If we don't have the common sense to limit our population size, I don't see how we'd have the common sense to do the rest. It's not "common sense" when peoples' livelihoods are on the line. We have to use every last resource we have to sustain so many people.
Every trim in usage you suggest, is somebody's lost livelihood. We just need fewer people and a more conservative rate of consumption would be ample for them all to live in luxury.