Evolving water, energy and carbon footprints in China's food supply chain

Food-supply related activities are depleting water resources, wasting energy and aggravating climate change to feed the swelling population. How the water, energy and carbon footprints (WECFs) transfer in the entire food supply chain (FSC) and evolve driven by socioeconomic effects remains elusive. Herein, we propose adapted models of structural path analysis (SPA) and structural decomposition analysis (SDA) specifically for the FSC based on input-output analysis. Beyond evaluating the WECFs in China's FSC induced by household consumption during 2007-2017, we track their transfer through the supply chain, and unravel their key evolutionary char-acteristics and socioeconomic drivers. With the WECFs increasing in aggregate magnitude, their growth rates decelerate, while the urban household consumption ascends to over 70% of the total household consumption. Except the food sector itself (Agriculture and Food processing), Chemicals and Electricity and heat are the key sectors, whose dominance is weakened by the surging contribution of Transportation and Services. Chemicals -> Agriculture -> Food processing -> Household food consumption is a critical shared path for three footprints. From supply-side perspective, the path length for WECFs is lengthening over time, with a general 5%-8% increase in the share of paths associated with second-order production layers. Increased premium food consumption imposes pressure on the WECFs, which is non-negligible besides per capita consumption effect and intensity effect. The findings inform policies required for synergetic control of WECFs along FSC and optimized decision-making on FSC management.