On 27 May 2010, with crude oil gushing into the Gulf of Mexico after the explosion of BP’s Deepwater Horizon oil rig, the Obama administration announced it would pause offshore drilling plans in the Arctic Ocean, one of the planet’s most pristine ecosystems. Hailed by environmental groups, the decision was a major setback to the oil industry, which was gearing up to tap what’s expected to be vast amounts of oil and gas lying under the Arctic’s treacherous waters, where sustained winds blow at 30 to 50 miles per hour, and menacing chunks of floating “pack ice,” some hundreds of feet wide and dozens of feet thick, threaten marine traffic.