<html><body>American Enterprise Institute June 3, 2008 [Edited transcript from audio tapes] <TABLE cellSpacing=1 cellPadding=1 width="100%" border=0> <TBODY> <TR> <TD> <DIV class=BodyText>12:45 p.m. </DIV></TD> <TD> <DIV class=BodyText>Registration </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD></TR> <TR> <TD> <DIV class=BodyText>1:00 </DIV></TD> <TD> <DIV class=BodyText>Introduction:  </DIV></TD> <TD> <DIV class=BodyText>Christopher DeMuth, AEI</DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD></TR> <TR> <TD> <DIV class=BodyText> <DIV class=BodyText>1:10 </DIV></DIV></TD> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText>Panel I: The Science of Geoengineering</DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText>Introduction:  </DIV></TD> <TD> <DIV class=BodyText>Samuel Thernstrom, AEI</DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText>Presenter:  </DIV></TD> <TD> <DIV class=BodyText>Tom Wigley, National Center for Atmospheric Research</DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText>  </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText>Discussants:</DIV></TD> <TD> <DIV class=BodyText> <DIV class=BodyText>Kerry Emanuel, Massachusetts Institute of Technology</DIV></DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> <DIV class=BodyText>Vaughan Turekian, American Association for the Advancement of Science</DIV></DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText>Moderator: </DIV></TD> <TD> <DIV class=BodyText>Samuel Thernstrom, AEI</DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD></TR> <TR> <TD> <DIV class=BodyText>3:10  </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText>Panel II: The Implications of Geoengineering for Climate Policy </DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText>Introduction:  </DIV></TD> <TD> <DIV class=BodyText>Lee Lane, AEI</DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText>Presenter:  </DIV></TD> <TD> <DIV class=BodyText>Scott Barrett, Johns Hopkins University</DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText>Discussant:  </DIV></TD> <TD> <DIV class=BodyText>Fred Iklé, Center for Strategic and International Studies</DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText>Moderator: </DIV></TD> <TD> <DIV class=BodyText>Lee Lane, AEI</DIV></TD></TR> <TR> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD> <TD> <DIV class=BodyText> </DIV></TD></TR> <TR> <TD> <DIV class=BodyText>5:00 </DIV></TD> <TD> <DIV class=BodyText> <DIV class=BodyText>Adjournment </DIV></DIV></TD> <TD> <DIV class=BodyText> </DIV></TD></TR></TBODY></TABLE>   Proceedings: Panel One Samuel Thernstrom:  Thank you, Chris.  Thanks very much. When the writer, Arthur C. Clarke, died in late March, I was struck by the following passage in his obituary.  The notions of the -- "His notions of the future remained unswervingly radical.  Sir Arthur knew that outlandish ideas often become reality."  "But they provoked," he wrote, "three stages of reaction.  First, 'It is completely impossible.'  Second, 'It is possible, but not worth doing.'  Third, 'I said it was a good idea all along.'"  At the moment, I think the idea of changing the earth's environment in ways that would counteract the effects of global warming lies probably somewhere between those first two stages of popular opinion.  Most people probably believe that it is impossible; although most scientists in the field increasingly believe that they are wrong.  Consequently, critics are retreating to the second idea that geoengineering may be feasible, but that it is undesirable.  That may be true, but only time and further scientific investigation and policy analysis will tell.  But, we are certainly altering our environment right now in a massive, uncontrolled, and certainly unintentional experiment, and the solutions proposed so far do not seem to be effective.  While the science is still in its infancy, it is clear that geoengineering offers a potential solution to the worst aspects of global warming in that it could be fast, effective, and affordable.  Those are three powerful virtues in a climate policy that mitigation, at the moment, cannot claim.  Given those facts, I think it is unavoidable that people will eventually embrace this idea if the science holds up. Geoengineering is without a doubt the most original and potentially important idea in climate policy that I have heard of since I first became interested in the general climate issue more than twenty years ago.  It is also certainly the most controversial.  There are many important and complex questions about both the science and policy implications of geoengineering and scholars have really only just begun to explore them.  That is, of course, the purpose of our conference today, and of the series of papers that we intend to commission over the next couple of years. Now, geoengineering is not actually a new idea.  It has been discussed as early as the mid-1960s, but it was never taken particularly seriously until now.  That is starting to change as a set of facts is becoming increasingly clear.  Unless we can radically curtail global greenhouse gas emissions, atmospheric concentrations of greenhouse gases will rise dramatically over the course of this century.  Warming could be as little as one degree Celsius or as much as six degrees.  That is a broad range and there is certainly significant uncertainty involved in such long-term projections.  But, they do give a meaningful sense of what future scenarios policymakers are considering.  Optimists may choose to believe that it is not only possible, but likely that the world will find ways to effectively phase out the use of fossil fuels in the coming -- in the next few decades.  Realists, however, are increasingly recognizing that the odds of that happening are not very good. We have two decades of experience now with climate policy and very few meaningful signs of progress.  We still face the same fundamental problems that have plagued this process all along.  The lack of clean energy technologies that can be produced on a mass scale at a cost that even developing nations such as China can afford and the lack of a global political consensus to develop and deploy these technologies.  Those facts seem unlikely to change in the near future. Voters, of course, are generally supportive of actions to address warming while remaining very reluctant to bear the actual costs of doing so.  We see this ambivalence among our elected officials as well.  Congress, of course, as everyone knows has finally taken -- is finally debating a climate bill this week and although it is not expected to pass, I do think that it is likely that legislation will be enacted of some sort within the next couple of years.  And it is also possible that a successor agreement to Kyoto will be negotiated in the same time.  But, if history is any guide, the environmental effects of these efforts are likely to be very modest. American and European emissions may slow somewhat in the coming years, but they will not cease.  Meanwhile, China will continue to build a coal fired power plant every week and global emissions will continue to rise.  Against this backdrop of policy failures, we have a growing sense of alarm from some -- from a number of climate scientists.  NASA Scientist, Jim Hansen, for instance, and a number of colleagues published a paper at the end of March calling for stabilization of greenhouse gases at 350 parts per million; a target that would significantly be more ambitious than the more commonly discussed 450 parts per million.  The authors of that paper note that if the present overshoot of the 350 part per million target is not brief, there is a possibility of seeing irreversible catastrophic effects. Just days after Hansen's article was published, Tom Wigley, who is with us today, and two colleagues of his, Roger Pielke, Jr. and Christopher Green, published another important article in the magazine Nature that looked into the assumptions behind the IPCC's assessment of how much emissions will need to be cut in the future.  Their conclusions were quite shocking.  Although the IPCC has been accused by its critics of alarmism, their assumptions about how much natural progress in energy efficiency will occur are surprisingly sanguine.  It is responsible, of course, to assume that there will be improvements in energy efficiency and carbon intensity in the coming years driven simply by the desire of companies and consumers to cut costs and reduce waste.  The goal of climate policy naturally is to accelerate that trend, but understanding the baseline of that natural trend is key to knowing how ambitious our policy targets need to be in order to be effective.  The authors of this paper found that the IPCC had assumed that two-thirds or more of all of the energy efficiency improvements and decarbonization of energy supply required to stabilize greenhouse gases will occur naturally absent any climate policies at all to promote them.  Unfortunately, the data does not seem to support the IPCC's assumptions.  The IPCC, for instance, assumes that carbon intensity will drop this decade.  So far, of course, it is not doing so.  It is increasing.  It further assumes that energy intensity will improve at a rate greater than one percent per year, which the authors believe may be neither realistic nor achievable even with a substantial policy effort.  To take one specific and particularly important example, the IPCC has assumed that China's emissions will grow at a rate of only two-and-a-half to perhaps five percent a year this decade.  While the actual data at the moment shows that the correct rate is likely to be at least 11 percent, if not 13 percent. The authors' conclusion is really quite serious.  They write, "The world is on a development and energy path that will bring with it a surge in carbon dioxide emissions; a surge that can only end with a transformation of global energy systems.  We believe that technological transformation will take -- we believe that such technological transformation will take many decades to complete even if we start taking far more aggressive action on energy technology innovation today." That dismaying conclusion, therefore, is even -- is that even with current policy proposals, we are likely to fall far short of the emissions reductions needed to make these efforts successful.  The question of the impact on warming -- the impacts of warming is far too complicated to explore in detail today, but I think there is a simple point that we could probably all agree on.  We do not really know how much warming to expect, one degree or six, but there is not much question that there is some real risk that the consequences of warming may prove to be significant and possibly even catastrophic.  For instance, Harvard economist Martin Weitzman has gotten a lot of attention for a paper that he published in February that explores the risk of possible worst case scenarios of catastrophic climate change such as a rapid melting of the polar ice caps that would produce dramatic sea level rises.  Weitzman acknowledges, of course, that these are low probability scenarios, but his point is that the risk is not zero by any means and that the public policy ought to take those risks into account.  And indeed it certainly ought to, but the question is, "How?"  We could say, of course, that we should simply redouble our efforts to cut emissions and certainly some people will do that, but I have already discussed the limitations with that approach.  So, a prudent response, it seems, would be to also consider what our options might be if that does not work, particularly because emissions reductions are very slow to take effect given the persistence of greenhouse gases in the atmosphere.  If the polar ice caps start melting quickly it will be too late then through mitigation. If mitigation fails, at the moment, our only other option is adaptation, but if the effects of warming are more severe than we can reasonably adapt to, what can we do?  A number of distinguished scientists believe that geoengineering, that is technologies that would change features of the earth's environment to protect us from warming, may be able to provide a crucial safety valve should other mitigation policies fail to sufficiently curb warming.  The various technologies and visage for geoengineering are obviously untested and the science, it should be acknowledged, is still in its infancy.  But, the research conducted to date is quite promising.  The National Academy of Sciences, for instance, examined this idea in 1992 and concluded that geoengineering is feasible, economical, and capable. The most likely techniques would involve reflecting about two percent of the incoming sunlight, thereby blocking just enough of this energy to cancel out the warming that is expected to occur during the remainder of this century.  There are various technologies that could achieve this -- there are various different ways of doing this using relatively simple technologies.  And there are other ways of achieving the same general effect, and Tom can certainly talk about a number of those specific examples.  But, the simplest, most popular idea is to artificially reproduce the cooling effect that was observed after the 1991 eruption of Mount Pinatubo, which cooled the planet by roughly a half of degree Celsius for two to three years.  The paper from Tom Wigley that is in your packet describes the potential effect of artificially reproducing roughly half of a Mount Pinatubo eruption every year. Now, volcanoes, of course, are very crude ways of doing this.  An engineered system would be much more precise and would use very fine particles rather than thick volcanic ash.  But that is, of course, by no means the only technique.  Scientists are, for instance, studying alternatives such as spraying sea water to increase the reflectivity of clouds over the ocean, which would have the same ultimate effect. Naturally, these ideas may seem quite farfetched to people who have never heard of them before, if not frightening, but a growing number of leading climate scientists take them very seriously.  The National Academy of Sciences, NASA, and the Department of Energy have all studied geoengineering and concluded that the science is credible enough to warrant a more systematic study of the field, yet the Bush Administration has declined to support such research, although the federal government currently spends in the range of $2 to $3 billion a year on climate science R&D, depending on how you count the figures. Given the administration's relatively poor public standing on this record, I think it is probably just as well that it did not embrace the idea.  But, obviously, Congress and the next administration will have the opportunity to consider funding it and the question is whether the fear factor will be too strong for them, as well. Certainly, there are a number of plausible objections and questions that come to mind when considering geoengineering.  The question is whether there are, upon reflection, reasonable answers to those questions.  And so, this is the first of a series of conferences that we intend to host to explore them with leading scholars.  Critics have two main concerns about geoengineering.  First, that it would have negative side effects such as ozone depletion or the disruption of rainfall patterns, and I am going to leave that question to our panel to discuss since they are the scientists. But, the second critical question is the so called "moral hazard" question; the fear that discussion of geoengineering will undermine support for mitigation, and I would like to talk about that just for a minute. Scientists naturally as a rule -- as a general rule are exceptionally strongly committed to the pursuit of knowledge.  "Find the facts and let the chips fall where they may."  So, the fact that some scientists have a rather different approach to geoengineering is somewhat extraordinary.  Geoengineering is an idea that according to some is simply too dangerous to talk about and has met with a surprising degree of hostility within the scientific and environmental communities.  When Harvard University and the Council on Foreign Relations recently held conferences on this subject, for instance, they did so behind closed doors.  I have also heard reliable reports that at least one other major university was simply afraid to hold any meeting on the subject at all.  I have heard and read reports of scientists who fear that even any discussion of geoengineering, much less real research and experimentation, could undermine the motivations for mitigation.  Geoengineering, it is feared, would be seen as an excuse to simply continue emissions forever.  With all due respect, I think this concern is seriously misplaced.  Geoengineering is a remarkable idea with great potential, but it is not the silver bullet.  It is not a permanent solution to warming and it is not a perfect solution to warming.  Obviously, there are risks involved in geoengineering and limitations also on what it can do.  I find it hard to imagine that there be any serious political support for policy of "Geoengineering forever and mitigation never."  It would be foolish, I think, to do -- to consider that and I do not know of anyone actually who advocates that. Aside from the risks of geoengineering itself, at least one important environmental effect of high CO2 concentrations in the atmosphere, namely ocean acidification, cannot be corrected by geoengineering.  Geoengineering, therefore, if it is ever undertaken, must be considered a complement to, rather than a substitute for, a long-term program to transition to a zero emissions economy.  But, what geoengineering does is it potentially buys us time, several decades, to make mitigation work.  And, consequently, in fact, it may be the key to mitigation's success, not its undoing.  Time, above all, is what we need to make mitigation work.  I do believe that it is possible to phase out the use of fossil fuels, but the prospects for doing so successfully improve dramatically if the goal is to do it over the course of a century rather than doing it in half that time or less.  Rather than being the death of mitigation, therefore, geoengineering may be the vital linchpin that makes it possible.  There are many challenges to mitigation, but every one of them can be potentially addressed with time.  Time coupled with sufficient dedication and resources is what will produce new clean energy technologies at a price that the developing world can actually afford.  If we can solve the technology problem, we can solve the cost problem, and from there the political problems will fall away, I believe.  I am particularly pleased that Tom Wigley could join us today since he is the author of a seminal article outlining this idea, which is included in your packet as I mentioned.  I just want to highlight the key conclusion of that article, which I think is quite striking.  "A combined mitigation-geoengineering approach to climate stabilization has a number of advantages over either alternative used separately.  A relatively modest geoengineering investment could substantially reduce the economic and technological burden on mitigation.  More ambitious geoengineering, when combined with mitigation, could even lead to the stabilization of global-mean temperatures at near present levels and reduce future sea rise to a rate much less than that observed over the 20th Century, aspects of future change that are virtually impossible to achieve through mitigation alone." I should be clear that the question for policymakers today is not whether to deploy a geoengineering system immediately or even to make it a primary focus on the U.S. climate policy.  Rather, it is whether to make a serious investment in the research and development so that we might understand whether it is really a feasible option and might develop the means to deploy it if we find that we actually need it.  Part of that research, in fact, as I hope we will discuss with Tom, should be the question of how long we can afford to wait before geoengineering -- before experimenting with some degree of geoengineering.  I do not consider myself an advocate of geoengineering, nor I think would any of our panelists today, and if my remarks may have given that impression so far, it is because I assume that most people on hearing this idea need to be persuaded that they should take it seriously.  It does seem rather outlandish to most people on first blush.  But, I am an unabashed advocate of conducting a rigorous research program into the science and engineering questions and in the coming months we intend to do that. Without further ado, let me just introduce our panel.  Tom Wigley is a senior scientist at the National Center for Atmospheric Research.  He is one of the country's most distinguished climate scientists and one of the leading scientists in the world researching geoengineering. Mr. Wigley has published widely in the field of climatology and related sciences and is the author of more than 250 referred journal articles and book chapters.  He has been a contributor to the -- all of the Intergovernmental Panel on Climate Change (IPCC) assessments and he developed the well-known MAGICC coupled gas-cycle/climate model used to produce temperature and sea-level projections given in IPCC reports.  He is also the former director of the Climate -- Climatic Research Unit at the University of East Anglia in the United Kingdom. We are privileged to have two superlative discussants join us today to respond to Mr. Wigley.  Kerry Emanuel, sitting next to Tom, is a professor of atmospheric sciences at the Massachusetts Institute of Technology, where he has been on the faculty since 1981.  He is one of the nation's leading atmospheric scientists.  Geoengineering is not his specialty itself, but he is a top climatologist and he has been generous enough to share his time today to offer his perspective on that question. Professor Emanuel is the author or coauthor of more than a hundred peer-reviewed scientific papers.  His most recent books include Divine Wind: The History and Science of Hurricanes and What We Know about Climate Change, MIT Press, 2007. Closest to me here, we have Vaughan Turekian, who is the chief international officer for the American Advancement -- American Association for the Advancement of Science.  Previously, Mr. Turekian served as special assistant for the under secretary of state for democracy and global affairs, where he was lead adviser on a variety of scientific issues, including the environment, technology, clean energy, sustainable development, and climate change. Mr. Turekian also worked at the National Academy of Sciences, where he was the study director for the 2001 White House-requested report on the study of climate change science.  He is published widely on a range of topics.  I would particularly recommend to you his 2007 Foreign Policy article coauthored with Paul Sanders -- Saunders entitled Why Climate Change Can't Be Stopped. We will follow our usual format for this conference this afternoon.  Mr. Wigley will present.  Mr. Emanuel and Turekian will comment.  I will give the panelists an opportunity to question each other, and then I will open up the floor to questions from all of you.  Thanks very much.  Tom. Tom Wigley:  All right.  Do you want me to talk from over there? Samuel Thernstrom:  You can either do it there or [inaudible]. Tom Wigley:  With -- first, I would like to thank Lee Lane and Sam here for inviting me to this important event to discuss a subject that is quite close to my heart.  And I would also like to thank Sam for giving such a comprehensive overview really.  I mean I am just going to fill in some of the details and I hope that -- and I appreciate the fact that you have introduced a number of topics very comprehensively that make my task a lot easier. Okay, so, Science of Engineering is the title of my talk.  That is not my title.  That was the title that I was asked to address, and I am a scientist, so I am going to try and talk about the scientific aspects more than the technological and the policy and political aspects.  But, of course, those things will spin off from what I have to say. Just to summarize the issues that I am going to try and cover here, I want to define a few terms, first of all.  I am going to concentrate on a particular type of geoengineering that is sometimes called Solar Radiation Management, and it deals with trying to change the amount of incoming solar radiation.  And there are different ways one can do that and, specifically, one can use a kind of artificial volcano idea by putting sulfate aerosols or some other particles in the upper atmosphere, the stratosphere, where they stay around for a few years, and they will reflect incoming solar radiation and cause a cooling that would perhaps compensate to some degree for the warming due to greenhouse gas emissions. I am going to say something about the mitigation issue per se.  And then, as Sam says, in my little science paper, I talk about combining both geoengineering and mitigation and the need -- the essential need for mitigation no matter what we do, and I will say a little bit more about that.  Then I will talk about the sea-level and temperature -- consequences of these combined strategies, and finally draw some conclusions or summarize some of the results. Okay, so mitigation -- I am sure most of you know the words, but I will define them nevertheless very briefly.  So, mitigation essentially means reducing greenhouse gas emissions.  Carbon dioxide is the most important and that can include things like reforestation or carbon capture and disposal and so on; just reducing the net emissions of carbon dioxide and the other greenhouse gases into the atmosphere. Adaptation is trying to reduce the impacts of those climate changes proactively by developing adaptive mechanisms.  And then, geoengineering and, specifically, Solar Radiation Management, is the deliberate modification of the earth's short-wave radiation budget to try to reduce the magnitude of global warming or climate change. Up until a few years ago, everybody realized that we were going to have to both mitigate and adapt.  We could not just do one or the other, and the reason why adaptation is important is that the climate system has a lot of inertia.  And so, no matter what we do, the continued global warming and the need for people to adapt to those changes in climate that are inevitable no matter what we do.  And more recently people have realized that perhaps a third corner of this triangle might be geoengineering, which should be combined with the other two strategies.  Some examples of geoengineering in the sense of Solar Radiation Management that I am going to concentrate on here are the injection of aerosols or aerosol precursors.  So, for example, if we put sulfur dioxide in the stratosphere and there is enough water vapor there, then the sulfur dioxide will be oxidized and hydrolyzed to form sulfuric acid droplets, and it is those droplets that reflect back incoming solar radiation.  There are other ways of doing that, but I am going to concentrate on that particular method. Another method that I mentioned is changing the reflectivity of clouds, and I have got some nice little pictures that show you that strategy.  And I think that that is a complementary approach that may also need to be explored because if it works then it is relatively inexpensive, and I do not think we should have a portfolio of just one strategy.  We need to have a full portfolio of a number of strategies because no one method is going to solve the problems that we face. And then, there are other things like painting roofs white, and changing vegetation albedo, and so on, that I consider to be aspects of geoengineering.  I am not going to say any more about that, but in a sense they are examples of Solar Radiation Management. Oh -- that is interesting -- oh, it is just a little slow response.  This is a picture just showing that if you increase the number of cloud condensation nuclei, then you do change the droplet size distribution in clouds and you change the reflectivity of clouds.  So, this is one of the geoengineering approaches -- and this is demonstration that in principle this approach should work in a very elegant way of changing cloud condensation nuclei and has been proposed by some English scientists.  And this is a very clever boat that they imagined might be moving about the world's oceans in the areas where there are the right sorts of clouds, where this is a self-propelled boat.  It has very strange looking sails here that rotate and allow the boat to be moved around by the wind and the rotation also pumps water -- sea water up into these columns and sprays it up into the clouds and those small droplets then act as a cloud condensation nuclei, change the droplet size distribution in the clouds, and thereby reduce their albedo -- increase their reflectivity.  So, this is a rather interesting and elegant approach that has many, or if not all of these geoengineering ideas -- it is okay on paper, but is yet to be demonstrated as a practical consideration. Okay, so why should we consider geoengineering at all?  You know, hopefully in an ideal world, we ought to be able to solve the climate change problem just through reducing emissions and through adapting to the inevitable changes that will occur.  Now, the real difficulty here is that if we are to follow Article 2 of the Framework Convention, and that is try to avoid what is called "dangerous interference" of the climate system, even though that is a term that is not well-defined, then there must be some stabilization target for carbon dioxide that will give a high probability of avoiding dangerous interference of the climate system.  A general opinion is that that CO2 stabilization level is about 450 parts per million.  And as Sam says, Jim Hansen and other colleagues have suggested that it may be much less than that.  It might be 350 parts per million.  And, in fact, there are even arguments to suggest that we might have to go back to below the pre-industrial level to stabilize the rise of sea-level.  The real question is -- you know, let us take this upper limit of the bound for avoiding dangerous interference at 450 parts per million.  The big question is, "Is that achievable?"  I mean do we have the technology level and do we have the political will?  But, do we have the technology to achieve levelization of 450 parts per million? Okay, so there are two issues here that need to be thought about seriously.  Firstly, suppose that we decide that 450 parts per million is a reasonable stabilization target and then we find that we cannot get there from here, that the technology is not available, the political will is not there, but particularly the technology is not there to stabilize at 450 parts per million.  What might happen is that we might have to follow what is called an overshoot pathway where the concentration of carbon dioxide goes well above 450 parts per million, and then is brought back down by appropriate mitigation strategies back to 450 as an eventual target.  And that is a case that I am going to consider the overshoot pathway. We might find out, as Jim Hansen believes, that the climate system is more susceptible to increasing greenhouse gas concentrations and that 450 parts per million is too high a target.  So, you know, how would we -- if we cannot even achieve 450 parts per million, then how would we ever get down to a lower level?  And that is where -- in both of these cases where we have to think seriously about geoengineering.  Unfortunately, geoengineering has a number of potential risks associated with it.  I am going to consider later a scenario where I think those risks are minimized, but many of the recent research papers on this issue have asked the question, "What would be the risks associated with trying to offset the amount of warming associated with a doubling of carbon dioxide with geoengineering alone?"  Okay, so that question can be posed in a slightly different way and one can say, "What if we wanted to cool the world by three degrees Celsius using geoengineering?"  We would have to implement a certain -- a magnitude of geoengineering and that magnitude would have associated with it certain risks.  So, what are those risks?  And most recent research has been trying to address those particular issues. I will not go through all of the risks associated possibly with geoengineering or with this rather extreme case of geoengineering.  But, one of the big uncertainties is what might happen to the ozone layer, and it happens that ozone is depleted more [audio glitch] on the surfaces of particles -- or the surfaces of particles are necessary for the ozone depletion in the stratosphere.  So, if we put more particles in the stratosphere then we might slow down the rate of ozone depletion or we might even reverse the situation where ozone would be increased temporarily and then the slow down would be delayed by many decades.  I do not think that is a serious problem if one considers a realistic geoengineering strategy, but in an extreme geoengineering strategy it is a very real possibility.  Another area of considerable concern and uncertainty is, "What is the effect of geoengineering on the climate system?  Would geoengineering completely balance the effects of greenhouse gases on the climate system?"  Well, geoengineering is a change in the short-wave radiation balance.  Greenhouse gas forcing is a change in the way of long-wave radiation balance.  And we know that the climate effects -- even for the same amount of radiation change, the effects on the climate are quite different.  So, we cannot just do geoengineering to completely balance out the effect of global warming associated with greenhouse gases, and we need to know more about what those counterbalancing and differential effects are.  So, those are just a couple of the issues that people are considering in doing research on possible geoengineering strategies. One of the other issues associated with geoengineering is cost.  And again there have been no definitive estimates for the cost of geoengineering, but it does appear that a significant amount of geoengineering could be done for much less than the cost of mitigation.  So, again that is an uncertain conclusion, but Paul Crutzen estimated that one could offset most of the global warming at the cost of $50 billion a year, which is a relatively small amount.  Again, I said that is a very uncertain quantity, but it does seem that geoengineering -- you know, once we get over the development of the technology to do this, could be relatively inexpensive.  We do not have the technology to perform these geoengineering experiments yet.  And this is a little profile  -- latitudinal height profile through the atmosphere, and it shows the tropopause and the boundary between the stratosphere and the troposphere there as that -- those little, curved red lines.  We have research aircraft -- an end car that flies in the upper tropical troposphere and actually in the stratosphere at higher latitudes, if we desire that to be the case.  There are research aircraft that can fly at about the level where people have suggested the injection of sulfur dioxide or some sulfur compound to produce aerosols.  So, we have got the technology available on a small scale, but do we have it available at a scale sufficient to be able to implement geoengineering in a way that will have some substantial effect on the climate system?  So, we are part-way there, but we are not -- certainly not fully there in terms of the technology. This is a point I made right at the start, and Sam has made it, and I cannot stress this too forcefully, and that is that geoengineering cannot be looked at as a replacement for mitigation.  Mitigation is absolutely essential, if for no other reason than the fact that increasing carbon dioxide increases the acidity of the oceans, and if that trend goes too far then the whole of the ocean biosphere is in jeopardy.  Simply because at the bottom of the food chain shell producing organisms, which require a certain pH level in the ocean to be able to produce those shells, if we increase acidity, they will not be able to produce shells.  They will die, and then the food chain will be disrupted, so that is not a consequence we really want to contemplate.  So, we have to mitigate.  We have to reduce CO2 levels to somewhere around to 450 to 550 parts per million to avoid this pH-related catastrophe.  So, for that reason alone, we should consider both mitigation and geoengineering as complementary approaches to solving the climate change problem. I mentioned some of the risks already associated with geoengineering.  One that has been mentioned is that if you are putting sulfur compounds in the stratosphere they are going to fall out.  If they fall out then what did that add to acid rain?  Well, the amount of sulfur that one has to put in the stratosphere is very small compared with how much sulfur dioxide we are producing in the troposphere now -- you know, 10 percent, 20 percent or so, so that definitely is not a serious issue. Sulfate falling from the stratosphere into the higher troposphere will affect high-level clouds.  And again that is something that has not been really examined at all, at least not in the geoengineering context, but that does not seem to be a very important issue.  If we inject a lot of sulfur dioxide and produce a lot of aerosols in the stratosphere that would certainly slow down the recovery of the ozone layer.  So, the issue there is just how much of the material we put into the stratosphere and I will come back to that one later. I have already mentioned the uncertainty and the patterns of climate change.  For example, Alan Roebuck and other people have suggested that if we were to counterbalance global warming exactly with geoengineering in the global-mean sense, then that would cause global rainfall to decrease simply because rainfall is more sensitive to short-wave energy balance changes than it is to long-wave energy balance changes.  And he suggested that the Indian monsoon or the monsoon systems of the world might become less active.  Now, I mean -- I think that is a -- not a sensible suggestion simply because the amount of reduction of the monsoon that might occur is a few percent and the interannual variability of the monsoon is plus or minus 30 percent.  So, whatever signal might occur there is completely masked by the noise of interannual variability.  And, furthermore, I am not sure that decreasing the intensity of the monsoon would be a bad thing, because flooding is one of the major problems of the monsoon, at least in India and Bangladesh.  I visited Bangladesh one time and the whole country was covered in water and I think a less intense monsoon might reduce the probability of those sorts of events.  So, there are a lot of unresolved issues here, not only in climate science, but also in the implications of these scientific experiments. I want to say a little bit now -- some background on mitigation before I move into the details of the geoengineering combined with mitigation.  And there are some standard concentration pathways that have been used in the literature for carbon dioxide stabilizing at different levels in the future, and this diagram shows those pathways.  And essentially they are rather arbitrary stabilization levels of 350, 450, 550, 650, and 750 parts per million, and a smoothly varying transition away from a no-climate-policy baseline eventually stabilizing at those different levels.  You can see we are already above the 350 pathway, so that is an overshoot case, and I am going to consider another overshoot case, which stabilizes at 450 parts per million. Now, what is important about stabilizing concentration is that it is not the same as stabilizing emissions.  In order to stabilize concentrations, we have to reduce emissions substantially and for a very long period of time, and these are the corresponding emissions pathways for those stabilizing levels.  And if you look at the 350 case, you can see that one would almost certainly have to go to some period of negative CO2 emissions in order to stabilize at 350 parts per million.  To stabilize at 450 parts per million, we have to reduce emissions immediately below the baseline -- the no-climate-policy baseline that would occur.  In the absence of policy, if we were to stabilize at 550 parts per million, we might be out a way to a few years to a decade before we had to move away from that no-policy pathway.  So, these are very, very challenging emissions targets that one would have to meet to stabilize at any of these particular levels.  And for 350, you know, one could almost say that it was impossible; although, there are technologies out there on the table for removing CO2 directly from the atmosphere in small amounts.  So, in principle, if we have another 75 years to wait, we might be able to develop the technology to extract CO2 directly from the atmosphere and have negative emissions.  So, one should never say "impossible" given the ingenuity of the human species. I might just skip through those numbers and just say something about this stabilization challenge as a concentration challenge, because it is really a technology challenge.  And as Sam mentioned, my colleagues, Roger Pielke and Chris Green, and I wrote a little commentary in Nature that was meant to show exactly what the magnitude of the technology challenge is. Now, in the literature, there are a lot of no-climate-policy emissions pathways into the future.  They are producing a book called The Special Report on Emissions Scenarios and all of those pathways they -- no-climate-policy.  So, these pathways of emissions into the future that will happen without any policy -- there is a huge range of uncertainty there because it depends on economic growth, population growth, technology and so on.  So, there is a range of possibilities, but all of these no-climate-policies trajectories assume that a large amount of technological change towards carbon-neutral technology, away from fossil fuels, will occur spontaneously in the absence of policy.  And the blue bars there are the spontaneous reductions in cumulative emissions, things that are meant to happen in the absence of policy.  The red bars are the remaining policy-driven changes in cumulative emissions. And as Sam said, you know, roughly two-thirds of the changes that are necessary to stabilize the concentration of carbon dioxide at around 500 parts per million -- roughly two-thirds are expected in these emissions scenarios to occur spontaneously automatically.  We have reason to believe, and many economists agree with this, that that is an optimistic scenario.  So, what that means is that the true technology challenge is not just the red bit there, but it is the -- it is from the top of the panel down to the yellow.  The true amount of innovative technology that has to be introduced is really very, very large.  Just how much will occur in the absence of policy and how much will have to be policy-driven is highly uncertain, but it is a huge challenge. I have just got a couple of quotes here from some leading economists in this area.  Carman Difiglio works for the -- or used to work for IEA -- works for the Department of Energy now, and I will read this out.  He says that, "A 450 stabilization scenario requires a complete transformation of investment in the electric power sector by 2012 -- that is not very far off.  And he quotes from the World Industry Outlook published in 2007, "exceptionally strong and immediate policy action would be essential for the 450 stabilization scenario to happen, and the associated costs would be very high." And then Jeffrey Sachs, in a nice little piece in Scientific American a couple of months ago, says this.  "  current technologies cannot support both a decline in carbon dioxide emissions and an expanding global economy.  If we try to restrain emissions without a fundamentally new set of technologies, we will end up stifling economic growth --."  And the word "fundamentally" is important -- "fundamentally new set of technologies," you know, that is really putting it out there that there is a huge and generally unappreciated technological challenge. And another colleague of mine, Marty Hoffert, has said many years ago that this technology challenge really requires a Manhattan Project to develop and deploy the technologies required.  It is like going to the moon again only we are not going to the moon, we are trying to save the planet.  There is no inclining that we are heading in that direction at all at the moment.  And if not -- I mean if you look at China and India, we are basically going in the opposite direction. Now, many people believe that geoengineering should only be used as a last resort and that raises the question, "What do you mean by last resort?"  And there are two ways to look at that question.  One is the standard way, and that is that geoengineering should be a last resort in the climate context.  In other words, if we realize and see that we are heading towards some really dangerous so called "tipping point" in the climate system such as Greenland rapidly decaying and melting and raising sea-level, if we can see that on the horizon with high confidence, then geoengineering becomes a last resort strategy that we might have to implement.  The other last resort aspect is the technology aspect and that is one that I think is really important.  If we see that we do not have the technology, we are not developing the technology to mitigate at some safe level of future climate change, then that is also a last resort.  If the technology is not there then maybe we need to think seriously about other approaches like geoengineering. Okay, so what geoengineering allows us to do is depart more slowly from the no-climate-policy CO2 pathway.  And in that sense, give us more time to develop carbon-neutral technologies that are appropriate for mitigation at a sensible level like 450 parts per million or less.  But, as I have said before, we have to combine geoengineering and mitigation because at least the effect of increasing CO2 on ocean acidity is something we want to avoid.  Okay, so geoengineering should be looked at as a way not to solve the climate problem, but to give us time to solve the climate problem through mitigation.  I dreamt up some different mitigation -- some different geoengineering scenarios, and if you look at the science paper you will see that this is the same material.  The three cases I considered were where I allowed 30 years to ramp up to some maximum loading of aerosols in the stratosphere.  And I assume that that maximum loading would reduce the radiation balance by three watts per square meter to give you that -- give a context that if we doubled the amount of carbon dioxide, then that is about four watts per square meter.  So, three watts per square meter is roughly equivalent to offsetting the effect of a doubling of carbon dioxide.  And then, I consider these three different pathways: a rapid ramp up to three, and then a decline back to a lower but continuous level of radioactive forcing.  Another case where I cut off the geoengineering not instantly, but fairly rapidly, and went back to no geoengineering at all, and that is the upper Low Geo case.  And then, I consider one where we ramp up to three watts per square meter and keep that level of geoengineering continuously, and I combine these three geoengineering cases with an overshoot scenario.  Okay, so here are the carbon dioxide concentration scenarios.  Firstly, the blue curve is a monotonic continuously increasing case that stabilizes at 450 parts per million.  The green curve is an overshoot case where for some reason -- lack of technology in particular -- we cannot go along the blue curve.  But, then given time we develop the technology to get back to 450 parts per million.  And then the red curve is a baseline case where there is no-climate-policy. And you can look at the emissions consequences of those concentration pathways in the lower panel, and you can see that in this idealized overshoot case then we could imagine technology developing very slowly, so the departure from the "business as usual" case is very slow for the first 15 or 20 years, and then becomes more rapid when the technology becomes available.  So, that is the green idealized curve for the emissions trajectory following the overshoot case.  And if you look at the economics of these things in some crude way, forgetting about the technology development issue, the green curve is economically less expensive than the blue curve.  It is definitely less costly to give oneself time to reduce emissions than to try to suddenly change the whole global energy system overnight to something that does not reduce -- does not emit carbon dioxide. I am going to consider a comparison of the mitigation case and the overshoot case here.  I will not say any more about the baseline case.  So, what I have done -- I am sorry this is a rather messy diagram, and I will give something simpler in the short while -- but I have a simple climate model where I can put these scenarios in and run them on my laptop and figure out what would happen to global-mean temperature and sea-level.  Of course, global-mean temperature is only part of the issue and we need to use more sophisticated models to look at the patterns of rain, food change and temperature change and so on.  And other people are doing this, but this is kind of a first pass at the global-mean level.  And let me just pick out -- yes okay, the purple curve is following the WRE 450 pathway.  Okay, that is the case where we gradually approach a 450 stabilization level, but do not go over the top. The green curve here is where I -- sorry -- no.  The blue curve is where I combine the low geoengineering scenario with the overshoot pathway, right?  So, once we get out beyond about 100 years, you can see that one can very easily get back to the standard 450 parts per million pathway.  This -- the warming is eventually about two degrees, which may or may not be optimum. You can also see that I have actually got far too much geoengineering in here because I am cooling things -- the globe -- way below the 450 pathway.  For sea-level, sea-level is a very difficult problem to cope with because even with stabilization -- okay, so let us look at the purple curve there, you can see that even stabilizing the level of CO2 in the atmosphere at 450 parts per million causes sea-level to continue to rise for many, many centuries. I will skip over some of these risks here and give you another simplified scenario.  Now, I just said that those ad hoc scenarios I considered were too intense in terms of the magnitude of geoengineering in the early decades out to about 100 years into the future.  So, is there some other pathway that we could choose, and what I can do is ask a different question.  I can say, "How much geoengineering do we have to do just to remove this overshoot area here?"  Okay.  And if I do that and then compare that radiative forcing scenario with the ad hoc ones that I considered before, you can see that what is needed just to allow us to do the overshoot is really very small compared with these other scenarios that I considered. The maximum amount of radiative forcing reduction is only about one watt per square meter, so that is about -- that is less than half a percent of a change in incoming solar radiation.  Sam mentioned that people have been doing studies where they consider a two percent reduction in solar radiation.  So, I am saying that we can actually implement a very useful amount of geoengineering at a quarter that amount of reduction in incoming solar radiation.  And, furthermore, the peak solar radiation does not occur until the second half of the century and at that level -- at that level there, the maximum -- that radiation deficit is equivalent to the average reduction in radiation that would occur if Pinatubo, a very big volcano that erupted in 1990/91, if Pinatubo occurred every seven years.  Okay?  So, it is hard to imagine that that sort of scenario would have any adverse consequences on the ozone layer, deposition of sulfur dioxide into the troposphere, climate change or anything.  So, if we do look just at geoengineering as a way of gaining time to develop and implement the technology, if that is our primary focus, then the risks I think are negligible.  But, the positive gains I think are enormous.  Okay, so I will just summarize now with these few conclusions and a final statement at the end.  That scenario is where the amount of sulfur dioxide or sulfur compounds emitted into the stratosphere has a maximum of about one teragram per year.  And that maximum is a slow ramp up over a 70-year period, and then a very slow decline back to zero over another couple of centuries.  The total amount of sulfur compounds emitted over -- cumulative over three or four centuries is only 100 teragrams of sulfur.  You know, we are emitting 70 teragrams of sulfur per year into the troposphere now.  So, we are talking about less than two years worth of sulfur injected into the stratosphere over a period of four centuries.  One of the things I really did not dwell on was that the continuous geoengineering case where I ramped up to three watts per square meter negative forcing and continued that for many centuries, that has the effect of stabilizing -- almost stabilizing sea-level.  And I just want to, as an aside, tell you that that is an incredibly difficult problem.  In order to stabilize sea-level at -- using mitigation alone, we have to go down to 250 parts per million CO2.  We have to go below the pre-industrial level.  And that is even accounting for stabilizing the other greenhouse gases, so not just the CO2 alone, that is a multi-gas strategy.  And the catch-22 of that is that if we go back to 220 -- 250 parts per million CO2 concentration, it turns out that sea-level stabilizes at about 20 centimeters above where we are now, but temperature drops to one degree below where we are now. So, that is -- I mean that is the perfect catch-22 situation.  We cannot stabilize sea-level -- and this is also, for the geoengineering case -- we cannot stabilize sea-level without going into a climate that was the norm in the 17th century, the time of the little ice age, when the world was about half to one degree cooler than now.  So, there are some really interesting issues there dealing -- that relate to what we have already done -- to be a little coarse -- to screw up the planet in a way that there are -- aspects of the environment that we cannot recover in any way that I can think of. I will just conclude with these summary points.  And they are very similar to the points that Sam made and it is very good to be on the same page here.  So, I really do not think that we can stabilize carbon dioxide levels at an appropriate point that would avoid dangerous interference of the climate system without either some radical breakthroughs in carbon-neutral energy technology -- and of course, those things might happen -- you know the future of technology is highly unpredictable and we do not know exactly what might happen there -- but I think that it is unlikely that we would develop the technology in a timeframe that would allow us, through mitigation alone, to stabilize the climate of the atmosphere at some sensible level.  So, that is why I think that we should be considering the science, the politics, the costs, the technology, and all aspects of geoengineering very seriously.  Sam mentioned that -- depending on how you define climate research -- this U.S. government is putting $2 to $3 billion a year in that area.  If we get -- were just to put in another one percent -- an additional one percent -- I do not want to take money away from other important areas of climate research.  But, one percent is another $20 million a year and I think that $20 million a year would make tremendous inroads into removing our uncertainties both in the climate science, in the technology, in the ethical aspects, in the political aspects, and the policy aspects.  So, I just hope that this project that AEI is developing now is opening the door towards a more serious consideration of additional funds to the community, in all aspects of the community, to investigate this problem in a serious way.  Well, thank you very much. [Clapping] Samuel Thernstrom:  Thank you, Tom.  That was terrific.  We can -- I guess I will turn to our discussants in order.  Kerry, do you want to start? Kerry Emanuel:  Sure.  Tom, before I get into some questions, I wanted to ask you if you might give this gathering a kind of flavor of what sort of technologies have been discussed for -- for example, doing this stratospheric sulfate injection, because I think that helps people actually envision what might happen in a more concrete way. Tom Wigley:  Yes, I am not -- Male Voice:  Tom, could you just turn the mike on please? Tom Wigley:  -- oh -- okay.  Thanks.  I am certainly not very knowledgeable about these issues.  However, I do know a number of possibilities are being put forward.  So, one idea in the Academy Report from a number of years ago was firing cannons and shooting the stuff up into the stratosphere.  A bit like H.G. Wells' Journey to the Moon or whatever the name of that movie was.  [Laughter] Another possibility is very high flying balloons and burning sulfur compounds up there in the stratosphere.  Flying planes high enough and either directly injecting material from tanks of sulfur compounds or less likely putting sulfur compounds into the fuel mix, and then the combustion material would lead to aerosol generation.  I mean that is not such a sensible idea because the sulfur I think just burns the engines out very, very quickly.  So, you would have these planes flying up and falling out of the sky.  So, all of these ideas are highly speculative and -- but I think that they are amenable to serious investigation. Kerry Emanuel:  Okay.  What I would like to do is explore with you a little bit about what I considered to be the main scientific issue here -- and that is one that you raised in your talk -- is that we are in a sense fighting apples with oranges here.  That is [audio glitch] that the CO2 induced warming, the greenhouse gas warming, is an effect in the earth's long-wave radiative budget infrared radiation.  We are combating it, potentially at least with the techniques that we have discussed here, by reducing incoming short-wave radiation by putting reflective particles in the stratosphere. And you can maybe cleverly enough engineer your way to getting a desirable rollback, if you will, in the earth's global-mean and maybe even zonal mean temperature to where you "want it to be," which will be an interesting discussion I think later for the other panels, "Where do we want it to be?"  But, we will not get into that now.  But, it is not a zero sum game and other quantities, and you mentioned precipitation.  I tried to actually verify the result that you mentioned that global precipitation would be reduced and I could not.  I came up with the idea that it might go either direction depending upon exactly [inaudible].  What I wanted to ask you is, have there been concrete modeling studies yet done to look at geoengineering scenarios?  And if so, what have they suggested about some of these non-zero sum properties of the change?  Tom Wigley:  Yes -- that is better.  Yes, there have been a few studies and, in fact, a number of years ago my -- one of my colleagues at NCAR, Jerry Meehl and I, and a number of other people, looked at the effects of changes in solar radiation versus the effects of changing carbon dioxide concentration.  And we found that there was a very interesting differential effect in the monsoon area in particular.  And the same amount of forcing -- of solar forcing versus greenhouse gas forcing, did not lead to the same amount of change in precipitation in that particular part of the world.  Now, more recently in the geoengineering context, Alan Roebuck has a paper which has just recently been accepted for publication where he has used a GODAD [sounds like] model -- climate model -- coupled ocean atmosphere general circulation model -- and tried to look at the effects of adding sufficient geoengineering to offset all of the warming that might occur under some "business as usual" scenario in the future.  So, that is a rather extreme geoengineering case, and he points out in his paper that there is this same differential effect between changing short-wave radiation and changing long-wave radiation on precipitation.  So, he has confirmed that issue. And there is another very interesting paper by some people at PCMDI, but I do not even know whether it has been submitted, where they -- and I am sure you would be interested in this actually -- where they try to explain why there is this differential effect.  Now, Alan Roebuck also tries to explain that and it is simply because the short-wave radiation effect has a different vertical profile in terms of radiative forcing compared with long-wave radiation effect.  So, somehow it is related to the vertical structure of the radiative balances and imbalances.  There is another -- there is at least one other paper where they have done similar analysis to show again in the model world that there is this differential effect. Empirically, I think this would be a very difficult thing to demonstrate.  You may know of some work that Kevin Trenberth did where he looked at the eruption of Mount Pinatubo as an analogy for possible geoengineering response and showed that in some parts of the world there were very large decreases in precipitation.  He did not compare those decreases with what the equivalent effect of long-wave radiation forcing might be, but they are sufficiently large that -- I think that that is a reasonable empirical demonstration that there is this differential effect. Kerry Emanuel:  Okay.  In that connection, you mentioned in your talk some of the risks of undertaking this.  You did not have a side that said benefits I think because we assume that the benefits are self-evident -- Tom Wigley:  [Laughter] Kerry Emanuel:  -- some of them no doubt are.  But, I wonder if these same studies we have just been talking about actually also show something on the other side of the ledger.  And my own work is in the field of hurricanes, and we know with increasing certainty that the Atlantic hurricane deficit in the '70s and '80s was almost certainly driven in part by manmade sulfate aerosol pollution of the [sounds like] copusphere, so that when we do this, one should be conscious of other perhaps side benefits to the -- do you know of any others? Tom Wigley:  Well, I -- Yes, I am sure there are benefits like that.  That is a very interesting one.  You know, my perspective is basically that I do not think we can get there from here unless we do some modicum of air -- of geoengineering.  So, that is an enormous benefit. Kerry Emanuel:  Well, I have one last question, which is more -- it is a question for a scientist, but somewhat philosophical.  As a scientist as opposed to a policy person, what do you think the next steps are in the field of science to try to flush out the viability of geoengineering aside from obviously wanting to take steps to promote research?  Should we move, for example, toward a geoengineering experiment?  We do not necessarily have to just switch it on and leave it on or conform to the scenarios -- one of the scenarios that you mentioned.  We might actually design a field experiment to do this for a period of years enough to have a detectable effect.  Make enough measurements to confidently quantify what effect particular geoengineering has, and then use that as a basis for designing an intelligent strategy.  Is that a way forward or how would you go about doing that? Tom Wigley:  Well, I think there is a lot more work that has to be done on the desktop through computer modeling, first of all.  We have only just begun to do experiments using coupled ocean atmosphere general circulation models and one of the problems even with those experiments is the signal-to-noise problem.  And that is, we usually have to force the model with a big signal in order to get something that is identifiable in a clear statistical sense. We are doing experiments like that at NCAR and have done experiments like that at NCAR.  And as I said, Alan Roebuck has done some experiments.  Other people have too.  But, none of the experiments that have been carried out in the modeling framework have been what I would consider realistic.  And I think the -- a realistic experiment is that that last case that I showed where we do just enough geoengineering to allow us to overshoot the stabilization pathway to something like 450 parts per million. So, that actually raises a significant challenge in identifying the details of the climate signal and also the stratospheric chemistry and loading signal.  We would have to run a number of experiments, maybe dozens of experiments, and then average the results to get rid of the noise and identify the signal.  Now, of course, that problem occurs in spades when we try to do some sort of field experiment.  I think, first of all, we need to figure out just what sort of experiment we could perform, where the signal was going to be identifiable above the noise, and where we were equipped to measure all of the right things in order to identify this multifaceted signal that is not just climate, but also stratospheric chemistry and vertical temperature profile signal.  So, we have got a lot of background work to do to decide on a field experiment.  And a number of people would be very nervous about performing field experiments, but I cannot see any alternative.  I think that that eventually would have to be the case.  In that last scenario that I showed you, I was ramping up the loading of sulfur compounds in the stratosphere very slowly to a relatively moderate level after 75 years or so.  So, you could consider the first part of that as the field experiment because it would be a very small injection of sulfur dioxide or an equivalent compound into the stratosphere.  So, it may be possible to consider the start of a real geoengineering strategy as the field experiment to determine whether or not we should continue with that. Vaughan Turekian:  Thank you -- and the science issues related to this, and sitting next to Kerry and Tom, I feel like I can just turn to them and say, "Yeah, what they said."  One question I would actually have is this question, which either of you started off saying that you do not really have the expertise on.  So, of course, that is where I will start, which is the engineering issue.  And I guess the question that I would have started is, where do you think we will be -- what will we get to first?  Understanding and being able to undertake the engineering or understanding the climate change feedbacks and the implications of geoengineering?  Because it is going to lead to my next question, which is going to get hopefully bridging towards the policy questions a little bit. Tom Wigley:  Okay.  That is -- well, thank you for reminding all of the audience here that I am not an expert -- Vaughan Turekian:  [Laughter] Tom Wigley:  -- so you can take what I say with a grain of salt.  Climate modeling experiments -- chemistry modeling experiments are pretty cheap really.  I think that developing the technology to put sulfur compounds into the stratosphere would be much more costly.  I think both of those things have to go on at the same time, but I can see that there might be much greater hurdles in developing the implementation technology simply because my guess is that that would be more expensive. Now, if I go back to that number from Paul Crutzen of maintaining some reasonable level of geoengineering -- would only be -- only be $50 billion a year, then I mean maybe we might need to spend $50 billion over a number of years in order to develop the technology.  And then, once we have got the right sort of -- or just suppose we are going to use high flying planes to put the aerosol precursor material in the tropics above the -- stratos -- above the tropopause, then yes.  Okay, how much does it cost to develop one new airplane and -- you know many billions of dollars.  You probably know that better than I do.  And most of those things are done not to save the planet.  I mean none of those developments have been done with an environmental focus at all.  I mean it is either -- the military -- the Air Force or commercial planes, and commercial planes do not fly up there so there -- maybe the military might be interested in very, very high flying planes and one could spin-off some of the costs towards the military.  But, the bottom line here is that the computer base modeling experiments are really cheap compared with the development of technology. Vaughan Turekian:  And again the question is though, would we be able to have a better understanding -- how long will it take us to better understand -- and I know climate modelings are the other dismal science in many ways -- but, it is to understand the feedbacks -- the secondary issue is the unintended consequences.  And are there many sort of the -- sort of the -- sort of known unknowns, unknown knowns, and the various things that we will not be able to necessarily understand?  And I ask this question because one of the issues that comes up when thinking about this issue is that we are now at a time when this kind of activity where sort of climate mitigation often requires the joint activity of many nations and is a global issue.  The question of whether individual actors or individual states that could develop the capability and the capacity due to the engineering without understanding -- to first approximation know that it does cool the climate, but not know really any of the unintended consequences.  Will we -- could we be out in front of ourselves in an engineering pathway, if not necessarily in the United States, in other places to think about? Tom Wigley:  Yes.  People have suggested that this geoengineering strategy is something that Bill Gates could do by himself, for example, you know, or India could decide to do by themselves.  I think that is an oversimplification really.  I mean I think that the infrastructure for developing the technology is huge, and it probably exists only in a few parts of the world and the United States is clearly one of those. The computer modeling side -- and I should not just restrict it to computer modeling because you know it requires the availability of observational data, and the interface observations, and model results, and so on in order to test.  So, I mean, I am just using that as a rather simple way of putting this kind of theoretical approach to -- into words.  But, the development of climate models, as you know, has been a slow process.  I do not think it is dismal.  I think it has actually been very exciting and stimulating science, and I am sure that a lot of economists would say that about economic models too.  But, it has -- Male Voice:  You may be wrong. Tom Wigley:  [Laughter] -- and I am right? Male Voice:  [Inaudible] Tom Wigley:  Yes.  If you look at developments over the last 20 or so years, one of the key climate model parameters -- or key climate parameters is the climate sensitivity, you know, how much the world would warm if we double the amount of carbon dioxide?  And the uncertainty there is not much less than it was 20 years go.  So, you might say that climate science has not progressed very far.  But, then when you look at, for example, how well models are able to simulate present day climate -- the current generation of general circulation models, is very good at simulating present day climate, even precipitation which is extremely difficult to simulate.  And that is a fantastic advance, but nevertheless it has taken decades. And throwing money at that problem is not the answer because there is a limited number of people out there in this field who can run the models, develop the models, validate the models, interpret the results, and so on.  I mean these models produce massive data sets, and we are talking about even more sophisticated models than exist now -- higher resolution, including stratosphere chemistry, and things like that.  So, there is a people problem, as well.  It is not just money.  I think we have to have a strategy that is long-term where we try to develop the intellectual infrastructure in order to run these experiments.  And that is something that may take a decade or so to do.  So, I do not see answers -- there will be advances all along the way, but I do not see satisfactory answers coming overnight or even within -- maybe within the next 10 to 15 years. So, the technology development issue I think is a longer timescale thing.  But, fortunately, I do think that provided we put a big effort into mitigation to the extent that we are capable -- and which is really epitomized by that overshoot pathway -- I mean I think we are capable of doing that.  I think that the technology development challenge there is something that can be met.  Provided we do do that then the amount of geoengineering required is relatively small, and the timescale for implementation is a decade or so.  So, I think all these things are possible.  Vaughan Turekian:  And I guess I will just ask one more question related to something that I think you both are experts on and definitely, Kerry, you are.  The question of the balance between -- and this is going to get into a world which people do not want to necessarily talk about too much -- the balance between climate geoengineering and weather modification.  And weather -- and you know people feel weather or are impacted by weather though they live in an umbrella of climate that impacts it.  Is there any room for whether modification in any of these studies, in any of these scientific studies, or is that something that should just be left and moved towards understanding the climate system and geoengineering?  I [Laughter] -- you are the expert on this environment [sounds like].  [Laughter] Kerry Emanuel:  Well, it is the boundary [inaudible] -- the boundary between weather modification and climate modification can be a fuzzy one.  So, for example, if one of the consequences of climate change is change in the incidents of some kind of violent storm, there will be an impetus to try to do something about those storms.  And so, weather modification research has had a very rocky history.  In the 1950s and '60s, it was a very respectable endeavor and there were very good scientists, physicists involved in such things as rainmaking and so forth.  Fog disbursal was considered a very respectable thing to do.  There were serious papers in scientific journals about modifying hurricanes.  Some of those papers -- and these are scientific papers, these are not things that occur in UFO magazines -- talked about modifying hurricanes with nuclear weapons.  And I mean it is crazy, but it shows you that the culture was very different then, then it is now, and particularly in the '80s and '90s, weather modification was not at all respectable -- a scientifically respectable line of research partly because when you do experiments in nature they are uncontrolled.  You do not know whether a particular cloud you seeded would have rained anyway.  It is a very, very tough problem and there was not much success with it. But what we see, for example, with this rash of hurricanes that occurred in the United States in 2003, 2004, and 2005 was a resurgence of interest, even in the scientific community, of weather modification research and some very interesting proposals had been fielded.  So, I do think that that will become part of it. And let me take the opportunity to say that one of the problems that we face -- all of us face in even contemplating these issues is that the human race has essentially no experience contemplating problems that affect it on a timescale of a hundred years.  I cannot think of a case in history where such planning on that timescale for some kind of environmental hazard ever took place -- or for any other reason that I can think of, actually.  We are just not genetically programmed to worry about those timescales. When you look at human history, human beings as an organism go back a few million years, and you look at the timescale of the great ice ages, which really were dramatic climate perturbations, we are talking about timescales of tens of thousands of years.  So, we were well-established as a race during the whole period of the last glacial cycles. It occurs to me and to my colleagues that on long timescales -- you know if you really want to stretch your mind and think beyond 100 years, if we are going to survive, we are going to have to learn how to engineer climate.  If for no other reason than to prevent us from going back into another ice age, which would occur naturally in a few tens of thousands of years for sure. Vaughan Turekian:  I am just reminded of the -- Kerry Emanuel:  Yeah. Vaughan Turekian:  -- of an abrupt climate change report that the Academy did which was co-chaired by Bill Nordhaus, who is an economist, and Richard Alley, who is a paleoclimatologist, and the two of them were trying to define the word abrupt .  And watching an economist and a paleoclimatologist [Laughter] come to terms with what was abrupt and what timescales that was is fairly interesting.  So, it speaks to your point exactly, that 100 years is probably -- actually was the compromised candidate there. Kerry Emanuel:  I have a number of questions of my own, but we have been talking up here a long time and I am sure the audience has a great deal of questions.  If -- is someone from conferences here with a microphone for us to start taking those questions?  Well, perhaps not, but we will proceed nevertheless.  Maybe Laura can try to run down a microphone.  Why do not we start right over here, sir, while we run down a microphone?  Please just, for all of you, could you just identify yourself as you ask your question? Martin Apple:  My name is Martin Apple [phonetic]. I am from the Council of Scientific Society Presidents.  Ultimately the population will grow over the next 50 to 100 years [inaudible] and an [inaudible].  Right now we have gathered a lot of that food that we cannot grow on land any more from the ocean.  If we geoengineer a partial solution to what we are doing, we will be simultaneously pumping more CO2 into the ocean.  That will cause the pH to drop and we will begin to end life in the ocean.  So, essentially we are going to create a conundrum here of being able to temporarily worry about the temperature at the expense of things that otherwise are much more important to us. Kerry Emanuel:  Tom, do you want to speak to the ocean acidification question? Tom Wigley:  Yes.  From what I know of the literature on the subject is that the ocean acidification problem becomes really serious once we pass about 700 parts per million.  Okay, I may be wrong there, but I think that if we were to keep the level of CO2 in the atmosphere below 550 parts per million -- and that overshoot case it goes up to 530 -- then, yes, the pH would drop by another one or two-tenths.  But -- and there is a delay too in that response -- in the ocean too. But, I do not think that will be a serious problem for the ocean biosphere as a whole, but there may be some coral area, some places like that, that would even be damaged by two-tenths of -- a further two-tenths of a drop in pH.  And coral ecosystems are very lively and productive and we cannot afford to lose any of those either.  But, of course, they are affected by temperature too and there is going to be a bit of a temperature overshoot if we follow that pathway.  So, we are jeopardizing some of those ocean ecosystems in two different ways at the same time. So, these are very serious issues that there have been some reports on -- Academy Reports and so on.  It is just not really my field of expertise to be able to give you more than that kind of general impression. Kerry Emanuel:  If I can just make one general point in response to that myself before I take the next question.  You know ocean acidification certainly does seem to be an important question, but it is not an issue, as I understand it, that geoengineering would exacerbate in any way.  It is simply an environmental effect of high CO2 concentrations that geoengineering does not resolve.  And so, that would certainly be one of the reasons why a combined geoengineering and mitigation strategy is important.  But, it is not an issue that -- as I said, that geoengineering exacerbates as I understand.  So, maybe over here, sir, in the yellow shirt.  Okay. Michael McCracken:  Mike McCracken [phonetic] from the Climate Institute -- excuse me.  First, Tom, I think 750 is way too high for the coral.  The [inaudible] that the coral community puts out say that the CO2 concentration in 2050 changes the chemistry.  So, it is not basically acceptable for coral given the experience with distribution.  I mean you are already seeing changes in the compensation depth and people in northern waters are already worried about marine kinds of things. I wanted to ask though a separate question and that is, why the focus so much on stratospheric aerosols?  I mean, all the model simulation models to date are assuming uniform change in radiation sort of over the planet -- almost all the planets, which is going to be very hard to get injecting SO2.  SO2 and sulfate, which also turn a lot of the direct radiation to diffuse radiation are going to make solar technologies more problematic by tenths of percent.  I guess -- why is there not more thinking about Angel's [phonetic] proposal of trying to put aerosol up in amounts not to balance two times CO2, but in looking at that overshoot that you were talking about Tom? Tom Wigley:  Yes, that is interesting.  I think that issue of diffuse radiation of solar energy is still slightly up for grabs.  But, I mean qualitatively, it is an issue that needs to be resolved.  And I -- the overshoot scenario that I have -- that I consider at the end of my talk really just has negligible -- I mean the issues you raise are just not important in that particular case. You stated at the start that you thought the experiments that have been done with models uniformly changed the radiation balance at the top of the atmosphere, and it is true that the earlier experiments did do that.  But, Philip Rasch's experiments with an NCAR model were not like that at all.  I mean he injected sulfur dioxide into the 10 north to 10 south band in the stratosphere, and then allowed it to disburse, and the same applies to Alan Roebuck's experiments.  And Alan furthermore did an experiment where he just injected the material in high latitudes, as well, and looked at the response.  And in that model there is chemistry in transporting the stratosphere that changes the nature of the aerosols and moves them around.  So, at least two recent experiments have not been quite so oversimplified as you implied. Kerry Emanuel:  Fred. Fred Iklé:  Fred Iklé -- a question to Dr. Wigley.  If I understood correctly you pointed out on the sea-level problem to -- that somewhat under control -- rising sea-levels, we might have to lower the temperature that might almost bring us back to the little ice age.  Is it not possible perhaps to do some of the geoengineering directed for that objective and focus it on the Arctic and Antarctic, that you can do regional geoengineering, which would not bring the ice age for the other parts of our world? Tom Wigley:  Yes.  I must say, I only did those that extreme stabilization experiment on my laptop a couple of days ago.   And I mean I could have guessed that something like that was going to happen because you can actually see it if you look at the results in the Nature paper, but -- you know, where sea-level does not stabilize and yet the temperature of the globe goes below the present level.  So, there is an inkling of this catch-22 problem there. Now, realizing that that is a problem in a very simple model at a global level means that we have to think of -- you know, is there some way to get around this?  And you are suggesting there might be and I do not know the answer to that question.  But, I think it will be fun trying to figure out whether there is some way to get the best of both worlds.  Kerry Emanuel:  David over here.  I always like it when questions are asked that we do not actually know the answer to.  It keeps us thinking. David Schneer:  Thank you, David Schneer [phonetic] from the Center for Environmental Stewardship.  A couple quick comments, the question of papers that are out, there is a new paper that has been submitted to Nature by a long list of people -- Ken Caldera is one of them -- that addresses several issues, including precipitation and temperature modeling that includes the scenario of only doing the polar regions.  It also takes on some of the precipitation issues that Roebuck's argued and I think pretty much put some of those, not to rest, but it does give a different view of them and they are much smaller in the way of effects.  I would say this about risks -- there is a question at the end of this -- models on risks use the same models that are used to generate estimates of climate change.  They are all the same models.  And so, when you are trying to ask the question, "How soon will we know about risks?"  It is sort of like saying, "How soon will be know what is going to happen to the climate?"  If we think we know enough to take large economic steps because of climate change today, then presumably we have enough confidence in those models to say we can also estimate what the risks would be of modifying the climate. So, the question that I had -- went back to an early chart that you talked about Professor Wigley, the stabilization target of 450 parts per million CO2.  My reading of the AR4 report and the background work in Working Group I was that it was 450 parts per million of CO2 equivalent, which we have already passed.  And so, I just want to clarify whether my reading of that was in error or whether, in fact, we are already beyond the 450 number. Tom Wigley:  Okay, yes, that is a very good question.  Now, the concept of CO2 equivalent is basically this, when asked the question, "How much carbon dioxide would there have to be in the atmosphere to give the same radiative forcing as the full mixture of anthropogenic gases?"  Now, if you put sulfate aerosol effects in then we have not past 450 yet, right?  Because the -- if you just look at the greenhouse gases alone, then we have passed 450.  I do not know what it is -- 470 or something like that, but there is negative forcing due to aerosols and if you put that in then the present equivalent level is pretty similar to where we are for CO2 alone.  The aerosol negative forcing is highly uncertain, so that is a highly uncertain number where we are.  Now, in my -- although I only showed results or numbers for carbon dioxide, and that was true, that -- project that stabilization scenario for concentration is carbon dioxide alone.  But, the experiments that I have done include other gases and, in fact what I have done -- you know there is a CCSP report where they have considered three different modeling groups.  They have considered a number of different multigas stabilization scenarios and in one of those scenarios they only go to 2,100.  But in the ones done by Jae Edmonds  and Steve Smith and people, we extended it out to 2,400 -- or 2,300 actually.  And I have used one of those to account for the effects of other gases.  So, although I am only showing CO2, I am not talking about CO2 alone.  I have not interpreted the results in terms of equivalent CO2, but I have not ignored the other gases. David Schneer:  Thank you. Kerry Emanuel:  Alan. Alan Carlin:  I am Alan Carlin [phonetic] from EPA.  I am somewhat -- I am quite a bit less optimistic then you are that we are going to stabilize at a 450, 550 number.  I do not see the forces that are going -- Male Voice:  [inaudible] Alan Carlin:  -- if that is true I would argue that doing a [inaudible] using geoengineering may be really only part of a larger approach, which would combine both mitigation and geoengineering.  I wonder if you have any comments. Tom Wigley:  Yes, I can add a little bit to that.  Yes, well, it is nice to have a little bit of pessimism thrown in at the end here.  Andy Revkin has something in the Times or on his blog recently where he was talking to Sherry Roland and Sherry says, I -- and I am misquoting him here, but he says something like, "Well, I think that we are heading to 1,000 parts per million."  Well, boy, I certainly hope not because I think that would be really close to catastrophic, not just for the climate system, but for the ocean as well. So, yes, I do not see the signs for stabilizing at 450, 550, 650, 750 -- I do not see any of those signs at all at the present.  But, the globe is warming -- well, it has not warmed that much over the last seven or eight years, but there is a long-term global warming trend that is inexorably continuing into the future and as that happens then I think even the most recalcitrant of policymakers will start to realize we have got to do something about this.  So, I am not quite as pessimistic as you.  Even though I agree, I cannot see anything out there happening right now.  So, -- Kerry Emanuel:  Well, I would like to wrap this up reasonably soon, so the next -- we can take a short break between the panels.  But, we could probably take two or three more questions.  I see one over on the side over there and one in the back over there.  Why do not we start here? Alex Echols:  Alex Echols [phonetic], Philanthropy Roundtable.  I have been in and out, so you may have covered this and I apologize and dismiss me.  One of the concerns I have heard about this has been the impact on photosynthesis and what do we know about -- will it be significant?  And if it will, in particular, will it be significant to agriculture and food production and oceans and microorganisms? Tom Wigley:  Well, again, totally outside my area of expertise.  And I think Mike McCracken has probably thought a lot more about this than I have.  But, I just want to say again that the final scenario that I considered would have a negligible effect on -- I believe -- on plants.  Whereas some of the more extreme cases where we try to offset with geoengineering, a warming of say three degrees Celsius, you know, the two times CO2 warming, it is quite possible that that would have effects on vegetation.  But, again, I just cannot say one way or the other simply because I do not know.  But, it is something that is an important consideration. Alex Echols:  Fair enough. Kerry Emanuel:  In the back here. Santiago:  Yes, my name is Santiago, so I am with the University of Maryland and NASA.  A question I have is about GCMs and the -- and my concern mostly is about public perception.  Perception of how we scientists deliver information from GCMs.  And I understand the use of them and why they help us to get a big picture and give us the constraints that we are going to be living on in the future.  But, what -- we see very little about regional impacts of the future geoengineering scenarios and actually [inaudible] warming.  And I think by focusing on more of those aspects of what is happening in the first two kilometers -- bottom two kilometers of the atmosphere, is where people will start to catch what is the real impact of these effects.  And I wonder what the panel thinks about why we do not see much of those regional studies of this geoengineering and [audio glitch] scenarios? Tom Wigley:  I can give you a quick answer and that is that we are just starting to do global GCM studies.  And to do regional studies, one of the approaches is to embed a high resolution regional model within a global model, so that it is driven by boundary conditions that are generated by the global model. Now, if you look at GCMs, they differ in their responses.  So, to get down to doing regional impacts of geoengineering, the first thing we need to do is have a number of global models that we can use to drive a number of regional models to get some idea of the inter model uncertainties both at the global and the regional level.  And hopefully those studies will be done over coming years. You know, for example, I imagine this impinges on the issue of whether geoengineering is going to do anything to tropical cyclones and maybe Kerry Emanuel can say something about that.  I think the details of the monsoon, for example, we really need to understand that better by imbedding a monsoon in Southeast Asia and India s monsoon region -- a regional model within the results of the global model because the aeorography is very extreme and the land ocean contrasts are really important.  And we are still at the bottom end of the learning curve in that regard. Kerry Emanuel:  I would just like to reemphasize that I think climate modeling is not today far enough progressed to answer your very important question of the regional effects.  If you look at the differences among models, and even among ensembles of the same model, they are pretty profound when you start getting down to regional levels. All we can do today -- and even this I think is a bit dicey, is to bracket the range of possible outcomes on the regional scale.  And this is something that I think we all need to emphasize, is that although there has been a lot of progress in climate modeling and climate science, it is still a field that is relatively young.  We have a long way to go. Samuel Thernstrom:  And I would like to wrap it up, so we can all take a break before the next panel, but I do not want to leave anyone hanging.  Is there anyone who has a specially burning question?  Male Voice:  [inaudible]. Kerry Emanuel:  We will take one last one over here from Raffe [sounds like] and then we will -- Raffe:  I just like your comments on the issue of masking.  And what you might -- is there anything we can learn from the fact that copuspheric [sounds like] aerosols are masking a large amount of warming at the moment [inaudible] the sulfates at a lower altitude?  And is there anything -- I mean it is kind of a -- we masked a lot of warming it appears over the last several decades and is that -- in a way it is geo -- an inadvertent geoengineering experiment?  And what I am wondering is if it suggests anything about the stratospheric issue itself or is it utterly different? Tom Wigley:  Oh, boy.  This really impinges on a field of analysis called "detection and attribution" and when we try to understand what has happened to the climate of the globe over the last hundred years, then what we do is we try to get some idea of the expected signal from greenhouse gases, some idea of the expected signal from aerosols, and so on.  And we can do a sophisticated multivariate regression analysis to back out the relative importance of the different contributing factors to changes in tropospheric climate.  And that is quite a difficult thing to do and just to give you one idea of the difficulties involved, people have included aerosol effects in those analyses, but they have not included indirect aerosol effects.  You know, they have only considered the direct effect of aerosols.  So, what we do is we look for a pattern of direct aerosol climate effects in the observation record when we know that indirect aerosol effects are probably larger.  So, we are hoping that the pattern of indirect aerosol effects are similar to the pattern of direct aerosol effects. So, it is a very difficult statistical problem partly because even though there has been a global warming of say seven or eight tenths of a degree, at the regional levels the signal-to-noise ratio is still not large because at the regional level, the noise is very high.  And in order to properly identify cause or factors, we have to look at spatial patterns.  We cannot just say, "Well, the world is warm and that has got to be carbon dioxide."  We have to look at the patterns of change and try to quantify the relative effects like the masking effect of aerosols in the troposphere.  Now, I think one of the big problems is that if we were to perform a field experiment in the stratosphere, then one could apply the same detection and attribution approach.  If we knew what composite signals we were looking for, then we can get the observations and see if we can identify those signals, particularly the geoengineering signal, in the stratosphere or in the consequent changes in the tropospheric climate. But, if we are considering a slow ramp up or a small field experiment, then the signal we are looking for is incredibly small and the obfuscating effects of other factors will be really difficult to overcome.  So, I think there are some supreme statistical challenges in store for interpreting observations from field studies in the future.  And they relate to this issue of masking where different effects are compensating each other in complicated, spatial pattern ways, so tricky stuff. Samuel Thernstrom:  I am sure we could keep going for a long time, but I know that Tom at least has a -- and Kerry actually both have planes to catch.  So, why do not we call it quits here for this panel and we can take a break for a few minutes and then Panel Two will start shortly. [Clapping]. [Start of File:  AEI9473-PanelTwo.mp3]   [Break in audio 1:50:00-2:03:24]   Lee Lane:  Welcome.  Thank all of you for staying around for our second panel, and I am sure we will have a very interesting discussion following up on the interesting discussion that we just had.  My name is Lee Lane and the second panel here this afternoon is, in contrast to our first session, focused on the policy issues associated with geoengineering and climate policy rather than the scientific issues.  I thought that I might make just a few framing remarks to get the discussion rolling, but most of the time I really want to give to our two excellent speakers this afternoon.  One way to start the discussion might be to simply pick up a little bit some of on Alan Carlin's discussion with Tom Wigley at the end of the prior session.  We are obviously having our meeting here this afternoon at what is an extremely eventful time in climate policy.  And it seems to me that the pattern of those events is seemingly on the surface very complex.  But, in fact, I think there are starting to be some underlying realities that are emerging from that complex pattern, and let me suggest a few contemporary events that suggest to me what those realities might be. This year, 2008, is the twentieth anniversary of the first meeting of the IPCC.  And so, one of the things that we might do in thinking about where things stand in climate policy is to compare what the situation is today with what it was in 1988 at the time of that meeting.  And that is a very -- it turns out to be, a very interesting question.  Today, CO2 emissions are slightly more than a third greater on an annual basis than they were when the IPCC met the first time.  Today, concentrations of CO2 in the atmosphere are increasing at a faster rate than they have been in several hundred years.  Today, even Europe, the heartland of ambitious rhetoric about greenhouse gas emissions control, is continuing to grow in greenhouse gas emissions. I suggest that if we look at the record of what is actually happening in terms of greenhouse gas emissions controls after 20 years of effort, that record is a pretty disappointing one.  And that tells us, I think, something important about the prospects for the future. The U.S. Senate, as we all know, starts -- has started already this week to consider cap-and-trade legislation.  But last week, throughout much of Western Europe, there were series of demonstrations protesting high energy prices.  In fact, in the UK two cabinet ministers last week suggested that the government's program of increasing road taxes and fuel taxes might have to be rescinded because of the political pressure on it. Today in the United States we have two presidential candidates, both of whom say they strongly support greenhouse gas cap-and-trade legislation, and yet support a gasoline tax holiday.  What, it seems to me, that suggests is just simply that for those who think that the greenhouse gas controls are right around the corner, I counter with the caution that the political problems posed by the international public's interest in lower energy prices have not gone away and are still very much an important part of the current policy environment. To me, one of the most troubling things that has emerged in the course of the last year's debate about U.S. climate policy is the appearance of proposals to use protectionist policies and to implement protectionist policies as part of cap-and-trade proposals. Now, on the one hand I think that is a completely reasonable and understandable response.  If we are going to impose greenhouse gas controls in some countries, but not in others, then obviously a problem arises with the potential of the flight of energy intensive activities from the countries with controls to the countries without controls. At the same time, it seems to me that it is just impossible to ignore that we are creating potentially, through proposals of this kind, an opportunity -- a strengthening of protectionism globally, which threatens what is already a quite fragile dynamic for international trade liberalization; one of the most benign tendencies in the world economy for the last generation or two or three. Closely related to the increased threat of cap-and-trade related protectionist policies is the last observation -- the last opening observation I want to make here, which is just simply that I have yet to hear any plausible solution that anyone has suggested to the problem of how to bring China and India into a system of international greenhouse gas controls.  I was just at a session a couple of weeks ago in which some research was presented suggesting that China's emissions may be growing even faster than the existing model suggests that they are.  China is, if one believes the numbers, already the leading greenhouse gas emitting nation in the world.  It is obvious that no problem to greenhouse gas controls is possible on a global scale without China's active participation.  But, I say again that I do not see any plausible policy that is available to us right now for how we are going to bring that about before China's society decides on the basis of its own internal dynamics and social evolution, that it has become in China's national interest.  And that seems to me like that would be a process requiring several decades. I think in response to all of those difficulties that certainly I am not the only person to see, a growing number of experts are becoming increasingly concerned about the need to broaden the debate on climate policy.  What I mean by broaden it is to expand what we consider as serious climate policy options from what has been a very narrow focus on greenhouse gas emissions limitations, and indeed rather steep and rather rapid greenhouse gas emissions limitations, to consider a much broader range of policies that go way beyond simply attempting to make short run reductions in greenhouse gases. I cite an example of that -- again at a conference, Scott was there as well -- I thought that Richard Richels made an extremely interesting presentation about two weeks ago.  In it, Richels, who is certainly one of the important pioneers in applying economic analysis to the problem of climate policy, made the observation that he thought that an economically rational climate policy required very serious consideration of at least five critical elements.  Those were mitigation, the reduction of greenhouse gas emissions, adaptation to climate change, geoengineering, climate science research, and R&D designed to advance the technologies that were required to really make progress on the first four of those objectives.  That is, obviously, a much broader range of climate policies than has been encompassed in the existing congressional legislation.  And Richels went on to make I think two then overarching observations about his own agenda. The first of those was that he suggested that we should evaluate climate policy -- we need to evaluate climate policy on how well it optimizes the mix of those five policy elements.  That there are, obviously, conditions that are going to change and knowledge will change.  We probably want to change the mix of our reliance on these various elements, but the real test of efficiency in climate policy is how well it combines those various elements. The second overarching observation that Richels made -- he actually applied it specifically to the question of emissions limitations, but I am going to broaden it to say it -- it actually applies to all five elements -- Rich said that, "Look, we all know that, with regard to mitigation, there are efficient policies and there are inefficient policies.  They are both in the category of mitigation, but the results, as far as the net benefits or net costs, depend enormously on the choice of specific policy implementation and the architecture of that policy.  And it really matters whether you implement these various policies efficiently or inefficiently.   The first reason I cite all this, and I actually called Richels and got permission to paraphrase it at this length, because I think what he was saying really illustrates the tremendous difference between what is coming to be more sophisticated climate policy analysis and what is still a real tunnel vision on the part of the existing legislative process, which is still very much focused on this goal of making relatively short run emissions cuts when short run is in the climate context of over the next 50 years. The second reason that I think it is useful to talk about what Richels had to say is because I think it actually sets the larger framework for the AEI Geoengineering Project, and I think for our session this afternoon, in a sense that talking about geoengineering is really one part of a larger process of expanding the range of options for climate policy that deserve serious consideration. Well, we have fortunately two speakers whose range of expertise is broad enough, not only to encompass this wider definition of climate policy, but to cover many things other than climate policy.  I hope you have all noticed that in the packages there are bios of all the speakers including Scott Barrett and Fred Iklé.  And in order to save time, I am, therefore, not going to go through those bios in detail and do detailed introductions.  I do want to do very quick versions of those.  Scott Barrett is a professor of environmental economics and was a political economist at Johns Hopkins SAIS.  I might try to add a note that gets perhaps a little bit below just the surface facts in the case of Scott, with whom I have worked for several years now.  I first met Scott after he published his book Environment and Statecraft, which presented what I thought was an absolutely devastating analysis of why Kyoto was very likely to fail, and then went on to suggest a very innovative and creative, entirely new technology-based approach to possible future emissions control strategy. Then a year or two later, Scott published an article in which he explained that having analyzed the situation further he was now persuaded that the -- most of the important technologies that were crucial to solving the climate problem probably did not have the economic characteristics that made them suitable for implementation through the mechanisms that he had developed in his book.  He has not -- I hasten to add he has not totally given up on this concept.  But, I think more important than the concept itself is that the combination of the creativity with the intellectual rigor and skepticism of the critique represents the exact kind of combination of qualities that we need much more of in the area of climate policy. Dr. Fred Iklé is a distinguished scholar at the Center for International -- I am sorry -- Fred Iklé:  Strategic and International. Lee Lane:  Inter -- Strategic and International -- Fred Iklé:  CSIS. Lee Lane:  Studies -- CSIS, right.  Fred has an incredibly distinguished career in both public service and scholarly accomplishment.  He has written on international relations, with a particular interest -- and I think some of his recent publications focus even more on the subject -- on how technological change may influence the future conduct of international relations.  And Fred has also published in the course of the last year or so with Lowell Wood, two of what I think are the most incisive and thought-provoking short articles on geoengineering that I have ever seen.  So, we are extremely fortunate to have both of these scholars with us and, Scott, perhaps you would be willing to start us off. Scott Barrett:  Well, thank you, Lee, for inviting me and for organizing this and for that introduction.  And the introduction is going to make me start a little differently than I had planned.  By the way, the first thing I want to say is that I asked Lee before how long -- for how long should I speak and he said, "Well, thirty to forty minutes."  Now, I have a lot of respect for Lee, but he knows I am a professor and you do not say to a professor, "You can speak for thirty to forty-five minutes," because they will take at least an hour.  So, what I would like you to do is tell me when I should stop or -- either because I have gone over my time or I have stopped being interesting for a few minutes.  Anyway, let me start with a little story because what you said about me is correct.  You know this is the most endlessly fascinating topic imaginable.  It is extremely difficult, and like a lot of people, I have struggled with it, particularly trying to figure out how we can address it.  And I did give it my best shot basically in this first book and I am still working on it.  I am still trying to figure out how we can address the problem.  But, Lee is right, when I worked on this other article later trying to build on the original idea, I came up with conclusions that meant I had to go out there and ask real people -- I am an academic, so I do not do this every day -- real people, you know, "Do technologies exist that have these features?"  And you were one of the people I called then. Well, I got terribly depressed because basically what I discovered was the technologies -- that the features I was hoping technologies would have, I discovered that this was a very small subset of these that really exist.  So, to be honest with you, I got pretty depressed that evening and had a glass of wine -- well actually probably more than one [Laughter].  Went to bed, woke up the next morning and decided I was going to start looking into geoengineering.  I had never done it before.  In fact, I checked to make sure that my thinking was accurate on this.  I do not use the term -- I never mentioned the term in my first book.  I have known about this concept for 15 years and I have been deliberately avoiding looking at it until the morning I woke up after coming up with this very negative conclusion -- a negative conclusion for how we are going to address the problem in a fundamental way. So, I think it is actually helpful if I start off by telling you this that I did not come to this with great enthusiasm and gusto.  It is really that I am looking at this because the other approaches that I have considered and others have considered really have not borne fruit or even shown the promise for that. Okay, why is that?  I mean basically Lee explained that we have made, frankly, zero progress in 20 years.  I mean let us just be honest, we have not addressed this problem in any kind of fundamental way.  And, in fact, everything seems to be going the other direction, not maybe in terms of discussions like we heard yesterday on Capitol Hill.  But, generally speaking, things have been moving the wrong way.  Why is that?  There are a lot of reasons, but one very fundamental reason is that global climate change, whatever else it may be, is the world's greatest collective action problem.  In fact, I would say it is the greatest collective action problem in human history.  And what I mean by that, the climate is shaped by the concentration of greenhouse gases in the atmosphere and that concentration is determined by the contributions by every single country in the world and, of course, over a very long period of time.  And what that means is that there is no individual country able by itself to address the problem in any fundamental way by reducing its missions -- its emissions.  It means also that each country that does take action on climate change will receive for itself just a fraction of the global benefit.  These two features have meant that we have not addressed the problem the way we really need to.  It is even worse than that.  There are other attributes of this problem that make it very difficult.  One is this concept called trade leakage that really relates to what Lee was saying before about using trade measures to enforce -- or to reinforce a domestic policy and enforce a multilateral policy.  If one country or group of countries takes substantial action, then the effect of that basically will be to shift comparative advantage in the greenhouse intensive industries towards the countries that are not taking action.  And it is probably because of that that these discussions of trade measures are taking place.  The difficulty here is that the responses we may have on the trade side carry their own costs, and they may not also work.  So, this is another thing that makes dealing with climate change in a fundamental way very difficult. Second is that there is a very long lag time.  Wigley spoke of long lags.  There is a very long lag between the time we take action reducing emissions and the time that that action will result in changes in something like mean-global temperature many decades lags.  So, that means that you are asking a current generation to make sacrifices for the future and that means that we have to worry about concepts of intergenerational equity and what economists call discounting.  And if you follow the debate between people like Lord Stern in the UK and Bill Nordhaus at Yale, you will understand that a very big part of the reason for why economists -- they disagree about what we should do about climate change is because we have fundamental disagreements about something as simple as discounting.  It is pretty amazing. Third, some countries may benefit from something that we sometimes call gradual climate change.  So, gradual climate change is just kind of gradual unfolding of the climate where it will be responding with these lags to the increase in atmospheric concentrations.  I will give you a sense for this; Bill Cline at the Institute for International Economics on Mass Ave. did this study of world agriculture.  So, he is looking at the effect of climate change on world agricultural potential basically by around 2084.  He is thinking about three degrees C temperature increase, okay.  And he in the study finds that agricultural potential would fall actually by quite substantial amounts for some countries.  For example, for some sub-Saharan African countries this potential would fall pretty dramatically.  For India it would fall pretty dramatically.  For other countries, it would rise.  Now, when you add it all up, it turns out that the effect worldwide is a reduction in agricultural potential of about three percent.  Now, think about this, he is projecting about 75 years ahead what is going to happen to agricultural potential as a consequence of climate change.  There are so many things that are going to be happening from now through that time that basically three percent total is being -- is close to noise. Now, that does not mean this is a non-problem; although, I do want to point out that the economic studies of climate change basically look at the average or the total.  They add it all up.  But, we may not care about the average.  We care about the variance.  We may care that some countries may lose tremendously in terms of their agricultural potential even if others gain.  I mean think about if you are a Rousseaun philosopher, you would actually care about the ones that would be the worst off, right?  So, there is a logic -- there is a logic, it may not be the one you like, but there is a logic for thinking about it that way.  This is part of the problem with climate change.  If you think about global climate -- gradual climate change -- there may be winners at least in the short to medium term.  Another problem is that we have got this other concept of climate change, for which I will just use the term abrupt , and I will not define it, because we know that will get me into trouble.  [Laughter] So, abrupt climate change and basically we are thinking here about things that are going to happen over relatively short periods and basically where no one is going to benefit.  Okay, that is one interesting feature of abrupt climate change.  No one really is going to benefit, so it is unlike gradual climate change in that sense, so we might be thinking here about changes in the thermohaline circulation.  We might be thinking about escapes of methane from tundra.  We might be thinking of the breakup of the West Antarctic Ice Sheet, this kind of thing.  No one is going to benefit from these kinds of consequences. Now, that means that the world should be together on this, but it is also true that there is terrific uncertainty about the possibility of these events occurring, okay.  Greenland melting does not -- there is not much uncertainty -- Mike McCracken or other climatologists here who can correct anything I get wrong here, but for some of the changes like Greenland I think we knew pretty much were going to happen.  But, for other things we do not really know and that means that we have to make decisions subject to tremendous uncertainty.  And that is why -- and somebody referred to Marty Weitzman and his talk at AEI some months ago, and that is why that is very relevant.  We do not really know how to handle this very well. Finally, the cost of dealing with this problem fundamentally, and fundamentally basically means -- what it basically means that eventually you want to reduce emissions to zero -- net emissions to zero, a long-term goal.  But, nonetheless, we need to be thinking very big about this problem.  The costs of that are going to be large.  Sometimes the climate problem is portrayed very simply.  You are told, "If we do not do anything about climate it will be catastrophic.  If we do something about it, it is cheap."  Now, if both of these things were true, we would have already done a lot about it.  It would not be the collective action problem I understand it to be.  Unfortunately, the reason it is so difficult is that it is really neither of those things.  It is much, much more complicated and that basically I would say -- those are the reasons why Lee's introduction -- you know these -- this sad tale of a lack of progress, that is really -- those are really the explanations that lie behind it all. Now, this puts us in a very difficult situation because we have a real challenge out here, and particularly I think we should be worrying about abrupt and longer term catastrophic climate change.  And we are really -- we have failed so far to address this problem in a straightforward and a fundamental way. So, what should we do?  Okay, we are going to need to do five things.  By the way, I am not sure who got the idea first, but anyway, my five are not exactly the same as Rich Richels', but very close.  One is we need to reduce emissions.  Okay, this is where I am going to start, and I want you to remember this because this is the most important thing even though this is a meeting to discuss geoengineering. Now, we can reduce emissions by some amount at very low cost using existing technologies.  We can also reduce emissions very substantially using existing technologies.  For example, we can just turn off the power plants, we can close down all the gas stations [Laughter] I mean those are all technically feasible things that we can do.  The difficulty there is that there is a large cost and economists when they use the term "cost" by the way are thinking about a welfare cost, okay.  For the rest of us, what it really means is politically you could not do it, okay.  There would not be the stomach for it, but technically you can do it.  And the third thing we need to do on this first category is we need to develop the technologies that will allow us to reduce emissions by substantial amounts in the longer term, and Tom Wigley I think and maybe others have used this description of a technological revolution.  That is what we need.  I mean that is absolutely what we need to address this problem. Now, this goes to the second thing in my list of five that we are going to have to do.  We are going to have to have R&D, because the technology -- Tom I think mentioned it -- the technologies we need to address the problem very, very substantially and at a cost the societies will accept, they do not exist.  They do not exist in a way that we can certainly plug them in today and get them to work.  This is something that has me very upset.  One of these technologies that we will definitely need will be carbon capture storage.  I think it is basically a scandal that it is 2008 and we still do not have up and running pilot programs -- pilot technologies for testing out a carbon capture and storage.  There is no way we are going to reduce emissions to keep any of the numbers that Tom Wigley was discussing in terms of atmosphere concentrations without demonstrating feasibility and looking through all the implications of using carbon capture storage.  I think it is outrageous that we have not done that yet.  And you might ask, "Why have not we done that yet?"  The main reason we have not done it yet is that carbon capture storage is an add-on cost, okay?  The only reason you do it is because you care about reducing emissions.  So, therefore, the value to society of that technology or the knowledge that you derive from doing R&D on that technology is itself connected to the value associated with addressing the global public good problem of reducing greenhouse gas emissions, okay.  And that takes us back to the original collective action problem I pointed out. Okay, now let me just pause here and point out that those first two things we need to do, reduce emissions and the R&D, these are complementary things.  The more you want to reduce emissions, the higher is the return in R&D.  The more successful you do -- you are on your R&D, the lower the cost will be reducing emissions and the more emissions reductions you will want.  Those two things go together.  They are complements.  I am emphasizing that because the next three things on my list of five, they are substitutes for reducing emissions, they are substitutes. Okay, the third thing then.  We need to adapt.  Okay?  This has already been said, but we need to adapt because the climate is going to change.  Adaptation is a substitute for reducing emissions.  We are going to come back to that. Fourth, we need to develop the potential -- I do not think this is on Rich's list -- we need to develop the potential to take CO2 directly out of the air.  Now, we can do that already with trees.  But, you may have heard of ideas of fertilizing iron -- pour regions of the oceans with iron to stimulate plankton blooms that will, at least theoretically, take carbon dioxide out of the air and then sink it into the deep ocean.  But, there is a third idea that I think is really more significant than the first two, for a variety of reasons, and that is called industrial air capture.  So, this is where you are going to have machines -- basically industrial trees.  Okay, these machines are basically going to take CO2 directly out of air, concentrate it, and then stick it somewhere, the same kind of place you would stick CO2 you would take out of fluid gases for carbon capture and storage.  The -- and the last thing we need to do, the fifth thing on my list is geoengineering, okay.  So, this is a meeting on geoengineering.  It has been a long introduction.  The fifth thing of this list is about geoengineering.  What is geoengineering?  I have looked into the literature.  There is not a consistent definition that I could see, but for me the definition that will work is interventions that will alter the global climate by means other than by focusing on atmospheric concentrations of carbon dioxide.  So, these atmospheric scatterers, for example, that were discussed are a clear example about those. Now, all three of these things: adaptation, air capture, geoengineering, those are all substitutes for reducing emissions, okay, and that is very important.  When you hear people say, "We need to worry about adaptation," and you have heard a lot more about that in the last two or three years then we did before, they might as well be saying, "We need to be thinking more about geoengineering."  It is just that talking about adaptation is more acceptable or it has been until very recently.  But, really those two things, the reason you are going to look at both of those things is because we have not dealt with the problem in a fundamental way, and what is underlying that is this notion of geoengineering, adaptation, and air capture being a substitute for reducing emissions. Now, they are imperfect substitutes.  Kerry Emanuel used the nice phrase, he said, "You are --" something like "fighting apples with oranges," or something like that, and that is basically what we are talking about, right?  So, these are imperfect substitutes.  And doing one does not mean that you no longer want to do the other.  Particularly, by the way, when you take into account risk, and this is something that I want to come back to later.  From the perspective of risk, you are actually going to want to have all these five things. Okay, now a few words about the collective action dimensions of these different policies.  Adaptation -- how much time do I have, by the way? Male Voice:  You are at -- Scott Barrett:  -- for the whole [inaudible]? Male Voice:  -- about 25 so far. Scott Barrett:  Okay.  So, I have got a couple hours to go.  [Laughter] Male Voice:  Depends on how interesting you stay. Scott Barrett:  Yes, that is right, that is right.  If I get dull, pull me out.  Okay, adaptation.  Let us look at this from the collective action point of view.  Who is going to do it?  We are going to do it.  A lot of people are going to do it.  A lot of companies are going to do it.  It will be done automatically.  Adaptation means adjusting to circumstances.  We have very strong private incentives to do that.  If it gets too warm, we dress differently, we turn up the air conditioning, we move, et cetera and so on.  The farmers are going to change when they plant crops, what other inputs they use, what crops they produce.  The seed companies will develop new varieties, et cetera.  So, there will be a lot of changes that will occur through markets, okay? Now, there is a -- one other aspect of this will be done through local public goods, and the clearest example is in London you have a thing called the Thames Barrier that protects London from these rising tides.  And that Thames Barrier is inadequate for rising sea levels.  So, it will have to be -- and there are already plans in place for this, it will have to be augmented, okay?  That is a local public good because it protects all of London from sea-level rise.  You will have a combination, so [inaudible] markets, local public goods. Okay, now where -- how is this going to unfold -- and to think about through the collective action problem, the incentives for the market to respond and for local public goods to be provided are very strong.  So, what I think can happen -- and this is an academic paper I am working on right now, is if you think of countries as being able to choose between adaptation and reducing emissions -- I used the metaphors dikes versus windmills.  Well, what can happen is because the benefits of the dikes are local there may be incentives for countries to substitute the dike for the windmill and the consequence may be, metaphorically speaking, a world of dikes and no windmills. But, the reason that this is interesting is because that may be a very inefficient place to be.  The world might be much better off with windmills and no dikes, okay.  So, when I said this was a collective action problem, those of you who have taken any game theory recognize that basically I am kind of talking about a prisoner s dilemma.  Okay, that is basically what is going on here.  But, the important point is because there is the possibility for substitution between adaptation and reducing emissions, we may actually substitute basically dikes for windmills. Okay, now air capture -- air capture has a number of features that will also aid collective action.  One is that it can be done as a project.  So, this is in contrast to reducing emissions where you have to get quite a large number of countries to do it with you and, of course, you are going to be influencing the behavior of large number of plants worldwide.  With air capture, you are actually going to think of doing it as a single project, and as I will explain, it is very similar to geoengineering. It is also like geoengineering in another way.  With air capture, you are not only eliminating the increase in atmospheric concentrations and greenhouse gases, you actually can choose that level.  So, that means we are not only limiting how much is going up, but we can actually choose the level we want.  So, this came up in an earlier discussion, what level do we want?  Do we want 450?  Do we want 550?  Do we want to go back to 280?  Jim Hansen proposed -- what was the number? Male Voice:  Three fifty. Scott Barrett:  Three fifty, okay.  And then Tom Wigley said if you want to prevent the oceans you have got 250 -- there are -- and this is what is interesting, of course, different countries will have -- different countries, different people with different views about where we ought to go.  So, from the collective action problem point of view, when you think about this technology, different kinds of questions from reducing emissions and limiting increases, now we are talking about actually choosing levels.  And as I will explain with geoengineering, you have a very similar feature there where the real big question is about who decides.  One big difference between industrial air capture and geoengineering is that air capture is very expensive.  It is very expensive.  It is more expensive than carbon capture and storage mainly because the CO2 in the air is not concentrated.  You would have some flexibility about where you locate the facilities and so on.  But, basically the numbers -- at least that I am aware of today, show that it is quite expensive and that is why it is not being done. Okay, now let me just turn specifically to geoengineering.  Is it feasible?  I am told it is.  I am not an engineer, but I have spoken to quite a few engineers.  Some of them think it is almost trivial.  I think -- I am sure they are wrong, but it does seem that it is feasible.  Obviously, more work needs to be done on this, but it does seem to be feasible.  Second, it can be used very quickly and it has very rapid effects.  When you throw -- you heard about Mount Pinatubo, after a few months delay, it reduced global mean temperature -- that is quite amazing.  So, a very rapid effect, unlike reducing emissions, which I mentioned before, you have decades long lags.  There is no leakage problem, okay?  Remember I mentioned before this trade leakage issue?  With geoengineering you create the project, flick on the switch, you are not altering prices in any country; therefore, there are no trade issues.  That seems to me to be an advantage.  Fourth, it is inexpensive.  Now, what do I mean by that?  I do not know exactly, but let me just tell you what other people have said about expensive.  Bill Nordhaus has written a report where he thinks you could do geoengineering to offset the effect of a doubling and CO2 at a cost of about $8 billion a year.  Okay?  Paper by Edward Teller, Roderick Hyde, and Lowell Wood, they think the number to offset the effect of warming by 2,100 would be just $1 billion a year.  Now, David Keith, a young physicist at the University of Calgary -- very good -- thinks that Lowell Wood and his colleagues were optimistic.  But, he says, "It is unlikely that cost would play a significant role in a decision to deploy stratospheric scatterers because the cost of any such system is trivial compared to the cost of other mitigation options." We heard from Tom Wigley that Paul Crutzen's article mentions the number $50 billion a year.  It actually was the upper bound.  He had a range of $25 to $50.  We do not know what the cost is going to be.  I am sure we can find ways to make it as high -- you know higher than these numbers, but basically the main point is, it looks like this is an engineering project and it will not be that expensive in terms of financial cost.  I am not talking about the broader economic cost.  We will come back to that in a minute. And finally, it can be done as a single project.  What that means is it can be done by an individual country.  Okay, that is very important because that is totally unlike emission reductions. Okay, now who would do it?  There is some discussion about whether an individual would do it.  David Victor has written on this and he has referred to the notion of a greenfinger.  You know, if you remember the James Bond movie, Goldfinger -- anyone else?  Well, this is greenfinger.  Now, I think they can -- the chances of any one individual wanting to do this are basically zero for a variety of reasons.  I mean one is that there is no money to be made out of this unless you create a system where there is some kind of offset that is created.  There will not be any money to be made. The second point is that a lot of people and countries are not going to want anyone to do this.  In fact, you may have heard the story that Planktos, this company that was planning to do an exercise of dumping iron into these desert regions of the ocean, when word got out about that to the parties to the London Convention on Dumping, which is a treaty on management of the world's oceans, they issued a statement saying they did not think it was appropriate for any kind of experimentation of that scale to be done, and Planktos withdrew their plans to carry out their experiment.  And finally it seems to me likely that governments will do it, and if governments will do it there is no need for the private sector to do it.  So, I do not think that it is very plausible that individuals are going to do it.  I think it very plausible the governments may do it.  And then you ask the question, "Which governments?"  Well, the United States is a clear candidate -- it would be the number one candidate for a number of reasons, but one of the things that makes the technology interesting is that the United States would not be the only country capable of doing it or with interest in doing it.  Who else might do it?  Europe might do it.  Japan might do it.  Russia might do it.  China might do it.  India might do it.  Brazil might do it.  Quite a few countries already have technical capability, for example, to have significant operations in space.  They would definitely have the capability to undertake geoengineering, and over time -- and I doubt if anyone is going to do any engineering on any kind of scale for decades -- over time the number of countries that will be able to do this will only increase.  So, one of the things that makes this interesting is that a lot of countries may do it, and in terms of exploring their -- the desire to do it, let me just mention a few numbers.  Bill Nordhaus, who has done terrific for many, many years on the economics of climate change, he has calculated -- one of his numbers -- sets of numbers, he calculates that the present value cost to the United States of a doubling in CO2 in terms of climate change damages would be $82 billion.  That is a present value cost of damages. Now, remember that if you reduce emissions, you cannot get rid of all these damages because you are kind of -- you know, you already -- this is kind of history behind all this, right?  No matter what you do, you reduce emissions you cannot get rid of that.  So, the benefits of avoiding this would be lower than the $82 dollars, but geoengineering -- leaving aside what Tom Wigley was saying about sea-level rise -- you actually can get rid of a lot of this. So, let us say just for the purpose of discussion, get rid of all of it.  So, geoengineering can get rid of all of this.  Well, then if you annualize this $82 billion figure, you are talking about an annual break even cost for geoengineering basically of about $2.5 billion.  Okay, which is -- depending whether you believe these engineering studies showing that the cost of geoengineering could be as low as $1 billion, you might want to do it.  But, this is for gradual climate change and I think the economics of this mean it is within reach for countries, but they are not going to jump to it, not for gradual climate change. One of the other reasons they are not going to jump for it is that if they do, they may irritate a lot of other parties.  A lot of countries are going to totally disagree with using it period, under any circumstances.  Some are going to say, "The circumstances are not right yet."  Some are going to say, "Hey, wait a minute, we are benefiting from gradual climate change and if you do the geoengineering, you are actually harming us relative to the existing status quo."  So, In other words, there are conditions here for conflict. Another problem, if we -- if one country flips the switch, so to speak, on geoengineering, it basically is permitting other countries to do the same.  That is basically what it amounts to, because you would take away any possible taboo that might exist.  And then, you think about what other countries, they may have very different ideas for when and under what conditions geoengineering might be tried.  So, I can see that there might be disagreements about this and that will actually make countries more restrained in how they act. Remember too that geoengineering can be used to heat the climate and not just to cool it, and if you want to use geoengineering to cool the climate and someone else likes the warm climate they may want to use it for the opposite purposes and wipe out your impact.  And another reason why countries may want to get together on this is to share costs.  It is worth remembering that for the first Gulf War, around which we had a global coalition of support, other countries basically financed about 85 percent of the total U.S. costs of the first Gulf War.  And so, there is a reason for wanting to work with other countries on these kinds of things.  Now, when will countries contemplate using a technology like this?  I think for all the reasons I mentioned before, it is unlikely that it will be used to deal with gradual climate change, which might be an interpretation of some of what Tom Wigley was actually discussing.  I think it is much more likely, particularly given the feature that geoengineering can work very quickly, it is much more likely that it would be used as a last resort, and he used that phrase I think in his presentation. If you were to start to see this abrupt climate change occurring, that seems to me more likely to be the scenario where geoengineering might be tried.  Of course, when there is abrupt climate change, no one benefits from it and at that point, a global consensus is much more likely to emerge. Okay, now I have not said any of the bad things about geoengineering yet.  I am not going to give a complete list, but let me just remind you that there are some things we should be worrying about. One is that geoengineering is an experiment, so we are talking about correcting or seeking to offset one experiment we are already doing on the climate with another one.  What is going to happen if we do this other experiment?  We do not know, just like we do not know what is going to happen fully with the first experiment.  Second problem with geoengineering, which was not mentioned, is when we go to turn it on, it may not work the way we are hoping it might work.  For example, one of the things that we should be concerned about would be the disintegration of the West Antarctic Ice Sheet.  Now, I am no expert on this.  There are people here who know an awful lot more than I do, but suppose it happens that the Ice Sheet -- the West Antarctic Ice Sheet, is affected much more by ocean temperature than by atmosphere temperature.  It might be that geoengineering, even if it cools the planet, will not address the problem that we are facing at that particular moment.  There are other problems with geoengineering that were mentioned before.  It may not maintain the distribution of climate that we have now and it will not address the problem we have of ocean acidification and so on.  Let me just leave this because that was discussed before. The main point I want to emphasize here though is that using geoengineering will itself involve risks.  So, I am thinking of a scenario where we are going to use geoengineering to address one risk, which is particularly the risk of abrupt climate change.  But, when we use geoengineering we are introducing another risk.  So, this is an area where you have what are called "risk-risk tradeoffs." Now, one thing that we need to bear in mind is that geoengineering is not the only area related to climate change where there are risk-risk tradeoffs.  Just think about reducing emissions.  I mentioned before that you are not going to reduce emissions dramatically without carbon caption and storage.  You are also not going to do it dramatically without nuclear power.  Expanding both -- using both of these will introduce new risks. Now, we can do some things to address those risks, and I think we should, and that -- those are some of the things I think we need in a climate policy.  The point I am trying to make is that when we make comparisons between choices we have to be consistent in our analysis as between what those choices actually are.  A comment about moral hazard that Sam mentioned before, I have heard this term used over and over again.  Moral hazard arises when you have a market failure around information.  So, basically it arises in a situation -- here is a clear example.  If you get -- if you were insured for damage let us say to your automobile, then you would take some fewer precautions to make sure that the automobile was not stolen or even you might drive a little less carefully.  This kind of behavior, by the way, it is extremely well documented that it exists.  But, what drives moral hazard is the incentive arrangement associated with an asymmetry of information when you have got different parties, okay?  So, one is offering the insurance, one is buying the insurance package.  With climate change, we do not have the same phenomenon.  So, what scientists are worried about when they use that term "moral hazard" is if you know that you have geoengineering as a back up, you are not going to bother to reduce emissions.  That is the logic.  It does not make any sense because the same party that is choosing to or not to reduce emissions is the same party that could use geoengineering.  So, the idea of moral hazard really does not apply to geoengineering. Geoengineering is not a market failure in the same sense.  It is a market failure in the sense of the collective action and that is where I think we need to focus.  And from the perspective of collective action, remember what I said before all this -- thinking about adaptation, you are thinking about substituting there a world of dikes for a world of windmills, which would be an -- possibly an inferior situation, and with geoengineering what you want to do is make sure if geoengineering actually would be beneficial to substitute for emission reductions, then you should actually allow it to go through.  There is not actually a problem with it from the point of view of any kind of information asymmetry. Okay, now how is this whole thing going to unfold over time?  If we continue to fail to address the problem fundamentally, or even if we do not, of course, already we may have built up a case for climate surprises, then I think the pressure for countries to do something different like adaptation will be extremely strong. Male Voice:  Scott, you should [inaudible] -- Scott Barrett:  Yes, I am just -- I am just winding down. Male Voice:  -- five more minutes. Scott Barrett:  I know, I stopped being interesting a couple of minutes ago -- Male Voice:  No, [inaudible] -- Scott Barrett:  -- so I am just going to wind right down now.  Okay, the problem with adaptation is not just that we may have too many dikes and not enough windmills. It is also that the ability to adapt is unevenly distributed around the world.  The poor countries are more vulnerable.  It is very easy to think about it this way.  The institutions that you need for adaptation -- remember that adaptation will be done by private markets and local public goods.  The institutions that you need for adaptation are really the same institutions you need for development.  Those are the two things governments do basically, they allow the markets to work by doing things like enforcing contracts, establishing property rights, and so on, and they provide local public goods, defense, clean air, et cetera, and so on. So, the countries that have failed to develop are also the countries that we can count on to fail to adapt.  And one of the concerns I have is that the richer countries who are more able to adapt will adapt -- and they will adopt the dikes instead of the windmills and the consequence will be that the poorer countries will be left not high and dry, but low and wet, so to speak.  In other words, I think climate change has the potential to widen existing inequalities. Now, geoengineering is different because geoengineering would apply and, of course, affect every country and we can think of geoengineering as providing a global public good; although, I want to repeat what I said before that geoengineering also introduces new risks and has downsides too.  So, I am not advocating its use, but if you think about geoengineering as being a technology we particularly would consider using in facing abrupt climate change, then the point is that richer countries and technically able countries would have an incentive to use it.  And in using it, the poor countries would benefit.  So, actually it has an attraction to it that is quite different from adaptation.  Adaptation you are separating countries.  Geoengineering you are actually -- you are-- all countries would be affected in a very similar kind of way. What is going to happen if we ever use geoengineering?  There seems to be two possibilities.  One is we will discover that it works and it works pretty well and we are happy with it.  In that case, I think we will continue to use it.  So, Tom Wigley in his picture, he was showing we are using it and then we are not using it, if we are actually using it and we find that we like it and it is still a lot cheaper than reducing emissions, we are just going to keep using it.  But, if we actually find that it does not have any problems with it that is not necessarily a bad thing to do, right?  So that is the first point. Now, suppose we try it though and we do not like it because it does all sorts of things that we had not anticipated.  Remember that we are only going to be using it -- I think it is likely that we are only going to be using it when we hit a situation we are trying to avoid some kind of abrupt [inaudible] long-term catastrophic climate change, then there will be other pressures created and we will want to move away from geoengineering. Now, one possibility we might adopt at that point, something that could work pretty quickly to take CO2 out of the atmosphere, would be to turn to air capture.  Now, air capture, as I mentioned before, is expensive.  On the other hand, if we are operating at this point where I think geoengineering might be applied, the marginal damages avoided would be high.  So, in other words, air capture may at that point be economic and it is a way in which you can shift risk away from the geoengineering -- by reducing atmospheric concentrations and doing so rather quickly, of course, along with reducing emissions. Now, this world I have been describing here is kind of a scary world, because I am thinking of a situation where deliberately modifying the earth's environment.  That is a very scary thing to even contemplate.  On the other hand, the only reason I am here and discussing this is because we are already modifying the earth's environment.  The only difference is we are doing this -- we are not doing it deliberately, but we are doing it.  We know we are doing it.  And these, unfortunately, are the choices that we have and as we looked forward in thinking through climate and climate policy, I think it is important that we bear in mind that as much as we wish we were not in the situation we were in, given that we are in the situation, if things start to turn as bad as some climatologists predict they might, at that point, I think we will be glad that we had the option of geoengineering available to us.  Thank you.  [Clapping] Lee Lane:  Fred. Fred Iklé:  Well, I agree with many of the five points or was it 50 points [Laughter] -- five points of Scott Barrett.  I disagree with some and I have only four points because I am a modest fellow.  My first point is that we must, we must move ahead to learn more about geoengineering because it is evident that mitigation is at least uncertain and there are indications it may not work for quite some time.  But, geoengineering is not a single option.  It is not "it" that we may like or "it" that we do not like.  It is a many faceted thing and new approaches may yet be invented that we have not discussed so far.  Hence, it is important to research and we cannot go that far in my view with modeling on computers without some kind of field testing -- field experiments.  And, therefore, I would disagree with hesitation about field experiments because the results may be statistically unsatisfactory or there may even be some risks that the field experiment may go wrong and may be wasted money or may cause a little damage. We sent a man to the moon.  I am not aware of a field experiment that we did before we did that, but it is all clear to us that if you had failed, it would have been quite an embarrassment and a disaster.  Sometimes you have to move ahead and take certain risk in testing things. Look at the contrast on mitigation, there people boldly want to legislate activities without even doing an analysis of it beforehand and without at least doing any kind of field experiment.  And these activities can have -- and indeed they do have unintended bad consequences.  Think cap-and-trade, mistakes in the pricing of the so called allowances have caused great embarrassment and damage in the European Union.  It is a complicated story, but some of you may have read about it.  Now, today we have Lieberman-Warner Draft Bill, which would involve trillions of dollars in allowances and allocations.  Well, that much money is an attraction for mafias, for corruption, for cheating, and they have already seen that corruption and cheating with cap-and-trade takes place, especially if it is supposed to be on a global basis, which eventually it would have to be to have a good effect. You have read about the Chinese industries or factories that had considerable carbon emission and then they heard about this wonderful cap-and-trade.  They got paid if they cut the emission, so they increased emission first a little till their number was fixed, and then they cut it back again and got paid for it.  And there are other tricks we have not even thought about, but I am sure people now seeing the trillions of dollars invent [inaudible] ways of cheating.  But, see we do not talk about how we need a field experiment; we just go ahead or want to go ahead.  My second point is, let me call it "a state of denial," and I have two parts here.  One if the denial that global warming as it has been observed so far has nothing to -- almost nothing to do with greenhouse gas emissions.  It is caused by change in solar radiation.  That is not totally absurd.  I think it was Caldera who asked about this and he mentioned, yes, maybe one or two percent contribution from a slight increase in solar radiation.  But, if solar radiation were indeed or were to become in the future before the sun turns into a nova, we would be gone entirely, if it were indeed to become the problem, then mitigation would not be the answer.  We would need geoengineering to protect yourself against the increased solar radiation. Now, another aspect of the state of denial, it is even more bizarre, but it is quite common, is that global warming is good for us with proper adaptation, of course.  If you adapt to it properly, you will get more food production.  CO2 helps grow plants and some additional warming also helps to grow plants in the northern region.  So, low and behold, you can grow spinach in Greenland and you can grow broccoli in Siberia from the barren sea all the way to Mermans, all the broccoli you want.  [Laughter]  And if you scratch the veneer of this denial, you might even discover some generous Saudi financing for the people who put this forward.  [Laughter]  And there is also more hazard here on the carbon reduction -- adaptation -- on adaptation.  First, people are very concerned with economic growth because this is all they need, you know, the club of growth.  Say, "Well, that is good adaptation, we have to build higher walls for the -- London.  We have to have higher dikes for Netherlands, that creates work and business, you know, that is very good."  It is the same line of reasoning that increasing crime is good, you build more prisons.  So, there is more business in economic growth.  Another form of adaptation, of course, that we can hear all the time here is air conditioning and air conditioning is now spreading into your -- it was not [inaudible] before considerably that was expected to spread in China and air conditioning it so happens, at least at this time, will create more carbon dioxide emission. Now, a third point and Scott Barrett has referred to this, is let me call it the timeframe.  The carbon dioxide accumulation we have discussed earlier -- and you see these charts for a 100, 200 years into the future.  And, of course, if it continues to grow it becomes all the more troubling and potentially disastrous.  The IBPC has only had its twentieth anniversary, so that is a shorter timeframe.  But, in 200 years, we will likely have vast technological changes.  The technological changes accelerated since the industrial revolution, and it is rather getting faster and bigger in its changes than it did in the last 200 years. And then, they also need to consider demographic change, an important factor in the larger timeframe.  If the world population had not grown -- had become stabilized in the fabulous '20s -- 1920, global warming would be hardly a problem, even if the world population had been stabilized after World War II.  Now, a lot of people are worried about the decrease -- decline in world population in Russia, Italy, Japan, and so on and others are pleased about the increase in population in the United States, for example, but if the demographic growth continue to drop massively and there is clear indication that in Africa, particularly in sub-Sahara Africa, it may have a fivefold increase in population over the next 50 or 80 years, then global warming may be more difficult to control. Also the timeframe when you had mentioned that properly, that we have to find cheaper ways for produce -- having clear -- clean ways of burning coal, better ways of nuclear power uses.  And then, there are other projects which really made changes to our global energy system in the long-term, 50 years or more.  Today there is the ITAR project participant -- participate in the United States, Russia, China, India, a lot of countries are spending money on that with the experimental site in Southern France trying to explore whether it is possible to have production of really clean energy, thermonuclear energy that would not have nuclear waste and would not have the emissions of fossil fuels.  And I think it is sensible to expect that there will be a change in the global energy system, but it may take quite a long time and here again [inaudible] for global engineering as a bridge till this change has taken place.  The -- let us see, I had a fourth point.  I promised four points at least or [Laughter] -- the question is, "How can we get the decision to move ahead?"  And that is a problem we will have heard.  Which countries will lead?  I do not see why the United States, with our work having -- that we have done already -- that many scientists have done here in cooperation with some other states cannot and should not move ahead.  I think we should move ahead with some small field experiments that -- hopefully some of them will be successes rather than failures, and may then stimulate others to follow.  And I think it would become apparent to others rapidly that mitigation as we try to do it now will not succeed.  And when the messages about why it will not work come in almost daily, and if you read the newspapers, decisions in China, costs involved in doing it -- in fact, several AEI obligations are papers that have made that point very strongly.  So, I think it will be -- we will be driven to geoengineering and it behooves us to be prepared to talk about it, better informed than we are today.  Thank you. Lee Lane:  Thank you very much.  [Clapping]  Scott, do you want to respond or shall we go to the audience?  What is your pleasure? Scott Barrett:  Let's go to the audience. Fred Iklé:  Yes. Lee Lane:  Yes, sir. Martin Apple:  Martin Apple.  Question, what we are trying to do is solve a problem and what we are not doing is looking at long-term ultimate solutions.  One, population control, zero population growth; two, capturing the sun because it is free, it is cheap, politically unconstrained because of all the other things that we could do with it.  Three, counting everything as though the economic driver [inaudible] and nothing else counts when we have all these other things that do count.  You know, we have been hunter-gatherers for energy for the whole century.  This is a pretty advanced society, we can certainly do better.  We know we have developed all kinds of things that are new technologies, new sciences that need a good push to get into a scale that could be useful and we are not doing it.  So, I think what we are doing is skirting a problem rather than addressing it. Fred Iklé:  I would agree so far.  I think it will change within a few years.  You need an incentive.  In this case the incentive probably has to be government funding and you explained it well.  It is a common good.  But, if you have incentives for doing -- developing things, you see where in a private market incentive in the Internet, cell phone, iPhones, and so on, the constant revolution of new technological ideas, constant improvements, so what keeps us moving so slowly is that governments, particularly our government here, but also in Europe, interestingly, have not allocated -- they have not even seriously looked at geoengineering and they ought to be stimulated to do that.  And they have not allocated money to it.  And maybe we could sort of create a competition.  We say, "We concluded we have to -- we the United States have to move ahead and here is a $100 million, $200 million, $500 million -- billion maybe -- budget to do more research on it.  If you do not want to be left behind, join us."  And I mentioned ITAR, the money there from a number of countries.  It is quite expensive and then as a CERN, the -- you know for the -- what is it, proton research near Geneva that is funded also substantial amounts?  So, it can be done, these collaborative research efforts. Scott Barrett:  I just had briefly - I want to be absolutely clear about this, geoengineering, at least from one dimension, is a Band-Aid.  It is a quick fix, no question about it, and remember, like I tried to describe that metaphor of adaptation dikes versus windmills.  Geoengineering is just another manifestation of that and it -- its use may be attractive given that we have failed to do everything else, but it would be much better if we were to deal with the problem fundamentally. So, what I was pointing out was not recommending what we should do, we should not reduce emissions and so on.  It is just that the collective action problems are pointing in this kind of direction and actually the work we needed to do is pushing back in the other direction.  So, that is why I spend 99.9 percent of my time working on the other things and not on geoengineering.  But, the problem is that the forces are pushing in this other direction so that -- [Break in audio] David Schneer:  Thank you.  David Schneer [phonetic], Center for Environmental Stewardship.  Scott, in looking at the collective action problem in historic terms, you say this may be the biggest one we have ever had in mankind, what -- have you given thought to what mechanisms are available to marry the Band-Aid solutions with the underlying energy issue, which is cheap energy? When we talked about -- when Fred talked about going to the moon, for example, the spin-offs that NASA claimed existed and which indeed do exist, were large in number.  They created a whole lot of more efficient ways of solving common everyday problems.  I do not know that geoengineering is quite like that because I do not think the technology is quite as sophisticated or as complex with -- and it is out of that complexity that you will get some of that.  But, have you given any thought whatsoever to trying to look at what the spin-off implications might be for mitigation that could come out of research?  And, Fred, I offer that to you too. Scott Barrett:  Well, let me make this point, okay.  And this may not be answering your question directly.  Someone mentioned before the suggestion that we need a Manhattan Project for climate.  And maybe that is the wrong metaphor, because the Manhattan Project had a very specific goal in mind.  With climate -- the thing about climate is it touches absolutely everything. So, for example, I was kind of suggesting this before, if you think we should -- we are going to need to adopt nuclear power on a large scale worldwide, then you need to have the institutions in place that will guard us from proliferation problems.  So, it is not a technical -- we are not looking for a silver bullet.  It is not like a mission to the moon in that sense either, where the technology is clear. You actually have to radically transform technology worldwide and this is what is most important about it.  You have to do this when the market will not do it by itself, okay?  The Google Corporation has this idea that they are going to develop a form of renewable that will produce electricity without greenhouse gases and more cheaply than coal, that is the important thing, more cheaply than coal. Now, if they can do this they will have solved a big part of the puzzle because, of course, the market will diffuse the technology simply because it is cheap.  It will be diffused worldwide and it will simultaneously address the climate problem.  I am told, by the way, that Google has eight guys working on this so let's hope they are smart.  [Laughter] Anyway, you know, I think the challenge of addressing climate change in a fundamental way is -- it is so unprecedented against anything we have seen before.  To the extent we are able to address it and Dr. Iklé has mentioned the ITAR project, so there will be -- of course there will be benefits that will spring from that.  But, what we have lacked so far is an understanding that this problem requires a technological transformation, that it will be expensive, but still it is worth doing. [Break in audio] Jay Gulledge:  Thanks.  This is interesting -- Jay Gulledge [phonetic] from the Pew Center on Global Climate Change.  What I am struck by is that -- and Scott, you described very, very adequately the market barriers to fixing the problem, but what you did not say is that we are -- what we are looking at is an enormous market failure, the fact that we have been emitting carbon into the atmosphere without paying for the consequences of doing that.  And when you look at this in terms of what it really is, a market failure, and you start to realize that ultimately when you talk about fundamental corrections, you have got to correct the market failure or you are not going to get anywhere in terms of a fundamental correction to the problem or fix to the problem -- solution. And if you put it in those terms, if you frame it as a market failure, you start to hone in on what the solutions are.  They are market-based and then you also have to look at the other side, the physics side of the problem, which says that there are certain physical risks that we incur. Now, without getting much into it, I am a scientist at the Pew Center and one of the things I have been studying is the risk aspect on the physics side of this.  And very, very likely the science has underestimated the actual physical risks at this point. So, then that is the other side of the framing.  So, you have got a market failure on the human dimension side and you have got very likely higher risk than probably most people in this room are aware of on the physics side.  What do you -- what does that say then -- and I will put this to both you and Fred -- what does this say then about what the solutions are and what the timeframe is that we have to solve the problem?  Thanks. Scott Barrett:  Very good point.  First of all, I did not -- I do not think I used the term market failure for a good reason.  I do not like the term in this context, okay.  Because the problem is not the markets, markets -- you know, markets do not work very well, and this is a hard thing to say at the AEI, but the markets do not work very well without governments, okay.  Because governments do things like they assign property rights, so there is not a fight over who actually has -- or if there is a fight it is handled in the courts and people are not killed over it, okay.  It assigns property rights.  It enforces agreed redistributions of property rights, by which I mean contracts, okay.  It does all these kinds of things.  Those are the preconditions for an effective market. Now, what I call this is not a market failure, but a collective action failure.  And the reason is that basically governments have not provided the public goods.  And the difficulty here is we do not have a world government.  Now, I do not want to get -- I do not want to say we should have a world government because that could be even worse than what we are now, believe it or not.  But, nonetheless, that basically is where we are, which means we need to be thinking about this in a kind of a second best way.  Which is why, in a very odd sense, I am not -- even though I am an economist, I am not always recommending classic market solutions to these things, because the enforcement challenges that exist at the global level are so huge, so unprecedented, it is not clear to me that those are the best means at getting at provision, which will determine efficiency, which is what we are basically interested in, okay.  Efficiency, by the way, broadly defined.  Okay, not a narrow definition of a -- Jay Gulledge:  Are governments good at efficiency? Scott Barrett:  Well, no, except that they may be better than markets on their own, so that is the basic point. Fred Iklé:  The word for it, the market failure is what is called the tragedy of the commons. Scott Barrett:  Sure, absolutely. Fred Iklé:  And [inaudible] over you -- air pollution, overuse of national parks, et cetera, water.  I would be interested, I have a question too; can you elaborate a little bit on the risks of physics, on the physics side that you alluded to? Jay Gulledge:  Do you want a -- Fred Iklé:  Can you give us some example? Jay Gulledge:  Do you want to add that -- Fred Iklé:  Later. Jay Gulledge:  Okay. Fred Iklé:  In our next meeting. Jay Gulledge:  We can -- Lee Lane:  Why do not we -- why do not you and Fred talk about this -- Jay Gulledge:  Okay. Fred Iklé:  All right. Jay Gulledge:  I would be happy to. Lee Lane:  Rafe. Rafe:  Thank you, Lee.  Lee opened with a commentary about this is the twentieth anniversary of the IPCC. Fred Iklé:  Um-hmm. Rafe:  I just -- I want to put a plug in here for people who tried to do something about the problem in a different way to frame this so you can fit geoengineering in a little easier.  It is not that we have failed; it is that we started too late.  The system -- by the time the scientific community figured out that we had a massive problem; it was the industrialized system was so far along that we were locked into a massive increase in the CO2 and other greenhouse gases.  Because when the IPCC was formed, it was just the beginning of acknowledging the problem.  I mean as foolish as one may think the debate in the Senate is right now, it is the first time there has been a significant debate about doing something in this country, as difficult as it is.  Anyway, that is just one thought. I want to raise the issue of timing.  I think we have already actually crossed various thresholds that have a dramatic impact on the earth's system, and that if you had the geoengineering option and it was relatively benign, you would want to deploy it. I give you one example.  Half the biodiversity in the world is locked up in the old coral reef's echo systems.  The oceans are now too warm to support it.  Well, could you cool off the oceans enough to maintain the coral -- the diversity of coral reef echo systems?  That I think you could characterize as an abrupt climate change across the threshold, an entire -- as much diversity as in the tropical rain forest was made -- was put at risk.  And there is lots of evidence that reefs are dying because the oceans are too hot already. So, question urgency, maybe for the project is, how do you get the -- I will ask now the question, how do you get the actual research together by the scientific community and others to actually examine the options?  I mean have you thought about it as a panel, who should do it?  How should it be done?  Should it be international?  Should it be U.S. government?  How do you get the politics of this together to protect everybody who thinks you -- at least you have to look at this as a research project. [Break in audio] Rafe:  [Inaudible] response to that as possible. Scott Barrett:  Okay.  And I think we may disagree on this too, so that might be interesting.  I was at another meeting on geoengineering where some -- is there -- one of these closed door meetings, so I think I cannot say who said this, but someone had a very good idea, which was that at the very least, in terms of doing these experiments, at the very least, we should be ready to collect the data to analyze nature's own experiments.  For example, Mount Pinatubo.  If there were another Pinatubo, let's be ready with the machinery to actually measure, as best we can, and take advantage of that situation  The effect of that on the climate and apparently there is much that we do not understand about how that worked.  There -- I think there will be two different views and this is where I think the discussion might be interesting about -- I mean that we can do on our own, okay.  Other countries may want to do it too, fine, but I think there is no issue with us doing that on our own. I think a program of research for geoengineering will -- can be done unilaterally just like geoengineering can be done unilaterally or through a coalition of the willing, but I think it may also create problems for [audio glitch] around the world if individual countries were to do -- what you called, Fred, the field experiments, particularly if anything were on any kind of scale, then I think the rest of the world will basically interfere.  And we saw that already with the London Convention and this potential for doing the experiment off of Galápagos with the iron fertilization. So, I think what would be most helpful in moving forward is we can do research in certain areas where there would not be any kind of difficulties.  And then, as we move forward have a -- kind of a combination of diplomacy.  We are trying to build relations with others who could do it with us at some kind of level.  I would call that kind of a coalition of the willing. Fred Iklé:  Yes. Scott Barrett:  You do not need any kind of formal agreements for this.  But, while at the same time we have a broader effort of diplomacy to build trust and eventually a form of consensus, because I think it is the potential that you could actually have divisions in the world on this and that may actually backfire in a number of different ways. Fred Iklé:  You are right in saying you -- we should move forward to get some momentum and some content to this whole idea of geoengineering, some more data, some more models, maybe some small field experiments.  So, it becomes kind of a visible thing and you do not talk to other countries in a very abstract and speculative way about it. But, then you can also move into one of the appropriate and international existing organizations that -- with United Nations supporting it or the subsidiary international organizations and you try to pick the right one.  We talked the -- there is a whole range of about three or four organizations that might be appropriate to give kind of a home for the international diplomacy and extend their activities into this area.  And I think that we should not start there, because then you get bogged down and you do not know what you are talking about.  You should interest other countries by having shown what it can be, maybe explicit models, more detailed description, the benefits and possible downsides, and then you start bringing it to the attention of the right international organization. Male Voice:  Actually, I would really like to follow up with a question about that.  Assume that the United States government for at least one stage is going to take the lead -- Fred Iklé:  Yes. Male Voice:  -- or be a leader.  I have certainly looked fairly closely at some of the climate related R&D that our government has been doing, and it is not always managed in a tremendously coherent [Laughter] and impressive way.  You must have a judgment through, Fred.  Where would you -- if we were going to have a domestic geoengineering R&D effort, where would you headquarter it or where would you put the center? Fred Iklé:  Well, if you can picture an ideal building -- Male Voice:  [Laughter] Fred Iklé:  -- in Colorado that is one place. Male Voice:  Okay. Fred Iklé:  The National Administration -- Space Administration could be another one.  There are about two or three options and probably have to check out what government committee you serve [sounds like] funding. Male Voice:  Yes, right. Fred Iklé:  And then, you have to ask yourself, "Will the chairman of the committee be supportive about it?" Male Voice:  Okay. Scott Barrett:  That certainly brings it back in a practical light.  [Laughter] Male Voice:  [inaudible] committee -- [Break in audio] Fred Iklé:  -- my point of view is not the right place. Male Voice:  Yes. Fred Iklé:  They -- in fact they have the -- they plan to do some work on modeling, which is good, but I do not think they could take the lead.  It is too much part of the Defense Department. Male Voice:  Now, there is an equivalent tarp in the Energy Department that has never been funded. Fred Iklé:  Right, yes, yes. Male Voice:  So, that it would be [audio glitch]. [Break in audio]. Michael McCracken:  Okay, all right.  Mike McCracken.  Scott, it seems to me you have maybe left one thing off your list of five, maybe more, and some people put on suffering, or you might say, "Grin and bear it."  What does not really come across is that there is going to impacts no matter what that you cannot adapt to.  I mean you were sort of jokingly talking about putting up dikes and things, but the Dutch have been able to do it in part because they did not build their cities out at the edge and then they had space to sort of do it.  I think it is going to be very hard to do for much of the U.S., trying to figure out how to protect New York Harbor.  You know, you can protect the inner harbor in certain ways, but Long Island and Brooklyn -- I mean there are whole bunches of places, Chesapeake Bay is going to be really hard to think about how you protect without dramatic changes.  I mean there are going to be huge changes occurring. In this regard, I really wanted to come back to Rafe's point.  I mean I agree with him that I think we are on the verge, or are already doing some things where we are causing -- you know we are really at that point of the early stages of abrupt change.  And [inaudible] these abrupt changes, they are irreversible in a way, I think, that geoengineering cannot easily prevent quickly.  I mean once you start losing Greenland - I mean we do actually have some ideas about what you might do, but once you start losing -- and it is going to be very hard.  Once you lose biodiversity, you do not get coral reefs back or something like that. And so, I guess I am -- I wonder if we should not refocus the thinking of geoengineering not to be to reverse warming or limit warming, but to limit these things that you were saying you would use geoengineering for, which is abrupt change.  So, maybe talk about it as, "We have got to prevent sea-level rise from becoming more than some amount."  I mean or we are going to lose something or we have got to use geoengineering to try and reduce biodiversity loss, which might also be something you do by preserving the Arctic or something. And do not put it as a temperature threshold that, "Oh, we are going to worry about three degrees or something."  But, focus it on these other aspects directly. Fred Iklé:  But, this broader, wide range of harm that global warming might do is often mentioned by diversity or affecting our harbors, losing course lines, you hear that in all the stories about the harm that global warming may do except for those who say global warming is good for you. Michael McCracken:  Well, and those who do not study it like this administration, which did not do really in passing. [Break in audio] Thank you.  [Audio glitch] I wanted to ask Scott if he could explain [audio glitch] in other terms why [audio glitch] carbon capture [audio glitch].  It strikes me that it is a [audio glitch] part of a new technology that we do not know much about [audio glitch] decades [audio glitch] -- and the other thing we know about it is that it is probably very expensive, much more expensive than [audio glitch].  So [audio glitch]. Lee Lane:  Scott, why do not you repeat the question if you do not mind. Scott Barrett:  Okay, so the question is, "Why on earth would I favor carbon capture and storage because we do not know much about it at this point and also it will be expensive?" Actually what I favor -- what I said was if we are to -- certainly if we are meet any kinds of these limits that are suggested 450, 550, and if -- you know, not to mention the lower ones, there is no other way we are going to do it.  It would have to include carbon capture and storage.  Now, it may be that once we open the box of carbon capture and storage, we will decide it is too expensive or we do not like CO2 storage or something.  I do not know what we are going to discover yet.  My major complaint is that, Rafe, I am going to disagree with here in the sense that 1988 to now is 20 years.  The idea of carbon capture and storage has been around for quite a long time and we still do not have a pilot program up and running.  We have to actually find out, does it work, and how does it work, and how do we do it, how expensive is it, and the rest of it. I think it is -- I think that is a scandal.  The one thing this administration, for example, could have left the future of climate change was at least some knowledge about this technology and whether it would work or not.  So, that was my main point about it. Male Voice:  Can I just respond briefly? Scott Barrett:  Mike had said before suffering, I am not going to put that as a list of things that we ought to do, but it is true [Laughter] that we will suffer.  There is no question about it and the way we are thinking about this and the way economists would think about it is you are basically going to minimize the sum of a lot of different things and one of those things is suffering, okay.  So, you will adapt, mitigate, all these different things you are doing to reduce suffering, but in the end, you are going to eliminate that.  You are going to -- there is going to be an element that -- Male Voice:  Better figure out what it is. Scott Barrett:  Sure, well, yes, sure.  And on the corals, I think one extra point needs to be made about corals and that is that we are losing them now for reasons having nothing to do with the temperature change, but just because run off from land, over fishing, there are a lot of things that are damaging the corals and let us not protect the corals for climate and then destroy the corals through these other things that we have been doing.  I think, Mike, the last point I wanted to address, I think it is a very good point, when do you use geoengineering?  Now, I have been saying, "Well, we are going to use it when there is abrupt climate change."  I did not ask the question, "Well, the sea-level rises, basically as I understand it, near dead certainty under business as usual, we just keep this thing running out, melting agreement, for example, I mean people take centuries?  No, okay. Michael McCracken:  You can replace it. Scott Barrett:  You can replace it?  Okay.  Anyway, this is what I have been told that under business as usual, substantial sea rises are near certainty.  It may be that the point will come that people will respond to that by saying, "We have to do something."  That something might be geoengineering and it seems with geoengineering, once you flick it on, if you are using it to address that problem, you have got to keep it going and you do not know the risks associated with using it and you have got to keep it going indefinitely. So, it seems to me you certainly would not want to -- even addressing things in a decentralized kind of collective action perspective, you would not want to rely exclusively on that technology for that purpose. Fred Iklé:  You might want something that works. Scott Barrett:  Well, as I said before, if you turn it on and you find that it does work, then yes.  But, of course, before you turn it on, you are not sure it is going to work. Fred Iklé:  That is why we need testing now. Scott Barrett:  Yes. Lee Lane:  Last comments from our [inaudible].  Fred. Fred Iklé:  Well, I sense a consensus here from the other speakers and informed scientists that nobody wants to say you should not do some -- [End of File:  AEI9473-PanelTwo.mp3] [End of Transcript]</body></html>