At the direction of President Barack Obama and after a considerable outreach effort, EPA on June 2 released the Clean Power Plan proposal, which for the first time cuts carbon pollution from existing power plants, the single largest source of carbon pollution in the United States.

According to EPA, the proposal “will protect public health, move the United States toward a cleaner environment and fight climate change while supplying Americans with reliable and affordable power.”

A slighter sharper tone was offered by EPA Administrator Gina McCarthy when she appeared on “Real Time with Bill Maher” on HBO on June 11.

In a discussion of the proposed plan, host Maher noted, “Some people call it ‘a war on coal.’ I hope it is a war on coal. Is it?”

To which McCarthy responded, “Actually, EPA is all about fighting against pollution and fighting for public health. That’s exactly what this is. Exactly.”

According to EPA, power plants account for roughly one-third of all domestic greenhouse gas emissions in the United States. While there are limits in place for the level of arsenic, mercury, sulfur dioxide, nitrogen oxides and particle pollution that power plants can emit, there currently are no national limits on carbon pollution levels.