In 2011, the trading program that existed since 1995 was supplemented by four separate trading programs under the Cross-State Air Pollution Rule (CSAPR).[2] On August 21, 2012, the United States Court of Appeals for the District of Columbia issued its Opinion and Order in the appeal of the Cross State Air Pollution Rule (CSAPR) for two independent legal reasons.[3] The stay on CSAPR was lifted in October 2014, allowing implementation of the law and its trading programs to begin.[4]