Global Sources and Transport of Air Pollution: A Chinese Case Jintai Lin 林金泰, PKU ACM Group Peking University 1

2 Group: D. Pan, R.-X. Zhang, Y.-Y. Yan, R.-J. Ni, M.-Y. Liu, J.-X. Wang, J.-W. Zhuang, Y. Zhang, C.-G. Wang... China: Q. Zhang, K. He, Y. Zhao, Y. Lei, P. Wang N.A.: S. Davis, D. Streets, D. Wuebbles, M. McElroy, C. Nielsen, R. Spurr, R. Martin Europe: D. Guan, K.F. Boersma, M. van Roozendael Funding: NSFC , , , etc. ACM Group, Collaborators and Funding

Chinese O 3 Transport Affects the U.S. 3 Verstraeten et al., 2015, Nature Geoscience Transport from China of O 3 and precursors has offset ~ 43% of O 3 reduction in the western US free troposphere expected from emission control

Foreign Pollution Greatly Affect China’s O 3 4 Upper Mid Lower From Europe From N. America ppb Spring 2009 Ni et al., in prep

5 Looped Mechanism of Pollution Transport China = Producer Consumer = Foreign Trade Atmospheric  Atmosphere: Move pollution from producer to consumer  Trade: Move Pollution from consumer to producer Lin et al., 2014, PNAS

Trade Redefines Chinese and U.S. Emissions  Trade increases Chinese emis, but decreases U.S. emis  Export-to-world contributes 36% of Chinese SO 2 emis in 2006  Sino-US-trade-related SO 2 emis are 19% of U.S. emis in 2006 Lin et al., 2014, PNAS SO 2 Emissions (Tg/yr) 6 wrt China’s consumption Produced in China wrt U.S. consumption Produced in U.S. supplied by China

Goods Export Contributes ~ 30% of China’s Sulfate Lin et al., 2014, PNAS 7 % contribution of China’s export-related pollution to total sulfate pollution

Export of Goods Contributes to China’s Pollution 8 % contribution of China’s export-related pollution to total pollution Lin et al., 2014, PNAS

USA Consumption Affects China’s Sulfate Pollution 9 USA imports goods from China versus self-production: (accounting for differences in emission intensity)  Increase China’s sulfate PM  Decrease USA’s sulfate PM overall, GOOD for USA Lin et al., 2014, PNAS This is in contrast to traditional view that China reduces USA air quality via atmospheric transport ! % change in sulfate

Trade-Transport Study Won PNAS Cozzarelli Prize ! (One of the 6 out of 3500 PNAS papers) 10

Summary Globalization of Air Pollution 11 Given the looped mechanism of pollution transport : Domestic economic and environmental strategy ? International collaboration to reduce pollution transport ? Roles of consumers and producers ? We Hire Postdocs Producer Consumer Trade Atmospheric