Sydney Morning Herald: A natural cause may account for much of the recent dramatic thawing of the Arctic region, in addition to man-made global warming, a new study finds. New research indicates a natural and cyclical increase in the amount of energy in the atmosphere that moves from south to north around the Arctic Circle, according to the study published in the journal Nature. But that energy transfer, which comes with storms that head north because of ocean currents, is not acting alone, …