A comparative study on carbon footprints between plant- and animal-based foods in China

Abstract

Agriculture supplies human with foods, and were considered as a crucial source of artificial greenhouse gas (GHG) emissions. Life-cycle carbon footprint (CF) could represent the comprehensive GHG emissions from foods, and attracted attentions from researchers. Previous studies had evaluated the CFs of quite a few foods including both plant- and animal-based products. However, the huge differences from system boundary definition, emission factors limited the comparability of the reported CF results. A few studies had tried to evaluate and compare the CFs of some plant products or animal products. However, the CF comparisons between plant- and animal-based foods were rarely reported. Here we used a consistent methodology, including unique life cycle definitions, identical data sources, and same byproducts allocation method to calculate CFs of 22 plant-based foods and 6 animal-based foods, as well as some processed foods. The results showed that the animal-based foods had greater CFs than the plant-based foods in general. Beef and mutton emitted more GHGs than the other foods, and the lowest CF was observed in the radish production. Manufacturing and field emissions were major parts of the CFs for the plant-based foods. The CF compositions varied in different animal-based foods. Daily dietary GHG emission of Chinese was 0.84 kg CO2/capita. China had emitted more than 427.64 Tg CO2 from dietary in 2013. Through measuring the impact of different foods on global warming, and quantifying the CF differences of various foods, this study can help to improve the comparability of the CF between plant- and animal-based foods. The results offered an instruction for GHG mitigation through choosing foods with lower CFs. The methodology developed in this study can also be used as a reference for the CF comparisons among different products.