Global Food-Driven Greenhouse Gas Emissions Are Highly Unequal across Income Groups

While food systems drive ∼30% of global annual total greenhouse gas (GHG) emissions, the quantitative relationship between income inequality and food system emissions remains poorly characterized. Our research addresses this gap by quantifying disparities in per-capita food GHG emissions by income tier over three decades (1990-2020). Combining multiregional input-output modeling with life-cycle assessments, we reveal an unprecedented disparity: the top 10% of earners emit 21 times more (10.49 tCO₂e yr^-1) and the top 1% a staggering 73 times more (36.85 tCO₂e yr^-1) than the bottom 50% (0.50 tCO₂e yr^-1). Crucially, we demonstrate that current emission trajectories are incompatible with the 1.5 °C climate target (0.81 tCO₂e capita^-1 for food systems), necessitating reductions of 86-95% for the top 10% and 38-83% for the middle 40%, while the poorest half already align with this target in many regions. Our novel quantification of this "emissions divide" challenges conventional climate policies focused solely on production-side reforms, instead of spotlighting overconsumption by wealthy individuals as a critical yet overlooked leverage point. This work redefines equitable climate action by establishing that fairness in food-system decarbonization requires targeting high emitters─a transformative insight highlighting the need for differentiated mitigation strategies to simultaneously reduce emissions and ensure global nutrition security within planetary boundaries.