It never really occurred to me to believe in God.

Before the BBC, I joined the Navy in order to travel.

Children start off reading in books about lions and giraffes and so on, but they also-if theyre lucky enough and have reasonable privileges of any human being-are able to go into a garden and turn over stone and see a worm and see a slug and see an ant.

Human beings, because we're so clever, have removed every single one of those population limiting factors... So nothing controls our increase in numbers except our own wish. Since I first started making television programs, the population of the world has increased three times. That's an extraordinary notion. Can it increase four times? Can it increase five times? The Earth is a finite size. So a point will eventually come when we run out of food, when we run out of space and when we will have destroyed most of the natural world. So ought we to do something about it before that happens?

Natural history is not about producing fables.

Humanity is facing a very big, slow, long, drawn-out threat, and that is to do with the way the weather is changing and the size of the population.

Its about cherishing the woodland at the bottom of your garden or the stream that runs through it. It affects every aspect of life.