On February 9, 2016, the United States Supreme Court dealt the Obama administration a setback when it temporarily blocked the Obama administration's efforts to regulate emissions from coal-fired power plants in its attempt to combat global warming. In a 5-4 opinion, with the Court's four liberal members dissenting, the Court granted a request by 29 states, along with dozens of corporations and industry groups, to temporarily halt an Environmental Protection Agency ("EPA") regulation
before the matter was fully considered by a federal appeals court. The EPA issued the challenged regulation in 2015. The regulation requires states to make major cuts to greenhouse gas pollution generated by electric power plants, which happen to be the United States' largest source of greenhouse gases. The aim of the regulation is to transform the generation of electricity in the nation by cutting emissions from existing power plants by a third by 2030, by closing hundreds of heavily polluting coal-fired plants, and by increasing production of wind and solar power. The 29 states challenging the regulation filed suit to stop its implementation because they contend the rule is unlawful, exceeds EPA's authority, and constitutes an unlawful invasion of the State's historic powers. The Supreme Court's decision to issue the stay was a shocking development. The Court has never halted a regulation before review by a federal court of appeals. The Circuit Court of Appeals has expedited the case and scheduled oral argument for June 2, 2016. 
80 Fed Reg. 64,662 (October 23, 2015), "Carbon Pollution Emission Guidelines for Existing Stationary Sources: Electric Utility Generating Units."