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.

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.

Quantification, experimentation, rigor, repetition, prediction - all of these are part of the experimental sciences. There's an iconography also namely man, and I do mean males in white coats who spin dials and wait for numbers to appear.

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.

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.

The general public doesn't know and probably doesn't care about punctuated equilibria nor indeed should they, or the greenhouse effect on some other planet - they barely have the ability to cope with the greenhouse effect on their own planet. So I think you have to distinguish between the broad visibility of a scientist when he or she is speaking to a general public and trying to address general issues and the continued position that a scientist may have into the history of a particular subject.

There are a whole other range of sciences that must deal with the narrative reconstruction of the inordinately complex events of history that can occur but once in their detailed glory. And for those kinds of sciences, be it cosmology, or evolutionary biology, or geology, or palaeontology, the experimental methods, simplification, quantification, prediction and repetition of the experimental sciences don't always work. You have to go with the narrative, the descriptive methods of what? Of historians.