远程耦合视角下西藏食物跨区域调运碳排放溢出效应

[Objective] Food systems are a major source of greenhouse gas emissions. Clarifying the carbon emission effects and mitigation potential of cross-regional food transportation is crucial for developing sustainable food systems. [Methods] This study developed a telecoupling-based analytical framework for the food system in Xizang. Using statistical data on food production, household food consumption survey data, and transport network data in Xizang, this study employed a doubly constrained spatial interaction model (DCSIM) and carbon emission factors to quantify the scales, routes, and associated carbon emission spillover effects of cross-regional food transportation between Xizang and food-surplus provinces in inland China in 2022. Furthermore, an autoregressive integrated moving average (ARIMA) model was applied to predict and evaluate the potential for carbon reduction by 2035 resulting from changes in food productivity in Xizang and improved transportation conditions. [Results] (1) The food supply-demand structure in Xizang was characterized by high self-sufficiency in advantageous agricultural and pastoral products, with staple grains, edible oils, and certain livestock products depending on external supply. In 2022, about 647300 t of food were transported into Xizang, and routes longer than 3000 km accounted for 43.49% of total transportation volume. (2) In 2022, total carbon emission spillovers from cross-regional food transportation were 102800 t CO2. The carbon emission intensity per unit of food transportation was 7.85 times the national average, and spillovers showed significant spatial imbalance. (3) Scenario analysis indicated that by 2035, increasing food localization alone would achieve only 7.06% reduction in carbon emissions, whereas structural optimization of transportation modes was expected to achieve nearly 60% reduction. The combined carbon emission reduction potential of both strategies could reach 62.86%. [Conclusion] This study proposes a methodology for tracing, quantifying, and managing the carbon footprint of food system telecoupling from specific consumption endpoints. Through a case study of Xizang, it reveals that for regions inherently constrained by limited food productivity, the most effective leverage for reducing the carbon footprint of food telecoupling lies in the green transformation of transportation. This conclusion provides valuable insights for food security strategies and cross-regional coordinated governance of resources and environment across Qinghai-Xizang Plateau and other ecologically fragile regions.