Agricultural production is closely linked to environmental pressures, and dietary transition is increasingly recognised as a lever for cleaner and more sustainable food systems. This paper examines how alternative diet scenarios in the United Kingdom (UK) interact with international trade to shape market and environmental outcomes. The contribution is novel in explicitly comparing unilateral and coordinated diet change across trading partners, and in jointly assessing impacts on prices, production, trade flows, greenhouse gas emissions, and soil nutrient balances. A series of counterfactual scenarios is simulated using a partial equilibrium commodity market model for the UK and the European Union (EU). Results indicate that the more globally integrated crop markets exhibit minimal price and production responses, particularly when diet change is confined to the UK, while livestock markets respond more strongly, especially under coordinated UK–EU transitions. International trade plays a critical mediating role, generating both benefits and trade-offs for cleaner production depending on the geographic scale of diet change. Reductions in red meat and dairy consumption lower climate and water quality pressures overall, even where pig and poultry consumption increases, reflecting higher feed efficiency. However, substitution towards monogastric livestock may create localized air and water quality risks depending on the spatial distribution of production. Greenhouse gas emissions attributed to the UK decline by substantially less than per capita consumption, underscoring the importance of aligning dietary transition with trade and production systems to realise cleaner production outcomes. • A commodity market model simulates diet change varying pattern and geographical scope. • Agriculture source emissions are strongly linked to relative prices and arbitrage opportunities. • Use emissions are sensitive to the emissions-intensity of international supply chains. • Soil nutrient imbalances improve but localized risks to water could rise. • Common trends in dietary preferences amongst trade partners increase the environmental benefits.
Sherry et al. (Fri,) studied this question.