[A-CG55] 分野横断型気候シナリオ研究：方法高度化とエミュレータとの融合

[ACG55-P02] Developing the integrated assessment model SCM4OPT-ECON (version 1.0) to explore optimal cost-benefit paths for Shared Socioeconomic Pathways scenarios

*蘇 宣銘^1,2、高橋 潔²、横畠 徳太²、田中 克政^2,3、藤森 真一郎⁴、高倉 潤也²、山口 臨太郎²、Xiong Weiwei³ (1.国立研究開発法人海洋研究開発機構、2.国立研究開発法人国立環境研究所、3.Laboratoire des Sciences du Climat et de l’Environnement (LSCE), IPSL, CEA/CNRS/UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France、4.京都大学)

キーワード：費用効果分析、統合評価モデル、社会経済共有経路、限界削減費用

Most recent cost-benefit Integrated Assessment Models have mainly focused on reducing CO₂ or greenhouse gas (GHG) emissions. This goal may not adequately account for the uncertainties arising from diverse socioeconomic developments and the potential for mitigating the effects of emissions of individual GHGs, aerosols, and pollutants. We developed an Integrated Assessment Model framework - the Simple Climate Model for Optimization - Economic version 1.0 (SCM4OPT-ECON v1.0), by combining a reduced-complexity climate module with a socioeconomic module. We represented the Shared Socioeconomic Pathways (SSP) scenarios by 1) calculating a new set of marginal abatement cost curves based on the most recent integrated assessment model, 2) creating a new SSP-dependent damage function based on process-based impact simulation results, and 3) extending the evaluation time to the year 2450. The cost-benefit analysis revealed that the SSP scenarios achieved various rates of control for emissions of individual GHGs, aerosols, and pollutants. The result was diverse patterns of optimal temperatures, including maximum temperature achieved and stabilized temperature by the end of the evaluation period. The model simulations showed the importance of distinguishing options for reducing emissions of GHGs based on distinct socioeconomic growth scenarios. We also show an example of a long-term socioeconomic projection spanning several centuries as well as a variety of socioeconomic assumptions for assessing climate change policies with long-term consequences.