Revealing hidden CO2 impacts from consequential consumption by matrix analysis: Application to Japanese single households

As a result, we found that the consumption of some products/services have the potential to increase/decrease CO2 emissions beyond their own CO2 intensities, because of consequential consumption. In spite of their relatively small CO2 intensities, several products and services (meat, dairy products and eggs, oils, fats and condiments, water and sewerage charges, domestic nondurable goods) have high net CO2 emissions per unit price (Japanese yen; JPY). This is because of high CO2 emissions from the consequential consumption of energy. In contrast, the net CO2 emission from charges for board are negative because of the substitution relationship between food and energy items. Compared with the results of other foregoing studies on food materials, the net CO2 emission by our approach is much larger than that indicated by the conventional process-specific approach.