When I set out to write a  story about the energy possibilities of garbage, portrayed as nothing but a sci-fi gag in the movie Back to the Future Part II, I knew I had to check in with National Geographic Emerging Explorer T.H. Culhane. (See related, “Four Energy Ideas ‘Back to the Future’ Got (Almost) Right.”)

Year after year, Culhane has been one of the most riveting storytellers of the extended Explorer family that National Geographic Society brings together at its Washington, D.C. headquarters each June. You’ll become a believer if you spend time listening to T.H. extol the little-known virtues of in-sink garbage disposals, or show photos of renewable energy outposts he’s catalogued in Nepal. (See related, “On Mount