I'm sure that in the fullness of time we'll learn that one or more of these seemingly promising technologies were dead ends. And that's the nature of innovation, and that's why we should spread our bets; we should not put our eggs in any one basket. Some of these will be grand successes, some of them will be average, and some of them will be abject failures.

So we are now still dependent on foreign oil, have a problem with global warming, and are losing jobs rapidly to the Japanese in fuel-efficient vehicles as a result of that very shortsighted progress.

President Bush's proposal to focus our resources on sending humans to Mars is intriguing, but it is not the most compelling reason that Americans ought to focus our interest on the Red Planet.

We need to do for clean energy what Kennedy did for space in the original Apollo Project: Set a bold vision that will light the fires of innovation and make a game-changing shift in how we use and produce energy. And nothing less is adequate.

We can't tell China what to do if we don't do it ourselves. You don't inspire someone to take an action by refusing to take it yourself. We are in a race to be the dominant clean-energy provider to the world. Maybe this goes without saying: We've got to get China into an international protocol and the magic words are "common responsibility with differentiated action."

If this ice melts in Greenland it can shut down the Gulf Current.

I reflect back 35 years ago, and look how far we have come in America with our environmental policy to improve the conditions of our air and water, and we have had some real successes.