Unlocking the potential of global greenhouse gas mitigation by reducing food loss and waste

Food loss and waste (FLW) are significant yet under-addressed contributors to global greenhouse gas (GHG) emissions, and the effectiveness of current FLW mitigation policies and valorization technologies remains insufficiently explored. This study aims to fill this gap by quantifying global FLW-related GHG emissions across four major commodity groups—(1) cereals and pulses, (2) fruits and vegetables, (3) meat and animal products, and (4) roots, tubers, and oil-bearing crops—using region-specific emission factors and supply chain data. Furthermore, it evaluates the potential for life-cycle GHG reductions by implementing achievable policy measures and food waste valorization strategies on a global scale. FLW contributes significantly to global GHG emissions, estimated at 6.8 Gt-CO₂eq per year (95 % CI = [6.5, 7.1]; p < 0.05). A substantial portion of GHG emissions occurs earlier in the supply chain, particularly during agricultural production and post-harvest handling due to infrastructure and technological limitations. Reducing 50 % food waste at retail and consumer levels could result in a ∼21 % decrease in the total FLW-related GHG emissions (i.e., 1.4 Gt-CO₂eq (95 % CI = [1.0, 1.9]; p < 0.05) for the four major commodity groups. However, reducing 50 % FLW at all levels together with food waste valorization using anaerobic digestion can achieve a ∼70 % reduction (4.8 Gt-CO₂eq per year; 95 % CI = [4.2, 5.3]; p < 0.05) in the total FLW-related GHG emissions. These findings highlight the importance of targeted, integrated strategies—including improved cold storage, sustainable procurement, and circular economy practices—for achieving meaningful emission reductions. While significant mitigation is possible, realizing these benefits will require coordinated global action and context-specific implementation. Our study provides a quantitative foundation for prioritizing interventions in FLW management to support climate goals and enhance food system sustainability.