Mr. EHLERS. Thank you, Mr. Chairman.

Mr. ROHRABACHER. Thank you, Mr. Ehlers.

And now we will have, Ms. Rivers will be able to ask whatever questions she would like and you have your five minutes, Ms. Riv

ers.

Ms. RIVERS. Thank you.

I guess I want to start out by putting my own biases on the table because in my district, I have a large scientific community in the west side of the district that may have views on this that probably will differ from people on the east side of my district where there are 16 automobile plants, and they are very concerned about possible outcomes.

So my desire, in this debate, and in ultimate decisions of this body, is to make sure we are moving forward to understanding this situation and making reasonable policy decisions. So I do not have a particular interest in a particular outcome.

One of things I wanted to ask Mr. Guerrero, you know, we may not all of us here understand the first law of thermodynamics, but thanks to polling that we use regularly, we understand the idea of plus or minus so many percents.

And it is interesting to me that often times in this area, when uncertainties get discussed, they get discussed in only one direction. That any uncertainty must be resolved in the direction that we are projecting too much.

Is there any possibility that the uncertainties can be resolved in the opposite direction, that we may be projecting too little change or too few consequences?

Dr. MAHLMAN. May I speak to that?

Ms. RIVERS. Please.

Dr. MAHLMAN. I think the question you have raised is absolutely fundamental, and that as a person who is interested in how mother nature works, rather than to make a political point of one kind or another, I do not care which way our knowledge is uncertain. I am trying to find out what the truth is. Okay?

And when you have made your best estimate of the way things are, it automatically says that you do not know whether you are wrong on the high side or the low side.

There are many, many examples of both kinds of uncertainties giving a lower number than you expected or a higher number than you expected. Okay?

And I would say uncertainty knows no politics, it just is.

Ms. RIVERS. Thank you.

Mr. GUERRERO. To reply to your question, I would say that that degree of uncertainty is expressed in the range. When scientists talk about a global surface temperature range by the year 2050 of one to 3.5 degrees Fahrenheit embodied in that range is the sense that it could be on this side, it could be on the low side or on the high side.

And fundamentally what affects that are key assumptions such as our inability to model successfully cloud formation and cloud feedback processes which influence a lot of that range.

Ms. RIVERS. Okay. You raised concerns, Mr. Guerrero, in the difficulty of the computer models or the difficulty, given our level of

ignorance, we are trying to create these models, and I understand that frustration and I see it across all of the literature.

The question that I have is, if we continue, is there an expectation that the models will get better over time? In other words, if we maintain the research, are we likely to just stay stagnant or are we likely to improve our ability to do the forecasting?

Mr. GUERRERO. There is no doubt that as we continue to learn more about climate systems processes and to increase our computer capacity, we will be able to have a better predictive capability.

Ms. RIVERS. And if we make funding changes so that there is less opportunity to do the modeling, less opportunity to do the research, will that move us forward in terms of our understanding or production of efficient models?

Mr. GUERRERO. I do not want to get into a debate over how much to fund these activities. I would simply observe that there are some of those activities that are more critical than others.

And what I would say is important, however. Much resources are allocated to funding, that they be allocated to the areas where there is the highest potential payback in resolving the current uncertainties.

Ms. RIVERS. Dr. Mahlman, I have a question I made in my notes last night when I was reading my materials. The whole issue of aerosols and the impact they play, aerosols are sulfur dioxide, right?

Dr. MAHLMAN. Yes.

Ms. RIVERS. So talk to me a little, I mean, it is presented as— here is an antidote to what is happening sometimes is the aerosol. My question is, both sulfur dioxide and CO2 have effects in our atmosphere, what is their comparative life span in the atmosphere? Dr. MAHLMAN. Okay, I would be pleased to speak to that.

First, the presence of sulfate aerosols, which are caused by oxidizing of sulfur dioxide, do exert a cooling effect on the planet. We do not know how much. That is a very important point.

This is the point I disagreed with Dr. Michaels in that I think we do not know how to quantify that very well.

But what we do know is that the sulfate aerosols are a result of sulfur being released from burning of fossil fuels. Okay?

Now the thing that makes this interesting is that if you are looking at today's record, sulfate aerosols are producing a cooling offset. And this is a hard concept to get across. But the lifetime of sulfate aerosols in the atmosphere is roughly one week. The lifetime of CO2 molecule is roughly hundreds of years. Okay?

And what that means is that aerosols are not increasing as you keep burning at the same rate, but CO2 keeps increasing. So if you look for very long times in the future, with constant emissions of burning of fossil fuels, the aerosol effect gets less and less because it does not keep increasing.

Ms. RIVERS. How do we know that the aerosol is not I mean, how do we know it is counteracting? I mean is there also a possibility it is masking the real problems here?

Dr. MAHLMAN. That perhaps is a theological question that I cannot get at. But the simple truth is that you add aerosols to the atmosphere, it has a tendency to cool the atmosphere.

Okay, you add carbon dioxide, it has a tendency to heat the atmosphere.

Mr. ROHRABACHER. You have time for one more question.

Dr. MICHAELS. I would like to follow onto that, if I could.

Dr. Mahlman's correct. The residence time of aerosols is on the order of days in the atmosphere.

That leads us to a very interesting problem. I just happen to have this planet down here.

[Laughter.]

Ms. RIVERS. I saw this on MTV.

[Laughter.]

Dr. MICHAELS. Hopefully, I can do a little better. All the aerosols are produced in the northern hemisphere. There is very little industry that produces the aerosol in the southern hemisphere.

And the amount of air that exchanges between the northern and the southern half of the planet is very, very low. It is a relatively small percent. So that the southern hemisphere is virtually sulfate free.

Now there is a paper in the literature you might want to take a look at, in the Journal of Technology from awhile back, because it tested the hypothesis whether the climate models that do not have aerosol in them-and please follow me-fail worse where the aerosol is and do better where there is no aerosol, a reasonable test, wouldn't you think?

Well, in fact the match-up of observed patterns of climate over the last 50 years in the southern hemisphere in the non-aerosol climate models is zero.

The point that I am trying to make to you, aerosols may have some effect. I believe they do, particularly in the northern hemisphere, but they are not a sufficient cause-please listen-they are not a sufficient cause to explain the difference between the projected and the observed warming, which is why I needed that high latitude data.

Ms. RIVERS. I want to ask Dr. Mahlman to respond.

Before I do, I support you in your need for that data, and I do not think this body would be diminished in any way to send a letter requesting that information. I think if we are going to build global policy on science of individual scientists, we need to have access to that, and I agree with that.

Mr. ROHRABACHER. Thank you, Ms. Rivers. And if you have one more question, go ahead, but we do have

Ms. RIVERS. I wanted Dr. Mahlman to respond to what Dr. Michaels just said.

Dr. MAHLMAN. Well, I happen to be a strong advocate of serious diagnostic research on what I will call the attribution question, which Dr. Michaels just spoke to.

Namely, how do you use the current data to evaluate the credibility or lack of thereof of theoretical or empirical predictions?

What we recognize is that there are many, many aspects of the climate system that vary naturally on regional scales on time scales of decades. And a good climate model is one that simulates not only the mean but its variability reasonably well.

Models do a fairly decent job of that, not wonderful, but a pretty decent job. And what you find is when you weigh in that natural

variability that you cannot quantify, the quest that Dr. Michaels is talking about, of trying to figure all this out and match the socalled fingerprint match of-are these changes consistent with greenhouse warming?-is an extraordinarily difficult scientific diagnostic problem.

And I think Dr. Michaels and I would both agree on that.

Dr. MICHAELS. Yes. The problem is that you do not see the match where the aerosols are not.

At 4:00 o'clock today, I am going to be giving a seminar down in Charlottesville on this, and I would like you to come. I will give you a ride.

Ms. RIVERS. I would love to come, but I do not think they are going to let me leave here.

Dr. MICHAELS. Too bad.

Ms. RIVERS. No matter how much I would like to.

Mr. ROHRABACHER. I wonder if this hearing will be over by then. [Laughter.]

Mr. ROHRABACHER. I appreciate that, Ms. Rivers.

Now we have been joined by the distinguished former chairman of the full Committee, who has my admiration, as Chairman of this Subcommittee, the way he handled the full Committee and has treated everyone as fairly over the years as anyone possibly could in this body. And so I would like to give him the opportunity now to ask any questions and make any statement that he would like to make.

Mr. BROWN. Your generous comments leads me to pass, Mr. Chairman, so that we can not be here at 4:00 o'clock, and go on to the next panel. Thank you very much.

[The prepared statement of Congressman Brown follows:]

PREPARED STATEMENT OF HON. GEORGE E. BROWN, JR., A REPRESENTATIVE IN CONGRESS FROM THE STATE OF CALIFORNIA

I believe this hearing will serve to point out the error in judgment made by this Committee in passing authorization bills earlier this year containing disproportionate, damaging cuts to global change research programs. Cuts to these programs will perpetuate limitations in our understanding of the earth's climate system. In the absence of real information people will be encouraged to substitute hand-waving and conjecture for substantive scientific inquiry into the phenomena that shape earth's climate. Cutting these programs will not stop carbon dioxide from increasing in the atmosphere or terminate interest in speculating on its effects.

It appears to me the budgets for climate research and climate change impact_research have been systematically targeted for deep cuts by this Committee. The budgets for global climate change research at EPA, NASA, NOAA, and DOE have been cut by over one quarter from the FY 95 funding levels. Budgets for research and development of technologies that would assist our nation in conserving energy and expanding our energy options have been cut by almost half from their FY 95 levels. This is short-sighted and foolish.

I believe we are all reluctant to advocate for radical changes that would alter our economy and our way of life without reliable information that such changes are indeed necessary. However, hesitation to embark on a difficult policy path is not a rational explanation for scaling back the global climate change research programs on the scale recommended by this Committee. I cannot understand anyone embracing ignorance in the face of a potential problem of this magnitude. I cannot understand why we should not pursue research which will provide explanations about how this planet functions. If climate change is real, then we will need to understand how it will affect us and what our options will be for adapting to any negative consequences or exploiting positive ones. If climate change is NOT real, then the research being done by these agencies will confirm that for us. Although there are scientists who question the severity of climate change impacts and the reliability of

global climate models, it does not appear that any are advocating an end to the research programs.

If climate is going to change in a way that will alter the future habitability of parts of this country of affect our food supply, we would be better off to find out sooner rather than later. If there are cost-effective steps that we can take now which provide benefits to our society in terms of energy efficiency, pollution reduction, and job creation then we should take them.

I am confident that the witnesses here today will all agree on the need for a better understanding of our climate system even if they disagree on the precise nature of climate change, the magnitude of its impacts, or on recommendation of policy options that we should pursue.

Mr. ROHRABACHER. We have now-is it Mr. Doyle or Mr. Minge? Mr. Minge.

Mr. MINGE. I just have a couple of quicker questions.

I noted with some interest that the NOAA budget had provided for a high performance computing system to improve global modeling.

How important is that to try and acquire the additional information that is needed to answer some of the uncertainties that have been discussed, and I direct this to you, Dr. Mahlman. Dr. MAHLMAN. I appreciate the opportunity.

I am a direct beneficiary and recipient of some of that High Performance Computing & Communications funds. We procured a new supercomputer system in August of this year, in response to that initiative that was funded for NOAA. It was competitively bid and competitively procured.

And what that additional increment of commitment on part of the HPCC program, plus the funds we already had for supercomputing, has allowed us over the next three years to increase our computer power by a factor of 17 because of the fierce competitive bidding that that process allowed.

We are now attacking aspects of climate problems, particularly with respect to local dynamics of clouds, that would have been inconceivable without that. And I am personally grateful to Congress and to the system that allowed this very, very difficult process to proceed.

Mr. MINGE. Is your purchase of that computer now at risk because of diminished funding, or will you be able to follow through and complete the purchase of that unit?

Dr. MAHLMAN. The commitment has been made, the first payment has been made, and if the House and Senate marks for HPCC for NOAA are sustained, then there will be no problem. Mr. MINGE. Okay. And the appropriations level is adequate? Dr. MAHLMAN. Yes, indeed.

Mr. MINGE. All right.

If this modeling can in fact be done, to try to improve our understanding of global climate and changes, how long do you think it will take before we have sorted out some of the differences that have been discussed here, such as the aerosol effect and so on that lead to some of the uncertainties?

Dr. MAHLMAN. I think that the harsh truth is is that aspects of the cloud and aerosol problem are very intellectually stubborn problems. Okay?

It would be dishonest for me to say that, "Give us this amount of money or give us ten times as much computing power, and we will solve this two years from now."