全产业链视角下建筑碳排放路径模拟:基于RICE-LEAP模型

从社会经济活动的角度出发,创新性地构建包含中国终端部门的新型综合评估模型—RICE-LEAP模型,并通过情景设置动态模拟2020~2050年建筑全产业链碳排放的发展路径及其结构性特征.结果表明:①与参考情景相比,考察期内1.5℃情景下中国碳排放总量的额外累计减排量将达到129.74Gt CO₂,而建筑全产业链碳排放的额外累计减排量为57.53Gt CO₂,占比44.28%.②建筑业是典型的“表观低碳、隐含高碳”的行业.建筑业直接碳排放占建筑物化碳排放的比例较小,仅占9.46%~11.75%.③3个动态情景下,建筑物化碳排放的下降速率均快于建筑运行碳排放.这是由于建筑物化碳排放主要依赖工业等终端部门的脱碳进程,在实现碳达峰过程中具有先发优势.④现阶段,建筑全产业链能耗仍以煤炭消费为主,但煤炭的消费占比在3个动态情景中均呈现出不同程度的下降,而电力的消费占比则呈现出明显的上升趋势.

Simulating building carbon emission path with a RICE - LEAP model from the perspective of the whole supply chain

This study develops a RICE-LEAP model, an integrated assessment model containing end-use sectors in the context of China, to dynamically simulate building carbon(C) emission path via the whole supply chain and identify the structural characteristics from 2020 to 2050. The results show that: ① Compared to the business-as-usual scenario, the reduction in additional cumulative emissions under 1.5℃ scenario from 2020 to 2050 will reach 129.74 Gt CO₂, and the mitigation of additional cumulative emissions from the building supply chain will be 57.53 Gt CO₂, accounting for 44.28% of the total C emission reduction. ② The building sector is a sector with low direct C emissions but high indirect C emissions. The direct onsite C emissions from the building sector only account for a very small part of building embodied C emissions with a proportion ranging from 9.46% to 11.75%. ③ The reduction rate of embodied C emissions is higher than that of operational C emissions of buildings in all scenarios; because the embodied C emission reduction in the building sector depends mainly on the decarbonization process of the industry. ④ Coal consumption is still currently dominant in building energy consumption but shows a decline trend under all three scenarios while the proportion of electricity consumption represents an obvious increase trend as a result of building electricification.