Implication Of Michigan v. EPA For Challenges To The Clean Power Plan

On June 29, 2015, the U.S. Supreme Court issued its opinion in Michigan v. EPA, which may have serious implications for legal challenges to the Clean Power Plan ("CPP"), which seeks to cut carbon emissions by 30 percent from 2005 levels by 2030. In a 5-4 decision, the Court invalidated U.S Environmental Protection Agency ("EPA") regulations setting limits on mercury, arsenic, and acid gas emissions from coal-fired power plants ("MATS Rule" or "Rule") by determining that EPA should have considered the compliance costs imposed on utilities at the first stage of the Agency's regulatory analysis.

The Court's opinion is a solid endorsement of the need for agencies to engage in a cost–benefit analysis in deciding whether to regulate. The opinion is also another example of the Court's gradual shift away from paying broad deference to EPA decisions. See , e.g., Utility Air Regulatory Group v. Environmental Protection Agency (rejecting EPA's request for deference to its