I would be absolutely astounded if population growth and industrialisation and all the stuff we are pumping into the atmosphere hadn't changed the climatic balance. Of course it has. There is no valid argument for denial.

Cameramen are among the most extraordinarily able and competent people I know. They have to have an insight into natural history that gives them a sixth sense of what the creature is going to do, so they can be ready to follow.

I had a huge advantage when I started 50 years ago - my job was secure. I didn't have to promote myself. These days there's far more pressure to make a mark, so the temptation is to make adventure television or personality shows. I hope the more didactic approach won't be lost.

I'm absolutely strict about it. When I land, I put my watch right, and I don't care what I feel like, I will go to bed at half past eleven. If that means going to bed early or late, that's what I live by. As soon as you get there, live by that time.