Evolution is a tightly coupled dance, with life and the material environment as partners. From the dance emerges the entity Gaia.

The tropical rain forests are a telling example. Once cut down, they rarely recover. Rainfall drops, deserts spread, the climate warms.

Nature favors those organisms which leave the environment in better shape for their progeny to survive.

The Earth's population will be culled from today's 6.6 billion to as few as 500 million, with most of the survivors living in the far latitudes - Canada, Iceland, Scandinavia, the Arctic Basin.

What we have lived through, the 20th century, has been like a great party. Adults now have had the best time humanity has ever had. Now the party is over and the Earth is reckoning up.

Those who fail to see that population growth and climate change are two sides of the same coin are either ignorant or hiding from the truth. These two huge environmental problems are inseparable and to discuss one while ignoring the other is irrational.

This programme to stop nuclear by 2020 is just crazy. If there were a nuclear war, and humanity were wiped out, the Earth would breathe a sigh of relief.