Estimation of Direct and Indirect Household CO₂ Emissions in 49 Japanese Cities with Consideration of Regional Conditions

• Main Authors: Yujiro Hirano, Tomohiko Ihara, Masayuki Hara, Keita Honjo
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: Sustainability
• Subjects: household energy consumption; consumption behaviors; indirect CO₂ emission; regional characteristics; lifestyles; low-carbon society
• Online Access: https://www.mdpi.com/2071-1050/12/11/4678

We conducted a detailed estimation of direct and indirect CO₂ emissions related to multi-person households in 49 Japanese cities. Direct energy consumption was decomposed into energy use in order to consider the relationship with regional conditions. The results showed that CO₂ emissions from direct energy consumption were almost as large as indirect CO₂ emissions induced by consuming products and services, suggesting that lifestyle improvements are important for both energy savings and reducing CO₂ emissions relating to product and service consumption. In addition, CO₂ emissions from direct energy consumption varied widely between cities, making them susceptible to regional conditions. We also calculated CO₂ emissions from direct energy consumption and examined the regional conditions for individual forms of energy use. CO₂ emissions were higher in cold regions and lower in larger cities. In Japan, large cities are often located in relatively warm areas, so we conducted an analysis to distinguish the effects of climatic conditions from those of urbanization. This analysis allowed us to clarify the effects of regional conditions on factors such as heating/cooling and the ratio of detached houses to apartments.