Global Land-Use Change, Biomass and Greenhouse Gas Emissions for Producing Plant- and Animal-based Human Food

Abstract:

Production and consumption of human food contribute greatly to greenhouse gas (GHG) emissions (e.g., CO₂, CH₄, and N₂O) and land-use change. However, the contributions of plant- and animal-based human food to global land-use change, biomass harvest, and GHG emissions have not been systematically examined. We use a model-data integration approach to estimate spatially explicit land-use change, biomass harvest, and GHG emissions from the worldwide plant- and animal-based human food production and consumption in circa 2010 (mean of 2007-2013) comprehensively for the first time. We establish a "cradle-to-dining table" life-cycle assessment framework, which includes the results of a land surface model, Integrated Science Assessment Model (ISAM), and other GHG emissions entering in the final consumption of food (such as emissions from fertilizer manufacturing). ISAM model is used to simulate biomass production and GHG emissions from farmland activities and land-use change caused by plant- and animal-based food production. Our framework accounts for 171 crops, pasture, and 16 livestock products at a 0.5 x 0.5 degree spatial resolution in circa 2010. The results show that global consumption-based food-related GHG emissions are about 16,640 Tg CO₂ eq/yr, accounting for 34% of total anthropogenic GHG emissions in circa 2010, with 9% from plant-based food, 21% from animal-based food (including feed emissions), and 4% from other non-food utilization (such as fiber). The food-related CO₂, CH₄ and N₂O emissions account for 20%, 11%, and 3% of total anthropogenic GHG emissions. Rice and beef have the largest contribution to GHG emissions from biomass consumed by plant- and animal-based human food, respectively. Hotspot regions of food-related consumption emissions include South and Southeast Asia, South America, and China. About 9‒12% of food-related GHG emissions have been transferred from producers to consumers through the trade of plant- and animal-based food. Globally, we have estimated the conversion efficiencies from biomass feed to livestock products are 5.2% based on biomass, 8.3% based on calorie, and 8.5% based on protein.