Interlinking Climate Change with Sub-global Environmental Issues

1. Integrated Assessment and IPCC:Links between climate change and sub-global environmental issuespresentation at Task Force Integrated Assessment Modelling, Brussels, 14-16 May 2001 Rob Swart Head TSU IPCC Working Group III INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC)

2. IPCC was established in 1988 as an intergovernmental, integrated assessment process by UNEP and WMO • Scientists in interdisciplinary writing teams are responsible for the substance of the assessments • Governments determine the report outline, they review the 2nd draft, and approve the Summary for Policymakers line by line • Work from 3 Working Groups (climate system, impacts/ adapta-tion, mitigation) is integrated in a Synthesis Report ( 5 year cycle) • Main client: UNFCCC/SBSTA • More information: http://www.ipcc.ch The IPCC Process INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC)

3. Climate change and other environmental issues in IPCC • The Special Report on Emissions Scenarios (SRES) includes scenarios for SO2, NOx, VOCs, CO in addition to all GHGs • The Third Assessment Report evaluates the climatic changes (WG1) and impacts (WG2) associated with these scenarios • The Third Assessment Report (WG3) notes that integration of climate change policies with other socio-economic and environmental policies (“co-benefits”) can make policies more effective • A WRI/RFF/OECD/IPCC Workhop on Ancillary Benefits was organized in 2000; proceedings available from OECD • A Special Report on Climate Change and Sustainable Development has been proposed which would explicitly address synergies and trade-offs between the various issues INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC)

4. Figure 1.1a: An Integrated Assessment Framework for Considering Climate Change Human & Natural Systems Climate change impacts Climate System • Floods and droughts • Biodiversity • Animal and plant health • Temperature rise • Sea level rise • Precipitation change Feedbacks Interactions Non-climate change stresses Enhanced greenhouse effect Environmental impacts Air pollution Atmospheric Concentrations Socio-Economic Development Paths Anthropogenic emissions • Carbon dioxide • Methane • Nitrous oxide • Aerosols • Main drivers are population, energy,economic growth, technology and land use

6. Special Report on Emission Scenarios • Revision of 1992 reference scenarios (IS92) • Based on 1994 IPCC evaluation • IPCC 1996 request for new reference scenarios, no additional climate initiatives • Based on literature review, development of storylines, quantification with 6 models, open process, and 2 IPCC reviews • Published 2000 INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC)

7. The SRES worlds INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC)

8. GLOBAL CO2 EMISSIONS FOR 6 SCENARIO GROUPS INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC)

9. GLOBAL ENERGY CO2 SCENARIOS AND DATABASE INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC)

13. The IPCC WG III TAR in one view • Technologies are available today to keep climate change impacts limited in the long term and stop the growth of global GHG emissions in the short term • The costs of implementing the Kyoto Protocol can be kept low, provided implementation is done efficiently and long-term costs can be kept relatively low if optimum timing is chosen • The real problem of controlling emissions is to overcome the many political, economic, social and behavioural barriers to implementing mitigation options • There is a strong link between sustainable development and climate change mitigation: look for synergies and avoid trade-offs INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC)

14. Findings SRES/TAR related to acidifying compounds and ozone precursors • In most SRES scenarios, after an initial increase, sulfur emissions are assumed to decrease worldwide after a few decades, due to concerted policy action • This is one of the main reasons that in the TAR the projected climate effects (temperature, sea level) exceed those in earlier IPCC reports • GHG mitigation can have very important ancillary benefits for regional and local air pollution, and vice versa • More detailed analysis at the regional level is needed, especially for future emissions of NOx and other ozone precursors, and options for abatement synergy INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC)

15. Excerpts from SPM IPCC WG3 • “Some mitigation actions may yield extensive benefits in areas outside of climate change: for example, they may reduce health problems; increase employment; reduce negative environmental impacts (like air pollution); protect and enhance forests, soils and watersheds; reduce those subsidies and taxes which enhance greenhouse gas emissions; and induce technological change and diffusion, contributing to wider goals of sustainable development. Similarly, development paths that meet sustainable development objectives may result in lower levels of greenhouse gas emissions.” • “The effectiveness of climate change mitigation can be enhanced when climate policies are integrated with the non-climate objectives of national and sectorial policy development and be turned into broad transition strategies to achieve the long-term social and technological changes required by both sustainable development and climate change mitigation. Just as climate policies can yield ancillary benefits that improve well being, non-climate policies may produce climate benefits.” INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC)