You mustn't take what I say as gospel because no one can second-guess the future.

Climatologists are all agreed that we'd be lucky to see the end of this century without the world being a totally different place, and being 8 or 9 degrees hotter on average.

We need a more authoritative world...What's the alternative to democracy? There isn't one. But even the best democracies agree that when a major war approaches, democracy must be put on hold for the time being. I have a feeling that climate change may be an issue as severe as war. It may be necessary to put democracy on hold for a while.

You mustn't take what I say as gospel because no one can second-guess the future.

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

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.

The Earth's population will be culled from today's 6.6 billion to as few as 500 million, with most of the survivors living in the far latitudes - Canada, Iceland, Scandinavia, the Arctic Basin.