When people say, 'You're not being realistic,' they're just trying to tag some thoughts that they can't otherwise handle.

It's like turning the space program over to the Long Island Railroad.

I began working with the John Muir Institute and then started helping found Friends of the Earth organizations here and there in other countries. That pretty well brings us up to the present.

We still need conservationists who will attempt the impossible, achieving it because they aren't aware how impossible it is.

Overpopulation is perhaps the biggest problem facing us, and immigration is part of that problem. It has to be addressed.

Keep your rivers flowing as they will, and you will continue to know the most important of all freedoms-the boundless scope of the human mind to contemplate wonders, and to begin to understand their meaning.

If something's going wrong with this planet we'd better fix it here and not look for some sort of escape.