Decomposition of factors affecting changes in non-CO greenhouse gas emission intensity of China's livestock sector based on the concept of "environment-food-economy".

The livestock sector is the main source of non-CO greenhouse gas (GHG) emissions in China. Decomposing the factors that influence non-CO GHG intensity in the livestock sector (LGI) serves as an important reference for the development of specific emission reduction policies. However, the difficulty lies in how to consider the relationship between emission reductions and the human food supply and economic development. In this study, a decomposition framework for the LGI in China was constructed from the concept of "environment-food-economy." The influencing factors that drove changes in LGI were interpreted at the environmental level, economic level, and scale level. Additionally, the logarithmic mean Divisia index (LMDI) method was used to quantify the contributions of these three drivers in 31 provinces across China from 1998 to 2016. The results showed that: (1) the LGI of China decreased by 80.02% during the study period. This decrease was mainly driven by the environmental and economic level factors of each province with a respective cumulative contribution of 51.96% and 34.10%. However, the scale-level factor of each province cumulatively suppressed the LGI drop by 6.04% in China. (2) For the contribution of the environmental-level factor, the top five provinces were Henan, Yunnan, Inner Mongolia, Guangxi, and Shandong. The top five provinces for the economic-level factor contribution were Henan, Sichuan, Shandong, Hebei, and Heilongjiang. (3) Under the concept of the livestock sector "environment-food-economy", improving the environmental and economic levels of the livestock sector in each province, and narrowing its inter-provincial gaps are two feasible ways that can be used to reduce China's LGI. Our research methodology is applicable to studies on the reduction of LGI in regions of different scales.