Optimizing dietary habits for climate benefits in China: Greenhouse gas emissions and sustainable substitution strategies

The transition in dietary patterns will impact future food consumption and greenhouse gas emissions (GHGs). In this study, we employed the Intergovernmental Panel on Climate Change (IPCC) coefficient method to evaluate the GHGs associated with dietary consumption across 31 provinces in China from 1978 to 2022. Additionally, we simulated the greenhouse gas emission reduction potential and the spatio-temporal changes under five food substitution scenarios for the period 2022–2050. The results indicated that GHGs from animal-based foods increased the most, rising from 1673.1 Mt. CO₂eq in 1978 to 6660.3 Mt. CO₂eq in 2022, with pork being the largest source of emissions, accounting for approximately 44 %. The grain-based food substitution scenario resulted in the lowest GHG emissions, about 533.88 Mt. CO₂eq. Conversely, the plant-based food substitution scenario had the highest emissions, reaching 635.49 Mt. CO₂eq. This study provides a benchmark for improving regional dietary structures and formulating policies aimed at reducing GHGs through dietary consumption.