Using Environmental Input-Output Analysis to Assess Energy, Water and CO2 Emissions in Tokyo’s Food System

Hu, Xujie and Yan, Wanglin (2021) Using Environmental Input-Output Analysis to Assess Energy, Water and CO2 Emissions in Tokyo’s Food System. CITIES 20.50 – Creating Habitats for the 3rd Millennium: Smart – Sustainable – Climate Neutral. Proceedings of REAL CORP 2021, 26th International Conference on Urban Development, Regional Planning and Information Society. pp. 1075-1084. ISSN 2521-3938

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The sustainability of Tokyo relies on a big food supply chain to meet the huge demands of a population of 14 million people. The production of food consumes enormous amounts of water and energy along with producing the accompanying vast amount of CO2 emissions. Excessive emissions create serious downward pressure on reaching the goal of being a carbon-neutral society by 2050. In order to relieve this pressure, it is required to first evaluate the CO2 emissions quantitatively and then identify the main emitters exactly. Most of the previous studies focused on the emissions by industrial sectors, ignoring nexus effects across sectors. They also ignored the contribution of carbon emissions in the entire food supply chain, from supply industries to final consumption. This paper aims to develop a framework to visualize direct and indirect resource consumption and emissions in the food system, from food supply to food demand, and identity the key nodes and paths to achieve reduction targets using input-output tables at different scales. First, we define the elements in the food nexus system and establish the relationships among elements, in which the supply-side includes agriculture, animal husbandry, fisheries, and food manufacturing, while the demand-side includes food wholesale and retail, catering, and households. Then by using a monetary input-output table compiled from the statistics from the Tokyo Metropolitan Government, direct and indirect resource utilization and emissions are calculated to identify the sources of environmental stress through combining environmentally-extended input-output analysis and energy-water-CO2 flow analysis. Finally, the reduction targets could be allocated to specific sectors and districts according to the results of emissions at different scales. The results show that the manufacturing and services sectors played the top roles of direct and indirect energy consumption and carbon emission, with manufacturing as the largest embodied energy consumer and CO2 emitter, and services as the largest direct and embodied water user. These results indicate that the Tokyo Metropolitan Government could provide more measures on energy conservation and reduction in manufacturing and services. In addition, government should promote the wide use of zero emission vehicles to reduce emissions in transportation. It was found that the food system emits 10.73% of total CO2 emissions and the embodied resource consumption and carbon emissions triggered by households is nearly a quarter of total embodied household consumption and emissions. Also, more than 80% of direct consumption and emissions comes from food demand. For embodied energy and CO2 emissions, the main sectors with a strong correlation effect were manufacturing–services, manufacturing–transport/post, and services–transport/post, while manufacturing–services, telecommunication–services, and services–telecommunications were the major sectors for embodied water use. These sector pairs are the key paths for formulating energy conservation, water saving, and reduction measures. Our findings show that the food-energy-water (FEW) system is a significant contributor of CO2 emissions in Tokyo. Thinking and acting on the FEW nexus across sectors could help the government to roll out its “Zero Emission Tokyo Strategy 2050” more effectively.

Item Type: Article
Uncontrolled Keywords: Food systems, energy-water- CO2 emissions, environmental input-output analysis, Tokyo
Subjects: G Geography. Anthropology. Recreation > GE Environmental Sciences
G Geography. Anthropology. Recreation > GF Human ecology. Anthropogeography
H Social Sciences > HD Industries. Land use. Labor
Depositing User: REAL CORP Administrator
Date Deposited: 06 Oct 2021 21:27
Last Modified: 17 Oct 2021 17:53

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