Clear Skies Act of 2003 : hearings before the Subcommittee on Clean Air, Climate Change, and Nuclear Safety of the Committee on Environment and Public Works, United States Senate, One Hundred Eighth Congress, first session, on S.485, a bill to amend the Clear Air Act to reduce air pollution through expansion of cap and trade programs, to provide alternative regulatory classification for units subject to the cap and trade program, and for other purposes, April 8, 2003, May 8, 2003, June 5, 2003.