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

Just after World War II, this country led the world in science by every way you could measure it, yet the number of scientists was a tiny proportion of what it is now.

One pound of uranium is worth about 3 million pounds worth of coal or oil.

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

I wouldn't be against them (large wind turbines) if they actually worked.

The big threat to the planet is people: there are too many, doing too well economically and burning too much oil.

There aren't just bad people that commit genocide; we are all capable of it. It's our evolutionary history.