Gina McCarthy: New emissions rules are clean and affordable
2 June 2014 Last updated at 16:44 BST
The Obama administration has released strong new rules targeting coal-burning power plants in an effort to curb global warming.
The Environmental Protection Agency's (EPA) Clean Power Plan seeks to cut carbon emissions by 30% by 2030.
The 645-page rule is a centrepiece of President Barack Obama's plans to leverage similar commitments other polluting nations like China and India.
EPA administrator Gina McCarthy dismissed criticism the rules would lead to an exorbitant rise in electricity prices.
"Any small short-term change in electricity prices would be within normal fluctuations the power sector has already dealt with for years," she said.