What humans do over the next 50 years will determine the fate of all life on the planet.

No, not a feminist. I'm a humanist. I'm neither one side nor the other.

If you watch animals objectively for any length of time, you're driven to the conclusion that their main aim in life is to pass on their genes to the next generation.

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.

Sentimentalising is anathema, as far as I am concerned. It leads you into ethical problems about violence and killing and eating meat. The whole world becomes topsy-survy if you impose moralities that were evolved within human society on what a blowfly or what a parasite does... there are lots of emotions you can deduce from an animal's behaviour that are correct, but when you start saying it's feeling guilty or thinking or a loved one or mourning, you must be very careful of those feelings.

It is vital that there is a narrator figure whom people believe. That's why I never do commercials. If I started saying that margarine was the same as motherhood, people would think I was a liar.

In the West, that's what's happening. The birth rate has been dropping steadily and still is. But there is still a vast amount of the world where that's not the case. And that is where the big population growth is taking place.