This file describes the following data base: INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC), WORKING GROUP 1, 1994: MODELLING RESULTS RELATING FUTURE ATMOSPHERIC CO2 CONCENTRATIONS TO INDUSTRIAL EMISSIONS. CDIAC DB-1009 (1995) CONTENTS I. Introduction II. Description of the data base A. Subdirectory "inputs" B. Subdirectory "results" C. Subdirectory "report" III. References I. INTRODUCTION This data base contains the results of various projections of the relation between future CO2 concentrations and future industrial emissions. These projections were contributed by groups from a number of countries as part of the scientific assessment for the report, "Radiative Forcing of Climate Change" (1994), issued by Working Group 1 of the Intergovernmental Panel on Climate Change. There were three types of calculations: (1) forward projections, calculating the atmospheric CO2 concentrations resulting from specified emissions scenarios; (2) inverse calculations, determining the emission rates that would be required to achieve stabilization of CO2 concentrations via specified pathways; (3) impulse response function calculations, required for determining Global Warming Potentials. The projections were extrapolations of global carbon cycle models from pre-industrial times (starting at 1765) to 2100 or 2200 A.D. There were two aspects to the exercise: (a) an assessment of the uncertainty due to uncertainties regarding the current carbon budget; (b) an assessment of the uncertainties arising from differences between models. In order to separate these effects, a set of standard conditions was used to explore inter-model differences and then a series of sensitivity studies was used to explore the consequences of current uncertainties in the carbon cycle. The specifications for these calculations, the models that were used, and the results that were obtained are discussed in the report, "Future Emissions and Concentrations of Carbon Dioxide: Key Ocean/Atmosphere/Land Analyses" (CSIRO Division of Atmospheric Research Technical Paper No. 31), which is included in this data base. II. DESCRIPTION OF THE DATA BASE The contents of this data base are found in three subdirectories: 1. "inputs" All input data are provided as annual time series. Atmospheric CO2 concentration data are smoothed versions of data from ice cores (Neftel et al., 1985; Friedli et al., 1986) and atmospheric observations (Mauna Loa Observatory data from Keeling and Whorf, 1991). They begin in 1765, which is the required starting year for all calculations. Industrial CO2 emissions are those given by Keeling (1991) and Marland and Boden (1991), linearly extrapolated back to zero in 1844 to avoid a step function start at the beginning of the published record. The additional data for 1990 and revisions for 1985 to 1989 are from Marland (personal communication). Data for CO2 emissions from land use changes are from R.A. Houghton (1993, personal communication). Atmospheric carbon-14 data were supplied by M. Heimann. The files in this subdirectory are as follows: readme.inp: Descriptive file explaining sources and formats (including units) of input files. co2spl.dat: Atmospheric CO2 concentration record derived from a spline fit to the Mauna Loa and ice core records. co2-sens.dat: Atmospheric CO2 concentration record derived from three different spline fits to the Mauna Loa and ice core records. The first was for the standard case (same as given in the file "co2spl.dat"), where the CO2 concentration growth rate at the end of the record is 1.7 ppmv/yr. The other two spline fits, used for sensitivity studies, give CO2 end-of-record growth rates of 1.6 ppmv/yr and 1.8 ppmv/yr. Details of these spline fits are provided in Appendix B of Enting et al. (1994), found in the subdirectory "report". deforest.dat: Annual net CO2 emissions resulting from land-use changes. deforest.all: Annual net CO2 fluxes resulting from land-use changes, 1765-2100. Data are a combination of Houghton and the IPCC scenario designated "IS92a", modified to go to zero in 2100 and linearly matched to Houghton over 1990 to 2000. foss91.dat: Fossil CO2 emissions, 1765-1989. fossil.dat: Updated fossil CO2 emissions, 1765-1990. New values for 1985-1990 were from G. Marland. stab.dat Prescribed CO2 concentrations for the stabilization scenarios [described in subsection 2 ("results") below], 1990-2300. c14sth.dat, c14equ.dat, c14nth.dat: Atmospheric carbon-14 levels for the Southern Hemisphere (extra-tropical), equatorial, and Northern Hemisphere (extra-tropical) regions. 2. "results" The data contained in this subdirectory comprise model output calculations submitted for the IPCC CO2 modelling study. Each different model is identified by a capital letter in the filename. The models are as follows [see also Enting et al. (1994), which is available in the subdirectory "report"]. Code Authors Institution A J.A. Taylor, J. Lloyd, and Australian National University G. Farquhar E I.G. Enting and K.R. Lassey Commonwealth Sci. and Indus. Res. Organisation, Australia; Nat. Inst. of Water and Atmos. Research, New Zealand H M. Heimann, J. Kaduk, K. Max Planck Institute for Kurz, and E. Maier-Reimer Meteorology, Hamburg J F. Joos and U. Siegenthaler University of Bern L D. Wuebbles and A. Jain Lawrence Livermore Natl. Lab. M B. Moore and B.H. Braswell University of New Hampshire Q C. Le Quere, J.L. Princeton University Sarmiento, and S.W. Pacala R J. Alcamo and M. Krol RIVM (Natl. Inst. of Public Health and Envir. Protect.), Bilthoven, Netherlands T L.D.D. Harvey University of Toronto W T.M.L. Wigley University Corp. for Atmos. Res., Boulder, Colorado The file categories in this subdirectory are as follows, where "X" is the author code defined above: readme.res: Descriptive file that repeats the information presented here, with additional information on formats of results files. fossilX.dat: Fossil CO2 emissions data for the stabilization cases. intfossilX.dat: Cumulative fossil CO2 emissions from 1990. co2isX.dat: CO2 concentration data for the IS92[a-f] scenarios. co2decX.dat: CO2 concentration data for the dec[0-2] scenarios. ocnX.dat: Ocean CO2 fluxes (i.e., net uptake by the oceans) for the stabilization cases. ocnisX.dat: Ocean CO2 fluxes (i.e., net uptake by the oceans) for the IS92[a-f] scenarios. ocndecX.dat: Ocean CO2 fluxes (i.e., net uptake by the oceans) for the dec[0-2] scenarios. ocnhistX.dat: Historical ocean CO2 fluxes (i.e., net uptake by the oceans) where these are not included in the other ocean flux files. Summary of emissions scenarios used to direct modelling exercises: Stabilization scenarios: Case S350: stabilization of CO2 at 350 ppmv (concentration history provided in the file "stab.dat", found in the "inputs" subdirectory). Case S450: stabilization of CO2 at 450 ppmv (concentration history provided in the file "stab.dat", found in the "inputs" subdirectory). Case S550: stabilization of CO2 at 550 ppmv (concentration history provided in the file "stab.dat", found in the "inputs" subdirectory). Case S650: stabilization of CO2 at 650 ppmv (concentration history provided in the file "stab.dat", found in the "inputs" subdirectory). Case S750: stabilization of CO2 at 750 ppmv (concentration history provided in the file "stab.dat", found in the "inputs" subdirectory). Case DS450: stabilization of CO2 at 450 ppmv following an initial delay during which concentrations followed a higher pathway (concentration history provided in the file "stab.dat", found in the "inputs" subdirectory). Case DS550: stabilization of CO2 at 550 ppmv following an initial delay during which concentrations followed a higher pathway (concentration history provided in the file "stab.dat", found in the "inputs" subdirectory). Case S450S1: same as case S450 (i.e., stabilization of CO2 at 450 ppmv), with deforestation scaled by 0.6/1.6 and growth factors scaled. Case S450S2: same as case S450 (i.e., stabilization of CO2 at 450 ppmv), with deforestation scaled by 2.6/1.6 and growth factors scaled. IPCC 1992 scenarios [assumptions are detailed in IPCC (1992), Table 1]: IS92a: "business-as-usual" scenario. Basic assumptions are: (1) world population of 11.3 billion by 2100; (2) economic growth at 2.9% for 1990-2025, 2.3% for 1990-2100; (3) energy supplies of 12,000 EJ conventional oil, 13,000 EJ natural gas, solar costs decreasing to $0.075/kWh, 191 EJ biofuels available at $70/barrel; (4) internationally agreed controls on SOx, NOx, and non-CH4 volatile organic compound emissions; (5) partial compliance with Montreal Protocol, with gradual phase out of CFCs in non-signatory countries by 2075. IS92b-IS92f: alternative scenarios. IS92a*: same as IS92a except that CO2 flux from land use goes to zero in 2100 A.D. IS92a*1: same as IS92a except that deforestation is scaled by 0.6/1.6 and growth factors are changed. IS92a*2: same as IS92a except that deforestation is scaled by 2.6/1.6 and growth factors are changed. Scenarios with specified emissions reductions: Case DEC0%: IS92a to 2000 A.D. then constant industrial emissions. Case DEC1%: IS92a to 2000 A.D. then industrial emissions decrease at 1% per annum. Case DEC2%: IS92a to 2000 A.D. then industrial emissions decrease at 2% per annum. Case DEC0*: Same as DEC0%, except that both industrial and land use emissions are constant after 2000 A.D., rather than just the industrial emissions as for DEC0%. Case DEC1*: Same as DEC1%, except that both industrial and land use emissions decrease by 1% per annum after 2000 A.D., rather than just the industrial emissions as for DEC1%. Case DEC2*: Same as DEC2%, except that both industrial and land use emissions decrease by 2% per annum after 2000 A.D., rather than just the industrial emissions as for DEC2%. 3. "report" This subdirectory contains a set of PostScript files that comprise the current version of CSIRO Division of Atmospheric Research Technical Paper Number 31. Queries about publication status should be addressed to Dr. Ian Enting via e-mail at ige@dar.csiro.au. The files in this subdirectory are as follows: readme.rep: Descriptive file that repeats the information presented here. Rstart.ps: Cover, indices, etc. Rissue.ps: Report sections 1 to 6. Rbody.ps: Report sections 7 onwards. Rref.ps: References. RappAB.ps: Appendices A,B. RappDE.ps: Appendices D,E. RappFGH.ps: Appendices F,G,H. Note: Appendix C, which contains descriptions of the models used to generate the calculations contained in this archive, is not available at this time. III. REFERENCES Enting, I.G., T.M.L. Wigley, and M. Heimann (eds.). 1994. Future Emissions and Concentrations of Carbon Dioxide: Key Ocean/Atmosphere/Land Analyses. CSIRO Division of Atmospheric Research Technical Paper No. 31. Commonwealth Scientific and Industrial Research Organisation, Aspendale, Australia. Friedli, H., H. Lotscher, H. Oeschger, U. Siegenthaler, and B. Stauffer. 1986. Ice core record of 13-C/12-C ratio of atmospheric CO2 in the past two centuries. Nature 324: 237-238. Intergovernmental Panel on Climate Change (IPCC). 1990. Climate Change: The IPCC Scientific Assessment. J.T. Houghton, G.J. Jenkins, and J.J. Ephraums (eds.). Cambridge University Press, Cambridge, U.K. Intergovernmental Panel on Climate Change (IPCC). 1992. Climate Change 1992: The Supplementary Report to the IPCC Scientific Assessment. J.T. Houghton, B.A. Callander, and S.K. Varney (eds.). Cambridge University Press, Cambridge, U.K. Intergovernmental Panel on Climate Change (IPCC). 1994. Radiative Forcing of Climate Change: The 1994 Report of the Scientific Assessment Working Group of the IPCC. Meteorological Office Marketing Communications Graphics Studio, Bracknell, U.K. Keeling, C.D. 1991. CO2 Emissions -- Historical Record, Global. pp. 382-385. In T.A. Boden, R.J. Sepanski, and F.W. Stoss (eds.), Trends '91: A Compendium of Data on Global Change, ORNL/CDIAC-46. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee, U.S.A. Keeling, C.D., and T.P. Whorf. 1991. Atmospheric CO2 -- Modern Record, Mauna Loa. pp. 12-15. In T.A. Boden, R.J. Sepanski, and F.W. Stoss (eds.), Trends '91: A Compendium of Data on Global Change, ORNL/CDIAC-46. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee, U.S.A. Marland, G., and T. Boden. 1991. CO2 Emissions -- Modern Record, Global. pp. 386-389. In T.A. Boden, R.J. Sepanski, and F.W. Stoss (eds.), Trends '91: A Compendium of Data on Global Change, ORNL/CDIAC-46. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee, U.S.A. Neftel, A., E. Moor, H. Oeschger, and B. Stauffer. 1985. Evidence from polar ice cores for the increase in atmospheric CO2 in the past two centuries. Nature 315:45-47.