More than 200 members of Congress filed an amici curiae brief [text, PDF] in the US Court of Appeals for the District of Columbia Circuit [official website] Tuesday, challenging the authority of the Environmental Protection Agency (EPA) [official website] over regulations on carbon dioxide emissions. The Clean Power Plan (CPP) [materials] proposes an incremental decrease of power plant emissions by nearly a third as soon as 2030. The mostly Republican group of lawmakers argue that the agency is “seeking to usurp the role of Congress to establish climate and energy policy for the nation.” In addition, they allege that the EPA has failed to follow guidance by Congress, and has overreached its authority by promulgating a final rule for the nation’ energy sector.

Earlier this month the US Supreme Court [official website] ordered that the Obama administration delay enforcement [JURIST report] of the CPP pending a resolution to legal challenges. The request to block the implementation of the CPP was made in late January, with states insisting [JURIST report] that the plan’s implementation would create a burden on states. In June the Supreme Court, in a 5-4 split, ruled [JURIST report] that the EPA could not make regulations regarding the toxic emissions of power plants without considering costs. In August the EPA proposed new rules [JURIST report] to cut methane emissions by the oil and gas industry as part of the Obama administration’s commitment to taking action on climate change. Also in August the US District Court of the District of North Dakota granted a preliminary injunction [JURIST report] against a rule granting the EPA and the US Army Corps of Engineers jurisdiction over small US waterways. In another recent case involving the Clean Water Act [JURIST report], two environmental groups filed a lawsuit last December against the EPA accusing the agency of failing to comply with a court order to strengthen storm drain pollution regulation. The presently disputed Clean Power Plan was announced [statement, video] by US President Barack Obama in an attempt to to improve air quality and reduce green house gas emissions