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.

People are not going to care about animal conservation unless they think that animals are worthwhile.

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

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

It's a moral question about whether we have the right to exterminate species.

Everyone likes birds. What wild creature is more accessible to our eyes and ears, as close to us and everyone in the world, as universal as a bird?

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.