Houston Chronicle: An environmental group is suing the Texas Commission on Environmental Quality to force the agency to regulate emissions of gases blamed for global warming. Public Citizen’s lawsuit, which was filed in Travis County District Court today, accuses the agency of violating the state’s Clean Air Act by refusing to issue standards for controlling the emissions of carbon dioxide and five other heat-trapping gases. The suit follows a 2007 ruling by the U.S. Supreme Court that found the …