The Arctic Report Card study suggests that changes at the top of the world have led to unusual weather patterns, a greener Greenland, and lots of plankton. At least the whales are pleased.
Global warming has brought a new normal to the Arctic, with warmer air and ocean temperatures, thinner and less expansive summer sea ice, and greener vegetation in coastal regions abutting the open water.
In addition, longer periods of open water during the annual sea-ice melt season is allowing the ocean to take up more carbon dioxide from the atmosphere, leading to seasonal bouts of ocean acidification in some areas.
These broad observations, along with more-detailed looks at some 32 environmental indicators, appear in the National Oceanic and Atmospheric Administration's 2011 Arctic Report Card, released Thursday.
The changes have wide implications, from opening new sources of offshore oil, gas, and minerals to speeding the release of heat-trapping methane into the atmosphere as permafrost melts.
Even on a continental level, changes in atmospheric circulation patterns at the top of the world can affect the intensity of winter weather well into the lower latitudes. Wind patterns that repeated during the past two winters – itself unusual, according to the report – brought relatively warm temperatures to regions of the Arctic, including Greenland, while subjecting the eastern US with cold temperatures and heavy snowfall.
Previous reports have been reluctant to pronounce a changed regime at the top of the world. But with nearly five years of additional observations and research in the region since the record-low summer sea-ice cover of 2007, the trends have become clearer, the researchers say.
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