LAUSR

Abstract Animal husbandry is a major source of global greenhouse gas emissions. To address this problem, the low-carbon characteristics of the circular economy provide a theoretical basis for reducing carbon emissions in this sector. Using a life cycle assessment approach, in the present study, we compared the differences in traditional and biogas-based circular economic models of pig farming by analyzing the carbon footprint inventories. Based on the carbon emission reduction in the circular economic model, we estimated the environmental and economic benefits under carbon trading. Using pig farming in Liaoning Province, China, as an example, the circular economic model could effectively reduce the global warming potential of large-scale pig farming by 3,091,891.8 t carbon dioxide equivalents by diverting otherwise-heaped pig excrement for biogas generation. Under carbon trading, the reduction in carbon emissions under the circular model could generate an economic benefit of USD 30.92 million. Therefore, the carbon emission reductions of this model could have major environmental and economic benefits. Based on micro-parameters examined at the provincial scale in China, the findings of this analysis can serve as a reference for the formulation of government policies to realize global environmental benefits and develop a circular economy in livestock and poultry farming.