Recently, the research group of Professor Qiang Zhang from the Department of Earth System Science (DESS) of Tsinghua University and the research group of Academician Kebin He of the School of Environment jointly published an online publication titled “Pathways of China's PM2.5 air quality 2015-2060 in the context of carbon neutrality” in the “National Science Review”, for the first time quantitatively reveals the continuous improvement path of air quality in China and key areas under the carbon peak and carbon neutrality target from 2015 to 2060, and points out the decisive role of achieving the carbon neutrality target for the fundamental improvement of air quality in China in the future.
With the implementation of the National Air Pollution Prevention and Control Action Plan, China's PM2.5 concentration has continued to decline in recent years, and air quality has improved significantly. However, the current PM2.5 pollution load is still at a high level. With the deepening of the pollution control process, the reduction of pollutants has gradually narrowed, and the difficulty of reducing emissions at the end of the treatment has become increasing, and the task of improving air quality is still arduous. In September 2020, General Secretary Jinping Xi announced at the general debate of the 75th United Nations General Assembly that China will strive to reach the peak of CO2emissions by 2030 and strive to achieve carbon neutrality by 2060. The proposal of this major strategic goal pointed out the direction for the overall planning of air pollution prevention and greenhouse gas emission reduction, and injected new momentum into the continuous improvement of air quality. On this basis, the Ministry of Ecology and Environment proposes to take "pollution reduction and carbon reduction synergistic efficiency" as the overall starting point to accelerate the transition from end treatment to source treatment, and reduce carbon emissions by responding to climate change, thereby fundamentally solving environmental pollution problem.
In the context of this major national strategy, Qiang Zhang 's research group and Kebin He 's research group established the China Carbon Neutrality and Clean Air Collaborative Scientific Assessment and Decision Support Platform (CNCAP) and constructed China's mid- and long-term emissions scenarios from 2015 to 2060 for the first time. It have proposed a path for continuous improvement of PM2.5 pollution throughout the country and key regions. The study found that, on the one hand, we should increase the intensity of source control, increase the proportion of renewable energy, promote the output of high-energy-consuming products such as steel and cement to reach the peak as soon as possible, accelerate the clean replacement process of loose coal, and continue to promote the non-electric industry, diesel engines and VOCs. The pollution control of key industries will achieve the carbon peak target in 2030. At the same time, the annual average concentration of PM2.5 in most areas of the country can reach the current ambient air quality standard of 35 μg/m3, and the average annual PM2.5 exposure level of the population across the country can drop from 55 μg/m3 in 2015 to 28 μg/m3. Realize the synergistic effect of "pollution reduction and carbon reduction".
Due to the extremely low threshold for the impact of PM2.5 on health, the World Health Organization (WHO) provides a guideline value of 10 μg/m3 for the average annual concentration of PM2.5, and China’s current PM2.5 standard is equivalent to the WHO’s first phase target value, there is still a certain gap from the WHO guidance value. As air pollution is more harmful to the elderly, in the context of the future population aging, we should promote the long-term continuous improvement of air quality in order to achieve the goal of comprehensively protecting the health of the population. After 2030, as the emission reduction potential of end-point governance measures is basically exhausted, deep low-carbon energy transition measures under the carbon neutral target will become the source of continuous and deep improvement in China's air quality. Under the carbon neutral scenario, China will basically complete the transition to low-carbon energy by 2060. Renewable energy will account for more than 70% of power generation, the proportion of final coal consumption in the industrial sector will be less than 15%, and the proportion of new energy vehicles will reach 60%. Above, the energy of the civil sector has been fully clean. The total national carbon emissions in 2060 is about 680 million tons, which is equivalent to a reduction of more than 90% based on the current emission level. At the same time, the national population’s annual PM2.5 exposure level will reach about 8μg/m3, 78% of the population's annual PM2.5 exposure level is lower than the WHO guideline value, and the air pollution problem will be fundamentally solved.
The picture shows the future carbon emissions and PM2.5 concentration changes in China under different scenarios (the percentage in the picture shows the proportion of fossil fuels in the total primary energy consumption)
The study puts forward and quantitatively evaluates China's future medium- and long-term PM2.5 air quality improvement path under the background of carbon neutrality for the first time, and points out that the deep low-carbon energy transition under the carbon neutrality goal is the only way for China 's air quality to reach the WHO guideline value. The research provides a scientific basis for China to formulate a roadmap for coordinated governance of “pollution and carbon reduction”, and has important reference value for other developing countries to coordinate their efforts to tackle climate change and air pollution. The study proposes that the next step should be to "reducing pollution and reducing carbon synergies" as the overall starting point, taking carbon reduction as the source of governance "starting point", and promoting the carbon peak and the carbon neutral goal of PM2.5 and O3 pollution synergies Governance, in-depth play and improve the role of structural adjustment in pollution reduction, accelerate the transition to clean and low-carbon energy, and gradually build a zero-carbon energy system; in response to the major needs of "scientific, precise, and legal pollution control", strengthen science and technology, leading and innovating mechanisms to build a new generation of carbon neutral and clean air pollution prevention and control technology system; taking the protection of people’s health as the starting point for the coordinated governance of climate change and air pollution, and tightening air quality standards after 2030 and gradually integrate with relevant WHO standards, leading to a fundamental improvement in air quality.
Professor Qiang Zhang from DESS of Tsinghua University is the corresponding author of the paper. Doctoral student Jing Cheng from DESS and Assistant Professor Dan Tong from DESS are the co-first authors of the paper. Academician Kebin He from the School of Environment of Tsinghua University jointly designed and guided the research. Experts and scholars from Tsinghua University, the Environmental Planning Institute of the Ministry of Ecology and Environment, the Pacific Northwest National Laboratory, and the Chinese Academy of Meteorological Sciences participated in the study. The research was supported by the National Natural Science Foundation of China and the The Energy Foundation.
Cheng J#, Tong D#, Zhang Q*, Liu Y, Lei Y, Yan G, Yan L, Yu S, Cui Y. R, Clarke L, Geng G. N, Zheng B, Zhang X. Y, Davis S. J, and He K. B.: Pathways of China’s PM2.5 air quality 2015-2060 in the context of carbon neutrality,https://doi.org/10.1093/nsr/nwab078
Writers: Jing Cheng, Qiang Zhang
Editor: Jiayin Wang
Review: Haiping Wu