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.

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.

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

The correct scientific response to something that is not understood must always be to look harder for the explanation, not give up and assume a supernatural cause.

There are perfectly good independent small nations.

It was regarded as a responsibility of the BBC to provide programs which have a broad spectrum of interest, and if there was a hole in that spectrum, then the BBC would fill it.

The climate, the economic situation, rising birth rates; none of these things give me a lot of hope or reason to be optimistic.