I share David Orr's optimism about the future, but mine comes from a different direction.
David says "we" must reduce our carbon footprints, individually and collectively, we must stop buying unnecessary stuff, stop traveling so much, stop buying huge vehicles for personal transportation, stop leaving the lights on when we leave the room, stop eating meat, stop being so destructive in our personal and societal choices.
The problem is "we" will never stop until forced to do so. I put the "we" in quotes, because my wife and I already live a frugal lifestyle that is ten times less productive of atmospheric carbon than most everyone else. We do it because we enjoy living this way, not to "save the environment." The other 90% of the people in the uS live so extravagantly, they consume far more than most of the rest of the world combined.
And they won't stop until they are physically forced to change.
Fortunately, force, in the guise of climate change and Peak Oil, is on the way. These two forces will bring about the collapse of Western Civilization, if that's what it is, and will cause the abrupt decline of American consumerism, if not wipe it out entirely. Less fortunately, it will cause untold misery elsewhere around the world where people are starting off with less material resources that we have in the United States, or more accurately, that the United States government has stolen from others.
The invasion and occupation of Iraq is just the beginning of the global insanity. Iran is obviously next, no matter who is "elected" as Resident in the next spasm of our perverted brand of "democracy," if that's what it is. (It's not.)
A hundred years from now, the uS will be in severe material decline, following hard on the heals of its present ideological and spiritual decline. "The Great Depression" will be a mild historical memory compared to the inevitable world depression on the horizon.
However, many will survive and thrive through the coming changes, especially those who learned from the few living who now practice a sane, modest and frugal life style. The Irish monks among us will keep the flame alive for our descendants, assuming we have any. Some one's descendants at least. Time to drag out "Canticle for Leibowitz" for a view of the future.
Good luck to you all. Best to start winding down now and avoid the rush. My wife and I lowered our standard of living and raised our quality of life. It's easy, it's fun, it's the wave of the future.