Relationship between Self-Sufficiency Rate of Food and CO₂ Emission in Japan

抄録

LCA inventory data based on input-output tables was used to analyze the relationship between the self-sufficiency rate of food and CO₂ emission in Japan. For the food item i with the total consumption C_i [M\] and self-sufficiency rate x_i, the total amount of CO₂ emission consists of (1) domestic production of i, (2) production of industrial product j to be exported for the import of i, and (3) transportation to export j and import i. According to this model, an effective carbon emission coefficient, σ_eff,i was calculated for each food item i. Because of the low self-sufficiency rate of food (∼40%), the amount of carbon emission was proved to have substantially increased in Japan. The difference between the present C-emission and that by assuming 100% food self-sufficiency easily reached the COP3 goal to reduce CO₂ emission. This means that an increase in food self-sufficiency rate can be an effective option to reduce CO2 emission in Japan.