Impact of healthy diet shifts on soil greenhouse gas emissions across Europe

Shifting towards healthy, plant-based diets is widely recognized as a strategy to reduce greenhouse gas emissions (GHG) from food systems, primarily through reduced methane emissions from livestock. However, the implications of this transition for soil-based GHG emissions, a major contributor to climate change, remain uncertain. We used the MAGNET economic model and the DayCent biogeochemical model to assess the impacts of dietary shifts aligned with the EAT-Lancet guidelines on soil organic carbon (SOC), nitrous oxide (N2O) emissions, and the overall soil GHG balance across the European Union and the United Kingdom. Adopting the EAT-Lancet diet reduced livestock production, organic carbon (C) and organic nitrogen (N) inputs from manure, and permanent grassland areas for agricultural use. This results in potential SOC losses of up to 50 Mg C ha-1 in livestock-intensive regions by 2100. However, afforestation of land released from production could compensate for most of the soil C losses. When above-ground biomass from afforestation is factored in, this could yield an additional 65 Mg C ha-1 of C sequestration, resulting in net savings in CO2 at the European scale. N2O emissions exhibited more moderate changes, with slight increases in the same regions resulting from intensified cropping systems and increased synthetic N inputs. These changes were driven by variability in agricultural intensity, soil types, and, to a lesser degree, climatic zones. This study’s findings underscore the importance of dietary changes in tackling climate change. However, practitioners and policymakers should consider potential soil-related trade-offs carefully and implement appropriate countermeasures to gain the full co-benefits of more sustainable diets.