With guided missile destroyer USS Stockdale in the background, Secretary of the Navy Ray Mabus talks about how the Navy is creating the "great green fleet," with the Stockdale becoming the first Navy ship to regularly run on a biofuel blend of traditional fuels and blend of cattle-fat that was turned into biodiesel. The Stockdale, part of the USS John C. Stennis Carrier Strike Group left North Island Naval Air Station on a seven-month deployment after the speech on Wednesday, Jan. 20, 2016. (Howard Lipin/San Diego Union-Tribune/TNS)
