Select Committee on Economic Affairs Minutes of Evidence

Examination of Witnesses (Questions 323-333)

Professor Nebojsa Nakicenovic

8 MARCH 2005

  Q323Chairman: Professor, I am sorry, the workings of democracy do cause some inconvenience from time to time, but I am grateful to you for coming along. I would not guarantee that was the only division we are going to have, and so I have asked my colleagues, including myself, to try and put our questions as shortly as we can and if you can make your central points brief in the answers we will get on much better. I am also told it is important to speak up so that the record is absolutely straight. May I start off with the first question? We have had a lot of evidence which has criticised the IPCC emission scenarios. The general criticism is that they are not credible, that there are methodology problems, and I wondered whether we could just take those criticisms in turn. The first is that the scenarios appear to bear no relation to past trends, so that high emission scenarios assume growth rates of the world economy that have no historical precedent. Is that a correct point?

  Professor Nakicenovic: Good afternoon. First, I would like to thank you for the invitation to this inquiry and for the opportunity to respond to some of these questions. As far as the issues are concerned, and your question whether the scenarios bear resemblance to historical rates of change and whether they are rooted in the history, I would definitely answer in the affirmative that they are indeed rooted in the history and I will try to give you some examples. I think one of the main reasons why this is important is that history teaches us quite a lot about the rates of change, about the great transitions in the economy and the energy system, land-use changes, all other driving forces that are important for the emissions. I do not think that anybody on the writing team of the IPCC Special Report on Emissions Scenarios (SRES) believed that the history will repeat itself, but rather that the rates of change are relevant. I think that it is also the sense of your question. May I just spend one minute to set the background? First, I would like to identify some of the terms of reference that were behind the scenarios, because I think it is important to have that up front. The SRES Report and the resulting emissions scenarios of it was not one single event in the work of the IPCC; but rather a part of a process. First scenarios were published in 1990, then a second set in 1992 with a newer knowledge, these scenarios were evaluated in 1994 and this led to the recommendations for the development of SRES scenarios. I think what is really important is that the SRES terms of reference specify that these scenarios have the same range of driving forces from the demography, through technological change, economics, land-use changes as the scenarios in the literature and that the range of emissions should be representative of that the literature, and in general, that the scenarios should be representative of the knowledge. There are about 500 scenarios in the literature, just so that you have an impression. It is a very large set there that served as the basis for SRES. A number of models were used to develop new scenarios, six different models. Modelling groups were not appointed; they volunteered to do the work. You will see later, (perhaps, in response to some other questions that might come up) why that is important. I would also like to mention, and with that I will conclude my brief introduction, that the writing team included 50 authors, many of whom were economists, but I would also like to stress, they were not all researchers and scientists, some were also from the private sector and from the environmental NGOs to bring in different perspectives. Five colleagues were from the United Kingdom. I am delighted that Professor Dennis Anderson will be giving evidence after me, who is one of the authors from the UK, but also included we have, for example, Dr Ged Davis, who was the head of the planning unit at Shell at that time of SRES and now is the Director General of the strategic insight to the Davos Economic Forum, and we had three more colleagues from the United Kingdom[1]. This is just the background I wanted to give you. The 40 SRES scenarios that were developed and the range of emissions are deeply embedded in the literature and in different methodological approaches, specifically the history, and I will try to be brief. I would like to refer to the work of Professor Angus Maddison, who is one of the great students of the history of economics, to his seminal book published in 2001, on the World Economy. He calculates the history of the economic growth, or estimates, for the last 1,000 years, but what is relevant for us here is perhaps starting in the 1820s, or so, at the beginning of the industrial revolution. His number for the economic development on a per capita basis (per person) for this last 200 years is about 1.2 per cent per year, so every year the economy grew 1.2 per cent higher. This estimate refers to the purchasing power parity (PPP). The most rapid period of human development economically was from the 1950s to 1970s. At that time the world economy expanded on a per capita basis per person at about 3 per cent per year (again in purchasing power parity). Let me compare that with the scenarios that were presented in the Special Report on Emission Scenarios of the IPCC. The lowest scenarios with respect to economic growth have average per capita PPP growth, economic growth, over the century of 1 per cent per year; the next lowest about 1.4 per cent per year—and you can see they bracket these 200 year rates—the two highest scenarios with respect to economic growth rates of about 2 per cent per year and 2.5 per cent per year. They are still well below the world experience between the 1950s and the 1970s; so I think one can indeed argue, and lots of effort went into that, that the future outlook in SRES is consistent with what we have seen in the history. There is a Chapter three in the SRES report, which is a huge book. Chapter three is 70 pages long and it goes into great detail about the historical context of these scenarios, not only with respect to the economics but also the demography, technology, land use changes, and so on.

  Q324Lord Elder: Sticking for the moment with the criticisms of IPCC emission scenarios, it appears that all emission scenarios are given equal status, and yet inevitably some will be more credible than others. Should there not be some attempt to see which are the most credible and perhaps to avoid in so doing giving some sort of alarmist outcomes as possibilities? Would it not be better for us to quantify the likelihood of the scenarios?

  Professor Nakicenovic: Thank you very much for that question. The language that was used in the special report, to which all of the 50 authors agreed, is that all of the 40 scenarios are plausible. I think the plausibility is based on a number of factors: one is, as I tried to explain before, that they are rooted in the historical rates of change; secondly, that they are representative of the 500 scenarios in the literature, both with respect to driving forces from demography to economic change and with respect to all the range of emissions. I think that is also important. Thirdly, six different models were used, developed by six different modelling groups, which represent different modelling approaches. There were macro-economic models used, sometimes called top-down models, that have much more detail about the economy and the relationship of the economy in particular to the energy demand and how that leads to the emissions, but there were also so-called systems-engineering models—those are the models that would represent single power plants, automobiles, user-devices—so they would go from the engineering detail up and calculate the emissions. There was this methodological pluralism that also, I think, supports the idea of the plausibility. Perhaps another important thing I would like to mention is that these SRES scenarios were published in 2000 in a report by the IPCC. We have had in the meantime five years of new literature. The new scenarios in the literature are also consistent with SRES range. They fall within this range, and it is not so that the SRES ranges of the driving forces or the emissions were biased in one way or the other. To indicate to you that the range of the emissions, which I think is a big concern in the criticisms, is credible or at least plausible, I do not even need to go into the area of economics. Let me just give you a very brief example that will illustrate why the emissions range is credible. We have today six billion people in the world and we emit six billion tons of carbon. That means that each of us emits one ton of carbon every single year. The highest population projections in the literature from a number of institutions that do global projections indicate that the highest global population is perhaps doubling to 12 billion people[2]. That is the highest (if we use the language of your question), credible population projection (but 15 is also imaginable) so that 12 billion people would already double our emissions to about 12 billion tons of carbon. If the whole world in 100 years from now would have the same emissions as we have on average in the wealthy countries, in the OECD countries (that include Western Europe, North America) of averages about three tons per person on average per year. that gives you 36 billion tons worldwide. That is about the upper SRES range. That is about the range I have given you. That results even though there is also efficiency improvement in the higher scenarios. The lower part of the range constructs similarly. The lowest population projections are—and this might be a little bit surprising—as little as four billion people, a substantial decline from today. That would be a much more elderly population, in particular in the northern regions of the world with most affluent societies. If they would be also only emitting one ton of carbon on average, that would be four billion tons, and the lowest SRES scenarios are in that range. One can assume much higher efficiency of the energy system, introduction of carbon-free energy sources, and one could cut that down to about two or so (tons of carbon per capita per year), and there are scenarios in the literature that have climate policies that reduce emissions far down. In the SRES scenarios climate policies were not allowed by the terms of reference—in mitigation scenarios we find climate policies—so no additional post-Kyoto agreements or anything of that sort was assumed in SRES. I think that if one looks at my very, very simple calculation, the SRES range is plausible, even without going into the economics and other factors, simply because energy is essential for human activities, and currently energy is fossil-based so even transitions away from fossil would still lead to some of the emissions over the next century.

  Q325Lord Vallance of Tummel: Professor, may I bring you back to the economics for a moment, because I suppose the third main criticism of the scenarios is that they use market exchange rates rather than PPP in their projections. We know that you responded to Henderson-Castles' critique on this, but we would welcome an update on what the current state of play is, because I noticed in your answers to one of the earlier questions that you were talking in PPP terms. Does that mean that you now acknowledge that PPP is the right way of approaching this, and, if you do, what difference might that make to the emissions forecasts?

  Professor Nakicenovic: First, I would like to state that the scenarios as published in 2000 were formulated both in PPP and in market exchange terms, so it is counter-factual to say that PPP was ignored. I think it is important that I stress that. I also want to explain to you how PPP is accounted, and, indeed, I am still puzzled why this is continuously being ignored. SRES report has an appendix of 200 pages (from pages 380 to 580) where every single scenario is precisely documented, and I will be happy to leave a copy here as evidence. Six models, as I mentioned, were used, according to intergraded assessment models, to develop the scenarios. One of those models, the model we have developed at IIASA, where I work, is calibrated in PPP and, since all of the models developed all of the four scenario families, we have PPP trajectories for all of the 40 scenarios, and this is why it was possible for me to compare the future PPP growth rates in the scenarios with those that Professor Angus Maddison published two years later after SRES report was published. I think it is really essential that I point this out, that there is a PPP calibration in SRES. At the same time, I think I also need to state that most of the literature—I mentioned that there are about 500 scenarios in the literature-at the time of the writing of the report (there are in the order of 600 scenarios now)—is still in market exchange rates. Perhaps this will change in the future. But it has stayed in market exchange rates for a long time. The reason why we developed a model in PPP is that during the 1990s I chaired a joint study of IIASA and the World Energy Council (WEC) that is situated here in London. It is the largest energy association in the world and they regularly do scenarios. Our group developed a set of scenarios, the IIASA-WEC scenarios that were published in 1998 by Cambridge University Press in a book called Global Energy Perspectives. One of the requirements of that study was to look—

  Q326Chairman: We are going to have to vote in a minute, so can you pause when you get to a good point?

  Professor Nakicenovic: I can pause in 30 seconds, if that is okay. I just wanted to complete this thought. One of the objectives was to look at why two billion people do not have access to electricity. This is a huge challenge today, partially because there is no infrastructure but partially because they cannot afford energy, and PPPs that I have measured to look at it, because people buy energy usually at different prices than the International Exchange Rate prices in many of the developing countries. So that was the reason why we developed it, for cross country comparison.

  Chairman: I am afraid we have to go and vote. We will be back as soon as we can.

The Committee suspended from 4.12 pm to 4.20 pm for a Division in the House

  Q327Lord Vallance of Tummel: Could you come to the second part of the question: how sensitive are the emission forecasts to the choice between MER and PPP?

  Professor Nakicenovic: If you will permit me, I wanted to add a few more points to the first part of your question, and then I will come to the second. I also wanted to mention that Mr Castles and Professor Henderson actually cited IIASA joint study with the World Energy Council as an example of how they feel these things (eg PPP calibration) should be done, but that is an example of a counter-critique on the IPCC scenarios because the same methodology was used in SRES. I would like to also mention that to my knowledge IIASA-WEC study was the first attempt to do a 100 year scenario using PPP. In the meantime there are a number of other studies, and let me just mention some of them for completeness so that you know that there is work going on. There is the model of Dr Chris Hope, the PAGE model, that is calibrated in PPP as far as I know, then there is the Global Scenario Group that has developed PPP scenarios with a simulation framework, then Dr Rich Richels and Professor Alan Manne from Stanford who have calibrated MEGRE model also with PPP, and then the World Energy Outlook that is published in regular periods by the International Energy Agency—the last one was 2004—is also calibrated in PPP, but this is a shorter term study. World Energy Outlook was for 2030, then there is the European Union's work on the World Energy Technology and Climate Report, the scenarios that were developed by Dr Patrick Criqui, (with POLES model) from France—that is also calibrated in PPP to 2030—and most recently (I think that is particularly interesting) Professor Angus Maddison has also produced a PPP scenario to 2015. All of these new scenarios have an economic growth rate on a per capita basis in the order of about 2.2 per cent per year[3], and that is in the upper range of SRES. I just wanted to point that out as well. Before I come to the second question, let me also say that great progress has been done in the PPP data in particular with the International Comparisons Projects, so the data is quite available on the expenditure side, but one of the big issues is that we often deal with trade. In particular in this kind of long-term scenarios, it is not only trade in oil and other commodities, in the future there might be also trade in pollution, in carbon, for example. That occurs at a market exchange rate; and not in PPP terms. There are also some other reasons, depending on the question, for why most scenarios stay with the MER (the market exchange rate) calibration. I think there is no universal approach to that (and expect that both PPP and MER will continue to be used in parallel). Another barrier to using PPP more widely is that the data are very sparse still. My personal impression is that they are about 100 times more sparse than the market exchange rate data. In particular, they are mostly expenditure oriented, there is very little information about the input, output relationships that we need in many of the models—for example, production accounting, and so on. The last thing I want to mention is that the engineering models of the types that we use (at IIASA), model individual facilities, they use prices to do that, and when we achieve cost minimum in the model, according to the theory, that is called the duality theory, that is supposed to emulate an location of very scarce resources by competitive markets. In other words the model is supposed to behave in the same way as the market would allocate scarce resources. If we would do that in PPP we would get the wrong answer; so here one has to use market exchange rates. There are also attempts to use hybrid approaches, but (what I would like to communicate to you) in particular is that most of the literature continues to be in MER. For whatever reason, that is the reality. Less than one per cent of all the scenarios are in the market exchange rate. The second question: what difference does it make whether you use PPP or MER? Let me try to illustrate that with the following argument. Let us take up a hypothetical situation of China, but we could take India or any other developing country. If we measure the Chinese economic output in market exchange rates, it would be four times lower than in purchasing power, roughly four times higher, but the factual situation on the ground is that the emissions are what they are. China is emitting about half a ton of carbon per person whether you measure Chinese affluence and standard in PPP or market exchange rates. There are compensating mechanisms in one shifting from one to another—in measuring economic activities in purchasing power parity results in lower energy intensity and carbon intensity and lower all of the other physical intensities of the economy. China in PPP has about four times higher GDP than in market exchange rates, but it also has about four times lower carbon energy intensity, so the emissions at the end of the day are the same; and in history that is, of course, the same. If you use Angus Maddison's PPP data for history or whether you use market exchange rate data for GDP and we look back in time, emissions factually do not change because they have been estimated from physical quantities, like how much coal was used, how much oil was used, and in principle the same thing should hold for the models and for the future scenarios, and in our case (IIASA scenarios) it does, and in our model of calibration it does so because of the off-setting mechanisms. So, when we evaluate one country in PPP terms and its possible development trajectory for the future, the energy intensities of that country are lower than if they would have been estimated in the terms of market exchange rates and carbon intensities are lower, so those two things offset each other so that the emissions are in principle the same[4]. In practice the models are complicated, so I use the words "in principle". In practice it is very complicated and one cannot turn all of the knobs and whistles always ideally, so there might be some discrepancy. In fact, maybe you have had evidence to that account in this Committee. For example, Dr Rich Richels and Professor Alan Manne in their PPP calibration of their model MERGE come up with 18 per cent difference. What other groups will come up with if they do PPP, I cannot judge. In our case we have really gone to a great effort to account for all of these compensating mechanisms and we do not see any noticeable difference, but I know that colleagues like Professor Richard Tol says that in his model it makes a great difference. I do not know whether he will change his mind if he looks at some of the, let me call it, behavioural equations (eg energy and carbon intensities), but it is important to say that an energy intensity measured in PPP of developing countries is very similar to the energy intensity of this (ie developed) country. If you measure it in market exchange rates it is four times higher and it looks more like our energy intensity perhaps 100 years ago. So I would argue very strongly that in principle it should make no difference on the future emissions trajectories. If it does make a difference, then that is because of the lack of data, lack of time to recalibrate the model. From my point of view doing a model in PPP instead of doing it in market exchange rates is almost the same amount of work as developing a new model. In any case, it is the same amount of work as developing a new base year for the model; so it is a huge effort.

  Q328Lord Lawson of Blaby: I would like to follow on with that, if I may, first, but shall try and be brief because we are very pressed for time because of the divisions that have been taking place on an important issue today. You quoted Angus Maddison as a great authority, and that is absolutely right—he is on growth rates. He has given us written evidence in which he has said, among other things, "An explanation of the importance of using PPP converters rather than exchange rates in comparing levels of performance between countries and in establishing measures of aggregate world output, with an illustration of the implausibility of using exchange rate converters in historical analysis of futurology as in the IPCC's Special Report on Emissions Scenarios." That is his view, that your scenarios are implausible, and he is the authority that you prayed in aid. You say that you have produced a PPP series. Are you aware that Mr Ian Castles, a very distinguished Australian statistician, again has submitted written evidence to us saying that the so-called PPP-based figures in the MESSAGE scenarios are not genuine measures of GDP? Also, are you aware that you have quoted in your preliminary remarks measures of population which go far in excess of anything that the United Nations or anybody else has put as likely population growth and population projections for 2050, which is not all that far away in population terms? We have a pretty good idea of what the population is going to be then, and yet yours go way above that. You also assume, in addition, that you get these high figures by saying that it is in the upper end of the range, that global per capita carbon dioxide emissions will increase significantly, whereas, in fact, global per capita carbon dioxide emissions have remained totally almost absolutely constant for the past 25 to 30 years, and that is an established fact. So it does seem that your scenarios are doubtful, and yet you seem to be content simply to defend everything you have done, to take no notice of informed criticisms that have been made. Are you aware, finally, that Professor McKitrick, a Canadian economist specialising in this area, has given evidence to us in which he says inter alia that one of the striking differences between the second assessment report of 1995 and the third assessment report of 2001 is the loss of participation of mainstream economists in the latter, and he gives details of that. He concludes, "Of even more concern to me is that even after serious flaws in the SRES have come to light, the IPCC has chosen to use the same scenarios for the fourth assessment report even though it is not due out until 2007." Would it not be better, instead of trying to defend the intellectual capital which you feel that the IPCC has built up, if you were to respond properly to the intelligent and informed critiques that have been made and produce something which is closer to the probable truth?

  Professor Nakicenovic: With respect, I beg to disagree on a number of points that you have raised. In particular the first two. I have not seen Professor Maddison's submission to this Committee, but I am not surprised that he says that PPP should be used because he uses PPP in his work; and I am of course aware of Mr Castles' critique on a number of occasions, but as I have tried to say in response to the other questions, SRES report does also use PPP and it would be good to at least hear whether the experts are contesting the fact that the report uses PPP or whether they feel it should have been done better. Simply to say that this is not PPP is not good enough as far as I am concerned. It is important to know what the development prospects should be and how the PPP trajectory should look. It is easy to talk hypothetically, but Professor Maddison's scenario goes to 2015. We would have to see longer-term PPP scenarios developed by this gentleman and other experts that go to 2100, and, of course, I would be very happy to include that into my own assessment and compare it to our results, but for the time being we are discussing most of those things hypothetically. There are many questions. I will try to take one at a time. The comment on the population growth and that it is not credible, I would unfortunately also have to reject that. The scenarios reported in this (SRES) book as the scenarios were done with knowledge about the future population roughly state of the art of the year 1996, and I do have to say a few things just by way of introduction. In the early 1990s it was felt that the most likely or medium population projection for the world was about 12 billion people, the top range perhaps 18 or so. By the time we were writing this (SRES) report the medium was 10 billion people. The highest range about 15, the lowest about six billion people. I am talking about the year 2100, 100 years from now. The two main organisations that do population projections for the world is IIASA that I am affiliated with—it is a very strong demographic group that publishes global population projections at regular intervals—plus, what was mentioned, the United Nations. Those scenarios are done very, very seriously and also reviewed with many, many groups and, as it happens, the two projections do tend to coincide. Ever since this (SRES) report has been published the population projections have been revised, and that is perhaps the biggest change in the literature since the publication of this report; and so that you have a feeling for the order of magnitude of the exchange, the medium projection is now no longer 10 billion people but about eight billion people; the higher is now in the range of about 12 and the lower is in the range of about four instead of six. One way to imagine it is that the global population 100 years from now is moving by two billion people down. That can be good news, of course, but it can also be bad news. The bad news is that the population is ageing and we will probably have to invest quite a lot in many of the support systems for the elderly population, but that in many of the developing countries that have a rampant and explosive population growth the population is going to be likely lower. I would like to pose the following argument just to conclude on the population issue (and this is a fact underlying the scenario literature behind this report and the new literature), that higher the rates of economic growth usually are associated with lower population—I think that is good news—but also with lower rates of emissions growth. It is not necessarily true that high economic growth rates lead to the highest range of emissions. High economic growth rates, because there is lots of capital investment, lots of research and development, lots of education and capacity building, usually mean that the newest technologies are applied, and usually the newest technologies are not only the saving of the input of energy but they are also emission saving; so high growth scenarios do tend to have, everything else being equal, lower emissions than the low growth scenarios. I think that is also important to keep in mind. Then it was stated that per capita emissions had not increased in the world. That is simply not correct. Per capita emissions have unfortunately increased over the last 200 years and continue to increase. In the long term the average per capita emissions increase is about point 5 per cent to about point 7 per cent per year. Every year emissions increase because the population is increasing a little bit over 1 per cent. We have 1.7 per cent increase in total emissions.

  Q329Lord Lawson of Blaby: Are we talking about emissions per capita?

  Professor Nakicenovic: If you divide it by population, they are still increasing on average, in particular in the developing countries. It is true that in some of the most industrialised countries the increase has been relatively low over the last two decades, but in the developing countries it is still increasing. If you take a country like China, there is an increase, they have revised recently their coal statistics, so emissions are indeed increasing around the world. I hope that I have addressed most of the points. I think there was one: why the four scenarios are used if there was such strong evidence that the scenarios should be revised. As far as I know, IPPC or its fourth assessment report is going to not develop new scenarios—that is simply not possible from my point of view[5]—but it is going to review all of the new literature. I have tried to give a glimpse to this Committee of my own analysis of how the literature looks. There is some revision on the population, there is very little revision, if any, on the economic growth rates across the range, on the technology it is very similar, and certainly the range of the emissions is still valid as published in this (SRES) report vis-a"-vis the new literature. I just want to stress that, because we put quite a lot of effort into looking at most of the new sources.

  Q330Lord Layard: I want to come back to the issue that was raised just now of whether the special report receives little exposure to mainstream economists and national accountants. Is this a fair impression and do you yourself have views as to how the scenario might be improved?

  Professor Nakicenovic: Many of the colleagues who participated in writing this report and in particular in modelling are economists, I would say roughly about a third are of the economic profession. I am trained as an economist and I am Professor of Energy and Economics. There were a number of colleagues also who are very, very close to national accountants that have been associated with the (SRES) exercise. I think it is probably unfair to say that it was completely decoupled from the mainstream, whatever that might mean, economic profession. In particular, the larger energy modelling community and the economic modelling community in general has a number of networks in which scenarios are compared all the time, for example the Energy Modelling Forum at Stanford University with which the authors of this (SRES) team had very strong collaboration and many of those were actually lead authors and who are themselves economists. Let me also mention Dr Knut Alfsen, who is the Director of Research at the Statistics, Norway. He was appointed as the lead author of this (SRES) report, and, as far as I know, is the lead author of the Fourth Assessment Report as well and, I believe, was also cited in this Committee as the Norwegian who did a very good study on the GDP. That is Dr Knut Alfsen. The other person from the Statistics community who was involved was Dr Ton Maders from the Central Planning Bureau in the Netherlands Bureau of Economic Policy Analysis. He was also involved in the IPCC scenario exercise. Let me also briefly mention that, after the initial discussions with Mr Castles and Professor Henderson that took place in Amsterdam two years ago, we had attained an agreement to organise a scientific meeting to deal specifically with this (PPP issue), and to invite people who have been doing PPP, but then there have been lots of polemics and public discussion and some of us decided to go along with that idea; and so we did have a meeting in Stanford exactly a year ago that included, for example, Professor Alan Heston, who is one of the key people in the PPP area, and many other colleagues. I understand there was a meeting at OECD later last year, in which I did not participate, so I cannot report on it, and I believe it was mentioned also in the proceedings of this Committee that in January there was a meeting that was organised by IPCC that spent a considerable amount of time on the issues of how to deal with PPP, how to calibrate models in PPP, and also spent lots of time discussing what is new in the literature and how representative these (SRES) scenarios are to what extent are they up to date five years later.

  Q331Lord Skidelsky: We were able to show that the global per capita CO2 emissions level is a stationary constant, neither drifting nor turning upwards, and the trend has not changed for several decades and, indeed, is trending slightly downwards since the early 1980s. That is Professor McKitrick. Is he wrong? It is directly contradictory to what you said. Is he just wrong? You are asserting he is wrong?

  Professor Nakicenovic: Yes, at the world level he is wrong, not necessarily in every single country[6].

  Q332Lord Skidelsky: He is talking the world over?

  Professor Nakicenovic: The world over.

  Q333Chairman: That is a good question and a clear answer, if I may say so. Can I say to you, first of all, I am sorry that we interrupted you, but you managed extremely well to keep coherent and clear and we are very grateful to you for coming to us, for giving us your very clear views on the issues that we are concerned with. It has been a great help to the Committee. I am very grateful to you. Thank you very much.

1   Mr Doug Mckay, Shell; Dr Laurie Michaelis, Environment Change Institute, Oxford; and Dr Ken Gregory, Centre for Business and the Environment. Back

2   Global population projections are regularly published by the United Nations (UN) and the International Instituted for Applied Systems Analysis (IIASA). SRES scenarios were based on the range of these population projections as published by 1996 ( when the work on SRES commenced). In the meantime, these projections have been updated by the UN and IIASA. Back

3   Maddison's contribution to the 2002 OECD publication "Development is Back" gives global GPD per capita growth rate of 2.1 per cent per year between 2001 and 2015; the International Energy Agency in its 2004 World Energy Outlook gives global (PPP) GDP per capita growth rate of 2.2 per cent per year between 2002 and 2030; and European Commission 2003 report World Energy, Technology and Climate Policy Outlook gives (PPP) GDP per capita growth rates of 2.3 per cent per year between 2000 and 2010, 2.1 per cent per year between 2010 and 2020 and 1.8 per cent per year between 2020 and 2030. Back

4   Higher GDP in terms of PPP is associated with lower emissions intensity of GDP. The two factors cancel out resulting in the same future emissions Back

5   Because the process takes a lot of time and requires a large effort. It would indeed be possible to develop a new set of scenarios for the next assessment report. There are many new scenarios in the literature since the publication of SRES and these are being reviewed and assessed. Back

6   Global energy-related carbon dioxide emissions have increased at about 1.7 per cent per year during the last 30 years while population increased 1.6 per cent per year (IEA World Energy Outlook 2004 or BP 2004 Statistical Review of World Energy). At face value this might imply that per capita increase was very low or stationary. However, per capita emissions are rapidly increasing in developing countries, so that temporary per capita decreases in the "North" during the late 1970s and 1980s no longer offset this pervasive development. In fact, global carbon dioxide emissions have increased at 3.1 per cent per year during the last three years (2000 to 2003), while population increased at 1.2 per cent per year, leading to per capita emissions increase of about 1.9 per cent per year, well above the average historical experience of the last 200 years of 1.7 per cent per year. Back

previous page contents next page

House of Lords home page Parliament home page House of Commons home page search page enquiries index

© Parliamentary copyright 2005