The American Association for the Advancement of Science (AAAS) held a symposium on February 15 addressing the question of whether greenhouse gas emissions from global energy production can be cut by 80% by 2050. Dr. Richard Lester, chairman of MIT's Department of Nuclear Engineering, delivered an insightful examination of whether this can be accomplished without nuclear power. He has been kind enough to allow us to post the entirety of his talk on our website for the benefit of our readers. His perspicacity in elucidating the issues will likely be appreciated by those who are serious about the interlocking issues of climate change and energy production.