Lifestyle changes overweighing technology improvement in household decarbonization: evidence from Japan during 1990-2020

Given that over 70% of global greenhouse gas emissions (GHG) stem from consumption, it is essential to promote lifestyle changes among end users and reduce emissions embedded in the upstream supply chain. We investigated the long-term (1990-2020) changes in household carbon footprints from such final users in Japan. Through factor decomposition, we found that the contribution of increasingly green technologies to household decarbonization is diminishing with time. In contrast, lifestyle changes - such as the shift to green products and services, as well as a reduction in overall demand - are becoming the main driver. Additionally, unlike most developed countries, the share of GHG emissions from food expenditures in Japan does not show a declining trend, highlighting the need to upgrade the domestic food supply chain and promote smart services for decarbonizing both homemade meals and eat-out preferences. Our long-term database can provide references to encourage sustainable behaviors and help Japanese policymakers evaluate the effectiveness of current efforts.