I suspect that happiness is not a state but rather a transition.

An understanding of the natural world and what's in it is a source of not only a great curiosity but great fulfillment...

All life is related. And it enables us to construct with confidence the complex tree that represents the history of life

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?

The World is full of wonders, but they become more Wonderful, not less Wonderful when Science looks at them.

Climate change will affect the whole of humanity, while terrorist attacks will only affect a small section of humanity. Of course, you wouldn't say that if you were related to someone who had been beheaded or blown up or murdered.

People must feel that the natural world is important and valuable and beautiful and wonderful and an amazement and a pleasure.