Scientists from the U.S. National Snow and Ice Data Center have confirmed that Arctic sea ice extent has reached a record low, beating the previous mid-September low in 2007. Ice loss is driven by emissions of long-lived gases like carbon dioxide and short-lived climate pollutants like methane and black carbon, or soot. Black carbon and methane have short atmospheric lifetimes, so emissions reductions provide near immediate climate benefit.
“It used to be that Arctic ice melt was something that was in the model prediction, but now we see not only that the reality is upon us, but that it is even more extensive than projected,” said Rafe Pomerance, a former climate negotiator and Deputy Assistant Secretary of State. “The loss of ice is an urgent message that calls for a comprehensive policy response.”
Ellen Baum, senior scientist with the Clean Air Task Force, said today’s news makes it more urgent than ever that black carbon and methane from pending Arctic oil and gas development be minimized. Arctic emissions of soot, methane and CO2 are set to increase this year as companies begin drilling for oil and gas. “The Arctic is slipping away fast,” Baum said. “We must immediately begin to slow down that process, first by requiring oil and gas operations to curb their soot and methane emissions.”
Recent studies including an assessment by the United Nations Environment Program and the World Meteorological Organization indicate that it’s possible to slow the pace of warming and melting in the Arctic in the near term by reducing emissions of two common climate pollutants: black carbon and methane, both of which are emitted from the extraction and burning of fossil fuels.
These “short-lived” climate pollutants remain in the atmosphere for only a few days to a decade, compared to centuries or more for CO2. “That means that reducing emissions of these climate pollutants would provide rapid climate benefits, especially in the Arctic where black carbon pollution accelerates the melting of ice and snow,” said Erika Rosenthal, the Earthjustice attorney who was part of the author team for the UNEP/WMO assessment.
Arctic sea ice cools the planet, while providing refuge for much of the region’s iconic wildlife. When ice melts it reveals darker Arctic Ocean water, which in turn absorbs more heat from the sun, further heating the region. “Because of its reflectivity, Arctic sea ice is a critical cooling component of the earth’s climate system; its loss will mean a much hotter world,” added Mr. Pomerance.
“The rapid loss of sea ice is a powerful indicator of the accelerated warming occurring throughout the Arctic,” said Earthjustice attorney Rosenthal. “This warming is causing the swift increase in the melting of glaciers and the Greenland Ice Sheet that led scientists to project a sea level rise of between 0.9 and 1.6 meters by the end of the century. For low-lying communities from the Pacific Islands to Bangladesh, and much of the U.S. Atlantic coast, this would be calamitous.”
The lowest amounts of Arctic sea ice on record since satellite monitoring began in 1979 have all been recorded during the last six years. The remaining ice is less dense and thinner. The volume of sea ice is also at a record low. The thinner the ice, the faster it melts. That this year’s record low is happening three weeks earlier than previous lows means that the 2012 ice extent and volume will continue to decrease even more until sea ice begins to regrow again in early fall.