Daniel Esty, the Hillhouse professor of environmental law and policy at Yale, called the dictator accusation “utterly ridiculous,” noting the president’s actions are authorized under the Clean Air Act, as well as sanctioned by the Supreme Court.

“The approach that the president and EPA have put forward is thoughtful, modest, and represents a commonsense approach to a challenging problem,” he told National Journal. The new regulations provide ample room for state-level innovation and tailoring of action plans to local circumstances, he added, but it’s by no means the best approach to addressing climate change.