US unveils sweeping initiative to cut power plant pollution
2 June 2014 Last updated at 23:34 BST
President Obama has laid out plans for big reductions in pollution from American power stations.
The proposed regulations are a central part of the president's efforts to tackle climate change and reduce air pollution.
The energy industry will have to reduce carbon dioxide emissions by 30% by 2030, with the individual states deciding how to do this.
But many in the coal industry accuse him of waging a war on coal and say they will fight the regulations.
David Shukman reports.