World?s Leading Automakers" Chairman F. SC HWAB Porsche 15: Vice Chairman D. MAZZA Hyundal 2nd Vice Chairman D. SMITH Toyota Secretary D. HELFMAN BMW Treasurer . AM ESTOY Mazda BMW Daewoo Flat Honda Hyundai Isuzu Kla Land Rover Mazda Morcedes-Benz Nissan Peugeot Porsche Flanault Rolls?Royce Saab Subaru Suzuki Toyota Volkswagen Volvo President P. HUTCHINSON TO: FROM: RE: AIAM Technical Committee Gregory J. Dana Vice President and Technical Director TECH-96-30 4/24/9 GLOBAL CLIMATE COALITION (GCC) - Science and 9 6 Technology Assessment Committee (STAC) - Minutes of April 11, 1 996 Conference Call Enclosed is a copy of the minutes of the April 11, 1996 conference call of the Science and Technology Assessment Committee (STAC) of the GCC. Also included are copies of two reports retereced in this and other STAC meetings. These are: the Scientific Uncertainties from the IPCC Second Assessment Report -- Work Group 1 and Work Group II. ASSOCIATION OF INTERNATIONAL AUTOMOBILE MANUFACTURERS, INC. 1001 19TH ST. NORTH I SUITE 1200 I ARLINGTON, VA 22209 I TELEPHONE 703.525.7788 FAX 703.525.8817 AIAM-051090 AIAM-051091 SENT BY: 7035258938;# 1/18 Mobil Corporation 3H5 GALLOW8 ROAD VIRGINIA TELEPHONE: 703/846-3530 L. 8. BERNBTEIN Mon-gunman? Environmorml Hun/1h a Sufi? FAC I I I VER TO: SCIENCE AND TECHNOLOGY ASSESSMENT COMMITTEE FROM: L. S. Bernstein - April 15, 1996 (Cover 17 pages) Com hers Information Mitchell T. Baer - 202/682-8031/ Chuck Hakkarinen - 415/855-1069 Greg Dana - 703/525-8817 George Lauer - 213/486-2021 Howard Feldman - 202/682-8270 Robert H. McFadden - 202/326?5567 Brian P. Iannery - 908/730-3301 James Pinto - 914/253-7895 Barry R. Friedlander - 908/873-6009 Belinda Rabano - 202/331 -9864 Bronson Gardner - 216/475-9674 John Shales - 202/638-1043 Robert P. Gehri - 205/877-7294 Charles R. Sharp - 202/326-5528 Jon M. Heuss - 313/556-9001 Elizabeth Fests Watson - 703/741-6091 Eric Holdsworlh - 202/638-1043 John Holt - 703/907-5517 Richard P. Janoso - 610/774-5930 Russell Jones - 202/682-8408 John Kinsman - 202/508?5150 Eric C. Kuhn 513/287-3499 Ned Leonard - 703/907-6161 C. V. Mathai - 602/250-3813 John M. McManus - 61 4123-2897 Stephen A. Pezda - 31 31594-4271 Tom Rasmussen - 202/833-9636 Eric Reiner - 612/773-6176 Eric Ridenour 810/576-7928 Jerrel D. Smith - 314/554-4830 or 314/231 -1 890 Fred Starheim - 216/384-5433 Mike Stroben - 704/875-5493 Porter J. Womeldorff - 21 7142-91 74 AIAM-051092 SENT BY: To: 7035258938 2/ 18 GCC Science and Technology Assessment Committee April 12, 1996 Members of GCC-STAG Results of April 11th Call Scienti?c views not adequately addressed by the IPCC - John Kinsman previded a summary of the House Science Committee testimony of scientists who disagreed with the IPCC consensus. Porter Womeldorff provided a list of topics which were sources of the uncertainty in the scienti?c assessment of climate change. agreed that it would be trying to put together write-ups on these topics. The following members volunteered to draft discussions on these topics: Models Chuck Hakkarinen Sea Level Rise Tom Rasmussen Solar Variability Bob Gehri Carbon Dioxide Lenny Bernstein Temp. Record/Measurement Eric Reine: These write-ups should be sent to Lenny Bernstein by May 9th for distribution to STAC members prior to our May 16th meeting. Another topic on Porter?s list was the politieization of science in the process. This issue was addressed in early drafts of the Science Primer, but STAC was unable to come to agreement on how to present the issue. At the May 16th meeting. we will discuss whether the Committee wishes to address this topic as part of the follow-up to the Science Primer. Bronson Gardner presented a list of eight issues which he felt were inadequately discussed in the IPCC Working Group I report. A written description of these issues is attached. STAC will decide at its May 16th meeting whether to ask Bronson to develop a paper for GCC members elaborating on these issues. Review of ?Climate Change Assertions and Facts? - We discussed the draft being developed by Communication Committee in general terms and provided a number of general suggestions to Tom Kirlin who is coordinating development of the piece. Speci?c comments are due to l? om by fax (202-682- -8071) or phone (202-682- 807 8) no later than the close of business on Thursday, April 18th. Bob McFadden informed actions in response to a request from the State Department for input on a number of issues which will be discussed at the next round of AIAM-051093 SENT BY: .L 7035258938 3/ 18 UN climate change meetings in July. One of the topics was views on the Second Assessment Report. This response was put together from. a summary developed by Bronson Gardner for the GCC Communications Committee. . John Kinsman asked whether STAC had reviewed the attached three updated GCC Backgrounders dealing with scienti?c issues. After the conference call it was determined that STAC had not been involved in the review of these papers. At the May 16th meeting we will discuss both the papers and ways to ensure that STAC review is part of the clearance procedure. . Bob McFadden also mention an article in the March 29 issue of Science which presented information about climate ?surprises.? A copy of that article is also attached. . Eric Reiner reminded members that we need about $500 additional funding to be able to invite Ben Santcr, one of the lead authors of IPCC WG I?s report to present his arguments for why there is a discernable human impact on global climate at our June meeting. - Additional items for the May 16th meeting: STAC involvement in the four IPCC Technical Reports scheduled for completion in November, 1996. - Status of ACACIA L. S. Bemstem 041 19602.wp6 AIAM-051094 SENT BY 1 7035258938 4/ 18 To: STAG From: Bronson Gardner Re: Concepts not adequately addressed in the IPCC Second Assessment Report There are at least 8 issues which I thought were inadequately addressed in underlying chapters of the IPCC's Second Assessment Report. Each ol?thesc are items which either generated controversy during the I plenary session or which most ol?lhe authors ot? the Report wanted to avoid discussing. Issue Quanti?cation ot?anthropogenic and natural effects in climatic data. Climate scientists have produced several historical data sets of climate trends. There is inadequate discussion 01? what scientists need (in terms of data or theoretical advances) to begin quantifying and di??rentiating between "natural" and ?andiropogenic" elIects. For example, missing is a good discussion ol?ourrent temperature trends, 0.3., why did the hull: ot?thc temperature rise in the past 100 years occur before the bulk ot'the CO2 emissions Issue Hypothesis Testing. What do climate scientists need in terms ol?data or themetical understanding) in order to establish the validity of the projections being made by climate particularly regional models What are the appropriate statistical tests It? the current data is evaluated with these statistical tests, what do the results show 5? What are the ?signs? of global warming that should be detected in the data a warming arctic) and what tests are needed to verity the existence of these signs Issue De?nitions ot?Keg,r Words: Two phrases generated signi?cant connoversy at the WGI plenary and at the Rome Plenary: "climate change" and "global mean temperature". It was clear that delegates could not reach consensus on the meaning of these terms- Part of the problem is a con?ict between what scientists ma).r mean when using these terms and what policymakers may mean. Issue Statistical correlations between observed and modeled data. A great deal has been said about how "broadly consistent" the observed and modeled data are, butthere is very limited discussion on the actual statistical relationships. For example, R2 values are quite low, leading one to believe that natural variability may dominate the histo?cal trends. Issue Divergent results produced from various models. There is some inter-model comparisons contained within the report, but much more discussion is needed. This would highlight the weaknesses and uncertainties within the models and allow policymakers a more realistic opportunity to evaluate the credibility of the models [or policy purposes. Issue Discussion of natural warming and cooling trends. The report clear indicates that there was a significant cooling trend several hundred years ago, but only suggests that one interpretation of the data is that recent wanning may be the result of a natural wanning trend which began alter the cooling trend peaked. For example, why isn't it plausible that most, if not all, ol?the observed warming is due to natural forces, and That the enhanced greenhouse effect is strictly an issucfor fhe??ur?? Ties back to a discussion on quanti?cation ofe??ects. AIAM-051095 SENT BY: 703525?938;# 5/18 Issue Methods of computing global mean temperamres and global mean temperature variations. This is a fundamental issue on which many people, even within the are confused. IPCC scientists made it clear that there is no reliable global mean average temperature. since it depends on how one wants to de?ne the mean and what data sets are used. Global mean temperature may vary lien: 10 to 15 C, depending on how its de?ned. Deparmres ?om the global mean temperature (the parameter generally discussed) is actually a quite complicated piuameter to compute. Since "global temperature" trends (meaning deviations item the mean) are one of the central political issues. a clear understanding of how these numbers are derived would seem essential. 1 question if IPCC would ever want to attempt this, since all the explanation could do is decrease people's con?dence in the numbers which they provide. Issue A clear and detailed explanation of the phrase ?discernible human in?uence." is needed . The Report states that the evidence for a discernible human in?uence comes from "changes in global mean surface air temperature and item changes in geographical, seasonal, and venical patterns of atmospheric temperature." Missing from the report are the necessary graphs and statistics which support this point. During the plenary at Madrid, the explanation was offered that the current is based basically on "visual inspection of the data?, leaving the hirerpretntion totally up to the individual scientist making the statement. Clearly, a much more defensible and quantitative justi?cation for this statement is needed. AIAM-051096 7035258938 6/ 18 PRESS OFFICE: (202) 6280622 BACKGROUN DER 1331 AVE. NW 0 1500 - NORTH TOWER I WASHINGTON, DC 20004?1703 Science and Global Climate Change: What Do We Know? What are the Uncertainties? About This Backgrounder in the past two decades, many scientists have raised concerns about the future of the earth's climate. In 1971, several leading scientists raised concerns about global cooling, leading to predictions of a coming ice age. Some scientists still recognize a cooling porential. In the mid-1930's, the concern shifted to global warming, with a number of scientists stating their belief that the earth was warming as a result of an increasing concentration of greenhouse gases in the atmosphere. Some scienrisrs predicted dramatic increases in temperature, which would lead to the melting of polar ice-caps. rising of sea levels, and other catasrrophic results. Today, after several years of investigation. many of these dire predictions are moderating. Global climate policy decisions must be made with the bene?t of an adequate scienti?c understanding of how and why climate changes. Scientisrs remain divided on a number of climate change issues: Are increases of man-made gases contributing to global warming? l-lave global temperatures increased over the century? How accurate are forecasts based on computer modeling? Are sea levels rising? and How will increases in carbon dioxide (a greenhouse gas) affect the world?s plant life? This backgrounder responds to these questions, which are being debated in the scienti?c community today. and provides a resource section for additional reading. Are increases of man-made greenhouse gases contributing to global warming? Scientists agree that the greenhouse effect is a real. naturally occurring phenomenon. Greenhouse gases trap the sun?s warmth in the lowest layers of the atmosphere, keeping Earth warm enough to SUStain life. Without the natural greenhouse effect. the average surface temperature on Earth would fall below zero Fahrenheit. indeed. in the natural greenhouse effect, atmOSpheric water vapor and clouds play a far greater role than other greenhouse gases. To put this in petspecrive, even if all Other greenhouse gases were to disappear. wateryapor and clouds would still leave us with 98 percent of the current greenhouse effect. Scientists also agree that atmospheric levels of greenhouse gases (such as C02) are increasing as a result of human activity. But scientists differ on whether the increase in the concentrations of these gases will cause an "enhanced greenhouse effect." or warming of the planet. because the role of greenhouse gases in climate change is not well understood. AIAM-051097 SENT -t 7035258338 7/ 18 As an example of this uncertainty, a recent Gallup poll of climate scientists in the American Meteorological Society and the American Geophysical Union asked whether there has been any identi?able. human-induced global warming to date. Forty-nine percent of respondents said no; 33 percent said they did no: know. and Only 18 percent thought some warming has occurred. Have global temperatures increased over the last century? Average surface air temperature readings appear to have increased about 1 degree Fahrenheit during the tact century. Just as the greenhouse effect is a natural phenomenon, so are climate cycles. While temperature records do not extend much beyond the century mark, making it dif?cult to view the observed temperature change in the context of an overall trend, many scientists believe the observed increase in temperature within the last 100 years is a result of natural ?uctuations in climate. Notably, almost all of the temperature increases in this century occurred before 1940. well before any signi?cant increase in man-made C02 emissions. The effects of man?triad: gases and natural factors may more completely explain this temperature record. Analysis of the temperature data records for the last [00 years are subject to several uncertainties. including the urban heat island effect. which can raise temperatures around measurement Stations as urban areas expand. Urbanization increases everything from lighting. automobile exhaust and retained heat from buildings and roads. Some scientists say this "heat island? effect must be considered when lookin at the long-term temperature record. Satellite measurements. which have been made for the last 14 years, which are relatively free from the distortions resulting from location. have shown no global temperature trend. The satellite techniques offer the future promise ofcomparing observational records with global climate model projecuoas. How accurate are forecasts based on computer modeling? Computer models are used to project future temperature and climate change scenarios. The fact is. however. that computer modeling is inexact anti uncertain. Many of the world's fOrcmost climate modelers concede that insuf?cient data are available to represent the complex interactions that determine temperature and climate. At this time. modeling is unable to resolve haw. where, or even whether porential global climate change can affect speci?c regions of the planet. Many scientists believe current climate models are an inadequate basis for policy decisions. The manner in which these models account for water vapor (the major greenhouse gas) and cloud cover. is among their greatesr shortcomings. Even small modi?cations in these factors can dramatically alter model projections. Current climate cannot credibly predict COZ-induced climate changes. The intergovernmental Panel on Climate Change (IPCC) was formed in 1988 by the United NatiOtts Environment Programme and the World Meteorological Organization to evaluate the science. potential impacts and potential policies for climate change. Presenting its ?ndings. the Stated. "Climate models are only as good as our understanding of the processes which they describe. and this is far fr0m perfect." Are sea levels rising? AIAM-051098 SENT BY: 7035258938 8/ 18 There has been a great deal of speculation about a potential sea level rise if the global climate gets warmer. Since even the most dire predictions ofa warming trend would still leave the polar regions well below freezing, some scientists question the notion of a dangerous melting of the polar ice caps. Several recent studies suggest that warmer air temperatures will increase snowfall. resulting in more, not less. snow cover. While most scientists agree there has been some observed rise in sea level over the lasr century, there are questions on the accuracy of sea level measurements. Taken primarily through tide gauge records, sea level measurements are difficult to assess because of vertical land movements. atmospheric pressure, winds, ocean currents and lunar cycles. How will increases in C02 affect the world's plant life? While scientists disagree on the link between C02 increases and any global warming, there is strong scienti?c evidence pointing to the link between C02 increases and plant productivity. Plant life "breathes" C02 as humans do oxygen. Recent studies have suggested. and many agricultural experts believe. that increasing atmospheric C02 levels may in fact accelerate plant grth. given adequate nutrients in the soil. In summary Sound policy making rests on resolving scienti?c uncertainty. Focused research is critically needed to address the outstanding scienti?c uncertainties that surround global climate change. The relevance of on-going research will depend in large part on how well it can scienti?cally clarify answers to the questions facing policy-makers. The research must resolve the questions raised above as well as other key uncertainties such as: i) What is the role of cloud cover, the oceans. polar ice caps. soil and forests and their interactions? and 2) How can we differentiate natural climate variations from changes attributable to man-made emissions? If the research fails to address these and other issues. the result may be stacks of good scienti?c articles, but little progress in translating data into information that policy makers can use to make effective decisions. Recommended Reading Boettcher, CJ.F. . I The Hague, Netherlands: The Global lnsritute for the Study of Natural Resources, 1992. (Capies are available through the Science and Eviranmental Policy Project at 703-52 7-0130.) Houghton. Jenkins. 0-1.. ed. Cambridge University Press. I990. Haugton. J.T., Jenkins, Ed. - Scienti?LAssessmem Cambridge: Cambridge University Press, 1992. Lindzen, Richard 8. "Global Warming: The Origin and Nature of the Alleged Scienti?c Consensus." (Spring 1992): 87-98. (Copies are available through the Cato Institute at 202-5 46-0200. AIAM-051099 7035258938 9/ 18 .L SENT BYZ Michaels. PatrickJ. .Washington DC: Cato institute. [9922. (Copies are available through the Cam Institute at 546- 0200. Singer. Fred S. ed. iti San Francisco. Press. 1992 (Copies are avaiiabl 1- 800?326- 0263. Pleas refer to [saw-55815433- 4} Singer, 5. Fred. ?Warming Theories Need Warning Label." Bulletin gf BI: - . .515 (June 1992): 34-39. AIAM-OSI 100 7035258938 #1 0/ 18 SENT BY CO4 Omar: (202) 628?3622 GLOBAL 9? 1.3.31 AVE. NW SUITE 1500 NORTH TOWER II WASHINGTON, DC 200044703 Climate Models: Shortcomings and Limitations General Circulation Models General circulation models (GCMs) are computer representations of global climate. They are based on mathematical equations derived from our knowledge of the physics that govern the Earth- annosphere system. By de?nition, "climate" encompasses a vast number of factors (cloud cover, air and ocean temperatures, rain and snowfall, air and ocean currents, barometric pressure, atmospheri composition, etc). These models are far from perfect, however. Policymakers should be aware of the limitations of computer models and recognize that while these models are useful tools for scienti?c research, they are not yet reliable enough to serve as the basis for multi?billion dollar public policy decisions. Important Weaknesses in GCMs The and the GAO have recently identi?ed several important limitations associated with GCMs which clearly indicate that GCMs are not yet ready for use by policymakers. The has identi?ed 5 major areas of weaknesses in GCMs: Poor model representation of cloud processes.- A coarse spatial resolution the grid-scale is too large). Problems in the parameteriration of regional and local atmospheric processes. Generalized topography, disregarding some locally important features. A simpli?ed representation of land-aunosphere and ocean-atmosphere interactions. (WGII FSM (Chapter 26, Technical Guidelines), section 6.5.3). Until these weaknesses are signi?cantly resolved, it is clear that policymakers will be hard pressed to rely on GCM output for policy decisions. The probability that the current output is misleading, or totally incorrect, is simply too high. Key limitations include: - Incomplete or inadequate quanti?cation of processes affecting climate. 'S'peci?callx they have not been able to uniquely and quantitatively distinguish the e?'ects of higher concentrations of greenhouse gases ?an: the e?'ects of other ?ctors that can change the AIAM-051101 SENT BY: Climate Model Shortcomings Backgrounder The Global Climate Coalition climate. Such factors include natural ?uctuations in the global climate system. increases in atmospheric ozone, air pollution. and aerosols emitted into the atmosphere from volcanic eruptions." (GAO. 1995. page 6). . Inadequate representation or inclusion of feedback mechanism include many of the most important feedback mechanisms. such as vegetation, water vapor, ice cover, clouds, and the ocean However. the models do not yet adequately represent the interactions of these mechanisms with greenhouse gases. Such interactions can employ, daMpen. or stabilize the warming produced by increased concentrations of greenhouse gases. (GAO, 1995, page 8). It is clear that ?edback mechanism (the interaction between the various components of the atmosphere) in GCMs have critical implications for policymakers. The net effect of feedbacks, from a policy viewpoint, is to determine whether a GCM indicates greenhouse gas emissions will be serious or benign. Clearly, the inadequate representation of feedbacks in climate models seriously undennines the usefulness of GCMs for policy purposes. Hence, until climatic feedbacks are adequately represented, policymakers should not rely on GCMS. - - Insuf?cient computer power "Imu??icient computer power a?'ects the accuracy of estimates because even the most powet?d computers are limited in their ability to store and analyze the vast quantity of data required to accurately simulate changes in the global climate. Modelers have tried to overcome these limitations by introducing assumptions into their models that deliberately some operations in order to ?ee the GCMs capacity and time for other. more critical operations. 1995, pg 8-9). The "simpli?cation" of science by introducing assumptions designed simply to increme computational ef?ciency, raises serious questions about the accuracy of the ?nal result It is certainly possible that these "simpli?cations" accomplish their intended purpose (Lg, achieving a reasonable computational speed) while sacri?cing the one thing that policymakers really need--an accurate theoretical projection of ?nite climate. The presence of these simnli?cations, and our current lack of understanding about how they affect projections of More climate, limit the reliability of these projections for policy making purposes. . Inability to reliably project regional changes in climate. ?Still another limitation ejecting the accuracy of estimates is the relatively large size of the grids into which the models divide the earth. These grids typically cover an area about the size of South Carolina. Although their use enables GCMs to depict larger-scale regional e??cts in relatively large homageneous regions. it does not allow modelers to incorporate detailed regional features. Consequently, the use oflarge grids- prehents the models from accurately forecasting climatic changesjbr smaller, less homogeneous regions. (6'40. [995, pg 9). AIAM-051102 SENT BY 3 7035258938 #12/ 18 Climate Model Shortcomings Backgrounder The Global Climate Coalition The stated the problem this way: outputs, though physically plausible, o?en fail to reproduce even the seasonal pattern of present-day climate observed at a regional scale. This naturally casts some doubt on the ability of to provide accurate estimates of ?tture regional climate. Thus GCM outputs should be treated. at best, as broad-scale sets of possible ?ours-- climatic conditions and should not be regarded as predictions. (WGIIFSM (Chapter 26, Technical Guidelines). section 6.5.3). From a policy permective, projections of regional climate change are the most important Output of climate models. Yet, it is clear that policymakers can have little con?dence in regional climate change projections. In fact, the IPCC recently stated: "Con?dence is higher in the hemisphe?c-to?continental scale projections of coupled atmosphere-ocean climate models than in the regional projections. where con?dence remains low. (FCC Report, paragraph 2.9). This limitation is critical, since it is potential changes in regional climate which are the basis for virtually all of the impact projections regarding greenhouse gas emissions. The question is naturally raised: If policymakers can have little or no con?dence in regional climate change projections, then shouldn't policymakers also have low con?dence in any resulting inspect projections? Clearly, policymakers should not make multi-billion dollar decisions which are based on impact projections in which scientists, at best, can only express "low con?dence". 1 Improving the Models General circulation models, particularly regional climate projections, must be improved substantially before policymakers should base decisions on the scenarios they generate. Improvements are needed in several major areas of ongoing research, including the following: Enamels-nag?: Current parametetization (a mathematical estimate of how neutral processes work) schemes are a major source of uncertainty. Improvements are needed in two areas: a) parameterizarion of cloud formation processes and b) understanding of interactions among the different pammetenzation schemes being used and portability of parameterization schemes between GCMs. A great deal of testing and development in this area is needed. the present time. weaknesses in the parameterization of cloud formation and dissipation are probably the main impediment to improvements in the simulation of cloud e?hcts on There is a great need observations ofcloud-scale dynamics and of the radiative properties of clouds. so that the parameterizations of the physical processes. can improve. FSM, section 6. 7.1.1). "While a given parameterization scheme may perform well in "of-line" tests, interactions with other parameterizations and with dynamics may not resillt in an improved simulation in a coupled model. A particular scheme may also perform well in one model but poorly when used in another model. (WGI FSM section 5.5). AIAM-051103 SENT BY: .. Climate Model Shortcomings Backgrounder The Global Climate Coalition Wm: Although still inadequate for policy purposes, current GCMs are much improved from those that existed only a few years ago. Still, much work remains to be done to improve con?dence in climate projections to the point that they can be relied upon by policymakers. In this regard, the IPCC has made it clear that priority should be given to improving the paleoclimatic data base. Without a signi?cant improvement in palco data, many uncertainties - - unlikely to be resolved. guiding 11mm hang: are "To build con?dence in the decade-to-centuot time-scale natural variability simulated by models, there is a need to camparemadel attempts to mimic the climate of the past 1000 years. with variability estimates from paleaclt?matic data with comparable time resolution. FSM section 11.7). ?Without a better paleoelimatic data base for at least the past millennium, it will be dt?lcult to rule out natural variability for recent observed changes. or to validate coupled model noise estimates on century time scales. (WGI SM. section 8.3.2) ?Unless paleoclt'matic data can help to 'constrain? the century time scale natural variability estimates obtained ?am it will be dt?icult to make a convincing ease for the detection and attribution of an anthropogenic climate change signal. (WGI FSM, section 8. 3. For these reasons, the GCC supports a coordinated intonatioml research program. the continuation of U.8. climate research efforts billion requested for FY 1995). in addition ?independent and industry sponsored research. GCC also supports activities to reduce greenhouse gas emissions that make sense in their own right. thus continuing sound business practices that will lead to more ef?cient use of energy. Relentless Global Warming: Limitation of General Circulation Models and Costs-of Modeling Elforts. I993 United sung GM Accounting Office. Document GAOIRCED-M-IM. Clint-to Change I995: The Science of Climne Change. Dra? Contributor: of Working Group 1 to the Second Assessment Report. Accepted by govenunents It Working Groin: I. Fifth Session. Madrid, 27-29 November. I995. Bowman: (91.1995). (W01 FSM) Climate Change I995: TheScimceofClimrte Change. DrIRCoun-ibutionot'Wm-lting Group 11 to meIPcc Second Amen: RM Acupnd by govemmentsat Working Gm ll. Third Session. 13m (3131111995). (?(611 FSM) IPCC Technical Guideline for Assessing Climne Change Imp-cl: Ind Adnpmions. 1995. 26 of me FSM). . DoulmenICGER-l?ls-?t. (Published scpuuely). Second Assessment of Scienti?c-Technical information Relevant To Inla'pluins Article 2 or um UN Framework Convention on Climate Change I993. Rome. ?45 Deounber, 1995. The Global Climate Coalition is an organization of business trade associations and private companies established in 1989 to coordinate business participation in the scienti?c andpollq debate on global climate change? ustos: 02mm 011: pm AIAM-051104 7035258938 #14/ 18 PRESS OFFICE: (202) 628-3622 BACKGROUNDER 1331 PENNSYIMANIA AVE. NW - SUITE 1500 NORTH TOWER - WASHINGTON, DC 20004-1 703 Understanding Carbon Dioxide (C02): Future Trends in Emissions and Emissions Control Understanding C02 Me At the heart of the global climate change issue is the concern that increasing levels of greenhouse gases in the aunOSphere could cause an enhanced greenhouse effect (a Warming of the global climate beyond what might occur naturally) or "global warming." Some scientists believe that a methane and HCFC's, C02 has been the primary target of efforts to reduce greenhouse gas emissions. Such efforts include proposed emissions limits, targets and timetables for reductions, and taxes on carbon or other energy sources. . It is important to understand that carbon dioxide is not a pollutant. It is a naturally occurring component of the atmosphere and is also a by-product of human, plant and animal respiration, a product of combustion, and a vital component of Of the C02 that is emitted as a result of human activities. about half remains in the atm05phere, while the other half is removed by "sinks" which naturally absorb C02. Sinks for C02 include the ocean, soils and vegetation. Currently, our understanding of these sinks is limited, adding to the uncertainties surrounding predictions of the climate impact of rising C02 emissions. Historical and Future Trends Understanding the historical data on C02 emissions and global temperature provides clues to determining the relationship between increased atmospheric C02 levels and possible future changes in global mean surface temperature. AIAM-OSI 105 SENT BY: 7035258938 #15/ 18 Understanding C03 Backgrounder The Global Climate Coalition Global temperatures can vary signi?cantly with little or no change in greenhouse gas concentrations. For example, global mean temperatures rose 0.46? between 1900 and l995, . . It is interesting to note that atmospheric CO: concentrations rose only 14.2 between 1890 and 1940. These facts led the to concluded that this rapid increase in temperature was caused by natural forces. "The rather rapid changes in global temperature seen around 1920- 1940 are very 11'th (a have had a mainly natural origin. "1 This means that natural forces, not greenhouse gases. have caused most, if not all, ofthe observed changes in global temperature during the 20th century. Many forecasters agree that greenhouse gas levels could double sometime a result of a number of factors, including: population growrh. increased economic activity in developing countries. Yet scientists cannot be certain whether the increased atmosPheric concentrations of or any other greenhouse gas will cause any is the toadqu representation of in the next century as increased use of fossil fuels and "GCMs[computer climate models] include many of the most important feedback mchanisms. such as vegetation, water vapor, ice cover. clouds, and the ocean. However, the models do not yet adequately represent the interactions of these mechanisms with greenhouse gases. Such interactions can amyll?z, dampen. or ?gain? the warming produced by increased concentrations of greenhouse gases. "2 Future Sources of Increased C02 Emissions According to the international Energy Agency, as much as 85 percent of the projected increase in manmade global C02 emissions will come from developing countries and countries with economies in transition Eastern EurOpean nations and Russia}. In fact, the U.S. contribution of made C02, which is less than 22 percent of total C02 emissions worldwide, has signi?cantly declined over the past twenty years and will continue to decline. Additional reductions in the United States' C02 emissions would be relatively insigni?cant in the context of reducing global greenhouse gas concentration levels. Policy Eliot-ts to Control C02 Emissions Most industrialized nations. including the United States, already have policies and programs in place that help to signi?cantly reduce emissions of 002. In the United States, some studies Show that existing programs (such as EPA's Green Lights Program) and policies (such as the Clean Air Act and the National Energy Policy Act of 1992) will come close to reducing C02 AIAM-051106 SENT BY: Understanding C02 Backgrounder The Global Climate Coalition emissions to 1990 levels by the year 2000. Many economic experts have concluded that the cast of radical reductions in greenhouse gas emissions in the United States would be enormous, perhaps overwhelming enough to cause severe unemployment, decreased international competitiveness of US. goods, and other grave economic disruptions. Some economists believe that carbon dioxide emission reduction policies carbon and other energy taxos) will only provide an incentive for carbon intensive industries to migrate to regions without such a tax. They say this movement to developing countries, where environmental regulations are signi?cantly less stringent than the U.S., will result in more greenhouse gas emissions, not less. As developed nations make progress toward reducing their emissions over the next decade, the greatest opportunities (and needs) for controlling the growth in C02 emissions will be in developing countries and countries with economies in transition. International policy efforts will need to be aimed at making the most of these opportunities by encouraging these nations to incorporate clean technologies into their economies. In fueling their economic growth, many deveIOping nations now employ outdated or inef?cient energy and environmental technologies and resource management techniques. For more information on reduCing emissions in developing countries, see GCC's information backgrounder on Joint Implementarion. I. Climate Change, the I990 Assessment. Cambridge University Press, section 7. l2. 2. Global Warming: Limitations of General Circulation Models and Costs of Modeling E?'om. [995, United 3mg General Accounting Of?ce. Document page 8. The Global Iimaie Coalition is an organization of business trade associations and private companies established in 1989 to coordinate business pmicipation in the scienti?c andpaliq: debate on global . climate charge. [15103: 02123196 02:40 AIAM-051107