Arctic Sea Ice

National Geographic Geographer Juan José Valdés calls the changes in the map of Arctic ice in the 10th edition of the National Geographic Atlas of the World, "the biggest visible change other than the breakup of the U.S.S.R."
Jun 12, 2014   National Geographic
The unprecedented decline in Arctic sea ice could cause the catastrophic release of methane, imperiling the world's climate and economy, reports a new paper published in the journal Nature.
Jul 25, 2013   The Guardian