relative cooling has occurred in the mid-1980s, in the early 1990s, and then again in the early 2000s. As a result, permafrost temperatures at 20 m depth experienced stabilization and even a slight cooling during these periods.
NOAA summarized the findings in this on-line story:
“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.”
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 .
2002 photo of meltwater stream flowing into a large moulin on
the Greenland ice sheet.
Credit: Roger J. Braithwaite, The University of Manchester, UK
NASA Earth ObservatoryA 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.”
