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

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.

Renewable energy also creates more jobs than other sources of energy - most of these will be created in the struggling manufacturing sector, which will pioneer the new energy future by investment that allows manufacturers to retool and adopt new technologies and methods.

We clearly need to break our addiction on Saudi Arabian oil that is a security threat to the United States.

We need to get our sons and daughters home and their responsibility for the security of Iraq needs to be assumed by Iraqis who will stand up and toe the line for their countries.

Air is one we hold in common; it has a limited carrying capacity for pollutants and that's being used up by those who pollute the atmosphere. So we have to stop that externality. We would never allow a utility to put their coal slag in a dump truck and back it up to the city park and dump it in unlimited amounts for free. But that is exactly what we do with carbon dioxide and methane.

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.