Study On The Mechanism Of Urban Agglomeration Urbanization Development On Carbon Emission Based On HLM Model

In recent years,the urbanization of our country has made great progress,but at the same time,the environmental pollution caused by the rapid development of urbanization and the extensive use of land have become more and more prominent.Based on the aim of how to improve the quality of urbanization development and reduce carbon emissions,this paper selects the Yangtze River Delta region with the highest urbanization level in China.Empirical analysis of the role of urbanization on carbon emissions mechanism.First of all,on the basis of summarizing the literature,this paper analyzes the present situation from the two levels of city and county.At the city level,the carbon emissions and urbanization level of each city in Yangtze River Delta are increasing year by year,and the difference of urbanization among different cities is obvious.At the county level,the urbanization level and carbon emissions of the Yangtze River Delta counties are increasing year by year,and there are great differences in the carbon emissions among counties.Secondly,the panel data model is used to analyze the factors affecting carbon emissions at county level.The results show that:(1)the effects of employed population and foreign trade on carbon emissions are not significant;(2)the level of economic development,the proportion of the secondary industry,the proportion of the tertiary industry will promote the increase of carbon emissions,the size of the population,the level of urbanization has a significant positive effect on carbon emissions;(3)the energy intensity of technical factors and the amount of patent application have a significant negative inhibitory effect on carbon emissions.Then,the effect of urbanization on carbon emissions is studied by using the county-city two-layer HLM model.The results show that the main results are as follows:(1)in the zero model,the variance test of random error term of the city level intercept term satisfies the significance level of 1%,which indicates that there is cross-scale effect,and the HLM model can be established;(2)in the stochastic intercept model,the area of built-up area at the municipal level and the proportion of the gross industrial output value above the municipal scale have a significant positive effect on carbon emissions by acting on the intercept term respectively.The coefficient of effect of per capita GDP,urbanization rate,municipal carbon emissions,and municipal energy intensity on the cut-off term is not significant,indicating thatthe effect on carbon emissions is not obvious.Among the four variables at the county level,the proportion of the tertiary industry has a significant negative effect on carbon emissions.(3)in the complete model,the proportion of the gross industrial output value above municipal scale has a significant positive effect on carbon emissions through the cut-off term,and the economic development level,population size and urbanization level have a significant positive effect on carbon emissions.(3)in the complete model,the proportion of industrial output value above municipal scale has a significant positive effect on carbon emissions.The municipal energy intensity has a significant positive effect on carbon emissions through the coefficient of the proportion of the tertiary industry,and the effect value is small.The statistics of other municipal variables were not significant.In addition,the differences among different regions also have a significant positive effect on carbon emissions.Finally,the HLM intermediary effect test model is used to test the mediating effects of urbanization on carbon emissions and their action paths.The results show that:(1)in the zero model test,88.13% of the changes in the county carbon emission level of the response variables are affected by the municipal level variables,so it is necessary to establish the HLM model;(2)the intra-group effect and the inter-group effect of the direct effect of urbanization level on carbon emissions are statistically significant,and the urbanization level has a significant positive effect on carbon emissions;(3)the level of independent urbanization is related to the level of economic development,the level of employed population,the intensity of energy,and the amount of patent application.Both the intra-group effect and the inter-group effect were statistically significant,and the total effect was positive.The proportion of urbanization level to the secondary industry,the ratio of the tertiary industry to the secondary industryFinally,the medium effect of urbanization on carbon emissions and its action path were examined by HLM intermediate effect test.The results show that:(1)in the zero model test,88.13% of the changes in the county carbon emission level of the response variables are affected by the municipal level variables,so it is necessary to establish the HLM model;(2)the intra-group effect and the inter-group effect of the direct effect of urbanization level on carbon emissions are statistically significant,and the urbanization level has a significant positive effect on carbon emissions;(3)the level of urbanization is related to the level of economic development,the level of employed population,the intensity of energy,and the amount of patent application.The intra-group effect and the inter-group effect were statistically significant in thedirect effect,and the total effect was positive.For the proportion of the secondary industry,the proportion of the tertiary industry,the level of foreign trade and the size of the population,the urbanization level has only passed the significant test of intra-group effects,and the effect values are all positive.(4)the intra-group and inter-group effects of the three variables were significantly positive when the urbanization level and the level of economic development and the amount of patent application acted on the carbon emissions respectively.The proportion of the secondary industry and the tertiary industry acted on the carbon emissions at the same time with the urbanization level,and the intra-group and inter-group effects of the two intermediate variables were significantly positive.In 1996,the intra-group effect of urbanization was significantly positive.The intra-group and inter-group effects of the level of foreign trade and urbanization were statistically significant.The intra-group positive effect of urbanization was greater than the negative effect of the groups,and the overall performance of the positive effect was positive.The intra-group and inter-group effects were significant and positive when the population size was intermediate variable,and the intra-group effects of urbanization level were significant positive effects.The intra-group and inter-group effects were significant and positive when the level of employed population was the intermediate variable,and the intra-group and inter-group effects of urbanization level failed to pass the test.The energy intensity was the intermediate variable,the intra-group effect was negative,the inter-group effect was positive,and the intra-group and inter-group effects of urbanization level were positive.(5)the level of economic development is the intermediate variable,and there is only the intermediate effect of inter-group variation,and it is the complete intermediate effect.The proportion of secondary industry,the level of foreign trade and the size of population only have the intermediate effect of intra-group variation.The intergroup and intra-group intermediate effects of the proportion of tertiary industry did not exist.The level of employment population,energy intensity,patent application volume group and inter-group effects exist,and except energy intensity,all are the complete intermediary effect;(6)in the complete intermediary effect model,the intra-group differences of the proportion of the tertiary industry,the population size and the level of the employed population have significant positive effects on carbon emissions,the urbanization level and the employed population have significant positive effects on carbon emissions.The difference of energy intensity had a significant positive effecton carbon emission,and the difference of energy intensity had a significant positive effect on carbon emission.