Jonathan Safran Foer, the author of "We are the Weather: Saving the Planet Begins at Breakfast" joins Christiane Amanpour to discuss why he's turned his attention to the climate crisis. Our Michel Martin talks to Marianne Williamson, the U.S. Democratic Presidential Candidate, about her campaign. Julian Fellowes, the award-winning Writer & Producer, talks about "Downton Abbey" the movie.To learn more about how CNN protects listener privacy, visit cnn.com/privacy