<p>Food loss and waste (FLW) generates ~19% of global anthropogenic greenhouse gas emissions, yet its determinants and mitigation potential remain insufficiently understood. To address this, we develop a mechanistic framework that disaggregates FLW emissions into those driven by techno-economic constraints, surplus production and mis-consumption, with the latter two constituting misbehaviour-driven emissions. We show that global misbehaviour-driven emissions amounted to 4.0 Gt of CO₂-equivalent emissions in 2021, representing 59% of total FLW emissions, with meat consumption and structural surplus contributing 50% and 15%, respectively. We further quantify country-level FLW emission reduction potentials through behavioural, technological and dietary pathways, finding that behavioural controls provide the greatest reduction potentials globally. However, any single intervention is insufficient to achieve Sustainable Development Goal 12.3 of halving FLW emissions, underscoring the need for integrated strategies. Sub-Saharan Africa is projected to be the largest regional FLW emitter and account for 21% of global misbehaviour-driven emissions and 18% of global techno-economic-constraint-driven emissions by 2050.</p>