Climate change will affect the whole of humanity, while terrorist attacks will only affect a small section of humanity. Of course, you wouldn't say that if you were related to someone who had been beheaded or blown up or murdered. But humanity is facing a very big, slow, long, drawn-out threat, and that is to do with the way the weather is changing and the size of the population.

Clearly we could devastate the world... as far as we know, the Earth is the only place in the universe where there is life. Its continued survival now rests in our hands

I think a major element of jetlag is psychological. Nobody ever tells me what time it is at home.

Terrorism is an immediate problem that people are very concerned about, and I am as concerned about that as anyone else. But it isn't an either or situation.

I don't think we are going to become extinct. We're very clever and extremely resourceful - and we will find ways of preserving ourselves, of that I'm sure. But whether our lives will be as rich as they are now is another question.

The climate, the economic situation, rising birth rates; none of these things give me a lot of hope or reason to be optimistic.

I suffer much less than many of my colleagues. I am perfectly able to go to Australia and film within three hours of arrival.