I would love to see a giant squid. Very few people have seen them. And only about half a dozen people have seen one alive.

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

Instead of controlling the environment for the benefit of the population, perhaps we should control the population to ensure the survival of our environment

I'm no longer sceptical. I no longer have any doubt at all. I think climate change is the major challenge facing the world.

I mean, it is an extraordinary thing that a large proportion of your country and my country, of the citizens, never see a wild creature from dawn 'til dusk, unless it's a pigeon, which isn't really wild, which might come and settle near them.

The notion of ever more old people needing ever more young people, who will in turn grow old and need even more young people, and so on ad infinitum, is an obvious ecological Ponzi scheme.

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.