We can now destroy or we can cherish-the choice is ours.

In the West, that's what's happening. The birth rate has been dropping steadily and still is. But there is still a vast amount of the world where that's not the case. And that is where the big population growth is taking place.

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

One in eight plant species face extinction.

If I can bicycle, I bicycle.

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.

It's coming home to roost over the next 50 years or so. It's not just climate change; it's sheer space, places to grow food for this enormous horde. Either we limit our population growth or the natural world will do it for us, and the natural world is doing it for us right now.