中国城市碳排放强度的空间溢出效应及驱动因素

Spatial spillover effect and driving forces of carbon emission intensity at city level in China

采用核密度估计、空间自相关、空间马尔科夫链和面板分位数回归等方法对1992-2013年全国283个城市碳排放强度的空间溢出效应和驱动因素进行了分析。①核密度估计结果表明,中国城市碳排放强度总体均值下降,差异在逐步缩小。②空间自相关Moran’s I指数表明城市碳排放强度存在显著的空间集聚性且空间集聚性在逐渐增强,但空间集聚水平的变化逐年缩小。③空间马尔科夫链分析结果表明:第一,中国城市碳排放强度存在马太效应,低强度与高强度的城市在相邻年份转移过程中呈现维持初始状态的特征。第二,城市碳排放'空间溢出'效应明显,且不同区域背景下溢出效应存在异质性,即若与碳排放强度低的城市为邻,该城市的碳强度能够增加向上转移的概率,反之亦然。④面板分位数结果显示:在碳排放强度低的城市,经济增长、技术进步、适当的人口密度起到减排作用;外商投资强度与交通排放是使碳强度增大的主要因素。在碳排放强度高的城市,人口密度是重要的减排因素,技术进步暂时没起减排作用;工业排放、粗放式的资本投资以及城市土地蔓延则是碳强度上升的主要因素。

Since the Paris Climate Change Conference in 2015,reducing carbon emission and lowering carbon intensity has become a global consensus to deal with climate change.Due to different economic development stages,carbon intensity is regarded as a better index to measure regional energy-related carbon emissions.Although previous scholars have made great efforts to explore the spatiotemporal patterns and key driving factors of carbon intensity in China,the results lack the perspective from city level because of limited availability of statistical data of city-level carbon emission.In this study,based on carbon intensity of 283 cities in China from 1992-2013,we used the kernel density estimation,spatial autocorrelation,spatial Markov-chain and quantile regression panel model to empirically reveal its spatial spillover effects and explore the critical impact factors of carbon intensity at the city level.Our result indicates that although the total carbon emission increased during the study period,carbon intensity saw a gradual decline and regional differences were shrinking.Secondly,the city-level carbon intensity presented a strong spatial spillover effect and diverse regional backgrounds exerted heterogeneous effects on regions.Thirdly,quantile panel data analysis result showed that for low-intensity cities,on the one hand,FDI and transport sector were main contributing factors,and economic growth,technical progress and high population density negatively affected carbon intensity.On the other hand,industrial activity,extensive growth of investment and urban sprawl were key promoting factors for high-intensity cities,and population density was beneficial to emission reduction task.Furthermore,technological advance has not exerted negative influence on carbon intensity in high-intensity cities.At last,we suggested that Chinese government should take different carbon intensity levels into full consideration before policy making.