I think this is actually a false choice. Or, at least, implies a choice between personal satisfaction and collective responsibility towards the environment.
Well, "personal satisfaction" isn't always the same as "overconsumption", of course.
But I think restraining consumption can increase personal satisfaction, if we do it thoughtfully and not as slaves of the market.
I made references to the market to indicate that some people don't equate market behaviour with relentless exploitation of natural resources and of people.
In the US everyone has a car or SUV and two televisions, but we also have a horrible healthcare system that shows off every disfunction of market based infrastructure. But we do nothing to fix that, because we have no idea how -- the idea of doing anything that isn't driven by the profit motive is beyond the conception of our institutions.
What's interesting is that there have been proposals to improve healthcare coverage which have been market-oriented and which have fairly obvious economic motivations: it's easier to prevent health problems amongst the uninsured than to provide emergency treatment later on. I can't see why, when both compassionate and financial justifications exist to improve healthcare coverage, that something decisive isn't done, but I guess that says quite a lot about the people dragging their feet on the matter.
Which really is an optimistic way to think about it, because there's so much potential. We are squandering our wealth and our technology; but it's there if we want it.
Perhaps the most promising sources of "alternative" energy can be brought online on a viable basis soon enough to make energy something we never have to worry about again, but there's the question of whether we'll ever get a better shot than right now (or in the next few decades) at achieving such things. It's much harder to muster the effort for nuclear fusion research or for things like a space programme in a society without access to cheap and convenient energy.