title: On-road vehicle emissions and their control in China: A review and outlook.
abstract: The large (26-fold over the past 25years) increase in the on-road vehicle fleet in China has raised sustainability concerns regarding air pollution prevention, energy conservation, and climate change mitigation. China has established integrated emission control policies and measures since the 1990s, including implementation of emission standards for new vehicles, inspection and maintenance programs for in-use vehicles, improvement in fuel quality, promotion of sustainable transportation and alternative fuel vehicles, and traffic management programs. As a result, emissions of major air pollutants from on-road vehicles in China have peaked and are now declining despite increasing vehicle population. As might be expected, progress in addressing vehicle emissions has not always been smooth and challenges such as the lack of low sulfur fuels, frauds over production conformity and in-use inspection tests, and unreliable retrofit programs have been encountered. Considering the high emission density from vehicles in East China, enhanced vehicle, fuel and transportation strategies will be required to address vehicle emissions in China. We project the total vehicle population in China to reach 400-500 million by 2030. Serious air pollution problems in many cities of China, in particular high ambient PM2.5concentration, have led to pressure to accelerate the progress on vehicle emission reduction. A notable example is the draft China 6 emission standard released in May 2016, which contains more stringent emission limits than those in the Euro 6 regulations, and adds a real world emission testing protocol and a 48-h evaporation testing procedure including diurnal and hot soak emissions. A scenario (PC[1]) considered in this study suggests that increasingly stringent standards for vehicle emissions could mitigate total vehicle emissions of HC, CO, NOXand PM2.5in 2030 by approximately 39%, 57%, 59% and 79%, respectively, compared with 2013 levels. With additional actions to control the future light-duty passenger vehicle population growth and use, and introduce alternative fuels and new energy vehicles, the China total vehicle emissions of HC, CO, NOXand PM2.5in 2030 could be reduced by approximately 57%, 71%, 67% and 84%, respectively, (the PC[2] scenario) relative to 2013. This paper provides detailed policy roadmaps and technical options related to these future emission reductions for governmental stakeholders.
authors.affiliation: School of Environment, and State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing 100084, China. Electronic address: ywu@tsinghua.edu.cn.
authors.forename: Ye
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: Shaojun
authors.initials: S
authors.lastname: Zhang
authors.affiliation: School of Environment, and State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing 100084, China.
authors.forename: Jiming
authors.initials: J
authors.lastname: Hao
authors.affiliation: School of Environment, and State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing 100084, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Liu
authors.affiliation: School of Environment, and State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China.
authors.forename: Xiaomeng
authors.initials: X
authors.lastname: Wu
authors.affiliation: Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
authors.forename: Jingnan
authors.initials: J
authors.lastname: Hu
authors.affiliation: International Consultant, Arlington, VA 22207, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Walsh
authors.affiliation: Research and Advanced Engineering, Ford Motor Company, 2101 Village Road, Dearborn, MI 48121-2053, USA.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Wallington
authors.affiliation: Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, USA.
authors.forename: K Max
authors.initials: KM
authors.lastname: Zhang
authors.affiliation: International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland 4001, Australia.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Stevanovic
keywords: Air pollution; China; Emission control; Policy; Vehicle emissions