This paper estimates the total greenhouse gas emissions (CO2, CH4 and N2O) of the global food system and breaks them down into those from plant-based and animal-based foods. It finds that, in 2010, 57% of food system GHG emissions was from the production of animal-based foods, including from livestock feed, 29% was from plant-based foods, and 14% was from other sources (biomass used for purposes other than feed or food).
The total food-related emissions reported by the paper are 17,318 TgCO2eq yr−1. As shown in the figure below, the single commodity responsible for the highest overall emissions is beef, which accounts for 25% of total food emissions. Rice is the plant-based food with the highest emissions, accounting for 12% of total food emissions.
Image: Figure 3, Xu et al. GHG emissions from the productions of top-contributing commodities. a, Top ten plant-based food commodities. b, Top ten animal-based food commodities.
The warming impacts of the three different greenhouse gases are compared on the basis of their 100-year global warming potentials, i.e. GWP100. For more on the different ways of measuring the climate impacts of short-lived greenhouse gases such as methane, see the TABLE explainers Agricultural methane and its role as a greenhouse gas and Methane and the sustainability of ruminant livestock.
Agriculture and land use are major sources of greenhouse gas (GHG) emissions but previous estimates were either highly aggregate or provided spatial details for subsectors obtained via different methodologies. Using a model–data integration approach that ensures full consistency between subsectors, we provide spatially explicit estimates of production- and consumption-based GHG emissions worldwide from plant- and animal-based human food in circa 2010. Global GHG emissions from the production of food were found to be 17,318 ± 1,675 TgCO2eq yr−1, of which 57% corresponds to the production of animal-based food (including livestock feed), 29% to plant-based foods and 14% to other utilisations. Farmland management and land-use change represented major shares of total emissions (38% and 29%, respectively), whereas rice and beef were the largest contributing plant- and animal-based commodities (12% and 25%, respectively), and South and Southeast Asia and South America were the largest emitters of production-based GHGs.
Xu, X., Sharma, P., Shu, S., Lin, T.S., Ciais, P., Tubiello, F.N., Smith, P., Campbell, N. and Jain, A.K., 2021. Global greenhouse gas emissions from animal-based foods are twice those of plant-based foods. Nature Food, pp.1-9.