There are essentially two possible futures. In one, we now invest the finite resources we have in the best way we can to create a (lower) standard of living that is truly sustainable for the future. In the other, we continue to live out our orgy of consumption, deluding ourselves that science and engineering will make it all OK - until one day we wake up to find a denuded earth can no longer supply our gluttonous desires. Sadly, the first is, I suspect, politically not viable.
Hit the nail on the head, I would say, except that anything using finite resources is by definition unsustainable for the (long term) future. There is no way to supply a planet of 5 billion + people with natural resources for an indefinite period, no matter how good the recycling! We are faced with an inevitable exhaustion of natural resources at some point. That will probably be sooner rather than later in the case of oil, with some minerals and metals taking rather longer. It is a frightening thought and I suspect that in the future nations will war over resources to a huge extent and the future imbalance between rich and poor will grow rather than diminish. Current consumption of resources will be sustainable for as long as most of the world remains poor!