中国二氧化碳的边际减排成本与区域差异研究

Marginal abatement costs of CO_2 emission in China and its regional differences

测算二氧化碳的边际减排成本有利于评估区域碳减排潜力与成本,也是落实区域碳交易政策的重要依据。在多投入-多产出的生产效率模型框架下,本文采用二次型方向距离函数,研究了全国30个省份2000—2012年期间的碳边际减排成本及其差异的时空演化特征。二次型方向距离函数通过引用时间变量,反应环境治理的中性技术进步,因此研究方法能充分利用参数估计的灵活性。研究结果显示:1二氧化碳的边际减排成本平均约为1 519元/吨,远高于我国碳市场的交易价格,表明当前试点的自愿性碳交易政策是无效的;2区域碳边际减排成本的泰尔指数分解表明,东中西部地区的减排成本存在明显的地区性差异性,且随着时间的推进,碳减排空间逐渐变小。减排成本的地区性差异表明环境规制政策并不能保证各地区碳治理成本的边际均等原则,而利用政策工具,促使碳排放权从治理成本较高的地区转移至成本较低的地区,可以减少总治理成本,实现总量控制目标。本文建议:一方面,为实现国家碳减排的总体宏观目标,各区域要加强合作,相互借鉴成功的碳减排技术与经验等,在执行政策上,应尝试执行区域协同治理机制,努力降低总减排成本;另一方面,各区域在推进产业结构调整、城镇化及能源消费结构替代过程中要遵从循序渐进原则,避免碳减排成本过度波动,增加减排难度。

Quantifying marginal abatement costs （MAC） of CO2 emission is beneficial to evaluate regional mitigation potentialities and costs. It is also principal evidence of implementing regional carbon emission trading scheme. Under a framework of production efficiency model with multiple input-output, this paper employs the quadratic directional distance function approach to estimate provincial carbon＇ s MAC and analyzes spatio-temporal evolution of its regional differences in China. The quadratic directional distance function introduces time variable to reflect neutral technical pogress, and the method can take full advantage of flexibility of nonparametric estimation. The result of this research shows： （1） The carbon＇ s MAC is about 1 519 RMB per ton, which is far higher than the carbon prices in the current ETS pilots in China, implying that the voluntary carbon trading markets are inefficient. （2） The Theil index decomposition of provincial carbon＇ s MAC indicates there are significant differences of MAC among three regions of East, Central and West China, and the room for reducing CO2 gradually becomes smaller as times go on. The wide range of MAC estimates show that the equi-marginaI principle does not hold for the regulations on carbon pollution at regional levels. Also, it makes clear that environmental policies should strive to induce the movement of carbon emissions from the higher cost region to the lower cost region, which can cut down total abatement cost and achieve total control target of carbon emissions. In the end, this paper suggests that in order to achieve general macroeconomical objects of carbon emssion reduction, the local government in each area should strengthen cooperation and learn from each other with the successful experience and technology of carbon emission reduction. On the one hand, when implementing environmental policy, the local government should reinforce regional cooperation mechanisms to reduce the total cost of emission reduction in environmental protection. On the other hand, the government should carry out industrial restructuring, urbanization and energy consumption structure substitution step by step and avoid excessive fluctuations in carbon abatement costs to increase the difficulty of abatement.