Are you proposing exterminating the majority of earth's population? That could get messy, and I think we'd end up exterminating everyone...
I agree with you that a big problem is the sheer number of people on this planet.
I remember when I was fifteen and proposed in a school debate that maybe the best course of action, concerning countries where famine strikes almost at a regular basis, would be to sit on the fence and let nature run it's course.
My proposition was not even considered, of course. Too barbaric, they said.
Sure, I said, and going in with just enough means to keep them on the brink of starvation in a land that can never support that many people no matter what they do is so much more civilized.
The fact is that extreme measures may well be required to preserve humanity. Not in the form of action, but in the form of inaction when our actions cannot do more than satisfy our need to feel good about ourselves. We seem to be incapacitated by our moral confusions.
Doctors realize that if death is inevitable, fighting it will only cause more suffering to everyone involved.
A part of me does believe that science may come up with a solution to how we can all live as we do without destroying our habitat. But for the time being, capitalism stands in the way of that scenario ever becoming a reality.