中国种植业碳补偿率区域差异、动态演进及收敛性分析
Regional differences, dynamic evolution, and convergence of the carbon compensation rate of planting industry in China
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摘要: 农业碳排放阻碍绿色农业转型, 探索种植业碳补偿率区域差异、动态演进及收敛性, 可为低碳农业良性发展提供有益指导。本文同时考虑碳源和碳汇, 测算2002—2018年中国31省、市、自治区种植业碳补偿率, 采用Dagum基尼系数分解法考察地区差异, 采用非参数估计中的核密度估计动态演进过程, 借助σ收敛、绝对β收敛及条件β收敛检视收敛性特征。结果表明: 1)种植业碳补偿率整体相对差异扩大趋势明显。东部地区相对差异扩大, 中部地区和西部地区变化较小; 东—西部、东—中部地区之间增加, 中—西部地区之间减小; 地区间差距是造成种植业碳补偿率差异的主要原因。2)中国种植业碳补偿率整体呈逐年增大的变动态势, 碳补偿率高值省份有所增多, 省域种植业碳补偿率差异有先减后增的趋势。东部各省种植业碳补偿率在逐渐上升, 绝对差距有所减少, 从两极分化演变为单极化; 中部各省种植业碳补偿率在逐渐上升, 绝对差距有所减小; 西部各省种植业碳补偿率变化较为稳定。3)全国及东、西部地区的种植业碳补偿率不存在σ收敛, 而中部地区不甚明显; 全国、东、中及西部地区绝对和条件β收敛均显著。本文的结论强调, 中国种植业碳补偿率的区域异质性凸显, 其时序变化趋势总体上升; 省域间的“追赶效应”显现, 地区间碳补偿率增长的趋同态势明显。因此, 合理制定区域农业绿色发展策略, 积极发挥区域减排潜力是提高种植业碳补偿率的关键。Abstract: Global warming is an increasingly serious problem. Carbon emissions from agriculture had hindered its transition to green agriculture, and carbon emissions from the planting industry cannot be ignored. Reducing the regional differences and clarifying dynamic evolution and convergence of the carbon compensation rates in the planting industry are conducive to the benign development of low-carbon agriculture. At present, few studies consider both agricultural carbon sources and carbon sinks, and an in-depth analysis of the carbon compensation rate of the planting industry is lacking. Existing studies on the agricultural carbon compensation rate focus only on the spatial effect of agricultural carbon but do not effectively analyze the sources and convergence of regional differences in the carbon compensation rate of the planting industry. Therefore, this study considered both the carbon sources and the carbon sinks and estimated the carbon compensation rate of the planting industry in 31 Chinese provinces (municipalities and autonomous districts) from 2002 to 2018. The Dagum Gini coefficient decomposition method was used to measure and decompose the regional differences, the dynamic evolution process of kernel density with non-parametric estimation was investigated, and the σ-convergence, absolute β-convergence, and conditional β-convergence models were used to test the convergence characteristics of the carbon compensation rate. The results were as follows: (1) The overall relative difference in the carbon compensation rate of the planting industry tended to expand. The relative differences in the eastern region expanded, while the relative differences in the central and western regions showed only little change. The relative differences between the eastern and western regions and the eastern and central regions increased, whereas that between the central and western regions decreased. The regional differences were the main reasons for the differences in the carbon compensation rates of the planting industry. (2) The carbon compensation rate of the planting industry in China increased annually, and the number of provinces with high carbon compensation rates increased. The provincial difference in carbon compensation rate first decreased and then increased. The carbon compensation rate in the eastern provinces increased gradually, and the inter-provincial absolute gap decreased, changing from polarization to unipolarization. The carbon compensation rate in the central provinces increased gradually, and the absolute gap decreased. The carbon compensation rate in the western provinces was relatively stable and showed little change. (3) There was no σ-convergence in the carbon compensation rate of the planting industry in the whole country and the eastern and western regions, but it was not obviously observed in the central region. The absolute and conditional β-convergences were significant in the whole country and the eastern, central, and western regions. The results of this study emphasize that regional heterogeneity in the carbon compensation rate of China’s planting industry is prominent and that the temporal trend of carbon compensation rate is generally increasing. The “catch-up effect” among provinces and the convergence trend of the carbon compensation rate growth among regions are apparent. In the future, it will be important to improve the carbon compensation rate of the planting industry to better formulate a green development strategy for regional agriculture and actively reduce regional emissions.