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

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

Local innovation and initiative can help us better understand how to protect our environment.

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

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

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

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

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

You may be able to fool the voters, but not the atmosphere.

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