Now, the trouble with these things is people do their addition differently because greenhouse gases overlap in their spectral properties. You can do another experiment, take away all the water vapor, and you are left with about 30 percent of

Dr. MACCRACKEN. Is that at the surface?

Dr. LINDZEN. Yes, surface flux.

Dr. MACCRACKEN. You are making an argument at the surface which isn't where you want to make the argument, though.

Dr. LINDZEN. It is where you want to make it for the surface heat budget. That is where you want to make it.

Dr. SCHNEIDER. You want to make it from the surface troposphere

Dr. LINDZEN. No. I'll tell you why.

Dr. MACCRACKEN. We will have our debate about that later.
The CHAIRMAN. What I am getting at is are we

Dr. LINDZEN. That is the point. We have done calculations where we, for other reasons, increased CO2 20 times, and we actually expected a profound effect. We found even then water vapor swamped the whole behavior of the system. There are reasons for it, and they don't add up. You can't linearly add them.

The CHAIRMAN. There are just a lot of unanswered questions, of course, in this.

Dr. LINDZEN. No. It is not an unanswered question. You take CO2 out of the system. You are still left with 98 percent of the greenhouse effect.

Dr. WATSON. But that isn't the relevant issue per se. Water vapor is the dominant greenhouse effect. There is no question. What we are doing is changing the other gases and we are changing them significantly enough. They are changed in the radiative balance.

An analogy in ozone would be chlorine is not the dominant gas that controls ozone. It is nitrogen, hydrogen, and oxygen. Yet, our additions of chlorine to the atmosphere have caused a major loss of ozone that is well recognized throughout the scientific and policy community.

So, it is what are we perturbing. We are perturbing greenhouse gases enough that they will change the radiative balance. The key question is how does that relate to surface climate.

Dr. SCHNEIDER. Senator, let me try to clarify that quickly. The current earth is something like about 33 degrees Celsius, 60 degrees Fahrenheit, warmer thanks to the natural greenhouse effect, which is our friend. You read about people saying the greenhouse effect is a menace. The natural greenhouse effect is, in fact, responsible for the evolution of life as we have it. So, it is a good friend. The problem is if you took all the CO2 out of the system, would that 33 degrees C drop by some, and I would guess it would drop to 30 or 28. Others may argue it would drop to 31. The question is if we now add enough CO2 to double it, are we going to go up from 33 to 36, or are we going to go up 34? Are we going to go to 38? That is what the debate is. Then we add other greenhouse gases on top of it. It is that incremental change that counts, and then you compare the magnitude of that incremental change to the magnitude of natural changes between, say, ice ages and interglacials, and

when those magnitudes become comparable, that is when people get concerned.

The CHAIRMAN. Now, I think it was Dr. MacCracken who said that would have to cut back fossil fuels by 80 percent in order to stabilize the CO2 in the atmosphere. Is everyone agreed on that? Dr. MACCRACKEN. 60 to 80.

Dr. LINDZEN. Yes. I think there would be general agreement. Stabilizing emissions does not stabilize atmospheric CO2. If you wanted to stabilize atmospheric CO2, you would have to cut back emissions. How much you cut it back depends on your model for carbon dioxide, and it can vary from 20 to 80 percent.

Dr. WATSON. I would say it would have to be greater than 50 percent in carbon dioxide, and 10 to 20 percent in methane, and probably 60 to 80 percent in nitrous oxide. So, for nitrous oxide and CO2, long-lived gases, you need very substantial global cutbacks. For a short-lived gas, like methane, only a 10-year lifetime, probably a 10 or 20 percent cutback would be adequate.

The CHAIRMAN. So, would you say basically without a revolution in lifestyle and economy and laws and without revolutionary type activity, it would be very difficult for us to affect this problem other than at the margins? Does that follow?

Dr. MACCRACKEN. I don't think that is necessarily a way to think about it. If you try and replace the global fossil fuel system by some single energy source, nuclear or solar power satellites, then it is really a very difficult problem to approach. If instead you try and approach it in each region and look at what the region should do, I think you have a much better chance. If you look in the wet tropical regions, you have the potential for hydropower and for biomass to do much more. You also can stop deforestation and help in that area. In the dry subtropics, you have the potential for photovoltaic and for wind power. You are not far off from being economic in that regard. In this country you have a lot of opportunities for conservation and efficiency and natural gas and nuclear and some biomass.

Probably the most challenging countries are China and India which are looking toward inexpensive coal as the way to go, and there a very important step is to work very hard on efficiency.

I think if you think you are going to solve it by just taking one action in this energy area, that's mistaken. What you want to do is

The CHAIRMAN. Well, S. 2166, the National Energy Security Act you can call that one action.

Dr. MACCRACKEN [continuing]. Take a lot of different ones. The CHAIRMAN. S. 2166 is the bill that came out this committee. Dr. SCHNEIDER. Senator, without getting into the specific whole range of policy options, of which we all have opinions, just again a perspective on this question. Can we stop greenhouse gases from building up in the next, say, 50 years? I doubt it without what people would call draconian action like 50 or greater percent cuts in CO2.

But I don't dismiss a 20 percent cut, for example, because as I had said earlier, what has me personally most worried about this problem is not the absolute magnitude of change, but the rate of change because it is the rate of change that is difficult to adjust to

because if you have time and you know what is going to happen, then you can adapt better, although ecosystems have more difficulty adapting because they can't plan as we can. But the key is slowing down the rate of change is a worthwhile thing in the sense that it takes the pressure off nature; at the same time, it buys us time to adapt. So, if we were to have 2 degrees warming instead of 4 and it were to be 100 years instead of 50, or whatever numbers you like, I would not be in despair over that. I think we can't prevent some preventable difficulty, but I think that making differences on that magnitude could be very significant. And we can also turn the heat up or down, depending upon what scientific findings suggest on both impacts and on the physical and biological science over the next several decades. So, I would not be deterred simply because we can't do it all at once.

The CHAIRMAN. Let me ask one final question and, Dr. MacCracken, I will put it to you and anybody else can join in if they wish. Can you give us any guide to get through the ideological fog on this issue?

I mean I look at this issue I think dispassionately, maybe not in the view of some people, but I see on both sides of this issue strong ideology. I see the interest-well, let's call them the energy interests, the economic interests. They want to burn fossil fuels. They want the economy to grow. They claim they want jobs. They don't want taxes, et cetera.

I look at the other side and I see those who have agendas which happen to match the greenhouse effect agenda. Some environmentalists who don't want growth, who don't want to burn fossil fuels, who want a transfer of wealth from the northern hemisphere to the southern hemisphere, who want carbon taxes, a long agenda. We see that on both sides. It is very clear to identify both groups. That does not mean to say who is right or who is wrong.

Do you have any guide as to how we can cut through that fog? Dr. MACCRACKEN. It is a very challenging question. [Laughter.]

Dr. MACCRACKEN. I think, as I commented, the first part is to try and look at each aspect of the issue separately; that is, to look at the scientific aspect first, the chemical and climatic change, and ask those scientists who are debating it so much, as it seems in the media, get together and work on synthesizing and integrating their statements. That is not happening much in the United States. I was on a National Academy panel that was supposed to try and do that, but that was 10 or 12 of us trying to do it on a few days in a whole year. You didn't have time. There is just not enough effort going into synthesizing.

I think with respect to impacts, there is very little research going into the impacts area. It is a very tough area. You have to keep trying at it. It is easier to build a satellite and take a measurement than it is to try and figure out ecological impacts. It would help to look at impacts.

I might just mention that, for example, DOE supports at congressional urging the National Institute for Global Environmental Change in these regional centers. I think what would have been most productive for them to focus on was regional impacts rather than trying to get in at the chemical and climatic aspects on a

global basis, so that the ones in the south are looking at sea level rise along the gulf coast, and the one in California is looking at water resources. That is not really happening, but I think it would have been beneficial. So, more on impacts.

I think that one of the solutions out of this in response is to make sure you build resiliency and flexibility and so you have a set of energy options. Quite frankly, I don't think sort of saying, well, we are going to cut emissions by some fractional percentage and do it by a tax is necessarily going to get you where you want to go, that you might be wanting much more strongly to be investing in building better energy options. If you can get photovoltaics so it is cost effective instead of a factor of 2 or 3 above that, that is going to be a major achievement. Wind power is almost cost effective and is doing much better. If you can focus on biofuels. There are a lot of things you can do to make those options cost effective. That is going to help build products for this country to sell. It is going to help this whole issue. I think that is perhaps the best way to work through it.

Dr. WATSON. Yes. I think that could be summarized to say if industry would stop looking at this as a threat to the economy, as an opportunity for expansion, then I think we would make significant progress. There is no question. There is significant progress going on, especially in developing countries on using sustainable biomass, micro-hydropower, winds, photovoltaics, and it really is starting to look like the opportunities are there. Those industries that start to recognize those opportunities-and they are being recognized by Japan investing heavily in these developing countries-then we will turn this from a threat to the economy to an opportunity in the economy.

The CHAIRMAN. Why do those who are most concerned about global warming, though, reject nuclear energy and never mention that?

Dr. LINDZEN. May I answer your first question? I think there is a criterion for separating out agendas from reality. I think one should ask about any proposed change or any proposed resistance to change, what its impact is on warming. Many of the proposed changes and I think what Mike MacCracken said is completely consistent with that-serve an agenda perfectly fine, but have no impact on our expectation of warming regardless of model. Those are clearly politically driven. If a suggestion, like reducing emissions profoundly is made, that at least has the virtue that regardless of model, that will have an impact on what anyone expects. By that criterion, most suggestions are political.

Now, the business of why people are anti-nuclear and yet against warming and so on. That fits into your picture. Does it have to do with warming, or does it have to do with something else? And usually you find it does not pass that test.

The CHAIRMAN. Let's give Dr. MacCracken the last word on that issue. I'm taking too much time.

Dr. MACCRACKEN. I think there is a sense among people that they can have a lifestyle with absolutely no risk. When you have 6 billion people almost on the planet, you can't not have an impact. With respect to options, I think people have to realize there is no such thing as a free lunch. There are better and worse lunches and

there are costly and less costly lunches, but there is no such thing as a free lunch. People have to realize they are going to have some impact and are trying right now to avoid all possible risk. We have to educate them that that can't happen.

The CHAIRMAN. Well said.

Senator Wallop.

Senator WALLOP. Mr. Chairman, the work that was cited in the Marshall report I think was probably that done by the two Danish scientists from the Danish Meteorological Institute that appeared in Science. Am I to understand that today's panel uniformly rejects that work and their stated correlation?

Dr. WATSON. Well, it is an interesting correlation between length of solar cycle and temperature record, but they and no one else has managed to put a physical mechanism by which you can relate length of solar cycle to a change of an adequate magnitude in radiative force and, hence, temperature. So, the basic point is that they themselves were at IPCC and they agreed to the very soft statement in IPCC that while it was an interesting correlation, it did not lead you to an understanding.

Senator WALLOP. Well, before I let Dr. Lindzen comment on it, does that mean that it is wrong?

Dr. LINDZEN. Look, there is a long history of functions where you have two peaks and another thing with two peaks looking like they are going together. Everyone in science has seen dozens of cases where people got burned on these relations. My favorite, which I found at NASA, was the correlation from 1965 to the present between sun spot number and Republicans in the Senate. [Laughter.]

Dr. LINDZEN. I mean, what do you do with that?

Senator WALLOP. Tell me about that.

[Laughter.]

Dr. LINDZEN. The thing about it is we are used to seeing it.

I have a feeling when Mr. Johnston presented the ice core data, that we are a society who don't, by and large, know how to read graphs, and we use graphs to show them to people so they will be impressed that we have a graph. But we hope to God they don't look at what they say.

The graph you had, for instance, had the peculiar feature, carbon dioxide hanging around at very high values for thousands of years while the climate plummeted into a cold period. Anyone looking at that would be hard-pressed to know what that showed except that maybe temperature doesn't follow CO2.

Senator WALLOP. Dr. Schneider, I don't want to paraphrase your recommendation. I wish you would do it again. Basically what I understood you to say is that we should do those things which make the most economic sense first and then move on. Is that a fair characterization?

Dr. SCHNEIDER. Yes, that is.

Senator WALLOP. Isn't that, in effect, what the administration is doing with its position on the global climate change treaty?

I think, Dr. MacCracken, that you said more or less the same thing, that we ought to do those things which make the most sense in the region of the world in which they take place.