The nature of human beings is that they'd far rather face the disaster that is happening tonight than the one that is happening tomorrow.

We keep putting on programmes about famine in Ethiopia; that’s what’s happening. Too many people there. They can’t support themselves — and it’s not an inhuman thing to say. It’s the case. Until humanity manages to sort itself out and get a coordinated view about the planet it’s going to get worse and worse.

If we were all to reduce our demands for energy, it would make an enormous amount of difference.

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

I don't think we are going to become extinct. We're very clever and extremely resourceful - and we will find ways of preserving ourselves, of that I'm sure. But whether our lives will be as rich as they are now is another question.

I don't approve of sunbathing, and it's bad for you.

If we and the rest of the back-boned animals were to disappear overnight, the rest of the world would get on pretty well. But if the invertebrates were to disappear, the world's ecosystems would collapse