Arctic warmer than in 2000, but it must be cool due to changes in the orbit of the Earth that causes the lack of direct sunlight.In fact, the cooling of the Arctic for nearly two thousand years, and then in the direction of the last century, and began, as human activities that add greenhouse gases warm the atmosphere.
"If it's not cool is the right man for the increased production of greenhouse gas emissions in the summer, temperatures in the Arctic and in the past century," said Bette Otto-Bliesner, National Center for Atmospheric Research scientist and co-author of the study of Temperatures in the Arctic, published in the Friday edition of the journal Science.
The recent 10 years, 1999-2008, was the warmest in the last 2000 years in the Arctic, according to the researchers, led by Darrell S. Kaufman, a professor of geology and environmental science at Northern Arizona University.
Summer temperatures in the Arctic average of 2.5 degrees Celsius (1.4 degrees Celsius) warmer than expected if the cooling is continued according to the researchers.
Assessment of the fuel for the debate on the House-adopted bill pending in the Senate climate. Administration supports the first measure would limit greenhouse gas emissions and, ultimately, to impose a reduction of 80 percent through a price for each ton of pollution, climate change.
This is the last beat of drums in a report on the situation in the Arctic warming, including:
- A researcher reported that the seas return from Alaska to the emission of acid gases quickly recognized as tropical waters, a potential threat to the state for 4.6 billion U.S. dollars of the fishing industry.
- NASA satellite that measures sea-ice in the Arctic more than just in the region decreased dramatically thinner. Share former major in the Arctic sea ice has decreased by 57 percent of the winter of 2004 to 2008.
- The effects of global warming in Alaska, including the melting of glaciers and the erosion of coastal forests north of Mars destructive beetles were restrained in winter.
And the melting of ice on land, as a huge Greenland ice cap, sea level rise around the world, the millions of people who threaten to live in the coastal cities.
The new report is available on the decades of reconstruction of the temperature for the year 2000, which was designed to use information from ancient sediments, ice cores, tree rings and other monsters. The results were then made with the climate models of complex computer simulations in comparison with the National Center for Atmospheric Research in Boulder, Colorado
"This study gives us a long-term records that show how emissions of greenhouse gases from human activities is a great natural environment of the Arctic," says NCAR scientist David Schneider, co-author of the study.
Added Jonathan T. Overpeck of the University of Arizona professor of earth sciences: "The Arctic is very vulnerable to human causes of climate change and our results suggest that it actually was. "
In addition, he said, as the Arctic warms less snow and ice reflect sunlight into space and the newly exposed soil included black and dark energy of the sea surface and the heat of the sun more, accelerating the warming.
Arctic Cooling is the result of the 21000-year cycle of ground movements in the north are less energy and cause less summer in the past 8000 years. This process will not change again a few one thousand years.
This research is funded by the National Science Foundation.
