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.

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.

The apologists for space science always seem over-impressed by engineering trivia and make far too much of non-stick frying pans and perfect ball-bearings. To my mind, the outstanding spin-off from space research is not new technology. The real bonus has been that for the first time in human history we have had a chance to look at the Earth from space, and the information gained from seeing from the outside our azure-green planet in all its global beauty has given rise to a whole new set of questions and answers.

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

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. 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. The world has not warmed up very much since the millennium. Twelve years is a reasonable time. The temperature has stayed almost constant, whereas it should have been rising - carbon dioxide is rising, no question about that.

I'm not a pessimist, even though I do think awful things are going to happen.

An inefficient virus kills its host. A clever virus stays with it.