From The Conversation's inception, geoengineering—the deliberate manipulation of the climate through technology—has been high on my list of subjects to include in the series. To address the issue, I spoke with David Keith, a Harvard professor with a joint appointment in Applied Physics and Public Policy. David has spent the better part of two decades researching climate science and geoengineering, was named a Hero of the Environment by TIME in 2009, and is also the President of Carbon Engineering, a startup dedicated to reducing atmospheric CO2. He is also publicly visible, having testified before the US Congress, spoken at TED, and appeared on numerous television and radio programs in an effort to spark a broader conversation about geoengineering. During these appearances, David steps refreshingly beyond science and into the thorny moral and philosophical questions raised by geoengineering—and that is exactly why I invited him to join The Conversation.
David's conversation starts wit