Well, that is the sustainability part of it. As I explained, I was initially going to talk about our rejection of consumerism when addressing sustainability, but after reading JakeS comments in the first diary I reckoned that sustainability was only one reason.

Even if it could be done with only one planet, most of us would probably not advocate more production / consumption as a target to obsess about.

Earth provides enough to satisfy every man's need, but not every man's greed. Gandhi