You know, it is a terrible thing to appear on television, because people think that you actually know what you're talking about.

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.

You'll discover in countries where women have control over their own bodies, where they have education, where they have birth control, where they have facilities and where they are literate, when those things happen, the birth rate falls.

It's coming home to roost over the next 50 years or so. It's not just climate change; it's sheer space, places to grow food for this enormous horde. Either we limit our population growth or the natural world will do it for us, and the natural world is doing it for us right now.

If I were beginning my career today, I don't think I would take the same direction. Television is at a crossroads at the moment. And although I am not up to date technologically, I suspect that somewhere out there people are conveying things about natural history by means other than television, and I think if I were beginning today, I'd be there.

You can only get really unpopular decisions through if the electorate is convinced of the value of the environment. That's what natural history programmes should be for.

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