Clean air advocates cheer as Mary Anne Hitt, director of the Sierra Club&#039;s Beyond Coal Campaign, speaks at a rally outside an Environmental Protection Agency hearing, Tuesday, July 29, 2014, in Atlanta. Utility and coal companies are expected to argue Tuesday against proposals from the Obama administration that would force a 30 percent cut in carbon dioxide emissions by the year 2030 from 2005 levels. The EPA is holding three public hearings on the proposal in Atlanta, Denver and Washington. (AP Photo/David Goldman)