"The Environmental Protection Agency said Monday that it would not require power plants or other industrial sites to obtain federal pollution permits for emitting greenhouse gases before next January. ...
E.P.A. regulation of carbon dioxide and other gases that contribute to global warming is a hugely controversial matter arising from the agency's finding late last year that such gases are a threat to human health and welfare. Numerous state officials, industry groups and members of Congress have protested the agency's intent to regulate those gases, and the E.P.A. is facing what could be years of litigation."
John M. Broder reports for the New York Times March 29, 2010. 
Congress has yet to enact greenhouse gas limits. U.S. elections are scheduled for November 2, 2010.