Saturday, December 8, 2012

Arctic Report Card: Dark Times Ahead

Conditions in the Arctic, where several environmental records were broken this year, are slipping rapidly from bad to worse as the pace of climate change accelerates in that region


white fox Decreasing snow amounts may be pushing Arctic fox populations in Europe toward extinction. Image: NOAA

Conditions in the Arctic are slipping rapidly from bad to worse as the pace of climate change accelerates in that region. That?s the message from an annual environmental assessment of the far North, released on Wednesday.

?Conditions in the Arctic are changing in both expected and sometimes surprising ways,? said Jane Lubchenco, head of the National Oceanic and Atmospheric Administration. The changes are having an impact far beyond the far North, she added. ?What happens in the Arctic doesn?t always stay in the Arctic. We?re seeing Arctic changes that affect weather patterns in the US,? Lubchenco said at a meeting of the American Geophysical Union in San Francisco, where the Arctic Report Card was previewed. The online report was written by 114 scientists from 15 countries.

According to the report, the Arctic broke a string of environmental records this past year. The summertime sea ice pack was the smallest ever seen. The amount of Northern Hemisphere snow in June hit the lowest mark on record. Virtually the entire Greenland Ice Cap showed some evidence of surface melting for the first time in observations going back to 1979. And permafrost temperatures on the North Slope of Alaska topped previous highs, said Martin O. Jeffries, a co-editor of the Arctic report and the Arctic science advisor at the Office of Naval Research. ?If we?re not there already, we?re surely on the verge of seeing a new Arctic,? he said.

The widespread reduction in snow and ice cover in summertime has darkened the ocean surface and land in the Arctic, allowing it to absorb more sunlight, which leads to enhanced warming. ?The Arctic is one of Earth?s mirrors and that mirror is breaking,? said Donald Perovich, an Arctic researcher at Dartmouth College, who participated in the report.

The darkening of the surface creates a positive feedback that explains why the Arctic is warming twice as quickly as lower latitudes, said Jeffries. ?This is what we call the Arctic amplification of global warming, a phenomenon that was predicted 30 years ago, which we?re now seeing happening in a significant way.?

The changes are putting stress on some creatures, including Arctic foxes in Scandinavia and nearby regions. The European population has crashed in recent years; and with only 200 individuals left, it is in danger of extinction, according to the report, which blames disruptions in the population of rodents. Lemming numbers have dropped in some regions, and scientists have suggested that reduced snow cover may be implicated, said Jeffries.

The Arctic assessment comes out a week after a report that documented accelerated melting of ice sheets in Greenland and Antarctica.

This article is reproduced with permission from the magazine Nature. The article was first published on December 5, 2012.

Source: http://rss.sciam.com/click.phdo?i=1d15bb6143c8c742e0f46e845d3eceb3

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