Despite recent data indicating that greenhouse gas (GHG) emissions from the oil and natural gas industry are nearly 20 percent lower than U.S. EPA’s initial estimates, environmentalists are urging U.S. EPA to impose limits, specifically, on the GHG methane. On April 4, 2013 the World Resources Institute (WRI) released a white paper suggesting limits on methane leakage rates from natural gas production to less than 1 percent of total production. WRI claims that methane emissions can be reduced by up to 30 percent by requiring the use of plunger-lift systems and low-bleed pneumatic devices across the entire production chain. U.S. EPA decided not to regulate GHGs in its April 17, 2012 New Source Performance Standards (NSPS) for the oil and gas industry. Several states sued U.S. EPA and a number of environmental groups petitioned the agency for reconsideration regarding the failure to regulate GHGs in the final NSPS rule. The lawsuit is being held in abeyance pending U.S. EPAs response to the petition for reconsideration.