The nation's largest business group is asking U.S. EPA to hold a public debate on climate change science -- or face litigation -- as the agency prepares to regulate greenhouse gas emissions under the Clean Air Act... "They don't have the science to support the endangerment finding," Bill Kovacs, the [US Chamber of Commerce's] vice president for environment, regulatory and government affairs, said in an interview. "We can't just take their word for it."... EPA Deputy Press Secretary Brendan Gilfillan rejected the chamber's claims. EPA Administrator Lisa Jackson based her proposed endangerment finding on "the soundest peer-reviewed science available, which overwhelmingly indicates that climate change presents a threat to human health and welfare," he said. [also refers to American Petroleum Institute]