For most of human history, the world above 66 degrees latitude has remained largely out of play for large-scale commerce. Explorers, speculators, and scientists long believed rich resources and shipping routes lay hidden beneath the Arctic's ice and snow, but the true nature of its wealth was obscured by the same deadly cold, debilitating darkness, and enormous distances that blocked its exploitation.
Today the Arctic landscape is greener than you are probably comfortable imagining, with fewer caribou and reindeer, more mosquitoes, warmer summers. The most visible and disturbing change has come at sea, where summer sea ice -- the floating expanse that covers much of the Arctic Ocean during the region's brief thaw -- has been disappearing at an astonishing rate.
While this floating sheet always shrinks in warm months and grows again with the return of the cold, the scale of ice loss has been unprecedented, and some researchers believe it's speeding up. NASA scientists estimate that on average the Arctic loses nearly 21,000 square miles of ice each year, and the experts who prepared the 2014 National Climate Assessment predict the Arctic Ocean will be ice free in summer before 2050.
"It's all happening much faster than anyone thought," said Michael Sfraga, director of the Polar Institute at the Wilson Center in Washington, D.C. "There's an ocean opening before us in real time."