1. Status of research Vienna 29 August 2007 Niklas Höhne, n.hoehne@ecofys.de

2. Overview 1.Introduction to the MATCH process 2.Preliminary results 3.Preliminary conclusions Modelling and assessment of contributions to climate change

3. Main question Modelling and assessment of contributions to climate change What are the contributions of regions, nations or sectors to man-made climate change?

4. MATCH process UNFCCC / Kyoto Protocol 2002 1997: “Brazilian Proposal”: Industrialized countries should reduce emissions proportional to contribution to temperature increase Ad-hoc group Initiated by Brazil and UK Modelling and assessment of contributions to climate change

5. SBSTA 17 (Oct 2002) Work should be continued by the scientific community, in particular to improve the robustness of the preliminary results and to explore the uncertainty and sensitivity Be of a standard consistent with the practices of peer-reviewed published science. The process should be inclusive, open and transparent. Capacity building: strongly encouraged Parties and institutions to facilitate capacity-building in developing countries, including by hosting scientists from developing countries Invited the scientific community, including IGBP, WCRP, IHDP and IPCC to provide information on how they could contribute Encouraged scientists to undertake further work, to make the results of their work publicly available and to report progress at SBSTA 20, June 2004 (side event). SBSTA decided to review the progress at its 23 rd session (Nov 2005). Modelling and assessment of contributions to climate change

6. MATCH process Assess methods for calculating the contribution of different emission sources (e.g. regional, national or sectoral) to climate change Provide clear guidance on the implications of the use of the different scientific methods, models, and methodological choices Where scientific arguments allow, recommend one method/model/choice Expert meetings, workshops and a coordinated modelling exercise Prepare papers to be published in peer reviewed scientific journals Open and transparent, www.match-info.net Scientific coordination committee Funds for developing country experts (provided by Norway, Germany and UK) Support unit Ecofys (funded by UK) Modelling and assessment of contributions to climate change

7. MATCH process Scientific coordination committee Modelling and assessment of contributions to climate change Guoquan HuNational Climate Center, China Michel den ElzenRIVM, Netherlands Jan Fuglestvedt (Co- chair) CICERO, Center for International Climate and Environmental Research - Oslo, Norway Jason LoweMet Office, Hadley Centre for Climate Prediction and Research, UK Joyce Penner (Co-chairUniversity of Michigan, USA Michael PratherUniversity of California at Irvine, USA Cathy TrudingerCSIRO Atmospheric Research, Australia Murari LalIIT, India José Domingos Gonzalez Miguez Interministerial Committee on Global Climate Change, Brazil Niklas Höhne (secretary)Ecofys, Germany

8. Participation in addition to SCC Modelling and assessment of contributions to climate change

9. Individual scientific papers Pinguelli Rosa, Ribeiro, 1997: “The share of responsibility between developed and developing countries in climate change, Greenhouse Gas Mitigation”. In Proceedings from the International Energy Agency Conference on GHG Pinguelli Rosa, Ribeiro, 2001: “The present, past, and future contributions to global warming of CO2 emissions from fuels”, Climatic Change den Elzen, Schaeffer 2002: “Responsibility for past and future global warming: Uncertainties in attributing anthropogenic climate change”, Climatic Change Andronova, Schlesinger 2004: “Importance of Sulfate Aerosol in Evaluating the Relative Contributions of Regional Emissions to the Historical Global Temperature Change”, Adaptation and Mitigation Strategies for Global Change Pinguelli Rosa, Ribeiro, Muylaert, Campos, 2004: “Comments on the Brazilian Proposal and contributions to global temperature increase with different climate responses - CO2 emissions due to fossil fuels, CO2 emissions due to land use change”, Energy Policy Muylaert, Cohen, Pinguelli Rosa, Pereira, 2004: “ Equity, responsibility and climate change” Climate Research Muylaert, Campos, Pinguelli Rosa, 2005: “GHG historical contribution by sectors, sustainable development and equity” Renewable and Sustainable Energy Reviews Campos, Muylaert, Pinguelli Rosa, 2005: “Historical CO2 emission and concentrations due to land use change of croplands and pastures by country”, Science of the Total Environment Trudinger, Enting, 2005: “Comparison of formalisms for attributing responsibility for climate change: Non-linearities in the Brazilian Proposal approach”, Climatic Change den Elzen, Schaeffer, Lucas, 2005: “Differentiating Future Commitments on the Basis of Countries’ Relative Historical Responsibility for Climate Change: Uncertainties in the ‘Brazilian Proposal’ in the Context of a Policy Implementation”, Climatic Change Rive, Torvanger, Fuglestvedt 2005: “Climate agreements based on responsibility for global warming: periodic updating, policy choices, and regional costs”, Global Environmental Change Höhne, Blok, 2005: “Calculating historical contributions to climate change – discussing the ‘Brazilian Proposal’”, Climatic Change Modelling and assessment of contributions to climate change

10. Timeline May 2006:SBSTA 26 renewed mandate and agreed on timeline 24-25 September 2007: MATCH meeting to finalize work and to prepare report for UNFCCC 31 October 2007: Submission of the final report to SBSTA December 2007: In-session special side event at SBSTA 27 to present the work to UNFCCC delegations 7 March 2008: Countries submit their views on the matter June 2008 or soon after: Official consideration by SBSTA 28 Modelling and assessment of contributions to climate change

11. Overview 1.Introduction to the MATCH process 2.Preliminary results 3.Preliminary conclusions Modelling and assessment of contributions to climate change

12. MATCH results Four joint papers Preparatory work –Uncertainties along the cause-effect chain (paper 95% final) –Historical emissions from forestry (paper 50% final) Results –First analysis of regions’ contribution to climate change (paper published 2005) –Detailed analysis of countries contribution to climate change (paper 40% final) Capacity developed IVIG (Brazil) developed a detailed and flexible model of land-use emissions which has recently been coupled with the JCM carbon/climate model developed in UCL-ASTR (Belgium) Exchange of researchers (China to New Zealand, Brazil to Germany) Modelling and assessment of contributions to climate change

13. Computer tools Desirable: computer tool to calculate contributions to climate change, user selects parameters such as time horizon and indicator. Several tools are already available, –Java Climate Model, Ben Mathews (www.climate.be/jcm) –FAIR model, Michel den Elzen (www.mnp.nl/fair) –CAIT tool, Jonathan Pershing (http://cait.wri.org/) The MATCH group would not develop a new tool, but would be available to assess and evaluate existing tools Modelling and assessment of contributions to climate change

14. JCM5 Demo 3: Contributions to Temperature. Absolute contributions (top left), include unattributed effect of other gases (grey), aerosols (cyan) and solar/volcanos (yellow), which are excluded from relative shares (top right). Attributed concentrations (below left) fall soon after the final attribution year (2002), as do temperatures, but attributed sea-level rise (below right) continues rising.

15. MATCH results Four joint papers Preparatory work –Uncertainties along the cause-effect chain (paper 95% final) –Historical emissions from forestry (paper 50% final) Results –First analysis of regions’ contribution to climate change (paper published 2005) –Detailed analysis of countries contribution to climate change (paper 40% final) Modelling and assessment of contributions to climate change

16. Method Modelling and assessment of contributions to climate change Global inventories of GHG emissions based on activities Emissions derived from atmospheric measurements Match? Emissions Concentrations Radiative forcing Global average temperature change All sources of historical radiative forcing Observed temperature increase Match? Total uncertainty of OECD Annex I countries’ contribution

17. Emissions and concentration Reported emissions of CH4 match observed concentrations Modelling and assessment of contributions to climate change

18. Emissions and concentration Components Fossil/industrial Anthropogenic forestry Biosphere Ocean Reported LUCF emissions do not necessarily match Modelling and assessment of contributions to climate change

19. Method Modelling and assessment of contributions to climate change Global inventories of GHG emissions based on activities Emissions derived from atmospheric measurements Match? Emissions Concentrations Radiative forcing Global average temperature change All sources of historical radiative forcing Observed temperature increase Match? Total uncertainty of OECD Annex I countries contribution

20. Total radiative forcing Collected historical estimates of all forcings Match relatively well with observed temperature increase Modelling and assessment of contributions to climate change

21. Method Modelling and assessment of contributions to climate change Global inventories of GHG emissions based on activities Emissions derived from atmospheric measurements Match? Emissions Concentrations Radiative forcing Global average temperature change All sources of historical radiative forcing Observed temperature increase Match? Total uncertainty of OECD Annex I countries’ contribution

22. Emissions from various sources Example case: Emissions of Annex I countries that are also OECD countries from 1990 to 2002 Adjusted uncertainty in emissions where necessary Modelling and assessment of contributions to climate change

23. Contribution to temperature Example case: Emissions of Annex I countries that are also OECD countries from 1990 to 2002 Contributions can be calculated and the uncertainty for this case is +/-50% Modelling and assessment of contributions to climate change

24. MATCH results Four joint papers Preparatory work –Uncertainties along the cause-effect chain (paper 95% final) –Historical emissions from forestry (paper 50% final) Results –First analysis of regions’ contribution to climate change (paper published 2005) –Detailed analysis of countries contribution to climate change (paper 40% final) Modelling and assessment of contributions to climate change

25. Land use change Why are historical estimates of CO 2 emissions from land use so different? Modelling and assessment of contributions to climate change

26. Data sets analysed Modelling and assessment of contributions to climate change Comparison of 7 data sets on land-use change area and emissions for the 1990s Detailed analysis of three countries: USA, Brazil, Indonesia

27. MATCH results Four joint papers Preparatory work –Uncertainties along the cause-effect chain (paper 95% final) –Historical emissions from forestry (paper 50% final) Results –First analysis of regions’ contribution to climate change (paper published 2005) –Detailed analysis of countries contribution to climate change (paper 40% final) Modelling and assessment of contributions to climate change

28. Analysing countries’ contribution to climate change: Scientific uncertainties and methodological choices –Michel den Elzen (RIVM, Netherlands) –Jan Fuglestvedt (CICERO, Norway) –Niklas Höhne (Ecofys, Germany) –Cathy Trudinger (CSIRO, Australia) –Jason Lowe (Hadley, UK) –Ben Matthews (UCL, Belgium) –Bård Romstad (CICERO, Norway) –Christiano Pires de Campos (Brazil) –Natalia Andronova (UIUC, USA) Modelling and assessment of contributions to climate change M. den Elzen, J. Fuglestvedt, N. Höhne, C. Trudinger, J. Lowe, B. Matthews, B. Romstad, C. Pires de Campos, N. Andronova, 2005: “Analysing countries’ contribution to climate change: Scientific uncertainties and methodological choices”, Environmental Science and Policy, 8 (2005) 614–636

29. Modelling and assessment of contributions to climate change Historical emissions OECD / REF ALM / ASIA

30. Choices Policy choices (values can not be based on objective ‘scientific’ arguments) : –Indicatorimportant –Timeframesimportant –Mixture of greenhouse gasesimportant –Attribution methodless important Scientific choices –Choice of the dataset on historical emissions important –Choice of the representation of the climate system (different models)less important for relative contr. Modelling and assessment of contributions to climate change

31. Models show similar outcomes Modelling and assessment of contributions to climate change

32. Temperature increase Unattributed Attribution start date, e.g. 1900 Region A Region B Region C Region D Time Attribution period Total temperature increase Attributed temperature increase Attributed effects Today

33. 1. Indicators Relative contributions using different indicators Source: Ecofys-ACCC Modelling and assessment of contributions to climate change

34. 2. Start-date With a shorter time horizon (e.g. 1950 or 1990 instead of 1890) relative contributions of OECD90 countries ('early emitters') is smaller. Source: RIVM-ACCC Modelling and assessment of contributions to climate change

35. End-date With a late end-date relative non-Annex-I contributions are larger, because it gives more weight to their larger future emissions. Impact of emissions scenarios (error bars) can be large Modelling and assessment of contributions to climate change Source: RIVM-ACCC

36. 4. Greenhouse gas mixture Two main effects i) Going from fossil fuel CO 2 emissions only to total anthropogenic CO 2 emissions, ii) Inclusion of CH 4 and N 2 O. Source: CICERO-SCM Modelling and assessment of contributions to climate change

37. 5. Historical datasets Fossil CO 2 emissions: small differences in relative attribution CO 2 emissions from land-use changes: differences in estimates leading to large differences. Data sets need to be compared and improved. CH 4 and N 2 O: Only one dataset is available (EDGAR) Source: RIVM-ACCC

38. 6. Other scientific uncertainties Source: UCL-SCM Modelling and assessment of contributions to climate change

39. Choices Policy choices (values can not be based on objective ‘scientific’ arguments) : –Indicatorimportant –Timeframesimportant –Mixture of greenhouse gasesimportant –Attribution methodless important Scientific choices –Choice of the dataset on historical emissions important –Choice of the representation of the climate system (different models)less important for relative contr. Modelling and assessment of contributions to climate change

40. Overall conclusions Modelling and assessment of contributions to climate change

41. MATCH results Four joint papers Preparatory work –Uncertainties along the cause-effect chain (paper 95% final) –Historical emissions from forestry (paper 50% final) Results –First analysis of regions’ contribution to climate change (paper published 2005) –Detailed analysis of countries contribution to climate change (paper 40% final) Modelling and assessment of contributions to climate change

42. Objective Provide results only for the most important choices –Temperature increase and GWP-weighted cumulative emissions –Start dates 1750, 1900, 1950, 1990 Finer resolution: –Country by country (starting from emissions reported to the UNFCCC) –Sectoral split (energy/industry, agriculture/waste, LUCF) –Gas by gas Include uncertainty range of historical emissions Calculated with several models Emission data and results will be made available electronically Modelling and assessment of contributions to climate change

43. Overview 1.Introduction to the MATCH process 2.Preliminary results 3.Preliminary conclusions Modelling and assessment of contributions to climate change

44. Preliminary conclusions Open research process, leading to peer reviewed papers and building capacity and tools Contributions to climate change can be calculated effectively and robustly Most important choices influencing results: –Indicator (cumulative emissions, impact on temperature…) –Start date as of which emissions are attributed –Different data sources for in LUCF emissions Uncertainties –Full uncertainty analysis performed for test case: +/-50% for absolute contribution –Model uncertainties (e.g. climate sensitivity) are not relevant if applied the same for all contributors. Missing –Translation from “contribution” to “responsibility” –How to use the results Modelling and assessment of contributions to climate change

45. Backup slides

46. 3. Attribution methods The differences between methods are fairly small compared to the effects of many of the other choices already considered. Source: CSIRO-SCM Modelling and assessment of contributions to climate change

47. 1. Indicators Modelling and assessment of contributions to climate change Source: Ecofys-ACCC

48. 2. Timeframe Start date emissions 1890, 1950 and 1990 End date emissions 1990, 2000, 2050 and 2100 Evaluation date of attribution 2000, 2050, 2100, 2500 Modelling and assessment of contributions to climate change

50. Table 3

51. Aerosol forcing Inclusion of SO2 emissions reduces the contributions from ASIA and REF, but the effect disappear when there is a gap between attribution end date and evaluation date. Again effect is less less pronounced on longer time scales Modelling and assessment of contributions to climate change Source: CICERO-SCM

52. Future work Two papers as first steps in a series Issues for a new paper combining earlier papers: –Other test cases with longer time scales including the 19th century –Uncertainty per region –Finer resolution of sources (countries, inside countries or over sectors) –Absolute and relative contributions –Substantial new work on uncertainties for early emissions. Possible to explore further areas of research in the same mode of working and building on the MATCH work so far. Many in the MATCH group plan to continue their work on the scientific and methodological aspects related to contributions to climate change. MATCH could report back to SBSTA in one to two years. Modelling and assessment of contributions to climate change

53. Historical Background Brazil made a proposal in the discussions of the Kyoto Protocol in 1997: Calculate historical contributions of countries to climate change: impact of historical emissions on temperature increase Share emission reductions of Annex I countries proportional to their contribution to temperature increase Presented model calculation: Modelling and assessment of contributions to climate change