A dynamic, physics-driven life cycle model for citrus supply chain: Evidence from a South Africa–Netherlands maritime trade route

Agri-food chains, especially fruit, produce about 10% of global GHG emissions, with more than half arising after harvest. Yet current methods, such as life cycle assessment (LCA), lack the spatial, temporal and physiological detail needed to resolve stage-specific drivers of environmental impact. We aim to overcome these limitations by developing a spatio-temporal, physics-based life cycle model that quantifies climate change (CC) and fossil resource use (RU,f) impacts for individual fruits and shipments across a transcontinental maritime supply chain. The proposed framework is demonstrated using a case study of the citrus supply chain connecting production in South Africa to consumption in the Netherlands. We show that variability among fruits and between shipments substantially alters CC and RU,f impact outcomes, demonstrating the need for dynamic rather than static supply-chain assessment. Energy use, maritime transport and food loss dominate impacts, with the farm-to-packhouse and overseas shipping stages contributing up to 0.5 kg CO₂-eq kg⁻¹ and 2 MJ kg⁻¹ of fruit consumed, depending on local conditions and cold-chain management. Stage-specific interventions, such as reducing field heat prior to forced-air cooling or increasing shipping temperatures from −1 °C to 1–3 °C under validated phytosanitary conditions, can meaningfully lower impacts. This dynamic framework offers a more realistic basis for identifying and achieving feasible decarbonization in global fruit supply systems.