Spatial Effect And Impact Mechanism Of Multidimensional Urbanization On Carbon Emissions In The Yangtze River Delta Urban Agglomeration

Scientifically analyzing the internal mechanism and impact mechanism of multidimensional urbanization on carbon emissions and achieving high-quality coupling between urbanization and resources and environment is a critical measure to achieve the "dual carbon" goal and seek green development.However,the rapid development of urbanization has not only achieved significant achievements such as rapid population and industrial agglomeration,accelerated evolution of land use types,and transformation of agricultural civilization to industrial civilization,but also triggered ecological risks such as extensive development methods,a heavy industrial structure,low emission performance,and inefficient environmental governance.In particular,China’s economic agglomeration,epitomized by the Yangtze River Delta urban agglomeration,is facing the dual dilemma of carbon emission reduction constraints and urbanization development contradictions.How to achieve the dual goals of carbon emission reduction and urbanization development,and explore a win-win path for urbanization development and environmental protection has become an urgent need for urban agglomerations to cope with global climate change and to solve the problem of energy saving and carbon control.To this end,this study takes the Yangtze River Delta urban agglomeration as the research object,constructs the "population-land-industry" urbanization variables into the STIRPAT model based on the whole-group variable approach,and explores the spatiotemporal evolution of multidimensional urbanization and carbon emissions in the study area.The spatial Durbin model was used to diagnose the mechanisms and spatial effects of different urbanization factors on carbon emissions,and then to propose optimization strategies,to provide references for achieving the dual objectives of carbon emission reduction and urbanization.The specific results are as follows.(1)In the temporal dimension,industrial urbanization is the highest,population urbanization is the second highest,and land urbanization is the lowest among all dimensions of urbanization in the study area,with little change in the three dimensions in general,with industrial urbanization increasing slightly and population urbanization showing a slightly decreasing trend.In terms of the evolution of carbon emissions over time,from 2010 to 2020,carbon emissions increased from 458.74 million tons to 558.71 million tons,showing a fluctuating increase,but the rate of increase gradually tapered off,with a slight dip in carbon emissions in 2015 and 2020.(2)In the spatial dimension,there is some overlap in the spatiotemporal evolution patterns of the three dimensions of urbanization,with the line from Nanjing to Shanghai being the high level of different dimensions of urbanization,and Yancheng and Chizhou on the fringes of the study area being in the low level.However,there are also some differences in the spatial distribution of urbanization in different dimensions,with population urbanization high in the east and low in the west,land urbanization high in the central and low in the west and northsouth periphery,and industrial urbanization high in the central and low in the north-south periphery.Carbon emissions show a core-fringe pattern of a central high and north-south low,as well as a high eastern and low western trend,with relatively small changes in overall magnitude.The global spatial autocorrelation changes from a weak correlation to a strong correlation,and the spatial distribution of cold and hot spots show a strong spatial agglomeration,showing a spatial pattern of "hot in the core and cold in the periphery" and a circle-like radiation structure with Shanghai as the core spreading to the surrounding areas.(3)In terms of spatial unevenness,the overall,inter-group,and intra-group Gini coefficients show a slight downward trend,with intra-group differences contributing the most to the regional disparity in carbon emissions,at between 58.6% and 65.6%,with a fluctuating upward trend.Inter-group differences are the second largest source of differences,with a contribution rate between 26.7% and 28.0%,with little variation.The impact of hypervariable density is smaller and its contribution is decreasing.In terms of inter-group differences,the difference in carbon emissions between Suzhou and Anhui is the largest,followed by the difference between Suzhou and Zhejiang.In terms of intra-group differences,Jiangsu has the largest unevenness in carbon emissions,with a mean value of 0.36,but also shows a smooth decreasing trend.(4)Population size and per capita GDP contribute positively to carbon emissions in the local region and neighboring regions.Energy intensity positively contributes to carbon emissions in the local region,while it negatively affects carbon emissions in neighboring regions.There is heterogeneity in the impact of urbanization on carbon emissions in different dimensions.Land urbanization has the largest positive effect on carbon emissions,industrial urbanization has the smallest effect,while population urbanization has a negative direct effect on carbon emissions.All three dimensions of urbanization have a positive spillover effect.(5)The study believes that to achieve the goals of compatible development of environmental quality and urbanization as well as maximizing the development of urbanization and minimizing negative environmental externalities,we should regulate and optimize the development of low-carbon urbanization with low energy consumption and pollution,control the upper limit of population size,guide the reasonable movement of population,promote the upgrading of industrial structure,develop a decarbonized economy and optimize the energy consumption structure,and promote green-biased technological progress,to achieve synergy between carbon emission reduction and urbanization development.