The invited participants included Eric Barron (chair), Joyce Penner, Chuck Hakkarinen, Dan Lashof, Jerry Mahlman, Pat Michaels, Roy Jenne, Richard Lindzen, Tamara Ledley, and Tom Wigley; a number of additional scientists were invited, but were only able to submit written comments. In addition, Michael MacCracken, Ken Bergman, Jay Fein, Michael Riches, Lowell Smith, Richard Poore, Robert Schiffer, David Goodrich, Courtney Riordan, Ghassem Asrar, Robert Watson, Tony Janetos, Rick Piltz and Scott Sandgathe participated as agency, congressional, and OSTP representatives. The report represents the collective and balanced perspective of the set of attendees; the views expressed should not be associated with any individual in that their individual evaluation may be either stronger or weaker.