Select Committee on Science and Technology Minutes of Evidence

Examination of Witnesses (Questions 100 - 115)



  100. The Hague conference was very much about carbon sinks and their role. Do you think that in European research, our contribution to the IPCC, we have tended not to have researched enough into that area or given it sufficient recognition?
  (Professor O'Neill) I would tend to agree with you. It is an area that we are recognising is important. There are important feedbacks that need to be brought into these climate models. The fact is that science evolves. It is not an oversight. We are starting to appreciate more and more the potential for these feedbacks and the importance of representing them. If you go back, say, ten years, it is only in the last decade or so that we have attempted to represent properly the role of oceans in these climate models. That is absolutely fundamental. We have to realise that we are involved in a very rapidly evolving and developing science.

  101. 20 or 30 years ago, of the coal, oil gas and all fossil fuels that have been used in the last century or whatever, the rise in carbon dioxide concentrations in the atmosphere would be much greater were it not for the amount already absorbed by the world's forests and oceans. It would be twice the rise that it has been. That is the case, is it?
  (Professor O'Neill) I do not know if it is a factor of two exactly but certainly there would have been much more carbon dioxide in the atmosphere it had not been for the natural absorption.

  102. In that Hague compromise, do you have a feeling overnight, and since then, that there is a compromise there and what is the shape of that?
  (Professor O'Neill) It is difficult because this is very much an area of considerable uncertainty. If we are talking about the role of, say, vegetation and planting forests as a way of absorbing the excess carbon dioxide that we are emitting, that could be slightly dangerous in the longer term because the existence of climate change could end up with vegetation which currently acts as a carbon dioxide sink under present conditions and could then become a source rather precipitously.

  103. How?
  (Professor O'Neill) For example, if we have changes in climate zones and vegetation dies away—it is not able to rapidly respond to a change of climate—or the type of vegetation that exists is a less strong carbon sink, the end result of that is that more carbon dioxide is released into the atmosphere.

  104. The higher is the per cent of tree cover of the land mass, the greater the concentration of carbon dioxide.
  (Professor O'Neill) If everything else is static. The problem also is that in between putting large bands of forest changes the reflectivity of the earth and the forests tend to be darker and they tend to absorb more solar radiation. When we are talking about the land surface by vegetation feedback in the climate, this is precisely the area that we do not know anything like enough about.

  105. Dr Shackley, as a social scientist, are social sciences adequately reflected in the work of the Hadley Centre?
  (Dr Shackley) No. They do not do any social science work. They rely on other social scientists, for example, to provide them with scenarios of future greenhouse gas emissions from different regions of the world, making different assumptions about economic growth rates or population change. They use other people's social science. Their mission is not within social science. Within the new Tyndall Centre that I am part of, part of the mission of that is to integrate social science much more effectively into the existing natural science. We will be working with the Hadley Centre to aim to do that.

Dr Gibson

  106. You have indicated there is not a lot of coherence; there are a lot of things missing and people doing different things in the way that academics do for the great fives and five stars and so on and this is full of five stars all doing their own thing, competing against each other. Do you think there would be a major advance if we worked together? People are getting a bit fed up with you crying wolf about global warming. It can be said too many times. Would a coherent science policy reflect any way of getting the message over much more substantially in a social context but also in the academic arena of scientific research as well? I am aware of the stuff coming from Norwich about to heck with it all; just let the coastline disappear. Why bother? It is too much money. Just do not let people build their houses too close to it. Build them in Norwich, not on the coast. People are getting rather fed up. It has been going on a long time. How can we get the arguments that you are portraying, and obviously care about, over in a coherent way in terms of selecting a science? You have said there are some gaps. What can we do to bring it all together in terms of a really big scientific message that looks coherent and not just groups competing with each other?
  (Professor Bowen) It is an extremely tall order. Had it been readily possible, I suspect it would have been done by now. Turning again to the States, people there are not anything like as bothered about global warming as they are in this country. I cannot tell you what the reasons might be, but they are more relaxed about things. Maybe there is something in that system that can help us, but yes, as one talks to ordinary people these days, people are getting fed up with it and they seem to sense that something is wrong. It is the same story and there is no great step forward to elaborate it.

  107. Let us hear the social scientist tell us what is wrong.
  (Dr Shackley) I am not sure I agree that there is anything wrong in having different messages and having some diversity because I think that encourages debate. It is useful to have those inputs. There is a danger if we try and coordinate things too much and try to create a single message. What if the message is the wrong one? Can we be sure that it is the right message? I think you will find there is disagreement about what the message should be.

  108. What is the message you have for us?
  (Dr Shackley) My message would be that climate changes the global scale. There is a surprisingly high level of confidence amongst the scientific community that climate change will occur on a global scale. When you go down to other scales like the regional scale and the national scale, the science is simply much more uncertain so it is much more difficult to start to attribute particular extreme events to the general climate change. Nevertheless, over the time periods we are talking about, it is likely that climate change will begin to influence climate at these local levels. We might as well act in ways that have benefits in terms of preparing ourselves for climate change but also have other benefits for other reasons. You mention the coastline. It is not just because of climate change that people—including noticeably the Environment Agency—are very keen on managed realignment. There are many other benefits around managed realignment. I think we have to be looking at responses that combine a number of different policy objectives and not just rely on climate change as the sole justification unless we have very good scientific evidence.

  109. Can you think of one piece of scientific evidence that would do it? That is a terrible thing for scientists to ever answer but is there one thing, in your wildest moments, if it was proven, that would do it and convince governments to sit up and take notice across the world. We are not convinced that floods are due to all that really. What would really make a difference? Is it just too long term and too imprecise?
  (Professor O'Neill) The fact that you are not convinced about the recent floods and global warming is absolutely fine because neither am I. You could not possibly say that that is the case. What we would be looking to see is that in the longer run of things there would be increased frequency of these kinds of events. It is very hard to pick on one single thing. What we are getting is from different sorts of quarters, different pieces of evidence fitting together into the big jig-saw puzzle. I do not see any missing corner piece that would absolutely clinch it. It is not likely that the west Antarctic ice sheet is going to fall off its ledge and drop into the ocean. I do not think there are things like that. It is mounting, cumulative evidence. Two things strike me in terms of public perception. One is the longer term in which it takes for the real signal of this global warming to emerge from the natural variability. Secondly, it is because perhaps wrongly people have been conditioned to the notion that scientists can talk about systems with a degree of certainty. It may be with some control systems we can do that. When we talk about the natural system, there is uncertainty inherent in that. It is not just about the fact that we do not know enough about the equations or we cannot stick them in the computer well enough. We are dealing with complex systems and frankly, when I went to university, I was not trained to deal with these kinds of things. It is a new dialogue we have to get with the public to appreciate how to balance the uncertainties that we are happy to talk about with the balance of evidence which is saying yes, there is something serious going on.

Dr Williams

  110. I am disappointed that you are so defensive. If I was working in your field full time and knew as much about it as you do, I would want to be reassured about the Arctic ice and so on. We did that for the ozone problem. Nobody has been there or found any effects of it and yet people out there, politicians, were persuaded about CFCs. There is a big consensus about it. Why are you not on soap boxes attempting to persuade the people or the politicians themselves?
  (Professor O'Neill) I do not think we are being defensive. I think we are trying to present the evidence with the right balance. The example of the ozone hole is a nice one because in fact this is a good example where scientists did work very hard to pin down the science. There was a huge amount of scepticism about this. People say, "Oh, it is natural. Look at the scientists coming up with this nonsense", but scientists have pinned it down. In this particular case the nations of the world did act and phased out the damaging CFCs and the United States was included in that. This was a happy circumstance in which there was a relatively straightforward technological solution. Of course the solution was that there were replacement chemicals and other things you could do. The problem with greenhouse warming is that fossil fuels are still the basis of energy production. There is no easy solution. The other point is, and this comes back to this soap box idea of shouting it from the rooftops, that we always have to recognise that one piece of evidence like the melting of the sea ice to some extent is not enough. That could occur naturally. It is the pattern of changes and the mounting evidence that comes with it, whereas the ozone hole is much more specific, it opens up every spring and then closes again. There are greater uncertainties I would say and the role of natural variability is much more dominant.

  111. But in terms of the general public out there—they take their views from Friends of the Earth and Greenpeace, rather than from the Labour Party or from MPs or, unfortunately, from scientists who know a hundred times as much as those members of Greenpeace in terms of the earth.
  (Professor O'Neill) Yes.
  (Professor Bowen) With respect to the melting ice in the Arctic, I do think the public are now aware that there is such a thing as the North Atlantic oscillation and it has been stuck in its present mode for the last 20 years and warm air is being pumped up into the Arctic. That could switch suddenly and as we are having mild, wet winters now, they could switch to the Mediterranean and we could have very cold winters. If you took it on a larger scale, possibly as a result of enhanced greenhouse gases which would produce greater run-off in the North Atlantic, you might produce fresh water which would freshen the surface of the ocean and would slow down the thermohaline circulation which pumps water up there.

  112. You are telling me that you have got a ready explanation for global warming for the Arctic melting?
  (Professor Bowen) Yes, an alternative to global warming.

Dr Turner

  113. Would it be fair to gather from what you have been telling us, both verbally and in writing, that having paleoclimatic evidence of global warming which is going on anyway now, overlaid with man's activities, makes it very difficult to disentangle the two processes and do you have any confidence in scientists' ability ever to predict it with any degree of accuracy or of governments to be able to respond to the advice if anyone can ever agree on what it should be?
  (Professor Bowen) What you are really asking me is to disentangle natural variability from anthropogenic forcing on which the IPCC said in 1996 that they could detect a discernible human influence. It seems to me that until we understand all the forcing functions, until we understand all the processes and the feedbacks, I do not honestly think that we are going to be able to say confidently what, for example, the global temperature will be in the middle of the next century.

Dr Iddon

  114. I just want to make a quick reference to volcanoes. The Geological Society have suggested that large volcanic eruptions can have a significant cooling effect on weather and climate. To your knowledge has this been addressed adequately in the debate?
  (Professor O'Neill) I think there is ample evidence that the eruption of volcanoes and the aerosols they release can have an effect on climate. We detected it in the eighties with satellite data. The thing is that these aerosols released from volcanoes tend not to reside that long in the atmosphere so we can represent if you like an ambient level of natural aerosols, and in fact in doing that we have got a much better agreement with the climate models with the recent temperature record than we had when we did not do that. I do not think it is something we have forgotten about. Again, it is by no means enough to account for what we have seen. Call that a natural forcing if you like, and that will tend to give us a climate cooling typically, whereas what we are seeing is a warming. We need other things to get that result.

Dr Gibson

  115. If there were one thing you could tell the Government to do what would it be, each in turn? I could give you five but what would be the most important thing to manage climate change as far as the Government is concerned? We have had lots of talk but what could we do that would be effective and win the support of the public?
  (Professor O'Neill) Try to recognise that there is a real threat of rapid climate change even acknowledging yet again the magic word "uncertainty" and that where we can institute changes in the way we live and the way we operate there are other longer lasting benefits, in other words a no risk strategy that we should inevitably try to go that way because when there are increases in energy efficiency there are knock-on benefits and what one then gets is sustainability.
  (Professor Bowen) Energy efficiency, cut down ruthlessly on all pollutants, and I do not include carbon dioxide as a pollutant. Carbon dioxide is an essential part of photosynthesis and the reason for our being here. If government did concentrate on those things which are eminently attainable, this would be putting the precautionary principle into action at a reasonable level.
  (Dr Shackley) I agree with the other two in the sense that we are now in the domain of solutions to the problem of climate change. The debate has moved on. The Hague aside, the Kyoto protocol is not going to go away. There will be negotiations. Even if the US are not involved, it can still be ratified if the industrialised countries get their act together. Business is taking this incredibly seriously now, including in the United States. We are moving into a world which will economically and socially change because of climate change, even if climate change is not manifest in the immediate future. The implication of that is what the government is already doing and it needs to continue to do that in relation to the climate change levy and emissions trading schemes. There is a lot of exciting development in the new Carbon Trust which is using some of the money from the levy to support new energy technologies, renewable energy, ways of decarbonising the energy system as well as storage of carbon by forests. There is a lot of opportunity for captured carbon storage in disused oil and gas fields, for example, and there are huge opportunities for business as well. These are the areas that I think government should continue to support.

  Dr Turner: Gentlemen, thank you very much. I apologise that we have run slightly over time. It is the loquacity of our members, I am afraid. Thank you very much.

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