I'm absolutely strict about it. When I land, I put my watch right, and I don't care what I feel like, I will go to bed at half past eleven. If that means going to bed early or late, that's what I live by. As soon as you get there, live by that time.

I'd like to see the giant squid. Nobody has ever seen one. I could tell you people who have spent thousands and thousands of pounds trying to see giant squid. I mean, we know they exist because we have seen dead ones. But I have never seen a living one. Nor has anybody else.

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

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.

The notion of ever more old people needing ever more young people, who will in turn grow old and need even more young people, and so on ad infinitum, is an obvious ecological Ponzi scheme.

Natural history is not about producing fables.

[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.