All our environmental problems become easier to solve with fewer people and harder - and ultimately impossible to solve - with ever more people.

There's a small worm called Loa Loa Filariasis. This parasite can survive in one environment exclusively- namely, underneath the skin and inside the eyes of human beings. Children and the elderly in tropical regions (usually the poorest) are the most widely affected. A painful, slow death is virtually certain. The worm can actually live in the host for 17 years before the host finally dies.

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.

Well, I'm having a good time. Which makes me feel guilty too. How very English.

If I were beginning my career today, I don't think I would take the same direction. Television is at a crossroads at the moment. And although I am not up to date technologically, I suspect that somewhere out there people are conveying things about natural history by means other than television, and I think if I were beginning today, I'd be there.

We keep putting on programmes about famine in Ethiopia; that’s what’s happening. Too many people there. They can’t support themselves — and it’s not an inhuman thing to say. It’s the case. Until humanity manages to sort itself out and get a coordinated view about the planet it’s going to get worse and worse.

We really need to kick the carbon habit and stop making our energy from burning things. Climate change is also really important. You can wreck one rainforest then move, drain one area of resources and move onto another, but climate change is global.