1. The links to global problems Presentation at the 25 th anniversary special event of the Convention on Long-range Transboundary Air Pollution “Past successes and future challenges” Henning Wuester UNFCCC Secretariat

2. Structure 1.Introduction 2.The substantive links between air pollution and climate change Atmospheric chemistry Techno-economic links (Impact interdependencies) 3.Lessons for global problems from 25 years of LRTAP 4.Challenges

3. Air pollutants act as greenhouse gases: Global mean radiative forcing 2000 relative to 1750 Source: IPCC Third Assessment Report, 2001

4. Special role for methane (CH 4 ) in the atmospheric chemistry 1. Radiative forcing: CH 4 emissions increase radiative forcing: Directly as a greenhouse gas Indirectly via its impacts on OH (Hydroxyl radical) concentrations 2. Ozone: CH 4 is precursor of ground-level O 3 (important for hemispheric air pollution) 3. Links to nitrogen and sulphur NO x emissions decrease CH 4 lifetime Sulphur deposition may reduce CH 4 from wetlands

5. Different projections for CH 4 emissions … further research and better data are needed! Methane emissions from developed countries for 1990-2001, UNFCCC data Methane emissions for the period 1990-2060 according to IPCC scenarios

6. Sources of air pollutants and greenhouse gases and joint abatement options Common sources: Energy (power generation, heating) Transport Industrial processes Agriculture Examples of common measures to cut air pollution and mitigate climate change: Enhance energy efficiency Shift to renewable energy Shift to natural gas There are also trade-offs, e.g. biomass burning, ammonia abatement.

7. Potential cost-savings estimated for EU by the IIASA RAINS model Control ofFuel-shift Multi-gas CO 2 +3.5 +2.1 CH 4 0 -1.2 GHGs (total)+3.5 +0.9 SO 2 -1.4 -1.2 NO x -0.3 -0.2 PM-0.6 -0.4 Air pollutants (total) -2.3 -1.8 Total+1.2 -0.9 Emission control costs compared to reference scenarios (billion €/yr):

8. Comparing LRTAP and UNFCCC Similarities Anniversary in December 2004 Atmospheric problem with similar sources Political problems with the 1 st protocol: concerns over the basic approach Strong role of science in driving policy Differences Affordable technical fixes available for air pollutants Autonomous structural change in the region Transition process of the 1990s for UNECE region Economic differences between Parties is lower in LRTAP

9. SO 2 emissions: European total 1960-2020: Avoided emissions compared to hypothetical levels

10. What lessons to learn from 25 years of LRTAP? Science-based approach: Critical loads and levels as a common metric to evaluate policy impact Variable geometry of obligations in more advanced protocols (emission ceilings, technology requirements, etc.) De-link substantive issues from economic concerns (equity)

11. Challenges Contribute to climate change objectives by reducing O 3 and BC at hemispheric scale Make use of synergies by policy integration at the national level At international level: –Consistent reporting systems –Cooperation at technical level (emission inventories, atmospheric and integrated assessment modelling) LRTAP has a responsibility to offer its experience, while recognizing differences: –To other regions on air pollution issues –To global processes on environmental issues