Just say no, to hydrogen

Gas prices have rising in the U.S. in recent months, but prices are still much lower than in other countries. Do you think that rising prices will encourage people to move to cars with better fuel economy?

I think that as it reaches higher and higher levels, it definitely affects more and more people. But I think that it's hard to believe that the price of gasoline is going to hit such a high price that it's going to really change the kinds of cars that people drive substantially.

I think that you're not going to see gas taxes in this country. And this issue of whether we're running out of oil or not, I don't think that's going to happen fast enough to have a big impact to change the world.

What do you think consumers and citizens can do now to fight global warming?

In the vehicle realm, they should go out and buy a hybrid. I think that you can reduce your greenhouse-gas emissions in half while buying a very clean car. Typically efficiency is the most cost-effective strategy that you can adopt for global warming, or any pollution reduction. So I think in your vehicles, people should go out and buy a hybrid.

In your homes there are lots of strategies. The simplest is to look for Energy Star products when you are buying appliances. And in companies there is also a lot you can do, and I wrote a whole book on that issue.

What about on the policy side? What should government be doing now to help reduce greenhouse-gas emissions?

If you want to reduce greenhouse-gas emissions from the vehicle sector you simply have the government intervene on fuel efficiency. There really is not much escape from government intervention, and this is true whether you like hybrids or hydrogen. The government simply has to weigh in and make sure that any efficiency gains in the vehicles end up going toward fuel economy, and not for instance for more acceleration or more weight.

In the case of the electric utility sector, we need to do something like the McCain-Lieberman bill. We need to have a cap on CO2 emissions in the electric utility sector, and let the utility sector figure out the best way, the most cost-effective way, to reduce greenhouse emissions.

Are you optimistic about either of these things being implemented under the current Congress or administration?

No, no. I don't think it's possible to be optimistic about that. I think realistically it's hard to see the political will.

What might happen if we fail to act? I don't think that it's going to look like the movie "The Day After Tomorrow," coming out at the end of May. But on the path that we're currently on, the average temperature in the United States is going to be 10 degrees Fahrenheit higher at the end of this century than it is today. And I don't think that most Americans have any idea that that is what is going to happen if we don't change our course.

I don't think that most Americans realize what the implications are of that for the way that we live. So I do feel that there is an urgency for action. Tony Blair said last year that if we're to avoid catastrophic global warming we need to reduce our CO2 emissions by about 50 percent by 2050.

If we started today it wouldn't be easy, but at least it would be doable -- a 50 percent reduction over five decades. If we do nothing for two decades, our emissions are going to rise by 50 percent. And then we'd have to reduce our emissions 75 percent in two and a half decades.

And that's just incredibly hard to do. So, I think that although it is true that global warming is a long-term problem, action has to be relatively soon, or else it just becomes prohibitively expensive.

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