BBC Horizon: How Many People Can Live on Planet Earth?

A poinant programme examining how much further mankind can push the Earth’s resources

In his lengthy career, Sir David has watched the human population more than double from 2.5 billion in 1950 to nearly seven billion. He reflects on the profound effects of this rapid growth, both on humans and the environment.

If you missed it it is essential but not comfortable viewing on BBC iPlayer [UK only]