What humans do over the next 50 years will determine the fate of all life on the planet.

I often get letters, quite frequently, from people who say how they like the programmes a lot, but I never give credit to the almighty power that created nature.

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

There are some four million different kinds of animals and plants in the world. Four million different solutions to the problems of staying alive.

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.

[W]hen we look at the graphs of rising ocean temperatures, rising carbon dioxide in the atmosphere and so on, we know that they are climbing far more steeply than can be accounted for by the natural oscillation of the weather ... What people (must) do is to change their behavior and their attitudes ... If we do care about our grandchildren then we have to do something, and we have to demand that our governments do something.

You have to steer a course between not appalling people, but at the same time not misleading them.