Pumpjacks at the Inglewood oil fields in California in March. Some of the most controversial methods of oil extraction, like fracking, oil sands production and Arctic drilling, are also expensive. That's made them less profitable as the price of oil continues to fall.
Four Americans injured in Iraq and Afghanistan visit Kabul as part of Operation Proper Exit, a program designed for wounded warriors. From left, they are Staff Sgt. Ben Dellinger, Capt. Casey Wolfe, Capt. John Urquhart (who is hidden) and Sgt. James "Eddie" Wright.
Lt. Col. Isaac Yacouba Zida, named by Burkina Faso's army as interim leader following the ousting of President Blaise Compaore, leaves after a meeting with diplomats on Sunday in the capital Ouagadougou.
Issouf Sanogo/AFP/Getty Images