Environmental factors are increasingly related to security concerns and governments around the world are responding. This week on dialogue, we examine the critical role that climate change and energy now play in national and international security policies. Our guests are: Sharon Burke, Assistant Secretary of Defense for Operational Energy Plans and Programs;  Rear Admiral Neil Morisetti , the UK's Climate and Energy Security Envoy; and Geoff Dabelko, former director of the Wilson Center's Environmental Change and Security Program.