Spatiotemporal dynamics of China's food supply chains and associated greenhouse gas emissions

Population growth and dietary improvements have increased food demand and changed the consumption structure, raising concern about food supply security and associated increases in greenhouse gas (GHG) emissions. The study aims to develop a cross-regional and cross-sectoral analytical framework to assess the spatiotemporal variations in food supply chains and associated GHG emissions in China, and to analyze the potential impacts of various future food supply scenarios. The framework integrates a spatial equilibrium model, GHG emission estimation methods and a coupling assessment, while also considering the four widely consumed food crops in China- rice, wheat, corn, and soybean. The results reveal a 36.13 % increase in total GHG emissions from food supply chains, rising from 344.97 million tonnes (Mt) carbon dioxide equivalence (CO2-eq) in 1990 to 455.98 Mt CO2-eq in 2021. Although the total food demand will continue to expand till 2030 in China, differentiated regional food policies can aid in increasing self-sufficiency rate by 9.45 % and decreasing emissions by 9.86 Mt CO2-eq. These findings provide valuable insights for agricultural policymakers in formulating regionspecific policies to improve food security and mitigate GHG emissions.