Emissions Scenarios for Effective Policies: China’s SO2 control

GEIA 2015 Conference, Beijing, Nov 20,2015

Yuxuan Wang1,2, Qianqian Zhang1,3

1Tsinghua University; 2 Texas A&M University; 3China Meteorological Agency

Researches to be discussed Air quality trend in China Emissions and future scenarios What are missing in current policies?

Deterioration of air quality over China

2

2001 2003 2005 2007 2009 2011 20130.4

0.5

0.6

0.7

0.8r=0.65 p<0.05

AOD

2008-2010 Olympics “heritage”

2012: PM2.5 at US

Embassy

Jan 201315 days > 300ug/m3

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

PM2.5 and AOD: R2 = 0.8

3x3 km PM2.5 map: 98% of Beijing population exposed to long-term PM2.5 pollution exceeding 50 ug/m3

SO2 is a key contributor to severe PM pollution in winter

3

<35 35-115 115-350 >350 ug m-3

Zheng G. et al., 2015, ACP

sulfate

nitrate

ammonium

OC

Does China have the right emission control policies to control PM pollution?

4

National level policies are set in the Five-Year Plans (FYP)

SO2 has been the only air pollutant regulated by China Five-Year Plans (FYP) until recently

Emission targets in the 12th FYP (2011-2015): 8% continuing reduction in SO2 emissions 10% reduction in NOx emissions

Only national level targets

National target vs. Regional target

5

Target: 8% reduction in SO2 = 2.3 Tg

Four Emission ScenariosS1: 8% reduction everywhereS2: 2.3 Tg reduction over NCS3: 2.3 Tg reduction over SCS4: 2.3 Tg reduction over SWC

Three Impact Metrics Surface concentrationsPopulation-weighted concentration (PWC)Outflow Fluxes to Western Pacific

∆ 𝑋𝑋 =𝛽× ∆𝐸𝐸

X: Impact metricsE: Emissionsβ: Efficiency factor

Zhang QQ, et al., 2015, ACP

Reducing SO2 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 SO2 emissions during 2006-2010 (MEIC inventory):

National mean: -9.4%North China: -4.7%South China: -16.1%

Southwest China: -23.1%

Effects of the 12th FYP policy on PM

7

NH3 emissions from Streets, et al., 2003a

2000-2015 Emissions of SO2 and NOx

+1.5%

-5%

Simulated difference in PM2.5

during 2006-2015

+8%

Constant NH3 emissions 16% increase in NH3

Wang Y, et al., 2013, ACP

Future Projections

8

6.6% 14% 8%

Control SO2 and NOX Control all threeControl NH3 only (NH3 down by 20%)

China’s Energy Consumption by Fuel (1995-2030)

(Zhao B. et al. ACP, 2013)

2010-2030 ‘optimistic’ scenario

SO2: -7%NOx: -20%

References Zhang, Q.Q., Y. Wang, Q. Ma, Y. Xie, K. He, Regional differences in

Chinese SO2 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