Cradle-to-grave emissions from food loss and waste represent half of total greenhouse gas emissions from food systems.

Global greenhouse gas (GHG) emissions from food loss and waste (FLW) are not well characterized from cradle to grave. Here GHG emissions due to FLW in supply chain and waste management systems are quantified, followed by an assessment of the GHG emission reductions that could be achieved by policy and technological interventions. Global FLW emitted 9.3 Gt of CO 2 equivalent from the supply chain and waste management systems in 2017, which accounted for about half of the global annual GHG emissions from the whole food system. The sources of FLW emissions are widely distributed across nine post-farming stages and vary according to country, region and food category. Income level, technology availability and prevailing dietary pattern also affect the country and regional FLW emissions. Halving FLW generation, halving meat consumption and enhancing FLW management technologies are the strategies we assess for FLW emission reductions. The region-specific and food-category-specific outcomes and the trade-off in emission reductions between supply chain and waste management are elucidated. These insights may help decision makers localize and optimize intervention strategies for sustainable FLW management.