Demographic transitions hinder climate change mitigation for Japan’s shrinking and aging households

The household sector is a major source of greenhouse gas (GHG) emissions and is key to achieving decarbonization targets. Household characteristics, influenced by demographic transitions such as population aging and shrinking, have a profound impact on energy use and emissions. This study explores how demographic changes in Japan may affect long-term emission mitigation in the household sector through the adoption of photovoltaics (PVs) and new energy vehicles (NEVs) under various scenarios for 2040. Using a comprehensive survey of 9,996 households, we develop a nuanced typology of households to understand variations in emissions and mitigation technology adoption. Household size and age emerge as key factors influencing emissions. The findings reveal that the increasing prevalence of smaller and elderly households may impede emission mitigation efforts in Japan, posing substantial obstacles to achieving long-term decarbonization goals in the household sector.