Pathways towards climate and health co-benefits in global ruminant sector

The global ruminant sector is a major source of greenhouse gas (GHG) emissions and a key provider of human nutrition. Yet, reconciling its environmental impacts with nutritional needs remains a critical challenge. Here, we first present a comprehensive, system-level global assessment of GHG emissions from the ruminant sector. We estimate that about 1,060 Gt CO2-eq or 0.3 °C of warming has been caused globally between 1961 and 2019. Contrary to previously assumed, land-based emissions resulting from livestock grazing and deforestation are the main contributor, particularly in tropical regions. Without intervention, ruminant-related emissions are projected to triple by 2100. We find that while a shift towards more plant-based diets could yield substantial climate benefits, these are limited by potential health trade-offs. A synergistic strategy combining demand- and supply-side measures could reduce ruminant emissions by up to 91% by 2100 while meeting the nutritional requirements of a healthy diet, together leading to a 6.5% increase in global gross domestic product. Under this scenario, 71% of countries could achieve neutral or negative ruminant GHG emissions by 2100, though optimal strategies vary: tropical countries should prioritize land-based interventions, whereas others may benefit more from demand-side measures. Our findings call for a rapid, integrated transformation of the ruminant sector to alleviate the dual burden of meeting national climate and nutrition targets.