Can the Earth sustain 9 billion people? We'll find out in the next 50 years.
We're living in lucky times. Living standards - in the Western world, at least - are the highest in history. It's an era of relative peace and plenty that would amaze our ancestors. But it's not going to continue forever; we're already stretching many of our natural resources to their limits, and the world's population will jump from 6.5 billion to around 9 billion over the next 50 years. Get ready for a painful correction - here are four interconnected resources that are headed for a catastrophic squeeze within our lifetime.