We live in a time of unprecedented population growth. People born 60 years ago have seen the population of the world triple. In the UK, in the past 100 years, the population has grown by over 20 million. But why is our population growing? What are the consequences if it doesn't stop? And is population growth necessarily a bad thing? Our reporter Benjamin Zand has been finding out.

Fracking...

(Media / Fracking explained: opportunity or danger)