Spatio-temporal Evolution And Influencing Factors Of Urban Carbon Emission Intensity In China

With the gradual implementation of peaking carbon dioxide emissions and aceviving carbon neutrality,the importance of reducing carbon intensity in cities has become increasingly important,while the research on the carbon intensity of prefecturelevel cities has not yet been saturated.The spatial and temporal evolution of carbon emission intensity in 286 Chinese cities between 2006 and 2020 was analyzed,using the Dagum Gini coefficient,kernel density analysis,and spatial Markov chains.The spatial heterogeneity of factors influencing urban carbon emission intensity was examined using a geographically weighted spatial-temporal regression(GTWR)model,and the result was analyzed by dividing all cities into four major regions.The study found that:(1)During the study period,the carbon emission intensity decreased steadily,with a general pattern of high intensity in the north and low intensity in the south.The cities with low carbon emission intensity mainly concentrated in the southeastern and some central provinces,and cities with high carbon emission intensity mainly concentrated in the northeastern provinces and some provinces in central and western regions.(2)There was a relatively obvious imblance of carbon emission intensity among all cities,and the degree of imblance was increasing,with hypervariable density between groups being the main source of imblance.By region,the degree of imbalance within the eastern and northeastern regions was relatively low,while the central and western regions were relatively high.With the exception of the northeastern cities,the differences within the rest of regions were gradually narrowing,but the degree of imblance between regions was deepening.The carbon emission intensity of the four regions showed a more obvious multipolar pattern at the beginning,but the trend gradually decreased in the latter part of the study except the central and western cities.(3)The spatial relevance of carbon emission intensity among cities was gradually increasing,and there was a tronger tendency for cities to maintain their carbon emission intensity in the same state.Carbon emission intensity could be reduced steadily but not by leaps and bounds.What’s more,there was "spatial spillover" effect of carbon emission intensity,that means if a city is located next to a low carbon intensity city,it will greatly increase the probability that the city will move to a lower carbon intensity.(4)Overall,to improve technology,economy,road network density,and to open more to the outside world could significantly reduce carbon emission intensity,while to develop financial and the secondary industry had significant promotion effects.Take it by regions,in the eastern,the improvement of economy,secondary industry and density of the road network could effectively reduce the intensity of carbon emissions,the first two factor had increasing strength of impact but with weakening strength of the second factor.The development of financial industry and technology was conducive to reducing the intensity of carbon emissions,with a mild effect.But the degree of opening showed slight effect on boosting carbon intensity at a later stage.In the central region,the patterns of changes in influencing factors were more similar to those in the east,with the exception of financial industry,of which there was significant heterogeneity of impact within the region.For the western region,the effect of improving technology,economy and openness on reducing carbon intensity had become increasingly significant,with the level of technology had the greatest impact.The development of the financial and secondary industries significantly improved carbon intensity,but with a decreasing strength of impact.For the northeast,the impact of openness on reducing carbon intensity enhanced,while the reverse was true for the level of technology and economy.The development of the financial industry,secondary industry,and road density significantly increased carbon intensity,but the impact of road density weakened as the transportation system improved.