Obama to announce new pollution targets for power plants
2 June 2014 Last updated at 06:49 BST
The Obama administration is preparing to set out plans to significantly cut the carbon dioxide emissions from power-plants in the United States.
It is thought a target of a thirty percent reduction by 2030 will be set.
As the US is the second biggest producer of greenhouse gasses, the measure would amount to one of the biggest ever attempts to reduce emissions that scientists say contribute to global warming.
Aleem Maqbool went to "coal country" in West Virginia to investigate.