The Clean Air Task Force, Environmental Defense Fund, Natural Resources Defense Council, and Sierra Club intervened on behalf of the Environmental Protection Agency in a September 7 brief filed in the U.S. Court of Appeals for the District of Columbia Circuit. The environmental groups charged that Texas lacks standing to challenge the agency’s decision to disapprove its state implementation because it does not address greenhouse gases on its own already, and does not intend to administer a permitting program by itself. Texas sued the agency after it issued an interim rule in 2010 removing the state’s prevention of significant deterioration permitting authority for GHGs followed by a final rule in May 2011. Texas’ reply brief is due September 21.