By the end of this century, climate change will reduce the human population to a few breeding pairs surviving near the Arctic.

The big threat to the planet is people: there are too many, doing too well economically and burning too much oil.

What I tend to do is to wake about five in the morning-this happens quite often-think about the invention, and then image it in my mind in 3D, as a kind of construct. Then I do experiments with the image...sort of rotate it, and say, 'Well what'll happen if one does this?' And by the time I get up for breakfast I can usually go to the bench and make a string and sealing wax model that works straight off, because I've done most of the experiments already.

What we have lived through, the 20th century, has been like a great party. Adults now have had the best time humanity has ever had. Now the party is over and the Earth is reckoning up.

If you start any large theory, such as quantum mechanics, plate tectonics, evolution, it takes about 40 years for mainstream science to come around. Gaia has been going for only 30 years or so.

Science always uses metaphor.

No one who has experienced the intense involvement of computer modeling would deny that the temptation exists to use any data input that will enable one to continue playing what is perhaps the ultimate game of solitaire.