1. Present & Potential Future Contributions of Sulfate, Black & Organic Carbon Aerosols from China to Global Air Quality, Premature Mortality & Radiative Forcing Eri Saikawa 1, Vaishali Naik 1, Larry W. Horowitz 2, Junfeng Liu 1, Denise Mauzerall 1 1 Princeton University, Princeton, NJ, USA 2 Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA – Submitted to Atmospheric Environment – December 19, 2008 AGU A54C General Contributions: Chemistry and Composition III

2. Background Fine particulate matter PM 2.5 has harmful effects on global air quality & human healthFine particulate matter PM 2.5 has harmful effects on global air quality & human health PM 2.5 affects radiative forcing on climatePM 2.5 affects radiative forcing on climate China is a major emitter of PM 2.5 and its precursorsChina is a major emitter of PM 2.5 and its precursors Beijing, China NYTimes, December 29, 2007

3. Adverse Health Impacts of PM 2.5 Association between PM 2.5 ambient concentrations and increased risk of adverse health impactsAssociation between PM 2.5 ambient concentrations and increased risk of adverse health impacts –Are linear –Have no threshold Mortality associated with 10 µg/m 3 increase in PM 2.5 occur within 2 years of exposure – reductions in air pollution can improve public health almost immediatelyMortality associated with 10 µg/m 3 increase in PM 2.5 occur within 2 years of exposure – reductions in air pollution can improve public health almost immediately [Pope, 2002, Schwartz et al.,2008]

4. Black carbon has positive radiative forcing Sulfate and organic carbon have negative radiative forcing Global radiative forcings due to emissions of aerosols and precursors changes from 1750-2005 [IPCC, WG1 4 th Assessment Report, 2007] Indirect effects of aerosols are negative

5. Objectives Analyze impacts of China’s anthropogenic emissions of SO 2, SO 4 2-, OC & BC in 2000 and for three emissions scenarios in 2030 on: –global surface concentrations –annual premature mortality –radiative forcing

6. Methodology Emission scenariosEmission scenarios –With & Without China’s emissions Calculate change in concentrations due to emissions from ChinaCalculate change in concentrations due to emissions from China –Global chemical transport model MOZART-2 Calculate change in annual premature mortality due to China’s aerosolsCalculate change in annual premature mortality due to China’s aerosols Calculate change in global radiative forcingCalculate change in global radiative forcing –Radiative Transfer Model (RTM)

7. Emission Scenarios 2000: Baseline CLE (Current Legislation, IIASA)CLE (Current Legislation, IIASA) 2030: Future Scenarios BAU (Business-As-Usual, IPCC SRES A2)BAU (Business-As-Usual, IPCC SRES A2) CLE (Current Legislation, IIASA)CLE (Current Legislation, IIASA) MFR (Maximum Feasible Reduction, IIASA)MFR (Maximum Feasible Reduction, IIASA)

8. MOZART-2 Global 3-dimensional chemical transport model Simulates chemistry & transport of 73 speciesSimulates chemistry & transport of 73 species Horizontal resolution: 1.9° × 1.9°Horizontal resolution: 1.9° × 1.9° Vertical levels: 28 from surface to 2.7 mbVertical levels: 28 from surface to 2.7 mb Meteorology: Year 2000 NCEP/NCAR reanalysisMeteorology: Year 2000 NCEP/NCAR reanalysis 2.5 year simulation with 1.5 years for spin-up2.5 year simulation with 1.5 years for spin-up

9. Premature Mortality Calculation [CIESIN, 2000] Mortality Rate of people 30 years or older Concentration-response relationship (4%) based on adjusted mortality relative risk associated with a 10µg/m 3 change in PM 2.5 for all- cause mortality. [Pope et al., 2005] [WHO, 2000] [µg m -3 ] Surface SO 4 2- concentrations resulting from China’s anthro emissions in 2000 Gridded population of the world

10. Radiative Forcing GFDL global 3-dimensional radiative transfer model (RTM)GFDL global 3-dimensional radiative transfer model (RTM) –Total net irradiance (solar+terrestrial) at TOA –Horizontal resolution: 2° × 2.5° –Vertical level: 24 from the surface to 3mb –Assumed random cloud overlap Adjusted radiative forcingAdjusted radiative forcing Only direct effectsOnly direct effects

11. Impacts of China’s Aerosols on Global Surface Concentrations in 2000 [µg m -3 ] SO 4 2- OCBC

12. Impacts of China’s Aerosols on Global Premature Mortality 2000 203020302030 BAUCLEMFR China 474,250723,920495,250243,050 Korea & Japan 11,28013,39010,2403,830 S. East Asia 10,27020,34013,1404,980 South Asia 8301,9801,160430 North America 320590400120 Rest of the world 6901,290860270

13. Impacts of China’s Aerosols on Global Radiative Forcings in 2000 [mWm -2 ] SO 4 2- OC BCNet

14. Impacts of China’s Aerosols on Global Radiative Forcing Unit: mWm -2 China’s SO 4 2-, OC & BCcreate net China’s SO 4 2-, OC & BC create net NEGATIVE radiative forcing 2000 203020302030 BAUCLEMFR Sulfate-108-154-109-33 OC-7-11-5-4 BC42703221 Net-74-97-83-15

15. Impacts of China’s Aerosols in 2030 PessimisticOptimistic BAUCLEMFR Premature Deaths China723,900495,300243,100 Rest of the World 37,60025,8009,600 Net Global Radiative Forcing [mWm -2 ] -97-83-15

16. Conclusion China’s aerosols have large impacts on global air quality and premature mortalityChina’s aerosols have large impacts on global air quality and premature mortality China’s sulfate produce large negative forcingChina’s sulfate produce large negative forcing Simultaneously reducing: 1. Aerosols – to protect health 2. GHGs – to protect climate is essential!

17. Acknowledgments Dr. Arlene Fiore, GFDLDr. Arlene Fiore, GFDL Geophysical Fluid Dynamics Laboratory (GFDL) for computational resourcesGeophysical Fluid Dynamics Laboratory (GFDL) for computational resources

18. Thank you! E-mail: esaikawa@princeton.edu