An ecosystem, you can always intervene and change something in it, but there's no way of knowing what all the downstream effects will be or how it might affect the environment. We have such a miserably poor understanding of how the organism develops from its DNA that I would be surprised if we don't get one rude shock after another.

Like all biologists I simply acknowledge the gravity of the current situation. There are scenarios under which things work out well and to that extent I'm a cautious optimist.

To appeal to an omnipotent deity is to allow that at any moment the regularities of nature may be ruptured, that miracles may happen.

If I put myself on the side of those who see the world as warming up in a bad way, who see the general march of industrial culture as something undesirable, the one thing I must be beware of doing and which my colleagues on that side don't beware of doing, we must beware of saying we've got to stop changing the environment. There is no 'the' environment which we can change, the world is changing all the time.

Scientists are educated from a very early time and a very early age to believe that the greater scientist is the scientist who makes discoveries or theories that apply to the greatest ambit of things in the world. And if you've only made a very good theory about snails, or a very good theory about some planets but not about the universe as a whole, or about all the history of humankind, then you have in some sense accepted a lower position in the hierarchy of the fame of science as it's taught to you as a young student.

If you can't write well then your ambition to become famous in this way will be frustrated. Either that or you have to get an amanuensis who will write for you.

As an American I must say I haven't been very encouraged by the way in which the people who run the government in the United States have been listening to those contrary voices. And so long as the power to run the world lies in the hands of people who are quite happy to see it get warmer, or fuel be used more, then would those people who oppose it are crying in the wilderness - that's the real problem.