Exploring sustainable food system transformation options in China: An integrated environmental-economic modelling approach based on the applied general equilibrium framework

Our food system drives global environmental change, and differences in environmental concerns of consumers may cause negative environmental ‘spillover effects’ in less concerned countries. While food system transformation is increasingly recognised as crucial for mitigating such negative environmental spillovers, possible unintended negative environmental consequences in other regions and/or economic sectors have received less attention. Using an integrated environmental-economic modelling framework and scenario analyses, we explored options for more sustainable food systems and to mitigate the negative environmental spillovers from trading partners to China. We found that doubling novel soy-based food (soy-based meat) consumption while reducing pork consumption in China decreased Chinese economy-wide emissions of greenhouse gases (GHGs) by 1 % and acidification pollutants by 3 %. However, it increased Chinese economy-wide emissions of eutrophication pollutants by 2 %, driven by the increased production of soy-based food and other food with relatively high emission intensities of eutrophication pollutants. Combining a dietary shift with the adoption of cleaner cereals production technology for half of the current resources used for cereals production decreased Chinese economy-wide emissions of GHGs by 1 %, acidification pollutants by 7 %, and eutrophication pollutants by 3 %, but required capital reallocation from other sectors. Implementing a unilateral environmental policy in China (i.e., implementing incentive-based emission permits to reduce emissions of all pollutants by 3 % annually) increased economy-wide emissions of GHGs in trading partners by 2 %. This ‘carbon leakage’ emerges due to the shift of production of products with relatively high emission intensities (i.e., nitrogen fertiliser and livestock) from China to its trading partners through international trade. We demonstrate that indirect environmental impacts are crucial to consider when analysing the economy-wide consequences of food system transformations, as these indirect impacts may inadvertently affect other regions and/or economic sectors that were not initially targeted. Our study offers policymakers insights into designing effective policies for more sustainable food systems and sheds light on trade-offs among competing environmental and economic goals.