Select Committee on Economic Affairs Minutes of Evidence


Examination of Witnesses (Questions 140-150)

Professor Richard Lindzen

25 JANUARY 2005

  Q140Lord Kingsdown: Not to mention global warming?

  Professor Lindzen: Right. If you go to the chapter on physical process and climate feedbacks, you do not find disagreement, that we do not know how to do water vapour, we are uncertain about the positive feedback. When you get to clouds, you get open admission that they are completely uncertain and a fundamental weakness in the predictions, and it is understood, but we were not permitted to say it, that these are fundamental to the predictions of large warming. That was a little bit peculiar. You do not find the disagreement that John is talking about. The only place you begin to see anything is in the Summary for Policymakers. This has been a characteristic of these documents from the beginning, as far as the press goes, as far as politicians go, they see the first two lines and maybe the first paragraph and that is it. Typically, in the Second Assessment, the line which carried the day was a discernible human impact on climate. That was the smoking gun for Kyoto. Discernible suggests it was less than the total, and that the total is about one-sixth of what the models predict does not seem very alarming to me, but it was enough to get people riled up.

  Q141Lord Lawson of Blaby: Lastly, can I refer to one particular part of his evidence, which is exactly the answer which Lord Lamont quoted, the very first part of his answer. He went on to say: "It"—that is the average global temperature—"has been a steadily rising trend during the 20th century." Then he says that for the first half of the century it was nothing to do with greenhouse gases because there were not greenhouse gases, it must have been something non-anthropogenic. Then he contradicts himself somewhat by saying that there was no temperature rise between 1950 and 1970, and then he says, and I quote: "From 1970 to the present time there has been a very steady increase in water vapour. The rate of increase is larger than it has been for a very long time, probably for 10,000 years. The total increase during the 20th century is quite out of scale with any variations known to us."

  Professor Lindzen: He said that about water vapour?

  Q142Lord Lawson of Blaby: Yes. This is an uncorrected transcript but I assume it is likely to be right. That, it seems to me, is the basis of his alarmist projections. What is your response to that?

  Professor Lindzen: Astonishment. The temperature change over the past century, as you pointed out, is irregular. It went up rather sharply from 1920 to 1940. There is even, between 1919 and 1921, a period where you had a half degree in one year, or two years. Between 1950 and the 1970s you had cooling, and Crispin Tickell even wrote a book about how society must respond to the coming ice age. Then you had warming and, as far as I can tell, on the surface record, you have rapid warming between '76 and about '85, and then you have fluctuations about it. I remember, when the first satellite data came out and there was only 20 years of it, they said, "Well, you can't make a trend from 20 years' data." All of a sudden people see a peak and they say "That's a trend." There is no steady increase through the 20th century, there is a net increase, and it is a few tenths.

  Q143Lord Kingsdown: You have already mentioned water vapour once or twice this afternoon, but I understand your position is you regard this as having probably a negative feedback effect, that is, that it calms warming down, whereas the scientific consensus, as we understand it, is that it has a positive feedback, that is, that it makes things worse?

  Professor Lindzen: The IPCC chapter is agnostic. The models say it gets worse. The modellers acknowledge they do not have the physics appropriate to water vapour. That is the situation as it is now. In 1990 I wrote a paper in which I said global warming scenarios depend on this water vapour feedback; without it you do not get much and we do not know much about it, and they said "Can you imagine any way that would be negative?" I said, "Sure." It turns out, if you have a warmer world and clouds go higher, they detrain, let us say, they merge with the environment where it is colder and you have lower humidity and that could end up reducing water vapour. That has actually been confirmed by studies since then. In the meantime, we wrote a paper in '93 examining this and found that the physics of water vapour in the tropics was different from that. That would work near the top, but, in fact, the source of water vapour in the tropics was rainfall evaporating into the environment, in large measure. We pointed out that the amount raining into environment depended upon how much did or did not rain in these tall, cumulus towers. It is well-known that, when the temperature increases, more rains in the towers and less is available to the environment, so there still could be a negative feedback. Subsequently, we realised that change in the humidity of a region in a sort of continuous way is rather difficult, even by this mechanism, but what you saw was a short boundary between dry and moist regions, cloudy and clear regions, and the change in area could really be a more significant feedback. We have been working on that since and it looks very much like a negative feedback that would be large enough to swamp any of the positive feedbacks in the model. It is a research area, but it is politically incorrect these days to speak of the world, or the earth, as in some sense being engineered. If any of you have a background in engineering, I do not know, you never build anything with positive feedbacks unless you want to amplify something. You build everything so that the feedbacks hold it in place. The whole notion, I grant you, this is metaphysical, that the earth is a system on the border of instability that is kept from running away only by the gentle ministrations of bureaucrats; it seems to me, strange.

  Q144Lord Kingsdown: Can I just go on to ask you how far your view of the role of water vapour is shared by other scientists?

  Professor Lindzen: That is shared universally. All of them agree, no model gets a lot of response to CO2, much more than you would expect on basic physics, unless water vapour and cloud kick in to make the system much more sensitive than it would be in the basic physics. That is true and accepted.

  Q145Lord Sheppard of Didgemere: Can we move on to the Kyoto Protocol. Your evidence implies that you consider it would have little or no effect on the rates of future warming. Is this because reductions targets are too low, is it that we are doing too much or not doing enough, or what?

  Professor Lindzen: In a sense, that is right. What you have with carbon dioxide is, first of all, as I said, you are already three-quarters to a doubling and quadrupling, just do it again. No matter what you do at present, unless you change the amount of these things in the atmosphere it is not going to change the forcing of climate. Kyoto, for instance, is changing the emissions but it is not eliminating the emissions, so you are still adding to the atmosphere and you can calculate the impact. It is less than a tenth of a degree by 2100, or something like that; it would be unmeasurable. The question is then, as you say, maybe it is not enough. What would be enough to impact the level of CO2 to get us down from the horrible point we are at now? I should mention, I find this a little bit mind-blowing. If Sir John says one degree will cause all sorts of havoc, we have already had 0.6 and we have seen a world of increased prosperity, we have seen a world of greater food production, we have seen all these things. I do not see the evidence of a horror story there. In any event, getting back to what you are asking, to cut down the CO2 itself would require not a few per cent below 1990 but probably in the order of 60 per cent below 1990. As far as I know, no-one knows how to do that. Even the IPCC, I should mention, in their Section 3, pretty much concludes we are not going to, even if you believe the models, even if you believe everything about it, they are not going to stop it. The primary concern is can we adapt, and the obvious answer has been that you need the resources to adapt.

  Q146Lord Sheldon: How do you see the work of the IPCC? Do they take full and proper account of all views, however different they may be, or are they all equally represented?

  Professor Lindzen: I think it is a very distorting process. As I have said, it has many stages, so you have the writing of the scientific text, or the substantive text; that is done by the lead authors with the co-ordinating lead author, and what I used to refer to as political correctness monitors, people who go around to the co-ordinating lead author, who is chosen by the executive, whereas lead authors are chosen by the Technical Unit at the Hadley Centre, Working Group One. The co-ordinating lead author has to make sure that it does not say anything that would be too far in one direction, not the other, but that is okay. At the end of the day, when I look at the Working Group One Report, I would not use it as a textbook, I would not find it all that helpful, but also I do not find it says anything terrible. It is very much on the level of saying "We don't know. There's uncertainty." I give an example in my testimony of how the Working Group describes what appears later in the Summary and it is like day and night. That is the problem. This came up recently. There was a kind of scandal. There was one group looking at the impacts of global warming and they had a guy called Chris Landsea. Chris Landsea is probably the leading expert on the statistics and history of hurricanes and he has written a lot of papers pointing out there is no obvious relation that can be discerned between hurricanes and temperature of the earth and no evidence that warming would increase hurricanes. On the same chapter committee was a lead author, Kevin Trenberth, and Kevin participated in one of these dog and pony environmental shows, in which he said "The hurricane season this year in Florida is a warning about global warming." That is ambiguous. Is it due to warming, or is it an example: who knows? Landsea said, "How could you say that when the evidence says there's no connection?" What Landsea realised, I think, was no matter what the chapter ended up saying, even if it said "There's no relation," it would be represented by Kevin, or John Houghton, or whoever, and it would be said that there is a connection. This has been the problem. You have this damn Summary for Policymakers, which ends up saying things that are rather different. They have a funny way of using language. For instance, apparently, maybe it has changed, the last time, but for the first two IPCCs there was an agreement that the Summary for Policymakers, which is not written by the scientists, it is written in a plenary session with NGOs and government officials, and so on, if it says something that is not in a chapter, the chapter can be modified. The way it is modified is interesting, at least what I have seen is. There will be a line thrown into the chapter that corresponds to the Summary. It is not that they pull out much of the rest but there is a sudden cognitive dissonance in the thing, and so their statement that the Summary is consistent with the text means that what is in the Summary can be found somewhere in the text. They do not go on to say that sometimes the opposite is also found in the text. I do not know. I have this statement at the end that when language becomes foolish our ideas follow suit, and the reverse can happen. I think we are seeing that within IPCC.

  Q147Chairman: Listening to a great deal of your evidence, and maybe we are just coming to the end and I would like to thank you very much for what you have said, there is one question that comes immediately to my mind. If it is like you present it, why are governments spending this enormous amount of money producing all this stuff, because there are enough of us sitting round this table who have spent our lives trying to control government expenditure in our previous incarnations and there are plenty of arguments for not spending it. If it is anything like you say, why are they spending all this money?

  Professor Lindzen: I will give you a semi-serious answer, because I do not know the answer. My semi-serious answer is that I have realised, over the last 20 years and in dealing with public officials and ordinary people, that the last thing in the world they want to do is dig into science, to deal with mathematics, read this. If they can avoid that by spending a trillion dollars, they will do it.

  Q148Lord Sheldon: I know you cannot give an answer to this question, but can you make a bit of a guess: how much do you think is being spent on this, the whole of this business, just a general figure?

  Professor Lindzen: I think at least 25 billion, 30 billion at the research end, but then there is probably a smaller but not insignificant amount surrounding. By now I figure that well over 10,000 diplomats and bureaucrats are working on negotiating the various things and analysing them and working out the economics, and so on, so it is a growth industry, but I do not think it is terribly productive.

  Q149Lord Macdonald of Tradeston: If I can go back to the question of the observed 0.5 per cent against the modelled 3 per cent increase.

  Professor Lindzen: Well, 3 degrees versus a half degree.

  Q150Lord Macdonald of Tradeston: Thank you. Three degrees; perhaps also the unknown factor that would have to be found. There was a science programme on our television here recently on global dimming, on "Horizon", which said the fact that these particulates have been multiplying has led to global dimming, this was all revealed to us after 9/11. Could this be the unknown factor?

  Professor Lindzen: It is an interesting thing. One of the claims, and I discussed this in the deposition, is that the models can simulate the past century and simulation is a very low-order activity when you have adjustable parameters. These aerosols you are talking about were a godsend to the models. The reason they were a godsend is two-fold. Even if you know the amount of aerosol you have in the air, calculating the thermal forcing leaves you with an uncertainty of about a factor of six to 10, because we do not know their properties very well. In addition, we have no records of sulfate emissions before 1964, so to match records before then you can devise ways of estimating how much you have. Between estimating how much you have produced, and some of these estimates are very weird, they have maximum production in the depression and minimum during wars, it is hard to figure, and the fact that you cannot calculate the radiative properties, it is completely disposable. There is even a name for it in the literature. The aerosol people say their ignorance is so big that it might be legitimate to plug aerosols into the models and tune the properties to make the models more nearly coincident with the data. That is called the inverse method. They do warn, in an article that I cite here, in Science magazine, that then to use those properties to test the models is circular, and it is.

Chairman: Thank you very much indeed. Really we are very grateful to you for coming and for answering our questions. Thank you very much.





 
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