Natural history is not about producing fables.

You've got to be fairly solemn [about the environment]. I mean the mere notion that there are three times as many people on Earth as there were when I started making television. How can the Earth accommodate them? When people, including politicians, set their faces against looking at the consequences-it's just unbelievable that anyone could ignore it.

Opponents say natural selection is not a theory supported by observation or experiment; that it is not based on fact; and that it cannot be proved. Well, no, you cannot prove the theory to people who won't believe in it any more than you can prove that the Battle of Hastings took place in 1066. However, we know the battle happened then, just as we know the course of evolution on earth unambiguously shows that Darwin was right.

The reverse side of the coin in having this extraordinary ability to go anywhere, is that no one anywhere is remote any more.

People talk about doom-laden scenarios happening in the future: they are happening in Africa now. You can see it perfectly clearly. Periodic famines are due to too many people living on land that can't sustain them.

Can a growing human population still leave space for wildlife?

I have no doubt that the fundamental problem the planet faces is the enormous increase in the human population