Oil pump jacks work behind a natural gas flare near Watford City, N.D., in 2014. The oil and gas industry is lobbying lawmakers to repeal a rule that aims to limit the emissions of methane, the chief component of natural gas.
A natural gas drilling rig's lights shimmer in the evening light near Silt, Colo. Methane is the main component of natural gas, and studies show some methane escapes from leaky oil and gas operations.
Crews work on a relief well at the Aliso Canyon facility above the Porter Ranch area of Los Angeles in early December. A leak has allowed tons of methane to escape into the surrounding neighborhood; stopping it is taking months because of pressure from the leak.
Dean Musgrove/Los Angeles Daily News/AP