Given that sustainable means capable of continuous re-use, I wish I knew what sustainable development is supposed to mean in the context of a finite, non-renewable resource. I have a hard time thinking it means anything at all. Oil is maybe renewable on geological time scales, if it doesn't require unique environmental conditions unlikely to be repeated to create it in the first place, but not on the scale we're using it. Could it mean we don't develop it faster than the environment can recycle its toxic byproducts? We crossed that line long ago. I incline to the view that sustainable is one of those eco-buzzwords that mean almost nothing. I think the idea Rae was really going for is more like managed, controlled, regulated, something like that.