More than a billion people worldwide lack access to clean drinking water. Sea water is one possible solution. But current methods of desalination are expensive, energy intensive, and require infrastructure not usually available in areas most in need of it.

On Feb. 2, 2012, MIT Professor of Mechanical Engineering John Lienhard P'15, who is also the director of the Center for Clean Water and Clean Energy at MIT and King Fahd University of Petroleum and Minerals, offered his thoughts on desalination and answered questions from the worldwide MIT alumni community. Watch the video then join the discussion online.