2030年中国主要省域间碳排放配额测算

Carbon Emission Quota Budget Among Main Provinces of China in 2030

[目的]在控制碳排放总量条件下,对省域间碳排放配额进行公平科学地分配是实现“双碳”目标的关键途径,也是碳排放交易机制体系的重要基石。分析不同情景下碳排放配额测算结果的碳减排边际成本,以期以最小成本确定最优的碳排放定额分配方案,为区域后期开展分配工作提供理论基础,为地区碳减排方案制定提供工作参考。[方法]在前人建立的碳配额测算指标基础上引入生态性指标,并设置公平、效率、生态、兼顾公平—生态—效率4种情景,利用SBM(slacks-based measure)对偶模型测算不同情景下区域碳边际减排成本,并以此为依据确定最优分配方案。[结果]在公平、效率、生态、兼顾情景下平均碳边际减排成本分别为2 950,3 120,2 910,3 090元/t,引入生态性指标的方案减排成本明显更低,可推断出是碳汇抵消掉部分减排难度较大,成本较高的碳排放所致;兼顾情景下减排成本明显高于公平、生态情景,表明碳排放效率的提升同时会导致碳边际减排成本增加。[结论]生态情景下的碳排放配额是以最低碳边际减排成本实现“双碳”目标的最优方案,在地区碳排放方案及碳交易机制制定时应予以重视。

[Objective]Under total carbon emission control,an equitable and scientific allocation of carbon emission quota among provinces of China is a key approach for achieving the“dual carbon”goal,as well as an important cornerstone of the carbon emission trading system.The marginal cost of carbon emission reduction was analyzed under different scenarios with regard to the results of carbon emission quota allocation in order to determine the optimal carbon emission quota budget scheme at the lowest cost,thereby providing a theoretical basis for subsequent regional allocation work and a reference for the formulation of regional carbon emission reduction schemes.[Methods]An ecological index was introduced based on the carbon quota budget index established in previous studies.Four scenarios(including equity,efficiency,ecology,and balanced equity-efficiency-ecology)were evaluated.The slacks-based measure(SBM)dual model was used to calculate the regional marginal carbon emission reduction cost under different scenarios,and the optimal budget scheme was determined based on these results.[Results]Under the scenarios of equity,efficiency,ecology and balanced,the average marginal costs of carbon emission reduction were 0.295 million yuan/t,0.312 million yuan/t,0.291 million yuan/t,and 0.309 million yuan/t,respectively.When the ecological index was introduced,the emission reduction cost of the scheme was significantly lower,and it can be inferred that the carbon sink offsets a portion of the carbon emissions that are more difficult and costly to reduce.The cost of emission reduction under the balanced scenario was significantly higher than under the equity and ecology scenarios,indicating that improvement in carbon emission efficiency will lead to an increase in marginal carbon emission reduction cost.[Conclusion]The carbon emission quota under the ecology scenario was the best scheme for achieving the“dual carbon”goal with the lowest marginal carbon emission reduction cost.Attention should be paid to the formulation of regional carbon emission schemes and carbon trading mechanisms.