A framework for analyzing car lifetime effects on carbon footprint of automobiles

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K22124
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0107:Economics, business administration, and related fields
• Research Institution: Oita University
• Principal Investigator: Nakamoto Yuya 大分大学, 経済学部, 准教授 (10881881)
• Project Period (FY): 2020-09-11 – 2023-03-31
• Keywords: カーボンフットプリント / 乗用車 / ライフサイクルアセスメント / 物理的寿命 / 経済的寿命 / 産業エコロジー

Outline of Final Research Achievements

This study proposes a new framework for estimating the effects of changes in the physical lifespan (PHL) of cars and the possession lifespan (POL) of new and used cars on stock, flow, and carbon footprint (CF). Applying this framework to all new and used cars registered in Japan from 1990 to 2016 showed that a 10% extension of the PHL of cars reduced the CF of cars by 30.7 Mt, while a 10% extension of the POL of new cars reduced the CF of cars by 26.4 Mt, and a 10% extension of the POL of used cars produced a 5.2 Mt CF reduction. On the other hand, a 10% lifetime reduction in the three cases increased CF by 42.2 Mt, 29.4 Mt, and 6.0 Mt, respectively. These results indicate that increasing the lifetime of new and used cars could contribute significantly to the mitigation of global warming. To achieve a large reduction in life cycle emissions, car designers should focus on ways to extend vehicle lifetimes.

Free Research Field

環境経済学

Academic Significance and Societal Importance of the Research Achievements

本研究成果の学術的意義は次のとおりである。
（1）自動車のPHLと新車・中古車のPOLを組み合わせることで，新車の生産，新車・中古車の使用，新車から中古車，中古車から中古車への買い替え，新車・中古車の廃棄を考慮した自動車の総合的な製品ライフサイクルをモデル化している
（2）自動車のカーボンフットプリントを，自動車の総合的な製品ライフサイクルを考慮した上で分析できる新しい枠組みと方法を開発している。