Evaluating food supply chain emissions from Japanese household consumption

Given its substantial contribution to greenhouse gas emissions, household consumption has been identified as a major contributor to climate change. Among various household activities, eating is a basic activity undertaken by everyone, and thus the environmental consequences of food consumption are attracting increasing attention. Although household food consumption has been widely discussed, there is still no comprehensive carbon footprint analysis of the entire food supply chain, including the differences among household segments. To address this knowledge gap, in this paper we use a modified environmental input–output model to quantify food-related carbon footprints throughout the entire supply chain. Taking Japan as a case study, results indicate that more than 60% of the food-related carbon footprint occurs at the production stage, while carbon emissions from the wholesale and retail stages account for up to about 38%. Furthermore, the consumption of the richest households produces the highest per capita carbon emissions of all income groups, and this holds true for their consumption across food types. Other findings include that in metropolitan areas, such as the Kanto area, dining out accounts for the biggest share, contributing 16% of total emissions, and that both the regional- or income-based disparity in emissions are significantly induced by red meat consumption. Optimizing food supply chain management and encouraging local consumption of fresh fruit, vegetables and meat are therefore essential for facilitating reduced household food carbon emissions.