CLRTAP 2016 Assessment: Key messages and HTAP contribution

Transcription

1 CLRTAP 2016 Assessment: Key messages and HTAP contribution Frank Dentener, European Commission, Joint Research Centre Terry Keating, US EPA Contributions from Oliver Wild, Zig Klimont, Augustin Collette and other assessment authors. Quadrennial O 3 symposium 2016

2 CLRTAP Established in 1979 Broad intergovernmental cooperation on air pollution problems 8 protocols on sulfur, nitrogen, acidification/eutrophication, heavy metals, POPs, ground level ozone Sharp decline of emissions of almost all components: success story EU and national legislation implement the protocols 2016 UNECE/CLRTAP Assessment report Taking stock of achievements Develop forward looking approach for CLRTAP HTAP is important CLRTAP is revising strategy in 2017.

3 10 Key messages of CLRTAP (2016) report: 1. CLRTAP had significant success in reducing emissions and impacts 2/3. Problems still exist; significant fraction in Europe/North America exposed PM levels above WHO guidelines; acidification solved; eutrophiciation is not solved 4. Even in urban regions, transboundary sources can have strong contributions 5. Long term risks for ozone, HM, POPs still exist. Coordination with other protocols and between North America and Europe needed. 6. Technical measures exist to bring levels of ozone/pm below the guidelines 7. Cost of mitigation generally significantly lower, cleaner technologies bring new jobs 8. Integrated approaches towards Climate and Air Pollution mitigation needed 9. Ratification/implementation of Gothenburg protocol reduces emissions of SOx, NOx, PM by 40-50%; NH3 only 17 %. 10. International collaboration and coordination on air pollution science remains necessary: harmonized emission estimations, monitoring of air quality and impacts, cost effective next steps.

4 Ozone trends in Europe- EMEP network Median annual trend [ppb/yr] 95 % CI: MDA8 MDA8: Daily maximum of 8 hour running mean Median annual trend [ppb/yr] 95 % CI annual mean 55 stations, more coverage in Northern Europe, regionally representative pronounced heat waves show up in maximum values In Europe peak values decline, annual average O 3 no obvious trend. Ca % of trends at individual stations insignificant (dep. Metric/period) What is the role of hemispheric transport and other factors? EMEP/WGE 2016 Assessment Report; Collette et al, EMEP/CC-report 1/2016

5 Ozone trends at baseline stations Remote measurements of ozone in Europe, East Asia and Rest of the world (Cooper et al., 2014) Cooper et al, ppb 10 ppb 14 ppb Basline Ozone increases in Europe: ca 14 ppb between , 10 ppb between , 5 ppb Large increases in Asia and western America, mixed trends elsewhere

6 HTAP1 attribution of past O 3 changes in Europe NA EU EA SA Total O 3 change Within EU Outside of EU Methane 6 4 vs -1 ppb 9 vs 3 ppb 14 vs 5.5 ppb Annual average - large region global models Largest O 3 (6 ppb) increases before 1980; small reductions in O 3 after 1990 O 3 reductions attributable to EU emissions compensated by increasing emissions elsewhere Important contribution from CH % Taken together changes in O 3 from outside Europe and CH 4 are larger than from Europe (60-70 % of total) External O 3 becomes more important when local sources are more regulated. Hemispheric transport more important at lower concentrations Only % of the observed changes in Europe can be attributed to emission changes! See also Parrish et al for more detailed analysis. Wild et al, ACP, 2012

7 Extrapolating to the future: HTAP air pollution benchmark scenarios No Further Control (NFC) Current Legislation (CLE) Policy Relevant Questions NFC: What are the benefits of implementing current policies in terms of health, ecosystems, and climate impacts? CLE: Given current policies, what are emissions likely to be in the future? GAINS Maximum Feasible Reduction (MFR) MFR: What technology and policy options will be available (at a reasonable cost) to further mitigate pollution problems in the future?

8 O 3 changes in Europe for HTAP global air pollution scenarios Total O 3 change HTAP2 scenarios: NFC No further control CLE Current Legislation MFR Maximum Feasible Reductions Within EU Outside of EU Methane 8 For Europe: Regional controls can still bring down ozone further, but requires ambitious and expensive air pollution policy Ambitious air pollution policy elsewhere may be beneficial for Europe, especially in the US. For the US it would be China, etc.. Methane emission reductions are going to be crucial for reducing ozone. Methane is included in climate policies, but we will need to reduce it also for reducing ozone air pollution. Reducing methane will require strong collaboration with countries in Asia A likely range for changes in ozone boundary conditions is therefore estimate to range between -4 and 3 ppb in 2030, and -4 and 5 ppb in Does not consider climate change, long-term variability Dentener, Klimont, Wild 2016

9 Europe-North America-World: CLE/climate/MFR ECLIPSEv5a ( HTAP ) by IIASA group Climate policies in energy/transport sector can reduce ozone. Ambitious air pollution controls reduce could reduce ozone further After 2020 REF-CLE is not sufficient to control ozone. Similar trajectories for North America and Europe.

10 Contribution to O 3 (M6M) changes in Europe comparing MFR and CLE in 2030 and 2050 Northwestern Europe South Eastern Europe In Northwestern Europe % of the O 3 improvements are from CH 4 and from AP controls in North America, Russia and East Asia. In Southeastern Europe strong benefits of implementation air pollution controls in Eastern Europe, but also North Africa and Middle East. Methane % of O 3 improvements. 10 Van Dingenen, TM5-FASST, 2015

11 Conclusions Important contribution of TF HTAP to CLRTAP air pollution assessment: HTAP1 SRs with new scenario information. New information will be used for the strategy discussion Keep improving the science information on contributions, trends, impacts E.g. roles of inter-annual and natural variability in determining trends need to be better understood for credible story. Evaluation of concrete AP mitigation packages in multi-sectorial framework