Obama to unveil 'biggest step ever' in climate fight

Washington

US PRESIDENT Barack Obama will on Monday unveil what he called the "biggest, most important step we've ever taken" to fight climate change, a sensitive issue central to his legacy.

The White House will release the final version of America's Clean Power Plan, a set of environmental rules and regulations that will home in on the pollution from the nation's existing power plants, setting limits on power-plant carbon emissions for the first time.