The problem is we don't know what the climate is doing. We thought we knew 20 years ago. That led to some alarmist books - mine included - because it looked clear-cut, but it hasn't happened.

I'm a scientist, not a theologian. I don't know if there is a God or not. Religion requires certainty. Revere and respect Gaia. Have trust in Gaia. But not faith.

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.

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.

I’m not religious, but I put it that way because I feel so strongly. It’s the one thing you do not ever do. You’ve got to have standards.

I don’t think we’re yet evolved to the point where we’re clever enough to handle a complex a situation as climate change. The inertia of humans is so huge that you can’t really do anything meaningful.

I’ve got personal views on the ’60s. You can’t have freedom without paying the price for it.

Let’s make hay while it lasts.

We are in a fool’s climate, accidentally kept cool by smoke, and before this century is over billions of us will die and the few breeding pairs of people that survive will be in the Arctic where the climate remains tolerable.

We rushed into renewable energy without any thought. The schemes are largely hopelessly inefficient and unpleasant. I personally can’t stand windmills at any price.