1. Emissions Scenarios for Effective Policies: China’s SO 2 control GEIA 2015 Conference, Beijing, Nov 20,2015 Yuxuan Wang 1,2, Qianqian Zhang 1,3 1 Tsinghua University; 2 Texas A&M University; 3 China Meteorological Agency Researches to be discussed  Air quality trend in China  Emissions and future scenarios  What are missing in current policies?

2. Deterioration of air quality over China 2 AOD 2008-2010 Olympics “heritage” 2012: PM 2.5 at US Embassy Jan 2013 15 days > 300ug/m 3 Aerosol Optical Depth (AOD) from MODIS Winter Mean AOD (North China) Jia B., Wang Y et al., 2015, ACP Xie Y., Wang Y et al., 2015 PM 2.5 and AOD: R 2 = 0.8 3x3 km PM 2.5 map: 98% of Beijing population exposed to long-term PM 2.5 pollution exceeding 50 ug/m 3

3. SO 2 is a key contributor to severe PM pollution in winter 3 350 ug m -3 Zheng G. et al., 2015, ACP sulfate nitrate ammonium OC

4. Does China have the right emission control policies to control PM pollution? 4 National level policies are set in the Five-Year Plans (FYP) SO 2 has been the only air pollutant regulated by China Five-Year Plans (FYP) until recently Emission targets in the 12 th FYP (2011-2015): 8% continuing reduction in SO 2 emissions 10% reduction in NO x emissions Only national level targets

5. National target vs. Regional target 5 Target: 8% reduction in SO 2 = 2.3 Tg Four Emission Scenarios S1: 8% reduction everywhere S2: 2.3 Tg reduction over NC S3: 2.3 Tg reduction over SC S4: 2.3 Tg reduction over SWC Three Impact Metrics Surface concentrations Population-weighted concentration (PWC) Outflow Fluxes to Western Pacific X: Impact metrics E: Emissions β: Efficiency factor Zhang QQ, et al., 2015, ACP

6. Reducing SO 2 over North China is most effective 6 Scenarios concentration outflow fluxes β Why North China? Sulfate chemistry Regional transport ( NC to SC: 23%) Outflow pathways Zhang QQ, et al., 2015, ACP Change in SO 2 emissions during 2006-2010 (MEIC inventory): National mean: -9.4% North China: -4.7% South China: -16.1% Southwest China: -23.1%

7. Effects of the 12 th FYP policy on PM 7 NH 3 emissions from Streets, et al., 2003a 2000-2015 Emissions of SO 2 and NO x +1.5% -5% Simulated difference in PM 2.5 during 2006-2015 +8% Constant NH 3 emissions 16% increase in NH 3 Wang Y, et al., 2013, ACP

8. Future Projections 8 6.6%14% 8% Control SO 2 and NO X Control all three Control NH 3 only (NH 3 down by 20%) China’s Energy Consumption by Fuel (1995-2030) (Zhao B. et al. ACP, 2013) 2010-2030 ‘optimistic’ scenario SO 2 : -7% NOx: -20%

9. References Zhang, Q.Q., Y. Wang, Q. Ma, Y. Xie, K. He, Regional differences in Chinese SO 2 emission control efficiency and policy implications, Atmos. Chem. Phys., 15, 6521-6533, 2015 Wang, Y., Q.Q. Zhang, K.B. He, Q. Zhang, and L.B. Chai, Sulfate-nitrate- ammonium aerosols over China: response to 2000-2015 emission changes of sulfur dioxide, nitrogen oxides, and ammonia, Atmos. Chem. Phys., 13 (5), 2635–2652, 2013 Jia, B., Y. Wang, Y. Yao, Y. Xie, A new indicator on the impact of large- scale circulation patterns on wintertime particulate matter pollution over China, Atmos. Chem. Phys., 15, 11919-11929, 2015 Xie, Y., Y. Wang, K. Zhang, W. Dong, B. Lv, Y. Bai, Daily estimation of ground-level PM2.5 concentrations over Beijing using 3 km resolution MODIS AOD, Environ. Sci. Technol., 49, 12280−12288, DOI: 10.1021/acs.est.5b01413, 2015 Zhao, B., S.X. Wang, H. Liu, et al., NOx emissions in China: historical trends and future perspectives, Atmos. Chem. Phys., 13, 9869–9897, 2013 Zheng G J, Duan F K, Su H, et al., Exploring the severe winter haze in Beijing: the impact of synoptic weater, regional transport and heterogeneous reactions. Atmos. Chem. Phys., 15: 2969-2983, 2015