A Study On The Socio Economic Drivers And Decoupling Efforts Analysis Of China’s Haze And Ozone Pollution

Since the implementation of the"Air Pollution Prevention and Control Action Plan"and the"Three-Year Action Plan to Fight Air Pollution",China has implemented a series of relatively strict pollutant emission standards and pollution control measures.At present,China’s air pollution prevention and control work has made remarkable achievements.The air pollution pattern has undergone profound changes,and the air quality has been significantly improved.For example,the annual average PM_2.5concentration has dropped significantly,and the number of days with PM_2.5 exceeding the standard has dropped significantly.However,it is worth noting that the annual average value of PM_2.5 in most cities has not yet reached the standard,and in recent years,ozone,as another major indicator of air pollution in China after PM_2.5,has shown a trend of aggravating the degree of pollution,expanding the scope of influence,and prolonging the pollution season.At present,studies have demonstrated the spatial correlation between haze and ozone from different regional and temporal scales.And in November 2020,the"Proposal of the Central Committee of the Communist Party of China on Formulating the Fourteenth Five-Year Plan for National Economic and Social Development and the Vision for 2035"clearly pointed out that it is necessary to strengthen the coordinated control of multiple pollutants and regional coordinated governance,strengthen the coordinated control of PM_2.5 and ozone,and basically eliminate heavily polluted weather.Therefore,in order to continuously improve the air environment quality and ensure the excellent rate of air quality,strengthening the coordinated control of haze and ozone has become the focus of China’s next stage of air pollution control.However,existing research focuses more on the temporal and spatial distribution characteristics and influencing factors of a single indicator of haze and ozone.Few studies have made an in-depth interpretation from the perspective of co-governance between the two.Therefore,based on the principle of problem-oriented scientific research,the study takes China and the five key polluted areas of Beijing-Tianjin-Hebei urban agglomeration,Yangtze River Delta,Pearl River Delta,Fenwei Plain and Chengdu-Chongqing city group as the research objects to study the haze and ozone pollution,and selects the annual average concentrations of PM_2.5 and O₃（MDA 8-90）as evaluation indicators for haze and ozone pollution.Based on the quantitative analysis of the spatial and temporal distribution characteristics of haze and ozone pollution in China from 2015 to 2019,the authors discussed the spatial correlation between haze and ozone pollution.At the same time,the decoupling elasticity model is used to analyze the current situation of haze and ozone pollution in the process of economic growth in different regions of China during the sample period,the decomposition model is used to explain the differences in the effects of socioeconomic factors such as economic development,industrial structure,and energy efficiency on haze and ozone,and the comprehensive decoupling effort model is used to compare and analyze the effectiveness of haze and ozone governance policies in each region.Furthermore,it provides a reference for the formulation of air pollutants coordinated control strategy.The main work and conclusions of this study are as follows:（1）This paper systematically reveals the temporal and spatial evolution pattern of haze and ozone pollution from 2015 to 2019.The results shows that during the sample period,the haze pollution emission was controlled,but the PM_2.5 still exceeded the standard seriously,and the ozone concentration increased year by year,and the spatial distribution of haze and ozone pollution had obvious regional agglomeration characteristics.Specifically,the low-pollution PM_2.5 agglomeration areas were mainly distributed in South China,Southwest China,Heilongjiang and surrounding cities,and the high-pollution agglomeration areas were mainly distributed in North China,Central China and Northwest China,and there was a trend of agglomeration in the eastern and central regions.O₃ low-pollution agglomeration areas were mainly distributed in Southwest China,South China and Northwest China,and high-pollution agglomeration areas were represented by the Beijing-Tianjin-Hebei urban agglomeration in North China,mainly in central North China,East China and North Central China.The range of the high-value area gradually expanded,and the range of the low-value area gradually shrinked.In addition,comparing the temporal and spatial evolution characteristics of haze and ozone pollution in different regions,it is found that there was a certain regional heterogeneity in haze and ozone pollution.The haze pollution in the Beijing-Tianjin-Hebei urban agglomeration and Fenwei Plain were the most serious,followed by the Yangtze River Delta and the Chengdu-Chongqing city group,and the Pearl River Delta had the most obvious improvement in haze pollution.The ozone pollution was the most serious in the Beijing-Tianjin-Hebei urban agglomeration,followed by the Fenwei Plain,the Yangtze River Delta and the Pearl River Delta.The ozone pollution level of the Chengdu-Chongqing city group was relatively low.（2）This paper interprets the spatial correlation characteristics of haze and ozone pollution in China.The results show that during the period from 2015 to 2019,the distribution of PM_2.5 and O₃ had a relatively obvious spatial correlation,and the correlation degree taked 2018 as the peak point,and there was an overall upward trend.In addition,the local spatial autocorrelation test showed that the agglomeration between PM_2.5 and O₃ was dominated by H-H and L-L types,showing an obvious positive correlation.However,the number of cities with the most negative correlation with H-L type also showed an increasing trend to varying degrees.（3）The author compares and analyzes the degree of decoupling between economic growth and haze and ozone pollution in different regions.The results show that between2015 and 2019,China’s economic growth and PM_2.5 emissions gradually showed a good interaction trend,but the contradiction with ozone pollution control intensified,and the decoupling status between economic growth and ozone pollution in different periods was different.Further comparison and analysis at the regional level found that during the study period,the haze pollution in each region achieved the most ideal absolute decoupling state,and the regional differences were small.However,the decoupling elasticity of ozone pollution is most obvious in the Fenwei Plain,showing the difference between the Fenwei Plain（1.30）>Beijing-Tianjin-Hebei urban agglomeration（1.00）>Pearl River Delta（0.86）>Yangtze River Delta（0.81）>Chengdu-Chongqing city group（0.18）.（4）Based on the LMDI decomposition model,the authors analyses the differences in the roles of haze and ozone pollution drivers from the perspective of socioeconomic.The results show that economic effects and population effects were the main and important driving factors for the increase of PM_2.5 and O₃ concentrations,and their effects were controlled and slowed down.However,industrial structure effect,technology effect and emission intensity effect,as important driving factors for emission reduction,had different effects on the governance of haze and ozone pollution,and different influencing factors had different effects on emission reduction in different regions.From the perspective of the differences in the driving factors of haze emission reduction,the emission intensity effect was always the main driving force of haze control during the sample period,followed by the reduction effect of technology effect and industrial structure effect.In terms of regional distribution,the role of industrial structure and emission intensity in Beijing-Tianjin-Hebei urban agglomeration on haze control was much higher than that in other regions,and the effect of technology effect emission reduction in the Yangtze River Delta region was the most obvious.However,in recent years,the driving ability of technological effects to reduce emissions had declined significantly,and it had even evolved into a driving factor for the increase of PM_2.5 concentration in Beijing-Tianjin-Hebei urban agglomeration,Fenwei Plain and Chengdu-Chongqing city group.From the perspective of the differences in the driving factors of ozone emission reduction,technological progress was the main driving force for ozone emission reduction governance,followed by the emission intensity effect during 2017-2018 and the reduction effect of industrial structure since 2015-2016 and2018-2019.In terms of regional distribution,with the exception of the Beijing-Tianjin-Hebei urban agglomerations and Chengdu-Chongqing city group where ozone emission reduction were dominated by industrial structure effects,the ozone control in the Yangtze River Delta,Pearl River Delta and Fenwei Plain were dominated by technological progress.Moreover,in recent years,the emission increase effect of energy emission intensity in each region had been significantly weakened,and the technical effect of Beijing-Tianjin-Hebei urban agglomeration,Fenwei Plain,and Chengdu-Chongqing city group had shifted from emission reduction to emission increase.（5）Based on the Tapio decoupling model and the LMDI decomposition model,this paper constructs a comprehensive decoupling effort model to evaluate the effectiveness of the current haze and ozone pollution control measures in each region.The results show that during 2015-2019,China had made significant decoupling efforts in haze control,but all decoupling efforts on ozone pollution control cannot fully offset the increase in ozone concentration caused by economic effects.All emission reduction control policies and measures had not achieved the expected effect on ozone pollution.Moreover,different influencing factors had different effects on haze and ozone pollution in different regions,and the decoupling efforts of haze and ozone pollution in different regions showed obvious differences.Therefore,in order to further promote the coordinated governance of haze and ozone pollution in different regions,it is necessary to formulate top-level plans under the guidance of the government,adhere to source governance,promote technological innovation,continuously improve the urban industrial structure,and focus on regional collaborative governance and construction of the whole process supervision system.