I don't think I've seen this before: The Long Now Foundation has a series of lectures available free for download on a variety of, long-term issues (they suggest you umake a donation if you like them).
I came across that via a summary of Paul Hawken's lecture from last year about the long-term history and future of the environmental movement. It's going to be big apparently.
I must admit that I get a little annoyed by some of the coupling of environmentalism and spirtuality/religion that pops up occasionally. To quote one comment from that page: "I was under the impression that greens were generally spiritual and/or members of liberal/tolerant religious denominations." I'm not sure why one must believe in imaginary gods and/or spirits to believe we're screwing the world, but it often seems to be assumed.
Anyway, I'm drifting off the point. Good futury downloady goodness, go listen/read.