I don't write a lot here about environmental and resource issues, mostly because I feel I lack the required expertise to say something valuable. But I recently looked at this piece by an Australian philosopher named Rowan (E. Loomis linked to this which in turn linked to it), and it raises some questions that need to be discussed more widely. As Rowan points out, even the most resource-efficient, 'clean' versions of economic growth are not sustainable propositions in the long term: eventually the world will run out of physical space (for the "stuff" that people are using plus the non-bio-degradable "stuff" they have thrown out), and well before that happens raw materials will have been depleted. The way to avoid this is to transition over time to a non-growth, steady-state global economy, while ensuring, or so one would hope, that it is also marked by considerably less poverty and more material equality than the present system. Sounds like a tall order, but the alternatives if it doesn't occur will be very unpleasant. Such a transition might (probably will, I suspect) require the wealthy and the upper-middle-classes in the 'developed' world to give up some of the "stuff" that they currently view as either necessary or desirable props of their existence.
The alternative to thinking about these issues and doing something about them will be an eventual (note "eventual" not "imminent") collapse of civilization. If it does happen, it will occur, I would guess, several hundred years after I am no longer around. But that isn't too much consolation. Humans, probably uniquely among animals, have the capacity to think about the long-term future, and that really is something more of us should do more often.