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.<br /><br /> The US Environmental Protection Agency estimates that it would cost 8.4 billion dollars (7.6 billion euros) to enact.<br /><br /> Officials there say total economic benefits could amount to up to 54 billion dollars.<br /><br /> Under Obama’s proposals, each US state will be given a target on cutting greenhouse gases emissions.<br /><br /> They will need to produce detailed proposals on how they will achieve it.<br /><br /> The plan aims to cut greenhouse gas emissions produced by US power plants by just over a third.<br /><br /> 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.<br /><br /> World powers will meet in Paris in December to hammer out a UN climate deal after years of negotiations. <br /><br /> But it won’t be easy; industry lobbyists say the White House has declared war on coal.<br /><br /> Senate Leader Mitch McConnell,
