Peter Gleick researches water and water policy at the Pacific Institute. In addition to co-founding the Pacific Institute, Gleick is a member of the National Academy of Sciences, has won a MacArthur Genius Fellowship for his work, and has been instrumental in the United Nation's designation of water as a human right. I learned about Peter through Lawrence Torcello, who you can hear in episode 29 of The Conversation. Unsurprisingly, this conversation is generally about water, though we also spoke about population in more detail than any interview since John Seager. You will also catch a few oblique glimpses of the philosophy of science as I ask Peter about the importance of cultural beliefs versus scientific knowledge in determining policy.