Consumption-based GHG footprint of global food systems (2000–2020)

Food consumption drives environmental pressures by shaping global agricultural production systems and international trade patterns. A growing body of literature has quantified consumption-based food footprints by reallocating production-based pressures, such as greenhouse gas (GHG) emissions, land use, and nitrogen application, to final consumers, highlighting the role of global demand in shaping agricultural impacts beyond national borders (Hertwich & Peters, 2009; Weinzettel et al., 2013; Henders et al., 2015; Oita et al., 2016).  However, existing approaches differ in their treatment of GHG emission sources, spatial characterization of production systems, and temporal consistency, often addressing individual pressures in isolation. Developing harmonized frameworks that consistently integrate multiple agricultural GHG emission sources and link them to food consumption through trade is therefore essential for fully assessing the sustainability of the agri-food system. Here we quantify the carbon footprint of food consumption by combining spatially-explicit (5-arc-minute resolution) agricultural GHG emission sources -including land-use change building on prior work by the authors, farm-level production processes (synthetic fertilizer and manure application, peatland drainage, and rice paddy methane), and transport- for 24 crop types with international trade data (FAOSTAT). We also quantify livestock-related emissions derived from feed production (crops and grass) and reallocate these to consumption via trade. Both results are reported at the global scale across four reference years between 2000 and 2020. By reallocating production-based emissions to final consumers through a consumption-based framework, we link global food demand to the geographic origin of agricultural GHG emissions, thereby enabling an analysis of spatial patterns and temporal trends of the carbon footprint of food demand worldwide.