The 2022 report of synergetic roadmap on carbon neutrality and clean air for China:Accelerating transition in key sectors

China is now confronting the intertwined challenges of air pollution and climate change.Given the high synergies between air pollution abatement and climate change mitigation,the Chinese government is actively promoting synergetic control of these two issues.The Synergetic Roadmap project was launched in 2021 to track and analyze the progress of synergetic control in China by developing and monitoring key indicators.The Synergetic Roadmap 2022 report is the first annual update,featuring 20 indicators across five aspects:synergetic governance system and practices,progress in structural transition,air pollution and associated weather-climate interactions,sources,sinks,and mitigation pathway of atmospheric composition,and health impacts and benefits of coordinated control.Compared to the comprehensive review presented in the 2021 report,the Synergetic Roadmap 2022 report places particular emphasis on progress in 2021 with highlights on actions in key sectors and the relevant milestones.These milestones include the proportion of non-fossil power generation capacity surpassing coal-fired capacity for the first time,a decline in the production of crude steel and cement after years of growth,and the surging penetration of electric vehicles.Additionally,in 2022,China issued the first national policy that synergizes abatements of pollution and carbon emissions,marking a new era for China's pollution-carbon co-control.These changes highlight China's efforts to reshape its energy,economic,and transportation structures to meet the demand for synergetic control and sustainable development.Consequently,the country has witnessed a slowdown in carbon emission growth,improved air quality,and increased health benefits in recent years.

Predicting PM_(2.5) Concentration in the Yangtze River Delta Region Using Climate System Monitoring Indices and Machine Learning

Changing meteorological conditions during autumn and winter have considerable impact on air quality in the Yangtze River Delta(YRD)region.External climatic factors,such as sea surface temperature and sea ice,together with the atmospheric circulation,directly affect meteorological conditions in the YRD region,thereby modulating the variation in atmospheric PM_(2.5) concentration.This study used the evolutionary modeling machine learning technique to investigate the lag relationship between 144 climate system monitoring indices and autumn/winter PM_(2.5) concentration over 0-12 months in the YRD region.After calculating the contribution ratios and lagged correlation coefficients of all indices over the previous 12 months,the top 36 indices were selected for model training.Then,the nine indices that contributed most to the PM_(2.5) concentration in the YRD region,including the decadal oscillation index of the Atlantic Ocean and the consistent warm ocean temperature index of the entire tropical Indian Ocean,were selected for physical mechanism analysis.An evolutionary model was developed to forecast the average PM_(2.5) concentration in major cities of the YRD in autumn and winter,with a correlation coefficient of 0.91.In model testing,the correlation coefficient between the predicted and observed PM_(2.5) concentrations was in the range of 0.73-0.83 and the root-mean-square error was in the range of 9.5-11.6μg m-3,indicating high predictive accuracy.The model performed exceptionally well in capturing abnormal changes in PM_(2.5) concentration in the YRD region up to 50 days in advance.

Synergetic roadmap of carbon neutrality and clean air for China

It is well recognized that carbon dioxide and air pollutants share similar emission sources so that synergetic policies on climate change mitigation and air pollution control can lead to remarkable co-benefits on greenhouse gas reduction,air quality improvement,and improved health.In the context of carbon peak,carbon neutrality,and clean air policies,this perspective tracks and analyzes the process of the synergetic governance of air pollution and climate change in China by developing and monitoring 18 indicators.The 18 indicators cover the following five aspects:air pollution and associated weather-climate conditions,progress in structural transition,sources,inks,and mitigation pathway of atmospheric composition,health impacts and benefits of coordinated control,and synergetic governance system and practices.By tracking the progress in each indicator,this perspective presents the major accomplishment of coordinated control,identifies the emerging challenges toward the synergetic governance,and provides policy recommendations for designing a synergetic roadmap of Carbon Neutrality and Clean Air for China.

Classification of ozone pollution and analysis of meteorological factors in the Yangtze River Delta

Serious regional ozone(O_(3))pollution often plagues the Yangtze River Delta(YRD).The formation mechanism of these regional pollution events,including the meteorological and emission factors leading to these pollution events and how to affect the distribution of O_(3),still needs further research and exploration.In this study,we first define the standard of O_(3)regional pollution in the YRD,and then select 248 regional pollution cases from 2015 to 2020 according to the defined standard.For the pollution cases in pollution months(May and June),PCT(principal component analysis in T-mode)classification method is used to classify the ozone concentration distribution in YRD area.The regional distribution of the O_(3)concentrations in the YRD is divided into five types,and the overall type(Type 1)accounts for 15%,which is related to the control of YRD area by high-pressure center.Under the control of high pressure,the weather is sunny with the high temperature,and this weather condition is favorable for ozone generation and intercity transmission,causing extensive pollution.The double center type(Type 2)accounts for 8%.This type of YRD is controlled by the front of the high pressure(the high-pressure center is located in North China),and the weather in the middle and north is conducive to the generation and transmission of O_(3).Inland type(Type 3)accounts for 24%.The main body of this type of high pressure is located in Mongolia.The easterly wind in YRD area is conducive to the inland transmission of O_(3)precursors.The northern coastal type(Type 4)accounts for 44%.This type of YRD area is mainly controlled by the weak pressure field.The weather in the northern coastal area is sunny and the solar radiation for a long time is conducive to the formation of O_(3).The southern coastal type(Type 5)accounts for 10%,the solar radiation is strong in the southern region mainly under the influence of the post-offshore high pressure.This study provides new insights into the relationship between O_(3)pollution distribution types and atmospheric circulation in YRD area,and reveals the difference of potential meteorological impacts of different O_(3)pollution distribution types.