Research On The Temporal Evolution Characteristics And Influencing Factors Of Regional Carbon Emissions

The excessive CO₂ emission has a negative impact on the earth ecosystem and human society.As the main source of regional carbon emissions,cities are also the basic units for the formulation and implementation of emission reduction policies.How to effectively control urban carbon emissions is the key to achieve the carbon emission reduction goals in the region.The Yangtze River Economic Belt spans three regions in China,East and West,and the natural environment,society and economic level of cities in different regions are very different.It is of great significance to study the current situation of carbon emission and the characteristics of influencing factors in this region,which is of great significance to the sustainable development of the Yangtze River economic belt and other regions to learn from the research results.Based on the related concepts of carbon emission and sustainable development,this paper finds that the previous researches on carbon emission impact factors are mainly on national or regional scale,and the relationship between urban development path and carbon emission impact factor characteristics is insufficient.In view of the above problems,this paper analyzes the spatial-temporal pattern of carbon emissions and carbon emission intensity of cities in the Yangtze River economic belt,and then selects 10 indicators from five fields of industrial structure,population size and structure,scientific and technological development level,external contact level and residents’consumption ability for correlation analysis,and studies the influencing factors of carbon emissions of 70 cities from two dimensions of time and space features.By using the self-organizing neural network model,the city groups with different carbon emission characteristics and the city development stage classification with progressive relationship are obtained by clustering based on the carbon emission characteristics of each city and 11 economic and social development indicators.Combining the two clustering results with the correlation analysis results,the relationship between urban evolution path and the characteristics of carbon emission influencing factors is discussed.The study found that:（1）carbon emission in cities around the Yangtze River economic belt has increased year by year,but the intensity of carbon emission has decreased year by year.Spatially,the amount of carbon emission decreases from the upstream to the downstream regions,and the high-value region of carbon emission intensity shifts over time from the Chengyu city cluster to the junction of the two urban clusters in the middle and downstream cities.（2）The results of correlation analysis showed that six indicators,such as Labor Productivity,Per Capita Consumption Expenditure of Urban Residents,Per Capita Consumption Expenditure of Rural Residents,Proportion of Urban Population,Internet Users Ten Thousand Households,and Proportion of Technology Appropriation to Government Expenditure,were all significantly and positively correlated with carbon emissions in 70 Prefecture cities.The correlation between the two indicators characterizing the industrial structure and carbon emissions shows a diametrically opposite trend,such as Proportion of the Secondary Industry shows a significantly positive correlation and Proportion of the Tertiary Industry shows a negative correlation or no significant correlation.With the exception of some of the cities that come from the interface between the urban cluster of the Yangtze River Delta and the central urban cluster of the Yangtze River,the foreign dependency is negatively or non significantly correlated in most of the cities.The correlation coefficient between Permanent Residents and carbon emissions is dominated by a negative correlation in upstream cities,and the closer the city is to the downstream region the greater the number of Prefecture cities that are positively correlated.The two clusters separate the 70Prefecture cities into nine subgroups,the urban development phase into 12,and the nine subgroups can be divided into three categories according to the urban evolution paths of the Prefecture Cities in each group:Groups 1-4（with the predominance of small and medium-sized cities in two urban clusters in the upper and middle regions）with low carbon emission levels and are in the early stages of urban development,groups 5-7（with the predominance of cities in the middle of the Yangtze River and urban clusters in the Yangtze River Delta）with high carbon emission levels and are in the advanced stages of urban development,groups 8 and 9（with municipalities,provincial capital cities and a few urban cluster cities in Yangtze River Delta）.With the improvement of urban development stage,the dominant industry has changed from secondary to tertiary industry,the population size has changed from negative growth to growth,the proportion of the urban population has increased,and indicators such as the consumption level of urban and rural residents,the degree of external connection,and the level of science and technology have gradually increased.（4）From the perspective of the relationship between the urban evolution path and the characteristics of the influencing factors of carbon emissions,it is found that the Prefecture Cities in different urban development stages do differ in their carbon emission influencing factor characteristics:the prefecture secondary industries in the early stages of development have a positive impact on the increase of carbon emissions.The three industries in the prefecture city at the advanced stage of development are positively correlated,while the second industry is negatively or insignificantly correlated.The correlation coefficients of the two industrial structure indicators of Prefecture Cities in the transition phase are also in the period of alternating change.In Prefecture Cities,where foreign capital dependence has both remained rising,the correlation coefficient between capital dependence and carbon emission of Prefecture Cities in the early stage of urban development gradually changes to a positive correlation,while those of Prefecture Cities in the urban development transition are dominated by a negative or insignificant correlation;Prefecture cities that are in the early stages of urban development show a negative correlation in the size of their urban resident population with carbon emissions,and those that go through this stage in turn show a shift to a positive correlation.（5）Based on the conclusions of theoretical research and empirical research,the corresponding emission reduction policy recommendations are put forward according to the different stages of development.Such as in the initial stage of development of the city through cooperation with other regions to improve the industrial structure,improve the level of technology,integration of idle resources to improve the efficiency of use.In the transition stage,cities formulate long-term plans to eliminate backward industries,transfer low-end industries,introduce high-tech industries,properly develop service industries,and build industrial chains with developed regions to promote the diffusion of technology.Cities in the advanced stage of development give full play to technological advantages and international cooperation advantages,research and development and introduction of clean production technology and advanced management experience.