Carl Pope - Former Executive Director of Sierra Club | Bill McKibben - Founder of 350.org | Sarah Ladislaw - Director of the Energy & National Security Program at Center for Strategic & International Studies | Roger Sorkin - Director & Producer of "The Burden: Fossil Fuel, the Military, and National Security" | Lena Moffitt - Director of the Dirty Fuels Campaign at Sierra Club. How could the battle against climate change drive a fundamental shift in American foreign policy?