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 PM concentration, 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, NO and PM in 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, NO and PM in 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.

Improving PM2.5 Air Quality Model Forecasts in China Using a Bias-Correction Framework

“…Consistent with previous studies, our analysis also shows that the percentage improvements by the CART-LM-KF-AN method are generally larger in relatively cleaner regions (e.g., the Pearl River Delta in South china, Northeast China, and other remote regions) than in heavily polluted regions (e.g., the North China Plain and the Yangtze River Delta in East China) (Figure 8), suggesting that there might be important factors missing in the trained relationship between model biases and predictor variables over polluted regions. One such factor is the fast-changing emissions in both magnitude and distribution in regions such as the North China Plain and the Yangtze River Delta during the modeled three years [48][49][50], a result of increasingly more strict emission control enforcements and/or economic fluctuations. The significant change of emission rates in these regions between the training years (2014)(2015) and the prediction year (2016) could confound the trained bias correction relationships.…”

Air Pollution Inequality and Its Sources in SO2 and NOX Emissions among Chinese Provinces from 2006 to 2015

“…Urbanization growth has increased the vehicle population, which further increases NO X emission in China [53][54][55]. For example, the nitrogen pattern is highly attributed to urbanization in Shanghai [56].…”

“…To measure vehicle population, we consider the number of urban vehicles (passenger vehicles, trucks, and other vehicles) which have a registered license. Gasoline consumption by vehicles has dramatically increased in proportion to the growth of vehicle population, which results in more NO X emission [55,63]. The China Vehicle Emission Control Annual Report [64] announced the gasoline-fueled vehicles accounted for 81.3% of motor vehicles and were responsible for 39% of NO X emission by the end of 2009.…”

“…In terms of proportion of gasoline vehicles (T b ), the slow reduction of inequality trend can be interpreted as a result of the implementation of national standards for fuel consumption by vehicles. As Wu et al [55] noted, China 3 and China 4 gasoline standards for vehicles could reduce NO X emission. Also, regulations on alternative fuel vehicles and strict standards on fuel consumption are expected to decrease not only gasoline consumption but also NO X emission by about 67% and 59% respectively by 2030.…”

Investigating the Potential of Ridesharing to Reduce Vehicle Emissions

“…They vary in several factors such as the vehicle type under study, urban structure, testing conditions and technologies, and the time of study, which correspond to the emission standards in place. Focusing on vehicle emissions, number of vehicles and emission standards, some studies also provide future trends of on-road vehicle emissions in China (Hao, Liu, Zhao, Li, & Hang, 2015;Wang, Fu, & Bi, 2011;Wu et al, 2017;Zhang, Wu, Wu et al, 2014).…”