Crains: Energy companies, businesses and environmental groups are readying for a couple of years of public policy wrangling at the federal and state levels over tougher air quality regulations to be implemented by the U.S. Environmental Protection Agency. President Barack Obama said last month the EPA will develop proposed regulations by June 2014 that will reduce carbon dioxide -- gases that trap heat in the atmosphere and are blamed for global warming -- by 17 percent from 2005 to 2020. After public...