The fight over climate change has spread to the U.S. Chamber of Commerce, where prominent members...including Nike, Johnson & Johnson and Exelon -- are publicly disputing the group's stance on global warming legislation...Exelon Corp, announced...it would not renew its membership in the chamber...follow[ing] moves by PG&E Corp and PNM Resources...Nike...criticized its recent challenge of the U.S. Environmental Protection Agency's authority to regulate climate-warming carbon dioxide emissions as pollution… "It's not unusual for us to have some dissension over policy issues," the chamber's Eric Wohlschlege...Exelon, Duke Energy, PG&E and PNM are all members of the corporate and environmental coalition U.S. Climate Action Partnership…Nike is a founding member of another environmental business coalition, Business for Innovative Climate and Energy Policy.