2℃和1.5℃目标对中国国家自主贡献和长期排放路径的影响

在《巴黎协定》设置的混合减排机制下,中国的INDC尽管自主提出,但也受全球气候目标及全球减排进展的影响。本文基于气候公平的不同原则,建立了公平分配未来碳排放空间的综合性框架,并利用最新情景研究数据,分析了2℃和1.5℃目标对中国INDC力度以及长期排放路径的影响。研究结果表明:第一,相比2℃目标,1.5℃目标对本世纪内全球累积碳排放空间、关键时点的减排目标、近期减排力度以及碳中和时间等都提出了更高要求。第二,根据公平分配方案的评估结果表明,2℃目标下,中国现有INDC在责任方案下能够满足减排要求,而在其他方案下存在排放差距。而在1.5℃目标下,中国在四个方案下均无法满足减排要求,且排放差距进一步扩大。第三,2℃和1.5℃目标对中国确定长期排放目标以及碳中和时间,也会产生显著影响。相比2℃目标,1.5℃目标下,中国2050年排放相对2010年下降率需要再增加约15个百分点,实现碳中和的时间需要提前15年左右。因此,中国需要根据公平分配研究给出的提高INDC力度要求的区间,提前准备《巴黎协定》后关于全球盘点和INDC更新议题新一轮谈判的应对策略,同时应尽早启动制定长期低碳发展战略的政策研究进程。

Impact of 2℃ and 1.5℃ target to INDC and long-term emissions pathway of China

Under the hybrid mitigation mechanism set by Paris Agreement, the INDC of China is proposed intendedly, and also is affected by global climate targets and mitigation progress.On the basis of different principles of climate equity, we established an integrated framework to allocate future cumulative carbon emissions permits, and analyzed the impact of global climate targets to China's INDC and long-term emissions pathway.The article put forward the following results.First, 1.5℃ target proposes more stringent requirements on carbon budget, emissions reduction at key time points, near-term mitigation efforts, and timeframe of carbon neutral compared with 2℃ target.Second, based on the results from effort-sharing assessment, China's INDC can meet the 2℃ target requirement under the most favorable effort-sharing schemes, and there are emissions gaps under other schemes.However, China's INDC lacks ambition to achieve 1.5℃ target under all schemes, and the emissions gaps further enlarge.Third, under 1.5℃ target, emissions reduction in 2050 related to 2010 for China needs to increase by 15%, while carbon neutral time needs to be achieved 15 years earlier than 2℃ target.Therefore, China should prepare for the coming negotiation on global stocktake and INDC update issues, and initiate policy research process on long-term low-carbon development strategy as soon as possible.