Recent Arctic warming reverses millennia-long cooling trend

(University of Arizona) Warming from greenhouse gases has trumped the Arctic's millennia-long natural cooling cycle, suggests new research. Although the Arctic has been receiving less energy from the summer sun for the past 8,000 years, summer temperatures began climbing in 1900. The decade from 1999 to 2008 was the warmest in the Arctic in two millennia, report scientists who tracked Arctic temperatures 2,000 years into the past using natural archives including lake sediments, tree rings and ice cores.