EcoWatch: U.S. power plants are an outsized contributor to the world`s carbon pollution, a new report released by Environment America Research & Policy Center and the Frontier Group says. It found that in 2012, they added more climate change-causing carbon to the environment than the entire economies of any nation other than China. The report, "America`s Dirtiest Power Plants: Polluter on a Global Scale," demonstrated that U.S. power plants produced more than six percent of worldwide global warming emissions....