The simple fact of the matter is that we are looking at this all wrong. There is a point where we must consider not whether we can sustain life, but what quality of life there will be for the survivors. We could all theoretically exist in closet-sized Japanese apartments, eating very small meals and moving very little to reduce caloric expenditure, etc etc and just keep having children etc etc who will grow up to live in smaller boxes and eating less...

There is going to be a point at which we realize it's not how sustainably we live, not how much we give up, not now conscious we are, but a matter of how *many* of us there are. A single locust does not eat much, but a swarm will desolate an entire valley.

If something were to happen (think Peak Oil etc) we would all be proper f*cked. Especially those of us in the cities. We have hardly got the means to produce enough food from our apartments. Millions would starve and die. ...that's nature's counterbalance. Like a cold winter, it will cull the excess of our population and those who do remain will have greater hope for the resources available. It's harsh, and it's tragic, but it's natural and the reverse swing of the pendulum.

It just p*sses me off and sickens me to occasionally see Hotmail or CNN headlines that say something like "Germany going extinct?" when population growth dips into the negatives for once. As if people need encouragement.