No one should be able to enter a wilderness by mechanical means.

Take a course in good water and air and in the eternal youth of Nature you may renew your own. Go quietly, alone no harm will befall you.

We learned that economic growth and environmental protection can and should go hand in hand.

When we realize we can make a buck cleaning up the environment, it will be done!

Birds are indicators of the environment. If they are in trouble, we know we'll soon be in trouble.

I think the cost of energy will come down when we make this transition to renewable energy.

Our world faces a true planetary emergency. I know the phrase sounds shrill, and I know it's a challenge to the moral imagination.

I did not become a vegetarian for my health, I did it for the health of the chickens.

Not all is doom and gloom. We are beginning to understand the natural world and are gaining a reverence for life - all life.

The only way forward, if we are going to improve the quality of the environment, is to get everybody involved.