What was it that convinced you that global warming was a real and pressing problem?

Oh, I think the weight of evidence over time [convinced me] that it's something that you ought to be careful about. As a conservative, I think you ought to be prudent, and it seems to me that the conservative approach should be to minimize the risk of a really catastrophic change.

And when did you come to that?

Well, I thought over the last eight or 10 years it was useful to move in that direction. I was strongly opposed to Kyoto treaty the way it was written; I think it was written by the Europeans as an anti-American document. I also think it doesn't get the job done because it excludes China and India. But I felt that was a lost opportunity to talk about: How do you design a pro-science and pro-technology strategy that lowers the amount of damage the human race does to the planet? ...

We're going to start in '88 because it's an interesting year; it's the year of radical weather and people start worrying about it. Back in the 1980s, the first President Bush said on the way back from [the Climate Change Conference in] Rio, that "Our way of life is not up for negotiation." Did you agree with him when he said that?

Yeah, I still agree with that. I think there's a false dichotomy. The left has this passion for using whatever issue they can find as an excuse to eliminate capitalism, to eliminate markets, to eliminate personal choice, to demand a lower standard of living. I think that's all, frankly, irrational. There's no reason you can't have a very high civilization with a terrifically good quality of life and do so with remarkably little environmental damage, but it requires different strategies.

And it was the approach of the environmentalists that Bush was responding to? I thought it was more a matter of there wasn't a solution on the table that he could see.

I think both were true. Look, I think the problem we've had is that the people who have been most aggressively emphatic about major environmental problems tend to be people who come from the left and who, a, exaggerate the problem's immediacy. If you look at the various things in [Al] Gore's movie [An Inconvenient Truth], they're just factually wrong -- you know, we're not faced with drowning Florida by Thursday -- and so you start with people reacting to the exaggerations.

Second, they tend to be very cheerfully anti-market and anti-entrepreneurship and anti-technology. When Gore wrote in [his book] Earth in the Balance that the greatest threat of the 20th century was the internal combustion engine, it was an utterly irrational comment. I mean, no serious student of the 20th century could look at Stalin, Mao, Hitler, the Holocaust and then say, "But boy, that automobile, that was really the big threat."

So first of all, you just have this whole reaction to an emotional assault on modernity. Second, the answers of the left tend to all be more litigation, more regulation, bigger government, higher taxes. People who share my values don't particularly want to be sold those particular solutions. So what happens is conservatives refuse to think about it. The left tends to come up with ideas that won't work and represent a value system that's not likely to be adopted, and you're caught in this kind of a model.

I'm writing a book called Contract with the Earth precisely to break out of that dialogue and to say that there should be, in the Theodore Roosevelt tradition, a science-and-technology, entrepreneurial, market-oriented, incentive-led system that solves things -- which we did to some extent. If you look at sulfur and the Clean Air Act of 1990, there was an amazing breakthrough. There was a substantial change from the way we had done business before. And it worked; it reduced total sulfur in the atmosphere by 50 percent for about one-tenth of what people thought it was going to cost.

In the early Clinton administration, their idea was a BTU [British thermal unit] tax, with the idea that you would raise revenue and you would reduce carbon. What did you think about that?

I think if you're in the left, the answer's always a tax; the answer's always bigger government; the answer's always more regulation; the answer's always more litigation. Just tell me what the question is.

You were against it.

I think it's nuts. I mean, I read newspaper columnists who ride subways explaining that a 50-cent-a-gallon gas tax is the right strategy. Well, if you're a big downtown newspaper and you're not a senior citizen in South Dakota riding around on Sundays, and you're not a suburbanite driving into Atlanta, and you're not somebody whose entire economy is based on trucks, it's easy to be for a 50-cent-a-gallon gas tax. This has been a favorite answer on the left since John Anderson, [who ran for president as an independent,] in 1980. And the rest of the country says, every morning, no. ...

Clinton said, at the time, that it was the biggest political mistake that he had made.

It was on the short list.

Was it an issue that cost Democrats their jobs the next time around?

No, not by itself. It was part of a pattern. They passed a very large tax increase that infuriated the people who paid taxes. They had taken a series of very left-wing positions on social issues. They had come out for an anti-gun bill, which had enraged the gun-owners around the country. There were a whole series of these things that came together in 1994. ...

You said you were anti-Kyoto; you must have been one of those 95-0 votes.

Well, first of all, on the Senate side it was 95-0, including at the time [Sen.] John Kerry [D-Mass.] and all sorts of people who now wish they hadn't voted no. As speaker of the house, I had a team in Kyoto who came back and were just appalled by the way the treaty was negotiated, by the role of the U.S. delegation, by the degree to which the Europeans rigged the entire treaty to be anti-American. For example, no act of carbon sequestration by farmers and by forests counted, because Europe doesn't have very many acres to do this in and we have lots of acres. So all the things America could do well didn't count.

The year that the baseline was chosen was the deal that happens to help Europe and not America. The fact that China and India aren't even included means that you give them a substantial economic [advantage]. If we implemented Kyoto, we would have been raising the cost of doing business in the U.S.

One of the arguments that President Clinton made at the time was there was a moral responsibility of the First World to go first, because we put the carbon up there, and that the developing world would come second. That, for some people, was a reasonable argument.

I would make the argument that the United States ought to take the lead worldwide in developing the technologies and in developing the techniques that dramatically reduce the carbon loading in the atmosphere, and we ought to do it for our own interests. The United States is the wealthiest and most successful country in the world; it is the leading country in the world; [it] has an interest in the best possible environment on the entire planet. And if we don't show leadership, then it's very hard to get the rest of the planet to do the right things.

So I don't care about that part of it; I cared about the idea that the Europeans had designed a treaty specifically harmful to America and specifically helpful to Europe, and that we had an administration that was prepared to go along with hurting America for no long-term gain. If you look at the total effect of Kyoto as it's designed, it's not very big in total, because China and India replace any carbon reduction in the United States and Europe. ...

Let me talk to you a little bit about a Frank Luntz memo that came out at about that time: ... "The international fairness issue is an emotional home run. Given the change, Americans will demand that in any international global warming treaty, nations such as China, Mexico and India would have to sign up for the majority of Americans to support it." He is going back to that fairness issue; it is unfair.

Look, at a time when many Americans are afraid of jobs leaving the U.S. for China, India and Mexico, to suggest that we're going to sign a treaty which puts a greater economic burden on America and accelerates the flow of jobs to China, India and Mexico -- it's an astonishing treaty for a liberal, Democrat administration to sign at the time that most liberal Democrats are screaming about unfair international competition.

But the core problem here is much deeper than this. The core problem is that the human race, for 400 years, has been using science and technology and entrepreneurship to create greater wealth, greater opportunities and more capacity to have a decent world. We now are trapped in this cycle where if it's not regulatory, bureaucratic and high tax, it doesn't count. I would like to see us go to a real market in which we accelerate the incentive to get rid of carbon. ...

Let me talk about another part of the Luntz memo that also happens in the mid-90s. And he writes: "The scientific debate is closing against us, but it's not yet closed. There's still a window of opportunity to challenge the science." There were Republicans who did challenge the [science] back then. Were you one of them?

Look, there are scientists who challenged the science. My conclusion is that you do not have to agree with the most hysterical interpretations to agree that, as a matter of prudence, we should minimize carbon loading of the atmosphere. ...

Were you saying that in 1995?

Yes -- I mean, I say it today. There's a big difference between long-term climatology and the weather, and the fact is that there are many things that happen that change climates. The Gulf Stream quit 11,000 years ago for 600 years. ... Nobody fully understands why it started again. Now, if you can't explain something the scale of the Gulf Stream, don't come and tell me that you have a computer model that says that in 2073, there will be .705 change [in temperature]. It's just not true.

A lot of what you see currently is science as collective anthropology: signatures on things by people who have degrees in science, but they don't have degrees in climatology.

[There was at that time] a group of scientists who get to be known as the science skeptics: the same four or five people who speak against global warming. And there's a connection between what Luntz writes and a campaign to discredit the science at the time.

That could be. I don't know.

There was a lot of it in the papers, and by 1995, when the first U.N. panel comes out, 2,000 international scientists, many of them Americans [were saying global warming is a problem]. In '95, were you onboard with --

Well, first of all, look: The whole idea of a U.N. panel of 2,000 scientists is anti-science. I mean, it's politics; it's not science.

Why is that?

Because science is Darwin writing a single book by himself, explaining a theory, and then the scientific world debating that. The fact is that before Max Planck proposed quantum mechanics, most physicists didn't believe it was true. When [Albert] Einstein produced [his theory of] relativity, most physicists didn't think it was true. The greatest English physicist of the 19th century, Ernest Rutherford, went to his grave believing that Planck and Einstein were nuts.

If you read [Thomas] Kuhn's The Structure of Scientific Revolutions, the older generation usually believes whatever it learned; you bring them new knowledge, they may or may not believe it. So if you say to me we've had this huge meeting and all these guys voted, my question will be, OK, and was it true? Yes, they got a vote. Was it true, or is it, in fact, politically correct? ... It's very anti-scientific to have science popularity contests. That's anthropology and politics; that's not science.

In 2000, candidate George Bush pledged mandatory carbon caps; it was a campaign pledge. What did you think of it at the time? Were you for that?

I think if you have mandatory carbon caps combined with a trading system, much like we did with sulfur, and if you have a tax-incentive program for investing in the solutions, that there's a package there that's very, very good. And frankly, it's something I would strongly support.

And did you, at the time, in 2000?

At the time I wasn't directly involved in the campaign.

He reversed that campaign pledge within months of taking office. Would we be in better shape today if he had kept that campaign pledge?

If he had instituted a regime that combined three things I just said -- mandatory caps, a trading system inside the caps, as we have with clean air, and a tax incentive to be able to invest in the new technology and to be able to produce the new technology -- I think we would be much better off than we are in the current situation. ...

The CAFE [Corporate Average Fuel Economy] system for automobiles hasn't worked. Everybody cheats and gets around it. The caps, with a trading system, on sulfur has worked brilliantly because it has brought free-market attitudes, entrepreneurship and technology and made it very profitable to have less sulfur. So people said, "Wow, it's worth my time and effort."

Americans get incentives. Americans like winning. ... What we ought to be doing is inventing a whole series of breakthrough mechanisms that create incentives for people to have a better environmental outcome in an economically positive way, to accelerate the transition to better and cleaner technologies. If Bush had led that effort in 2001, or if somebody will lead that effort in 2007, we will get much further down the road than we're going to get with litigation and regulation. ...

We've had three administrations: one early, and maybe not technology there yet; a second administration that reportedly knew everything about global warming; and now we've got another administration that has been saying all along that it's not a problem. Why do you think we have had three administrations who have not been able to deal with this issue on the federal level?

Because the left insists on pain, and the right insists on avoidance, and you've had no real leadership that says there's a positive, economically rational, science-and-technology way to solve this that makes your life better, not worse, and gives you more options, not fewer. ...

Is it because there are institutional impediments? I'm talking the oil and gas lobbies.

No, I think it's intellectual. I think that we're right at a tipping point where you could begin to imagine the development of an entirely new generation of systems; where you had a combination of a carbon cap with a trading system; you had prizes for the invention of major breakthroughs; you had incentives for investing in the new breakthroughs and accelerating their use and their development. And you could imagine a world 15 years from now that is dramatically greener than the world we're currently in.

But what you have is: People on the right know they're against regulation, and they're against taxation, and they're against bigger government, so they don't want to think about it because the only answers they ever see are things they hate. People on the left know the environment's important, but their answers are all regulation, taxation and litigation. So you're caught in this gridlock.

The average American, in fact, wants a healthy environment, but they also want a healthy economy. And the average American would like their political leadership to figure out a solution which is economically rational, environmentally favorable, and which leads to the creation of a better future using better science and technology to give them more choices and a higher quality of living.