Abstract To achieve a low-carbon society, it is crucial to make the transition away from wasteful lifestyles that are shaped by mass production/mass consumption towards low-carbon lifestyles. Research in the field of urban environmental studies examining human behavioral factors affecting energy consumption, has mostly focused on CO 2 emissions relating to direct energy consumption, such as the use of air conditioners and water heaters. As CO 2 emissions from the industrial sector are greater than those from the residential and transportation sectors in Japan, it would be prudent for consumers to work on reducing CO 2 emissions relating to products and services. In an effort to provide some basic research to achieve the aforementioned objectives, this study looked at statistical data from sources such as the Japanese Family Income and Expenditure Survey and the Japanese National Survey of Family Income and Expenditure to estimate direct and indirect CO 2 emissions relating to daily expenditures and consumption. As a case study, we selected a sample denizen to calculate the CO 2 emissions relating to daily living. Based on the obtained results, we examined the lifestyle and consumption patterns and their relation to CO 2 emissions. The results suggest that while it is still important for consumers to reduce their direct energy consumption in an effort to create a low-carbon society, there is still potential for indirect CO 2 emission reductions in areas of production and consumption.