Select Committee on Science and Technology Minutes of Evidence

Examination of Witnesses (Questions 80 - 99)



  80. Dr Shackley made a point about the international dimension in this. There are forces out there, Saudi Arabia, Kuwait, President Bush or dissenters in the United States that are looking for your kind of point of view.
  (Professor Bowen) The best forum that exists right now is the American Geophysical Union in San Francisco but yet again I do not think it meets all the criteria that everyone is there talking with everybody else. There was a PPARC/NERC meeting in London last month looking at the sun climate links and there were just three non-solar physicists there out of 75 people. It seems to me that a conscious effort has to be put into this to obtain all shades of opinion on the definitive facts that different groups of people can produce.

  81. Professor O'Neill, you are involved as well in IPCC work. What is the consensus among scientists? Is it 80 or 90 per cent likely that it is carbon dioxide and methane and these greenhouse gases and not these sun spots or whatever?
  (Professor O'Neill) The relationship of solar variability to climate is a very challenging issue and we do not know all the answers. We know the solar connection with climate change must be important because we have had ice ages and periods in between ice ages. What is more controversial is the extent to which solar variability on a timescale of 100 or so years, which is very pertinent to us now where we are seeing changes in the temperature record—that is much more controversial. Broadly speaking, 90 per cent—probably more—of scientists involved in climate research in terms of what is happening now and what could happen in the future will be of the opinion that it is associated with greenhouse gases, but the effect of the solar variability—and there is a contribution, albeit uncertain—is of rather lesser magnitude on that timescale.

  82. Professor Bowen, you disagree?
  (Professor Bowen) I do not believe science works by consensus. The only consensus in this business is that one computer model replicates more or less what the other computer model shows.

Sir Paddy Ashdown

  83. Precisely on that, let me see if I can tempt Professor Bowen to a rather more brutal statement. Is it your view that the closeness of the relationship with the Hadley Centre is leading to the danger of the fact that the Government is caught in something of a fad here which is self-reinforcing or, at the very least, is insufficiently challenged by dissenting views and other scientific disciplines?
  (Professor Bowen) I really would like some notice on such a question but perhaps by saying that you have my answer!

  Sir Paddy Ashdown: I will presume yes!

Dr Jones

  84. What would you do about it? You talk about the need for all the different disciplines to get together. Is not the IPCC the appropriate forum for that? Have you any suggestions as to how we improve the way that functions? What has the IPCC achieved? What do you think of the way it functions? How could it be improved?
  (Professor Bowen) I think the IPCC in their publications have done an absolutely marvellous job of describing the climate system in its various aspects, quite magnificent. Where I am less happy and would like to see a larger range of people involved would be in some of the details that would not necessarily strengthen the position of the statement that says that greenhouse gases are causing climate change and will cause a major climate change in the future. There are distinguished scientists around the world who will say very clearly that we simply do not know and if we pretend that we do know that is the worst possible thing we could do.
  (Professor O'Neill) I do not think we pretend we know. We recognise that there are uncertainties and chains of uncertainties. The international effort has been very much geared up to narrowing those uncertainties and removing them. I am not aware of any sense of international conspiracy because the best way for scientists to make a reputation is to break the mould and I would not hesitate to do that if I could. It is always possible to have a dissenting voice and one would encourage it. What we have to do is take the dissenting voice, see what it is based on scientifically and test out the science. That is the acid test in the end, to see whether we can explain what we see by the mechanism that is being used or by the hypothesis that is being used. I agree with Professor Bowen: I think the IPCC has done a magnificent job. It is realising more and more the importance of the role of uncertainties. I do not think people in IPCC feel that the uncertainty is going to turn around dramatically the basic tenor of the advice that has been given. One has to feel much more comfortable about the nature of the advice when some of the significant uncertainties in various parts of the system have narrowed down.
  (Dr Shackley) We have to distinguish between different disciplines in terms of how they contribute to science and climate change. There is a group of scientists who make predictions or scenarios of future climate change using models and then there are other people who, say, do studies of historical climate change, but those people doing historical studies are not the people who are making predictions of future change. They might provide material that can be used to validate the models that are used for predictions, but a lot of these other communities who have not been so centrally involved are not actually the communities who are making the key claims in the science about the future change, which is after all what really matters in policy terms. That probably explains why there is this different arrangement of disciplines and why some have not been so involved. Amongst the scientists who are making predictions there is, as well as a common understanding of the science, also an element of a precautionary ethic in the work of, say, the IPCC in the sense that there are some values in there that we should be erring on the side of caution when it comes to issues like climate change. I would not try and pretend that this is purely driven by science. I think it is also partly driven by an emerging set of values about protecting the global environment.

  85. Does it really matter? Irrespective of whether the models and predictions are accurate, based on the precautionary approach, should we not actually be doing absolutely everything we can to reduce greenhouse gases and other forms of pollution? Would the other members wish to comment on Dr Shackley's comments and that further question?
  (Professor Bowen) Absolutely. I think we are doing that, are we not? If you look at the record of lead, for example, in Greenland ice cores since unleaded petrol has been used it has actually plummeted. If we pay attention to methane and we pay attention to aerosols in the atmosphere, I think we are paying attention to the precautionary principle but how far do you take it? How far do you take it on coastlines? How far do you take it, if you can take it any further, on flood plains? How far do you take it in certain circumstances when it is going to take a great deal of the gross national product? I hesitate to introduce a moral point at this stage but at a time when most of the world's people are living in absolute destitution might the money not be better spent in raising their standard of living?

  86. Which money is this? The money that is being spent on what?
  (Professor Bowen) The money that is being spent to a large extent on negating perceived aspects of climate change, various defence schemes.

  87. What about changed behaviour? All the research is used by Government to develop their policy and obviously the issue is how far governments should go to restrict CO2 emissions and so on which could result in considerable changes in lifestyle, which could have financially beneficial effects, not just cost money.
  (Professor Bowen) This is a political matter. It is really up to what the voter can take in such situations.

  88. They want a prop, if you like, in taking those difficult political decisions.
  (Professor Bowen) I think the things we are talking about are so esoteric as far as the public are concerned that they are either unable or unwilling to evaluate them and it seems to me therefore that you would never convince the public to stump up their pound in their own pockets in this quest.

Dr Williams

  89. The British public, the German public, the European public, has accepted Kyoto, have accepted carbon dioxide, have accepted global warming and are very environment sensitive. The American public is not but perhaps their politicians are. Could we just talk about unleaded petrol? The great thing about unleaded petrol, or the problem of lead pollution, was that there was a technical solution, a ready economic one, but in this case it is much more intractable. I challenge your pessimism about the understanding and the desire of the European public to have something done.
  (Professor Bowen) I did not come here to talk about Kyoto; I came here to talk about climate systems.

Dr Iddon

  90. I want to make sure that we have got all the uncertainties on the table. I have written down—while we have been talking uncertainties, about the modelling experiments which after all are experiments, and there must be various models being explored there, so that is one possible uncertainty - I have written down the question: have we taken solar sources into account adequately, and I have put a question mark on greenhouse gas emissions? Are we, for example, taking into account all the forest fires that there are in a year, for example? I read a statement recently that all the forest fires in a year put out more dioxins in one year than man has ever put out synthetically himself or herself. Are we not tinkering at the edges with carbon dioxide when we look at the forest fires that occurred last year? Are we taking that uncertainty into account? There are three uncertainties. Could you give us any more uncertainties that we should be considering in this debate?
  (Professor Bowen) If you would like a paradigm of uncertainties, I think we are currently aware of a whole variety of forcing functions as far as the climate is concerned, some of them acting at different cycles. These are the pacemakers, and very often we can see the end product of these forcing functions, but in between there is a great black box. We see the forcing going in and what comes out very often amplifies the forcing that has gone in, so there are powerful non-linear feedbacks operating within the system. These are uncertainties that fall into the realm of the unknowability at the present time and will remain in that realm of unknowability for a long time. It is frequently said, for example, that we know what caused the ice ages. We do not know what caused the ice ages. We know that the forcing function is the pacemaker to orbital changes of the earth around the sun and we know what the output is. It is the geological record of ice ages, but the record of ice ages doubles the input that goes into that system. We simply do not know how the atmosphere, the cryosphere, the world of ice and snow, the greenhouse gas system, the ocean circulation, work; we do not have an adequate handle on these. It is only through increased high quality data and modelling of that data that we shall ever get to that position.

  91. Do either of your colleagues want to add to that?
  (Professor O'Neill) It is an interesting question about whether or not we have an adequate knowledge. I would certainly agree with you that there remain uncertainties in every corner we look at. In terms of what is likely to be the outcome of pumping greenhouse gases into the atmosphere for the next 50 to 100 years I am less pessimistic in the sense that we do not have an adequate knowledge of all these factors. I would add a few areas of uncertainty. We are going to witness one evolution of the planet in the next 50 years. If we were to set up lots of different worlds under pretty similar conditions each of these world would evolve slightly differently, so we would get natural variability. It could well be for example—let me be specific—that in the next 30 years we will see a decline in temperature. That would not in any shape or form rule out the underlying notion that there is a longer term trend in the temperature record because we have got superimposed on the forcing of the greenhouse gases natural variability in the system. That is one area of uncertainty. Another area of uncertainty I would say is the response of the biosphere to changing climate. There are very significant sources of things like carbon which are quite natural and you have mentioned that point already. As climate changes vegetation will inevitably change. We are talking about changes in quite rapid timescales again. It could well be, and some calculations suggest, that changes in the natural carbon cycle may exacerbate what man is doing in that area. I would caution that there are lots of uncertainties in that one. Possibly one of the biggest uncertainties is how human beings themselves will respond. This is ultimately the fulcrum process. We are part of the natural system in some respects, and how we respond to what we see happening, what the predictions will be and how the nations of the world get together or do not is going to be a major area of uncertainty for climate modelling.
  (Dr Shackley) The uncertainty I see in a sense is the bread and butter of what scientists do and scientists love talking about uncertainty and can sometimes give the impression that that is all there is. What is actually quite remarkable about the climate change is the degree of certainty that has been formed internationally through the IPCC, through a very rigorous process of review. Scientists will always find uncertainties, but if you push them and say, "Do you really think that greenhouse gas emissions will cause global temperatures to increase within a range of 1.5 to 4.5ºC for the doubling of CO2?", then the vast majority of those scientists will say that they do believe that. At a certain point when this uncertainty is not affecting their basic judgment the science of climate change is rather sound and is quite well understood.

  92. Do you feel that the policy makers that you advise, and other scientists advise, are capable of understanding all the uncertainties in the argument, or do you find that they are putting pressure on you to provide black and white answers to their questions?
  (Dr Shackley) I think the policy system does tend to prefer certainty and finds uncertainty difficult to deal with. That is often because the amount of time you have to invest to understand the significance about uncertainty is rather high and most policy makers simply do not have the time so they prefer the story to be told without excessive mention of uncertainty and relying on scientists' judgment. That is where the IPCC has been very useful because it has provided an international forum where the world's best scientists can actually have this discussion and they are all coming from their own particular viewpoints, their own organisations, but additionally it is including governmental representatives, representatives of industry and representatives of environmental groups, so you have got all these different perspectives that have to be taken account of in how that knowledge is distilled and then presented without excessive mention of uncertainty. It is rather an interesting process by which this distillation does not just involve scientists and its strength is that it is being reviewed by the wider community.

  93. I might throw a naughty question in here which is not on the sheet, and that is: why does not the American Government listen to its scientists?
  (Professor Bowen) Who says they do not? I think a great deal of advice does go to the American Government and this is quite independent of the so-called industrial interests that are supposedly financing some of the people. I think the quality of advice that goes to the Government from NASA, for example, from the NSF, from various high powered institutions like the Lawrence Livermore Lab, Berkeley, California, is very high and I think that the calibre of many congressmen in scientific terms is also quite high.

  Dr Turner: We have met one of them that possibly was not, but perhaps that is colouring the question.

  Dr Jones: The member of the committee that we met when we were in the States a couple of years ago completely and utterly denied that climate change was happening.

Dr Iddon

  94. What you are saying is that the advice is there, obviously the Government is listening, but the industrial lobby is preventing them from taking any action?
  (Professor Bowen) No, I am not saying that at all. I do not know if my colleagues would agree with me.

  95. I am sorry if I misrepresented you.
  (Professor Bowen) In terms of manpower resources that are devoted to this issue the United States far eclipses what is being invested in the British Isles. Most of the front line action is taking place there, not in this country. France is slowly catching up but it is the US. It is a massive effort.

Dr Williams

  96. But is it a massive effort in these negative areas that you are involved in rather than the modelling and so on?
  (Professor Bowen) No. I think you will find at least 50 per cent of the scientists who write the IPCC reports take the position that there will be enhanced global warming in the future. I do not think that is the case at all.

Dr Jones

  97. Taking up what Dr Shackley was saying, do you consider that the IPCC as a process is a good model for scientific advice to government in other areas? Is there not a danger that they are too consensual? Peer review was mentioned. How satisfied are you that those invited to participate in peer review are sufficiently diverse?
  (Dr Shackley) I think it is a good model for some issues. Obviously, it arose because it is a global issue. We are talking about systems that are connected globally so to do any science or assessment you have to start from the global level. There are many other issues you do not have to start at the global level. You can start at the local level and work in a range of scales. I do not think automatically it would work for political reasons for certain issues but when you are talking about—

  98. One issue you suggested was genetically modified organisms, for example.
  (Dr Shackley) I have not thought that through but I can see the value of some sort of international assessment. You have to recognise that the climate change work builds upon at least three decades of dedicated scientific effort. As Professor Bowen says, the US has put huge amounts of resource and in a sense allowed the capacity to be there for the process. I am not sure if in GMOs that is the case. On your point about diversity, I have been to IPCC meetings where what typically happens is that the industrial lobby of the United States will be looking for any signs of weakness in the science and any uncertainties which it can use to try and reduce or weaken the argument. They will send somebody over to the Kuwait and Saudi Arabia delegation in order to get the question asked within the plenary. This is quite an effective mechanism by which any uncertainties or questions of credibility of the science are seized upon and communicated rather quickly to the political faction which might find this helpful. That is a legitimate process within the IPCC and they live with that. They have to have it out in discussion, which is why their meetings tend to last until the early hours.

Dr Williams

  99. Professor O'Neill, I would like to ask you about the Hadley Centre climate modelling. It has a lot of mathematicians and physicists and an international reputation for its work, but does it have enough biologists and other social scientists?
  (Professor O'Neill) No. That is an area that I believe the Hadley Centre recognises increasingly, although I would not want to speak for them: the importance of those disciplines in getting the full picture of how climate is likely to change. They are moving slowly in that direction. There is a large community of extremely capable biologists who have relevant knowledge in the United Kingdom and in Europe. If I was in the position of encouraging them, I would encourage them to tap into that knowledge base.

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