Flexible animal-sourced food consumption varies environmental outcomes across different country groupings

Abstract

Shifting towards the planetary health diet (PHD) as defined by the EAT-Lancet 2.0 Commission provides a key opportunity to spare land for nature, offering co-benefits for climate and biodiversity. However, the implications of flexibility through suggested intake ranges for animal-sourced foods (ASF) across countries remain unclear. Using spatially explicit, multi-regional input-output modelling, we explore the impacts of ASF flexibility within the PHD on land use, carbon sequestration, and biodiversity loss across high-income countries (HICs) and upper-middle-income countries (UMICs). We outline the plausible impact space with three diets: Low ASF, Moderate ASF, and Zero ASF, whose ASF intakes align with the mid-point (the reference diet), upper bound, and lower bound of the recommended levels. We show that, Low ASF diets spare half of the land currently used, Zero ASF 80%, and Moderate ASF 17%. Low ASF intake yields carbon sequestration opportunities of 53 PgC and a species extinction risk reduction of 2%, with greater benefits under Zero ASF (93 PgC; 4%) and limited benefits under Moderate ASF (9 PgC; 0·4%). Across scenarios, global gains are achieved with trade-offs in vulnerable regions, and UMICs show greater sensitivity and variability in land responses to ASF flexibility than HICs. Due to higher baseline ASF consumption in HICs, similar reduction levels in carbon and biodiversity loss are observed when HICs adopt a Moderate ASF diet and UMICs shift to a Low ASF diet. These findings support differentiated dietary targets, with deeper ASF reductions required in HICs than in UMICs to unlock land, carbon and biodiversity benefits.