Hao Jiming team, academician of Chinese Academy of Engineering: attention should be paid to the joint improvement of PM2.5 and ozone pollution

    Recently, Hao Jiming, Professor of School of environment, Tsinghua University and academician of Chinese Academy of engineering, published a review article in the journal engineering of Chinese Academy of engineering. This study systematically combs the process of air pollution control in China, and points out that China's air pollution control policy has changed from emphasizing pollution emission control to paying attention to the continuous improvement of air quality. From the perspective of ecological civilization construction, we should pay attention to the joint improvement of PM2.5 and ozone pollution in the future.

    With the rapid development of social economy, in the past 30 years, China has faced the most severe, complex and difficult regional air pollution problems, such as acid rain, haze and so on. This paper systematically summarizes the progress and challenges in the field of air pollution control in the process of promoting the construction of ecological civilization in China.

    Since 1980, acid rain pollution has occurred on a large scale in southern and southwestern provinces of China. Before 2006, the average pH value of rainfall in China continued to decrease. In the peak year (2006), about 1 / 3 of China's regions were faced with acid rain problem, and the severity was similar to that of central Europe in the 1980s. Sulfur dioxide and nitrogen oxides emitted from coal combustion are the main causes of acid rain pollution. In 1995, China revised the law on the prevention and control of air pollution to strengthen the control of acid rain and coal-fired pollution. In 2000, China divided "acid rain and sulfur dioxide control areas" (namely "two control areas"). During the Eleventh Five Year Plan period, the state implemented the total emission control policy of sulfur dioxide, strengthened the political assessment of the local government's responsibility for sulfur dioxide emission reduction, and successfully curbed the rising trend of sulfur dioxide emission through a series of economic and technical means, resulting in the gradual improvement of acid rain pollution.

    In 2012, China revised the ambient air quality standard to include the fine particulate matter (PM2.5) which has significant impact on human health into the monitoring index. In 2013, only 3 of the 74 key cities in China could meet the PM2.5 annual concentration limit. The sources and causes of PM2.5 pollution are complex, and the traditional policies and measures for some pollution sources and pollutants can not meet the requirements of air quality improvement. Therefore, it is necessary to make joint efforts of multiple departments and regions to achieve substantial emission reduction of various precursors. Under the top-level design of the CPC Central Committee, the State Council has formulated the "action plan for air pollution prevention and control (2013-2017)" (namely "ten articles on air pollution"). The "action plan" is the first large-scale action plan directly formulated by the State Council for environmental pollution, which strengthens the emission control of various pollution precursors from coal-fired sources, industrial sources, mobile sources, dust sources and residential sources. The proposal of the concept of ecological civilization construction has prompted the central and local governments to feel clearer improvement goals, provide more powerful policy incentives, and implement more stringent control measures. From 2013 to 2017, the average annual concentration of PM2.5 decreased by 23% in all cities above prefecture level, and 40%, 34% and 28% in Beijing Tianjin Hebei, Yangtze River Delta and Pearl River Delta, respectively.

    Although PM2.5 pollution control in China has made significant progress, the construction of ecological civilization in China is still a long way to go, and air pollution control is still facing many severe challenges. From 2013 to 2017, the 90th percentile of daily ozone concentration in 74 major cities increased by 20%, while that in Beijing Tianjin Hebei region increased by 24%.

     The researchers believe that collaborative PM2.5 and ozone pollution control has become a necessary work to promote the construction of ecological civilization. It needs to integrate complex factors such as chemical mechanism and meteorological conditions to optimize and formulate a scientific scheme for reducing the emission of O3 precursors. The paper also points out that from a larger perspective, the construction of ecological civilization needs to pay attention to the multiple challenges brought by social and economic development to energy, environment, health and climate systems, and coordinate the governance of PM2.5, ozone, greenhouse gases and unconventional pollutants; it needs to develop a multi system coupling decision support model, so as to actively respond to air pollution and climate change and continuously promote ecological development in China It provides theoretical and technical support for the construction of civilization.