I talk about reducing our dependence on foreign oil. If we're buying electricity from a solar-thermal plant in Tijuana, I'm not sure we should say that's evil. If we are buying wind power from Alberta, I don't have a huge objection to that.

The need to help spread democracy and the ability to do that will be much greater if we break this addiction to oil, which gives the oil princes and sultans the power in the Mideast.

All of the economic signals in the marketplace are essentially subsidizing the use of dirty fossil fuels and penalizing clean energy. There's really only one entity in society that can solve that problem, and that is government. And the air is a scarce resource.

Back in the mid-1970s, we adopted some fairly ambitious goals to improve efficiency of our cars. What did we get? We got a tremendous boost in efficiency.

On Earth, we still have a beautiful atmosphere that precisely maintains a thermally driven climatic system that shelters, shields and sustains our natural treasures.

We must start... rebuilding our cities around energy efficiency and human needs, rather than around the car and wasted energy.

A lot of people do not think of forests as a health issue, but we have found out that is where our clean water comes from, from the forests.