THE RELATIONSHIP BETWEEN CO₂ EMISSIONS FROM URBAN TRAFFIC AND URBAN AREA DENSITY

Abstract

 To become a low carbon society, we must reduce CO₂ emissions from the transportation sector. In this study, we calculated and analyzed the CO₂ emissions from cars and public transport vehicles in major Japanese cities. We used data from a variety of sources, such as family income and expenditure surveys, life-cycle CO₂ databases, retail price statistics, etc. To calculate the emissions from cars, we added the direct CO₂ emissions from gasoline combustion to the indirect CO₂ emissions associated with the production and maintenance of cars and related components. Our results indicate that CO₂ emissions from traffic tend to be lower in larger cities. We found that population density, which can be considered as a proxy for the extent of urbanization, is strongly negatively correlated with CO₂ emission levels. The number of cars owned is positively correlated with CO₂ emission levels.