Mr. McKinstry has assisted clients on preparing comments on federal and state rules relating to regulation of greenhouse gas emissions and other major air rules affecting the utility industry. He served as counsel of record representing (with several co-counsel) a group of 18 of the leading climate-change scientists who submitted amicus briefs to the U.S. Supreme Court supporting petitioners in Massachusetts v. EPA, where the court reversed the EPA's refusal to regulate greenhouse gas emissions under the Clean Air Act. He represents utility clients supporting major air rules in the U.S. Court of Appeals for the District of Columbia and the U.S. Supreme Court in EPA v. EME Homer City Generation and Michigan v. EPA. He serves as a Senior Advisor for the Center for Climate Strategies and served as General Counsel to Carbon Trap Technologies, LLP, a start-up company developing a proprietary process for chemical sequestration of carbon dioxide emissions.