One thing that being a scientist has taught me is that you can never be certain about anything. You never know the truth. You can only approach it and hope to get a bit nearer to it each time. You iterate towards the truth. You don't know it.

A billion could live off the earth; 6 billion living as we do is far too many, and you run out of planet in no time.

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.

I suspect any worries about genetic engineering may be unnecessary. Genetic mutations have always happened naturally, anyway.

I have a feeling that climate change may be an issue as severe as a war. It may be necessary to put democracy on hold for a while.

Life does more than adapt to the Earth. It changes the Earth to its own purposes.

Only rarely do we see beyond the needs of humanity, and he linked this blindness to our Christian and humanist infrastructure. It arose 2,000 years ago and was then benign, and we were no significant threat to Gaia. Now that we are over six billion hungry and greedy individuals, all aspiring to a first-world lifestyle, our urban way of life encroaches upon the domain of the living Earth.