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.

Imagine a survivor of a failed civilization with only a tattered book on aromatherapy for guidance in arresting a cholera epidemic. Yet, such a book would more likely be found amid the debris than a comprehensible medical text.

The climate is doing its usual tricks. There's nothing much really happening yet. We were supposed to be halfway toward a frying world now.

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.

I think that we reject the evidence that our world is changing because we are still, as that wonderfully wise biologist E. O. Wilson reminded us, tribal carnivores. We are programmed by our inheritance to see other living things as mainly something to eat, and we care more about our national tribe than anything else. We will even give our lives for it and are quite ready to kill other humans in the cruellest of ways for the good of our tribe. We still find alien the concept that we and the rest of life, from bacteria to whales, are parts of the much larger and diverse entity, the living Earth.

Humans are too stupid to prevent climate change from radically impacting on our lives over the coming decades.

I would only have been too pleased if someone had asked me for my data. If you really believed in your data, you wouldn't mind someone looking at it. You should be able to respond that if you don't believe me go out and do the measurements yourself.