US President Barack Obama’s Clean Power Plan is set to be the most ambitious climate change policy ever to be taken up by an American president.
The US Environmental Protection Agency estimates that it would cost 8.4 billion dollars (7.6 billion euros) to enact.
Officials there say total economic benefits could amount to up to 54 billion dollars.
Under Obama’s proposals, each US state will be given a target on cutting greenhouse gases emissions.
They will need to produce detailed proposals on how they will achieve it.
The plan aims to cut greenhouse gas emissions produced by US power plants by just over a third.
These moves are, in part, an effort to boost the credibility of the United States when it comes to fighting the effects of climate change.
World powers will meet in Paris in December to hammer out a UN climate deal after years of negotiations.
But it won’t be easy; industry lobbyists say the White House has declared war on coal.
Senate Leader Mitch McConnell, a Republican, has already written to all 50 states urging them to oppose Obama’s plan.
And many other top Republicans in Congress are already threatening to do all they can to torpedo the proposals.