All our environmental problems become easier to solve with fewer people and harder - and ultimately impossible to solve - with ever more people.

I mean, it is an extraordinary thing that a large proportion of your country and my country, of the citizens, never see a wild creature from dawn 'til dusk, unless it's a pigeon, which isn't really wild, which might come and settle near them.

Fundamentally not to waste energy. If we were all to reduce our demands for energy, it would make an enormous amount of difference.

I like animals. I like natural history. The travel bit is not the important bit. The travel bit is what you have to do in order to go and look at animals.

You can cry about death and very properly so, your own as well as anybody else's. But it's inevitable, so you'd better grapple with it and cope and be aware that not only is it inevitable, but it has always been inevitable, if you see what I mean.

The process of making natural history films is to try to prevent the animal knowing you are there, so you get glimpses of a non-human world, and that is a transporting thing.

How could I look my grandchildren in the eye and say I knew what was happening to the world and did nothing.