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Dec 022011
 

From Green Right Now Reports

The world’s frozen Arctic has reached a “new state” with less ice and a darker look that portends accelerating warming for the ice cap and the planet, according to a 2011 assessment by 121 international scientists.

Sea ice extent in spring and fall of 2011.

This changing marine climate contains less ice and more open water. That has produced more plankton which helps feed whales — the single positive outcome noted in the report, but threatens the survival of marine mammals dependent upon the sea ice, like the polar bear and walrus.

The scientists’ 2011 report card tagged several Arctic changes as alarming:

  • 2011 saw the second lowest “extent” of sea ice in the past 30 years of Arctic monitoring, with both the southern and northern routes of the Northwest Passage remaining open.
  • The five lowest September ice extents have all occurred in the past five years (the lowest was in 2007).
  • Continued loss of mass in ice sheets and glaciers is contributing to ever faster warming.

As the Arctic continues to lose ice, both in the thickness of the ice cap and its breadth, sea routes are remaining ice free, wind patterns are changing and the tundra permafrost nearest the ocean is warming and greening, according to the report card.

All these changes fuel additional warming, creating a positive feedback loop that has led to widespread speculation by climatologists that the Northern ice cap will vanish within a few decades, if not sooner, forcing more warming and rising ocean levels across the planet.

The report card, released this week by the National Ocean and Atmospheric Administration (NOAA), stops short of making specific predictions about outcomes, but does conclude that the changes in the Arctic are on a trajectory to worsen.

“The 2011 Report Card shows that record-setting changes are occurring throughout the Arctic environmental system. Given the projection of continued global warming, it is very likely that major Arctic changes will continue in years to come, with increasing climatic, biological and social impacts.”

The 121 scientists, representing a range of expertise, catalog changes in marine life, habitat, ice sheets, winds, and chemical and geophysical markers  in the ocean, and issue a report annually.

In addition to the ice measurements, the 2011 report highlights a dramatic shift in Arctic winds, which have continued on a clockwise rotation for the past 14 years instead of following their historic pattern of shifting direction every 5-8 years.

Warmer Arctic winds have contributed to harsher winters in lower latitudes, such snowy and abnormally cold winter of 2010-2011 in the Northeast.

“In 2011 there was continued widespread warming in the Arctic, where deviations from historical air temperatures are amplified by a factor of two or more relative to lower latitudes. This phenomenon, called Arctic Amplification, is primarily a consequence of increased summer sea ice loss and northward transport of heat by the atmosphere and ocean. December 2010 to January 2011, and summer 2011, repeated the shift in wind patterns observed in December 2009 and February 2010 that resulted in relatively warm Arctic temperatures and severe cold weather in eastern North America, northern Europe and eastern Asia.”

The report also notes that the Arctic appears darker than it has in the past, an ominous sign because a less-than brilliant white ice cap is not as effective at reflecting the sun’s rays.

As all these changes have moved in concert over the past decade, the Arctic Ocean climate “has reached a new state, with characteristics different than those observed previously,” and appears destined to be re-shaped by what “can only be described as profound and continuing changes,” the report concludes.