If coal is going to be used, the only response - because it is the dirtiest of all fuels - is that we have to learn how to do carbon capture and storage and we have to learn how to do it quickly on a commercial scale.

Coal is responsible for as much atmospheric carbon dioxide as other fossil fuels combined and it still has far greater reserves. We must stop using it.

If we build coal plants with no carbon dioxide capture mechanism, there is no way we can prevent massive global warming.

Because fossil fuels are not only a finite resource but hazardous to the environment, it is imperative that we diversify the resources used in generating electricity.

I think it's important that people think about what they are doing and that includes what they are eating. I am 61 now and attitudes towards drinking and driving have changed radically since I was a student. People change their notion of what is responsible. They will increasingly ask about the carbon content of their food.

Carbon capture and carbon sequestration are two issues we must understand completely before we can expect U.S. industry to put down billions of dollars in investment.