I met Andrew Revkin through the World Science Festival this year, then recorded at my visited me in my New York apartment. I wish I could have brought you the whole conversation. You get the highlights. We covered global warming, pollution, history, relevant people, and why he is hopeful, even seeing the challenges he sees from the vantage point of National Geographic and the New York Times. Andrew shares the decades work heâ€™s done on these issues. He reinforces the importance of action, not just talking, He takes the challenge seriously, even -- gasp -- flying less, which most people consider impossible. Want to expand your horizons? Listen to hear how a guy who has already done a lot takes on doing more -- to improve his life. Read the transcript.