Environmental footprints of food systems in China

In his thesis, Junjie Yi assesses the environmental sustainability of China’s food systems, examining the interconnections between food production, consumption, and environmental footprints. His findings are relevant worldwide, with recommendations that can improve water quality and minimize the ecological footprint of agriculture. Yi evaluated land, water, and carbon footprints, alongside agricultural water pollution caused by fertilizers and pesticides. 

Yi emphasizes the need to assess dairy production systems and food consumption’s impact on water quality. He compared water (WF), land (LF), and carbon footprints (CF) of six dairy systems, showing industrial systems' dominance and reliance on irrigation. Future projections suggest that if milk consumption aligns with dietary recommendations, WFs, LFs, and CFs in China could increase four to six times by 2035. 

Yi furthermore highlights agricultural water pollution, with grey WFs from pesticides dominating total agricultural WFs. Five provinces in China contribute 37% of pollution, and eliminating a few highly polluting pesticides could reduce water pollution by 64%. Yi furthermore explores the spatial-temporal dynamics of pesticide pollution, showing seasonal variations and hotspot regions. Replacing the most polluting pesticides could cut grey WFs by 20–90%. 

Finally, Yi examined food consumption patterns and their impact on water pollution. Livestock-based diets have the highest grey WFs, with pork and beef making up 57% of the total. Shifting to plant-based diets could reduce grey WFs by up to 74%. Summarizing his findings, Yi advocates for reducing polluting pesticides and promoting sustainable diets.

Dissertation: https://hdl.handle.net/11370/254e1c97-52b6-40aa-9ce9-2a943377a123