Workshop on Global Climate Change - John Deutch, John Sununu, guests - Sloan School

[MUSIC PLAYING]

DEUTCH: The purpose of this workshop is really quite simple. It Was to gather together for a one day session a group of people who have been thinking about the issues of global climate change from a variety of points of view, tackle scientific issues, economic environmental effects, and what some of the policy issues are facing the United States both domestically and in the international arena.

The idea of the workshop came, I guess, in last November when John Sununu and I were at a gathering in Washington. And we were talking about whether there was, in fact, a common view-- not an exact and precise view, but a consensus-- on what some of these issues were among those people in government and outside of government who had been diverting attention to this question. And we allowed-- I guess both of us felt that there was an opportunity for everybody to become better informed by spending a day looking at these issues.

It's especially timely with the international activities going on in this and the meeting coming up in Brazil in June. And so we put together this one day session. And I'm really very pleased and delighted that all of you have managed to attend.

Let me make a remark about how the day will go. We have divided it into three sections. The first will be the technical session, where we will have brief presentations-- 15 or 20 minutes-- from Gordon MacDonald and Ron Prinn on what some of the technical issues are. We'll then proceed to spend about an hour of time discussing this from whatever perspective points of view is of interest to the group.

Second session will deal with economics and environmental effects. We will hear from Bill Nordhaus and Bob Frye. We'll then go right across the way to have lunch at the faculty club. And the last session in the afternoon will be on policy matters with Jake Jacoby of MIT, focusing on domestic issues and Richard Cooper focusing on international matters.

It is my firm intention to conclude the day at 4:00 PM because I have arranged for John Sununu and possibly a couple of others of us to go over and talk with some students. And I hope that that will be more or less convenient for those of you who have travel plans.

Let me also say that I decided some months back to have this session recorded in its entirety. I did that for principally one reason-- in the hopes that there might be some educational value to the session that we're having here and that the tapes would be available to any and all members of the public who care to find out what enormous pearls of wisdom were scattered among us. So the tapes will be available to anybody who wants them through MIT-- the Center for Advanced Engineering Studies, which is for the people who put this together.

I should also say that I was very pleased that the modest amount of cost to put this conference together was provided by the Sloan Foundation. And I do want to thank them for, once again, providing me and this institution with some support.

I don't know whether you want to make any remarks, John, at this stage of the game. Do you have anything you'd like to say?

SUNUNU: Just a couple. Even in phasing out from the White House, I have to keep the lawyers happy. Therefore I have to tell you that everything I express today is my own personal view--

[LAUGHTER]

--and not the view of the administration. I certainly can speak historically from the point of view of one who make policy historically. But I must say I am very fortunate that, in the last couple of weeks I'm there, I'm not involved in making policy on this issue. And I think that will keep the lawyers happy.

But beyond that I want to thank all of you for accepting the invitation to be a part of this. It is an important issue. It is an issue that is not easy to deal with, even when we are having discussions amongst those who understand it well.

Therefore, there is an added obligation since there are those who don't understand it at all who will be making policy on it based on issues that are developed in the realities of the analysis. I hope it's the realities of analysis that flows from both the technical side, the scientific side, and as well as the economic side.

And what, under other conditions, might have made for interesting academic lunchtime discussions are now leading to interesting significant-- I think that it is not an exaggeration to say trillion dollar decisions. Over the long haul, it will be based on a perception of what the issues associated with global climate change are. And therefore, it adds a little bit to the obligation to try and hone this down as well as possible and as rapidly as possible.

I just-- I will confess to a bias. And I'm sure that it has been apparent in some of the comments printed in the press. But I can assure you the press never reflects reality. And therefore, let me give it to you first hand.

I am very concerned that there is a rush to judgment. I have no idea which direction the rush to judgment really is in. But it always bothers me when there is a haste to make policy. It means that people have an uncertainty in their position that they are afraid will be clarified over time in a direction that is not favorable to their perspective.

I can tell you this administration has committed well over a billion dollars a year in trying to fund the clarification of the nuances of this issue. It is in recognition that it is a trillion dollar decision that a billion dollars a year for analysis model improvement data collection is not an unreasonable sum to request and, in fact, was received.

And I can tell you that having talked to the president about this issue specifically, he is committed to a long term funding and is willing to take action. I think the action the administration took in '89 on ozone was real and a reflection that when the data and the conclusions are relatively clear, it will move. But I think it is incumbent on the technical community to try and help sort out the differences.

I have two examples in my mind that are always the nightmare examples of public policy. And fortunately, they did not get acted on, even though there was a momentum established. One is the global cooling phenomena that a comet was supposed to produce. And the other was the Club of Rome-- the world is going to end tomorrow scenario, no matter what you do.

And both of those, I think, are excellent examples of at least some constituencies out there who constantly seem to be looking for calamitous surrogates to creating anti-growth, anti-dynamic investment policies. And the impact on billions of people in terms of their standard of living and quality of life that decisions of that kind can make has got to be put on the ledger someplace.

And it is incumbent then that analysis of the structure of response to complicated systems such as climate be looked at as more than just involvement by people who are good and interested in that area and be recognized to have to be presented at all times within the limitations of the assumptions and the certainty or the lack of certainty that the conclusions have.

And there is no question that we are dealing with a multiplicity of constituencies. We are dealing with a press that has a bias and a perspective in one direction. They always will. It is part of the process of selling papers.

No change does not sell papers. Tranquility does not sell papers. And that is real. And there is no way to cope with it.

There is a political constituency around the world that in parliamentary structures carries a non-linear capacity to influence policy. You look at the way parliamentary majorities are made around the world. The 3, 4, 5% of the political constituency that is defined by the Green Movement, which has a perspective and a viewpoint that is significant on this issue, has a non-linear impact on-- it is weighted well beyond their elected role in that structure.

And that is real. And I bring all this up because I think it defines the scope of responsibility that is involved in the discussions that will follow from what is evolving on this issue around the world.

I do feel that there is an opportunity to do well what scientists and engineers, technologists ought to do well. And that is define what they know and define what they don't know with a little bit more precision than perhaps they are usually accustomed to. And try and be active participants in the framing of this policy.

This policy will be framed in very specific terms in the next five years. There are those who would like it to be done in the next five days and those who would like it to be done in the next five decades. But I think it will be framed in the next five years in ways that will impact the next generation rather drastically.

And there will be derivatives to that policy that will be significant. And that's why I'm so pleased that you've all been willing to come down and help us, perhaps, create a framework under which that policy development can be done in a slightly more rational way than has been taking place over the last decade.

DEUTCH: Well, there's one thing I want to stress here. There is obviously, in this group, a wide variety of views on these issues. People will have an opportunity to express and discuss them as the day goes by.

I thought that maybe one thing which might be helpful is to just briefly go around the table, have everybody identify where they are from. Although many of us know each other, it is not universally true. And it might be helpful to just start with you, Lester, and go around the table and identification [INAUDIBLE].

LAVE: Lester Lave, an economist from Carnegie Mellon University.

MAYNARD: Nancy Maynard, Office of Science and Technology Policy.

WHITE: Bob White, President National Academy of Engineering.

AUSUBEL: Jesse Ausubel, the Rockefeller University.

JACOBY: Jake Jacoby from MIT.

HOGAN: Bill Hogan from the Kennedy School at Harvard.

SCHMALENSEE: Dick Schmalensee, an economist at MIT.

NIERENBERG: Bill Nierenberg, Scripps Institution, oceanography.

FRYE: Bob Frye, Resources for the Future.

YEAGER: Kurt Yeager, Electric Power Research Institute.

COOPER: Dick Cooper, Harvard University, economics.

LEVINE: Duane LeVine, Exxon Incorporation.

LEE: Tom Lee from MIT.

MACDONALD: Gordon MacDonald, University of California.

BRAS: Rafael Bras, MIT.

SUNUNU: John Sununu, still at the White House.

WASHINGTON: Warren Washington, the National Center for Atmospheric Research.

PRINN: Ron Prinn, MIT.

BROWN: Harold Brown, Johns Hopkins, Foreign Policy Institute.

BRADFORD: David Bradford, Council of Economic Advisers.

OPPENHEIMER: Michael Oppenheimer from the Environmental Defense Fund.

NORDHAUS: Bill Nordhaus, economics, Yale University.

DEUTCH: And you can now say, Dale.

JORGENSON: I'm Dale Jorgenson--

DEUTCH: Perfect.

JORGENSON: --University.

DEUTCH: Thank you very much. Well, with that, I think we should begin with the technical section. And I guess that my friend Gordon MacDonald is going to give us a bit of a orientation.

MACDONALD: Thank you, John.

SPEAKER: Televised for education.

MACDONALD: Let's do the smart [INAUDIBLE].

20 minutes or so to touch on four topics. One, the changing composition of the atmosphere-- what we know about it and what we don't. What we can learn from the observed temperature records that extend back a little over a century. Some comments on predictability of climate-- what is meant by that. How well can you tell what the future holds.

And then end up on what I consider to be the most important and also a very neglected subject-- extreme events. And how does one try to get a handle on what might happen by and by extreme events. I mean, changes in the nature and intensity of storms, changes in the nature and frequency of droughts or floods and so forth.

Let's start off by reviewing briefly the story on carbon dioxide. This is, of course, familiar to all of you. The variation of carbon dioxide in terms of parts per million, as a function of time.

It's the closely spaced points that are of course Dave Keeling's observations. The points before that are taken from observations and composition of gases trapped in ice. A much greater scatter in those observations.

I go back to 1740. There are data that can extend the carbon dioxide concentration back to about 10,000 years with increasing scatter. But the points at 10,000 years would be around 280 parts per million.

Concentration of carbon dioxide was more or less constant for a very long period of time. And since the beginning of the Industrial Revolution, has increased. The current rate of increase is about a half a percent per year.

The same kind of story holds for methane. Here is a representation. It's a little different. This is going back in time.

A much greater scatter because of the difficulties in the instruments. But again, a very rapid rise over the last two centuries. For a number of years, the rise was about a percent a year. In the last five or six years, it seems to have increased to about 7/10 of a percent per year.

And quite importantly, you have similar variations and concentration of both these gases over much longer periods of time. The curve or the solid line links the observations made on carbon dioxide from bubbles that they are trapped in our core of ice taken in Vostock, Antarctica. This is the concentration of CO2 on the right-hand side, the concentration of methane on the left-hand side. The methane concentrations are even triangles or solid dots, depending where they're taken.

Now the point here is that in the previous glacial period, concentrations were low. Interglacial concentrations higher. Past glaciation was characterized by lower concentrations, both of methane and carbon dioxide. And then the present interglacial period-- high concentrations once again.

The association is close. The issue of cause and effect is open. I have argued that there is a [INAUDIBLE] mechanism that involved methane clathrates-- that is methane stored in compounds buried at shallow depths near the surface of the Earth and release due to warming. There are alternative hypothesis related to changes in ocean circulation.

But I think one can say, the correlation is close. The arguments as to whether it is a positive feedback or just a result of changing climate where the climate is changing for other reasons.

There is a further mystery with the changing composition of the atmosphere. And we can sum it up in a very few figures. Currently, as of 1990, we're putting about 6 billion tons of carbon into the atmosphere-- six gigatons of carbon. And you can multiply by whatever it is-- 44 with 12 to get CO2.

That comes from a mission of power plants, other industrial and transportation activities. That's probably an uncertainty of 5% to 10%.

SPEAKER: It's all man-made.

MACDONALD: That's all man-made. There's an additional 400 million tons of carbon that come from the oxidation of methane. So the total carbon input is 6.4. Now, some of that 4/10 of a gigaton due to methane is natural. Some of it is associated with man-made activities.

The observed increase of carbon dioxide in the atmosphere observed by measurements at Mauna Loa and around the globe corresponds to 3.8. The difference between 3.8 and 6.4 then go someplace. The best estimate for the ocean uptake, in my view, is 2 gigatons. This is a number also adopted by the Intergovernmental Panel on Climate Change, the international effort that is preceding the negotiations currently underway at Greenhouse Convention.

So 3.8 and 2 gives you 5.8. The difference between 5.8 and 6.4 probably is well within the uncertainty. But left out of these considerations is what happens in the biosphere. The best guess, according to IPCC, of the carbon introduced into the atmosphere as a result of deforestation is 1.6 but with a large uncertainty band.

And I've worked on some of those problems of going from satellite photograph and a few field observations. And I must say that those numbers-- that number is quite uncertain.

But that means if 1.6 is added, and there's already 6/10, another 2.2 gigatons of carbon must be taken up somewhere. And that is a current mystery. There are some people who would point to the northern temperate forest, say, regrowth is taking place there. And some of the carbon is being absorbed. Observations are just beginning to be made at various places to see if that uptake can be measured and at least some estimate be made. Currently, it's very much a problem.

Now let me turn to what we can say about temperatures.

[INAUDIBLE]

Sure.

SUNUNU: Isn't there a-- these are looked at as the components to the carbon flux into the atmosphere. It's from man-made. Isn't there a huge component of natural fluxes that are also there?

MACDONALD: There is a seasonal fluctuation. But you can see in-- I didn't bring the--

SUNUNU: I don't mean in the concentrations. I mean transfers into the atmosphere.

MACDONALD: During the growing season, carbon goes into plants.

SUNUNU: That's right.

MACDONALD: During the--

SUNUNU: And those numbers are huge.

MACDONALD: Those numbers-- let's see. The total seasonal flux-- it's about 5%.

SUNUNU: But you can average it out.

MACDONALD: You can average it out.

OPPENHEIMER: Isn't that 200 gigatons a year each way. But the point is that it's been-- we know it's been in balance because of the ice core measurements for 10,000 years. It's really finely balanced so that the 7 or 8 gigatons from human activity make a big difference because the system is so close [INAUDIBLE].

MACDONALD: These figures-- okay. You've got the appropriate view graph. There it is.

PRINN: Even those numbers on this is a bit foxy.

Photosynthesis exceeding respiration decay that occurs in the spring and summer pulls down the amount by 2%. And then that's given back at 2% in the fall and winter. But an additional important thing is since this record began in '57 to the present time, [INAUDIBLE]. Oscillation is growing. And that's odd.

One possible hypothesis put forward is that CO2 fertilizers-- photosynthesis in vegetation. And CO2 is rising and leading to this [INAUDIBLE]. But that's pure hypothesis.

MACDONALD: Yes, that's one of theirs when we were talking about the sink for carbon. The fertilization is one possible sink.

Now, let me turn to the observations on temperature. This is temperature versus time derived from reductions of observation, reduction carried forward at East Anglia in Britain. The technique is to take observations from the logical stations, from ships at sea, average them, in this case, over the globe and over the years. So these are global annual average temperatures as a function of time.

There's two other sets that have been reduced by a group in the Soviet Union. One by Jim Hansen, [INAUDIBLE] that have similar characteristics. There is one individual record, which I think has some validity. It goes back to 1680 central England put together by a man by the name of Manley, again, having many of the same features.

Now what can we learn about this graph that may guide us in looking ahead? I decompose it into three components. One, a linear trend. Two, a low frequency component. And three, a high frequency component.

The purpose of that is to start to feel our way towards what aspects of the atmosphere do we have a chance of predicting in the future-- Large changes. What might we do?

With the removal of a linear trend, you find that the residual values are indistinguishable from that of a normal distribution. That is that the values themselves are distributed as if they were normal, not only about the mean, but very importantly, in my view, in the extremes.

This curve is in time. The dotted curve is the expected range-- maximum minus minimum for a normal distribution. And the stepped curve is what you get out of the observations.

Now what do the-- let's say this is important curve. This is the power spectrum for that temperature curve once the linear trend has been removed. And the important thing is the very large amount of power contained within the low frequencies.

And you can see that the first dip in the power spectrum is at about 0.45 or 0.4 cycles per year-- 0.04 cycles per year for about 20 years-- 25 years. We see that in frequencies less than corresponding to [INAUDIBLE] is less than 10 years, 60% of the energies there, 60% of the variance.

Now let's filter that and see what the residual temperature looks like. This is the low frequency part of that curve. That is the dashed one. The solid curve is the same operation conducted on Hansen's record of global temperature.

These are the swings in temperature, having periods on the order of 20 years or longer. Now if you remove this part and the linear track, the residual record is white noise, indistinguishable from white noise. No correlation structure whatsoever. And therefore, any attempt to predict, you have the classical problem of predicting white noise.

Here, however, you have structure. My argument is, of course, that this represents slow motions in the ocean, that on a short term, when you're looking at weather forecasting, the coherent structures in the atmosphere lead to persistence. That is high pressure areas, low pressure areas give rise to persistence over periods of days or weeks.

There is no long term persistence in the atmosphere per se. That you have large coherent structures in the ocean that could give rise to persistence. And this persistence may provide, if one can obtain adequate models of the ocean, a guide to predictability.

The next one just shows the white noise after you've removed the low frequencies and the linear trend that really is, by any test, independent increments that give rise to a random walk-- classical random walks.

This strives makes another point. This now is the integrated spectrum for-- the global T is the East Anglia record. That's the observed temperature record. And you can see that for 10 years, 60% of the total variance is at frequencies longer than 10 years.

This is a model provided of the atmosphere run for 100 years on the community climate model one, where the ocean only interacts with the atmosphere through putting the seasonal fluctuation-- observed seasonal fluctuations in the ocean into the model. Therefore, it cannot represent changes in ocean circulation. And as you can see, it has very little energy at the lower frequencies.

The top is a much simplified ocean atmospheric model that captures much more of the energy in the lower frequencies than does the observed.

Out of these kinds of analysis, I think it becomes very clear that an emphasis in both observation and modeling should be placed on the ocean. It is the great region of uncertainty. It obviously controls the low frequencies. And we have to develop better schemes.

Warren Washington, of course, is one of the most active workers in that field. And Warren may wish to comment.

Now, let me turn to extreme events and argue by analogy. This is a busy chart. But I think you'll find it entertaining.

This is Venice.

SPEAKER: California?

[LAUGHTER]

MACDONALD: Starting at 580 AD more or less to the present, this is relative sea level where the gondolas come in and out over time. Part of it is due to actual changes in sea level. Part of it is due to the drop of land. As you can see, sea level has gone up almost 2 and 1/2 meters over this period of time.

The frequency of extreme events is shown by those solid lines at top. Those are the periods when there's heavy flooding. And when the sea level was low, of course, there were infrequent advance. A thin line is a single event.

As you come into the 19th century, you get the lines now are much heavier-- four amounts, three amounts. As you go into the 20th century, the lines now represent eight 25 events.

I mean, there's something magical about this. The sea level goes up. Relative sea level goes up. The frequency of flooding goes up.

You also see here what happens to the population. In those times in which there were heavy flooding, there were drops in population. Of two causes, it related that during the flooding sanitary conditions were very bad. You had plague. Even when plague wiped out, you see in this last period a very large drop in the population.

Then there are some wonderful things as far as the distribution of population. What I found incredible was around 1600, there were the female population, which numbered approximately 40,000, had 2,500 registered whores. And you can see that as a great trading center, Venice had a variety of forms of entertainment.

I think this is trying to make the point that as climate changed, the incidence of extreme events will also change-- either go up or down. Very, very little work has gone into this area. Yet it is those extreme events that have the biggest impact on economic and social conditions as seen clearly in these correlations. That's it.

DEUTCH: Thank you. Do we have any brief questions for Gordon? Or we ready to hear from Ron?

NIERENBERG: I do. Just one thing.

I, like a lot of oceanographers-- my colleague Walter Munk learned a good deal about the preservation of Venice, which is-- most of you are familiar with the severe problems involved. That last drop is, I thought, very well understood. Bill Nordhaus, somebody can correct me, was strictly due to economic changes-- that the young people just leaving in droves, and have been for the last 40 or 50 years, because of lack of employment. And they're going to the nearby coastal towns. Nothing to do with extreme events.

LINDZEN: Yeah. I mean, I don't doubt for a minute that as you stress something, extreme events become more likely. But that diagram is specious in the sense, first of all, as you correctly mentioned, sea level rise in Venice is not a marker of climate but a marker of construction on Venice. It's just like LaGuardia Airport. Its construction changed the sea level a foot and a half.

And then you pick extreme events associated with the population in the bay without referring to the fact that most of those occurred throughout Europe, where there was no such climatic or other environmental stress.

MACDONALD: Certainly the [? efflux ?] where plague was dominant is quite correct. There were-- in more recent times, those changes are not reflected in the rest of Europe. And as I pointed out, that is relative sea level-- a major component being the movement of sediment and of the land with an added component of the smaller added component of increase in sea level.

SUNUNU: Gordon, I would like ask a clarifying question about this amount of material-- carbon-- which is placed flux into the atmosphere due to the biosphere. That can be the biosphere. What is that amount of material placed in and the amount of material taken out?

MACDONALD: We couldn't--

SUNUNU: I'm not talking about-- that's a composition.

MACDONALD: No. This will give it to you quite clearly. What is this amplitude? That's-- it's about 8.

SPEAKER: It's 4, 4.

MACDONALD: 4?

SPEAKER: It goes down 2. Maximum is 4.

MACDONALD: Down 2 parts per million and up-- no, it's 1.

SPEAKER: The percent.

MACDONALD: No, I'm thinking of it as actual figures because I'm going to convert it to bigger times. So this is, let's say, 5.

SPEAKER: It's 10.

MACDONALD: The total lanes-- it's let's see, 11--

SPEAKER: It started out around 5.

MACDONALD: 5. Let's say 5. That's 5 times 2.12, which is what concentration converts to at the gigatons. So that's 11 gigatons of carbon.

SPEAKER: No. No. It's 200 gigatons of carbon.

MACDONALD: No.

SPEAKER: You direct the total annual flux.

MACDONALD: No. Sorry.

OPPENHEIMER: It's natural source-- the total annual flux is about 200 up and about 200 down. It's a seasonal variation in the balance, but it's about 200 up and 200 down.

SUNUNU: But then the annual flux is, as you say, 200 out, 200 in. And what we are talking about is a collection of phenomena that impose on what you want to call as the base case or mother nature's reference case or whatever you want to call it is 200 going up, 200 going down. And you're adding 3.8? Is that what you said?

MACDONALD: 3.8.

SUNUNU: OK. Net.

MACDONALD: That's net.

BROWN: That's a well taken point. But what you have to ask then is what's the difference between the about 200 up and 200.

SUNUNU: That's what he's saying. I'm not asking the question. I'm merely asking that we keep on the table the reality of 200 up and 200 down. And imposed on that is 3.8 as an argument.

MACDONALD: And imposed on that is a [INAUDIBLE]. What do you conclude on that?

SUNUNU: I haven't concluded anything. I just ask that you don't hide it in the back of the appendix and that you at least leave it on the front of the table for the policy makers to look at.

MACDONALD: And you observe about 11 gigaton shift in carbon from winter to summer.

SUNUNU: Does this change depending upon which hemisphere you're taking-- I mean, is it an out phase?

MACDONALD: Yes. This is in Hawaii. The amplitude-- in the northern hemisphere the amplitude increases as you go to the pole-- the amplitude of the seasonal fluctuation. At the south pole, the amplitude essentially vanishes.

BROWN: How much of a change is there between the beginning and the end of that chart in the size of that 200, which may be another thing. That'd be another thing to compare.

SUNUNU: Yeah, and we need that too. Right.

[INTERPOSING VOICES]

MACDONALD: 2 gigatons more in the seasonal amplitude.

SUNUNU: And 40 where?

SPEAKER: No use.

MACDONALD: 40 and 58 versus 90?

BROWN: The difference between the swing in 58 and 90 is how much?

SPEAKER: 20%.

BROWN: 20% of?

MACDONALD: 2 gigatons of carbon.

BROWN: Okay, so it's 2 compared with 4, essentially.

SUNUNU: Okay.

DEUTCH: Thank you.

SUNUNU: Can I ask one more question? Because this is-- and maybe you can solve what has been a fundamental intuitive problem I've had with the modeling structures. And it has to do with some data you put up there. The thermal capacity of the top 1 meter of the ocean is as large as the thermal capacity of all the atmosphere.

MACDONALD: Yes.

SUNUNU: It's a well-mixed one meter. The thermal capacity of the top 10 meters is obviously 10 times as large as the thermal capacity of all the atmosphere. That's not as well-mixed but not too badly mixed. The coupling between the ocean and the atmosphere-- both thermally and as a result of water mass transfer-- is quite good.

There is an-- there are two arguments. Number one, that there is a long time lag in thermal response as a result of increase in CO2 concentration. If it were an instantaneous response that the models were giving, I could understand that what was being changed was the thermodynamic characteristics of the atmosphere in a way that created a very different system.

If it's argued that it's a long term response and that there is strong coupling between the atmosphere and the ocean, I have a very difficult problem in following why the damping effect of the ocean is not much more significant than has been observed in terms of any temperature change. What you have argued reinforces the fact that the ocean phenomenon is a very strongly coupled relationship.

And therefore, I feel less comfortable, not more comfortable, about the fact that the big problem in the models that I've seen is an inability to bring the dynamics of the ocean and rationalize that with what is the dire consequences being predicted for the atmospheric response. And I've got a real problem with that.

And I know it's probably because I don't know enough about it. So why don't you tell me a little bit about what I'm missing.

MACDONALD: No, I don't think you're missing anything. I think that the long time scales are associated with changes in large coherent structures in the ocean. And in order to predict and predict now rather than setting scenarios-- in order to predict, we're going to have to do a far better job of modeling the changes of those structures.

SUNUNU: And if I have any decent coupling then between the top 100 meters of the ocean and the atmosphere, I've got a heck of a dampening to any possible change in that temperature over the long term. And if I have, on an annual basis, a decent coupling, I should have an awfully good relationship between the ocean being a mitigating factor to the dire predictions that are there.

And my question then is why is there so little effort-- at least it appears to me-- being made to effectively-- even on a parametric basis-- provide that coupling in the long term scenarios that we've seen.

MACDONALD: No. I certainly don't have any disagreement with what you've said. I do think we have a couple of experiments that relate to the shortened time response. That is, what happens to the global temperature when you have a volcanic explosion? Does the temperature really go down?

SUNUNU: Jesse, you have the last word. Oh, I'm sorry. You can have the last word.

AUSUBEL: You make a good point. But I would take it in a slightly different direction, which is that the obsession with temperature is misguided. The issue is really climate change. And we can have a very significant global climate change, even with no change in global average temperature. And we're chasing something that really may not be a very important indicator.

And so you could change the circulation of the oceans a great deal. You could put a lot of heat into the oceans. And there could be a very different climate.

SUNUNU: I'd be more worried about that than what people are trying to draw a trillion dollar legislation.

DEUTCH: We are going to give Warren Washington the last word. We're supposed to be discussing this subject after these talks.

SUNUNU: I'm sorry.

DEUTCH: No, it's not-- no, it's my fault. Warren.

SUNUNU: I shouldn't have invited myself.

[LAUGHTER]

WASHINGTON: I just want to just add that there is a lot of misunderstanding about this issue of how the heat capacity of the ocean comes into the climate modeling. And obviously, the models of the 1980s, most of them dealt with just the very top part of the ocean-- something down to 50 or 70 meters thick. And that essentially lead to interactions between atmosphere and the ocean in terms of climate change of only one type of interaction.

In the late 1990s, and certain-- I mean '80s into the 1990s, we're going to have ocean models that are going to do a much more realistic job of having these interactions. And this is especially important for the very low frequency. You know, where you're talking about time changes of the order of hundreds of years-- frequencies of all of those spectra from 10 years to annual means, to el niños, to century time scales will be included. And even from our rather imperfect models, we're seeing that.

So I think we shouldn't judge what the models are telling us right now as being the definitive answer for how the--

SUNUNU: But you've got to formulate policy right now. They are shaping the debate. That's why the question is relevant.

SPEAKER: That's why I keep raising it.

SUNUNU: You're absolute right.

SPEAKER: Warren, the focus is on temperature.

SPEAKER: [INAUDIBLE]

MACDONALD: That's right.

DEUTCH: Sir.

SUNUNU: When did you say you thought we'd see these improved models?

WASHINGTON: I would say in the mid-1990s and of course into year 2000. But that doesn't mean that we have to wait entirely until the models give us definitive answers before we can start thinking about policy. I think that even right now they can tell us some things.

LINDZEN: I've given up. And this is the small thing in support of what Jesse is saying. In the rhetoric of the subject, temperature's given extreme prominence. But, for instance, typically, the climate of the earth has not dealt with mean temperature but difference in temperature between the equator and pole. And temperature of the earth has been a residual.

And yet one will hear comments like the Ice Age was only 5 degrees colder. In presence, you see what 5 degrees can do. 5 degrees was nothing to do with it. It's a residual calculation.

DEUTCH: Ron.

PRINN: May I begin?

DEUTCH: You may begin.

PRINN: I actually had a hand out. But there's copies of-- if you grab some, I'm going to show it. I made them especially for John Deutch, whose eyesight is getting very weak. And he may not be able to see the machine.

SPEAKER: The eyes are the second thing to go, John.

[LAUGHTER]

DEUTCH: I'm glad to hear that.

PRINN: Well, Gordon made an interesting introduction to some of the science issues. What I want to do in my 15 or 20 minute is first go through what I've called here emerging science issues. And I've chosen these because I think, at the end, they're going to have important policy implications, particularly if one wants to make policies in the next two or three or four years.

So if you'd like, these are sort of key uncertainties or big questions that are emerging out of the science community. And they sort of hit on the whole issue of what is the uncertainty with which we can predict climate change.

And I think that uncertainty is pretty easy to define if we think we know all of the physical and biological processes that are going on that control climate. And the difficulty is that we don't. And it's the things that we don't know and that we sort of discover from time to time or almost stumble upon that those are the things you really worry about-- the things that will just change the viewpoint all of a sudden that we have.

So I'm going to go through some of these emerging science issues. And there may be others. There may be others that people around the table can add to this list.

First, they concern the greenhouse gases and the budget uncertainty. Three years ago, the talk that Gordon MacDonald gave and said that the ocean was the big sink for CO2 would have been just fine. But one thing that's been done since then-- and I'll show the view graph-- is to just try to fit the latitudinal gradient of carbon dioxide with a model that just has the ocean as a sink and says the land does nothing. Okay. And I'll put those up. And I'll just--

This is a study by Tans, Fung, and Takahashi. It was published in Science in 1990. The observations of the red dots with standard deviations on them-- this is latitude here-- north, south. I don't know why south is always minus on these things. It should be plus.

Average CO2 concentration-- and the observations are there. And that red line is an important line. You can't obtain that red line with a model that just has the ocean as sinks. Now here are three ocean models, okay.

Now, these ocean models are done in an interesting way. There's not an attempt to model the dynamics of the process of the water from the surface of the ocean dropping to the bottom of the ocean and so on. One just simply takes all of the available measurements of CO2 partial pressure in the ocean water and the CO2 above it. And you use what's called a bulk flux formula to estimate the flux in and out of the ocean.

And if those ocean observations are sufficiently good and they cover all of the right geography of the ocean, then this is a pretty good approach. The point is that if you look at it, it says the oceanic sink only models just don't work. And they miss the latitudinal gradient bifactors of something like two.

So that's a serious issue. And you can fit that red curve there. You can produce that red curve by having a large sink in the northern hemisphere. And it's got to be not the ocean. Therefore, it's the land.

And that sink is about the size of the ocean sink that Gordon talked about before-- a couple of gigatons a year of carbon. In other words, if that's the case, we don't know. We've now got a big argument between oceanographers who think CO2 is going into the ocean and now biologists, if you'd like, who say, wow. Maybe it's going into the northern hemisphere land.

And there you've just got to look at things like the growth of carbon in the soil. The soil is a pretty big reservoir of carbon. And you've got to think of ways in which that reservoir could be growing.

A pure hypothesis is that that increasing amplitude in the up and down of CO2 is signaling a fertilization effect. Whether it be CO2 or anything else, it doesn't matter. It's growing in amplitude, which means more leaves are growing in the spring and summer and more falling down to the ground in the winter. And, of course, soil carbon is built up by the residual that doesn't decay. It's the more lignin based, often in the leaf and so on.

So maybe that's it. But it's pure hypothesis. I mean, that's where we are right now with state of knowledge.

So I would argue that we don't know enough about the carbon dioxide budget right now to take the anthropogenic input and project what that's going to be based on human activity for the next 50 years and then say, we've got a model for the biogeochemistry of that gas which is reliable for predicting ahead 50 years. I don't think we're there.

BROWN: Does the north south-- is there a disparity in north south observations that reflects the disparity in land mass amounts?

PRINN: I'm not sure what--

BROWN: Well, there's much more land in the north than in the south.

PRINN: Oh, of course.

BROWN: And I don't see a corresponding asymmetry in the observations. But maybe it's there.

PRINN: Well, the question of the normalization and moving up of this-- up and down on this curve-- is not the issue here. That just gives you the total amount removed. So as long as you-- and you've got to fit that. It's where it is removed as a function of latitude that this graph is really talking about.

BROWN: But this says it should be flatter in one place than the other. [INAUDIBLE] it is.

PRINN: I don't want to give the sense that I'm all equally certain that it is the land that's a big sink. The point is we don't know at the present time. So that's pretty-- that's not a very good circumstance if you're making policy, I think.

Methane-- another one of the big greenhouse gases-- its trend is decreasing. 10 years ago, it was rising at 1.2% per year. Now it's going up at only 0.8% a year. What's going on?

Methane has got a whole lot of natural sources. It's got some human induced sources. And they're about 50 50-- human activity versus natural processes.

And the sink is reaction with this hydroxyl free radical. John, you remember what that is. You used to be a chemist, right?

So the hydroxyl radical could be increasing. In fact, we've got some evidence from a network that we run measuring a compound that's very similar to methane, but it's totally man-made. So we can actually do a titration and determine what OH is. And we've actually looked and said, is there a trend in it? And it appears to be statistically significant.

So it may be that the sink is increasing. Or it may be that the source is decreasing. The point is methane, which was rising at 1.2% per year 10 years ago, is now rising at 0.8% per year.

Back 10 years ago, nobody would have predicted that would be the direction. People were predicting it would be the other direction-- that we're throwing all of these hydrocarbons into air through human activity, taxing this hydroxyl radical, which is the big cleanser oxidizing agent in the atmosphere. And it ought to be going down.

So here's another sort of big question mark that just simply appears as well. If that's the case, how do we have a predictive model for methane levels? Going into the future, if we restrict big methane sources like rice agriculture, how sure are we that the restrictions, which may be very costly to the people who depend on rice-- how sure are we that it's based on a good understanding of how methane behaves?

Nitrous oxide-- another of the naturally occurring greenhouse gases is increasing its trend. It was about 0.2% per year about 10, 12 years ago. And now it's around 0.3% per year. And we have that from our own network-- the so-called ALE GAGE Network. And Ray Weiss has a separate network that shows a similar acceleration.

Why is that? We don't know. I mean, I've got hypotheses, but I don't want to burden you with them here. But the point is it's increasing its trend. It's another of the greenhouse gases.

So greenhouse gases-- there are budget uncertainties that everyone should be aware of that make it difficult to reliably predict 50 years ahead what the levels of these gases will be if we try to restrict emissions in various ways.

The next issue is what's called indirect forcing these days. And this gets really complicated and affects policy in probably at least equally serious ways.

If you increase the chlorofluorocarbons-- well, the chlorofluorocarbons are a greenhouse gas, okay, and a very, very powerful greenhouse gases. But if you increase them in the atmosphere, well, you should increase the greenhouse radiative forcing, okay? But at the same time, you're going to decrease ozone.