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

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

We won't have a society if we destroy the environment.

Harmony with land is like harmony with a friend you cannot cherish his right hand and chop off his left.

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

By polluting clear water with slime you will never find good drinking water.

Much of the debate over global warming is predicated on fear, rather than science.

Never doubt that a small group of thoughtful, committed citizens can change the world indeed, it's the only thing that ever has.

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

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