If everybody on the planet today had the same standard of living as the average European or American, we would need three new planets. But we don't even have one new planet. We have this one, and with the way we're polluting it, the shrinking water resources, the climate change, the experimentation with plants... the outlook is grim.

It was both fascinating and appalling to learn that chimpanzees were capable of hostile and territorial behavior that was not unlike certain forms of primitive human warfare.

We have to create more and more vegetarians, and help people to understand that it is not only the suffering of the animals (which is what made me vegetarian) but also the incredible harm to the environment, the tremendous amount of greenhouse gas created by the whole vast machinery of intensive animal farming.

As a child, we couldn't afford holidays overseas, so instead I travelled through books. I was inspired by Dr Dolittle and Tarzan.

I never wanted to give up. I thought I might have to. Especially at the beginning when chimpanzees had never seen a white person before.They gave one look at me and ran away! They were scared, but eventually I got their trust.

I shouldn't have named the chimps. It wasn't scientific. I didn't know. I knew nothing. And worse sin of all was that I was ascribing to them emotions like happiness, sadness and so forth.

I would never say I was an icon, but so many people have said I am, so I suppose I am. I mean, I can't not be what everyone says I am. But I don't feel like an icon.