For the past year a diverse group of experts, under the direction and leadership of the Center for a New American Security (CNAS) and the Center for Strategic and International Studies (CSIS), met regularly to start a new conversation to consider the potential future foreign policy and national security implications of climate change.

The group consisted of nationally recognized leaders in the fields of climate science, foreign policy, political science, oceanography, history, and national security, including Nobel Laureate Thomas Schelling, Pew Center Senior Scientist Jay Gulledge, National Academy of Sciences President Ralph Cicerone, American Meteorological Society Fellow Bob Correll, Woods Hole Oceanographic Institute Senior Scientist Terrence Joyce and former Vice President Richard Pittenger, Climate Institute Chief Scientist Mike MacCracken, Georgetown University Professor John McNeill, former CIA Director James Woolsey, former Chief of Staff to the President John Podesta, and former National Security Advisor to the Vice President Leon Fuerth. The mandate of the exercise was, on its face, very straightforward: employ the best available evidence and climate models, and imagine three future worlds that fall within the range of scientific plausibility.