陕西省碳排放强度收敛性及趋势演进分析

Analysis of Convergence and Trend Evolution of Carbon Intensity in Shaanxi Province

随着陕西省经济步入新常态,未来降低碳排放强度仍面临诸多挑战。由于传统收敛检验工具自身的局限性,基于非线性时变因子模型对2005—2017年陕西省11市(区)碳排放强度差距及收敛进行检验,结果发现该省碳排放强度整体上不存在收敛,进一步采用聚类方法发现该省内存在3种收敛类型及1种离散类型,合并检验后发现4个初始类型是稳健的。类型C与类型D的相对转移路径呈现上扬态势,而类型A与类型B呈现下降态势,它们之间的碳排放强度演变呈现分异特征。从陕西全省范围来看,碳排放强度的核密度曲线不断向左移动,说明在样本期内碳排放强度水平整体趋于下降。2012年进入新常态前碳排放强度波峰高度持续上升、宽度大幅缩小,2012年之后波峰持续下降,波峰形态逐渐由陡峭变为扁平,同时样本期内核密度曲线由一个主峰和一个侧峰构成,表明该阶段碳排放强度的分布呈现两极分化的态势。

As Shaanxi Province’s economy enters the new normal,there are still many challenges to reduce carbon emission intensity in the future.Due to the limitations of the traditional convergence test tool,the carbon emission intensity gap and convergence in 11 cities of the Shaanxi province from 2005 to 2017 were tested based on the nonlinear time-varying factor model.The results showed that there was no convergence in the carbon emission intensity of Shaanxi province as a whole.Further,clustering method was used to find that there were three convergence classes and one discrete class in the province.The relative transfer path of class C and class D showed an upward trend,while class A and class B showed a downward trend,which means evinces the characteristics of differentiation between them.From the perspective of the whole province,the kernel density estimation curve of carbon emission intensity kept moving to the left,indicating that the overall carbon emission intensity level tends to decline in the sample period.Before 2012,the peak height continued to rise and the width significantly decreased.After 2012,the peak continued to decline and the peak shape gradually changed from steep to flat.Meanwhile,the nuclear density curve was composed of a main peak and a side peak,indicating that the distribution of carbon emission intensity at this stage presented a polarization trend.