Author, activist, ring-leader and sage, Bill McKibben has been warning about the dangers of a changing climate since he was in his 20s (his book "The End of Nature" was the first to alert the general public to this thing called 'global warming'; along with a handful of students he founded 350.org; he's been arrested for civil disobedience more times than he can count). Now, in his 60s, he's started a new group: Third Act. Enjoy today's conversation with Bill on the Green Radio Hour and check out thirdact.org. In the second half of the show, Riverkeeper's Rebecca Martin cautiously celebrates New York State's DEC request that NYC's DEP do a better job managing releases from the Ashokan Reservoir into the Esopus Creek. You'll remember last winter the Esopus picked up a new nickname, The Big Muddy.