Lisa Heinzerling, a Georgetown Law Professor who played a key role in the Supreme Court case Massachusetts v. EPA, has left the university to take a position at the EPA. At the EPA, Heinzerling will serve as Lisa Jackson’s advisor on how to best address climate change. In the Supreme Court case, Heinzerling was the lead author of arguments claiming that the EPA had a legal obligation under the Clean Air Act to regulate carbon dioxide emissions from motor vehicles, suggesting that, the EPA under the new administration is potentially amenable to regulating greenhouse gas emissions under the Clean Air Act.