Trend and inequality in livestock CO2 emission intensity: Evidence from 341 prefecture-level cities from 2006 to 2022 in China

Abstract

As global warming intensifies, the livestock sector—a major source of carbon emission in agriculture—has gained growing attention on fair and green mitigation. However, existing studies have rarely focused on the spatiotemporal evolution of CO₂ emission intensity (CEI) and its inequality drivers. This study conducted a more detailed analysis at the prefecture-level city scale. Specifically, we estimated livestock CO₂ emission (CE) across 341 prefecture-level cities in China from 2006 to 2022. Using the standard deviation ellipse and spatial autocorrelation models, we analyzed the spatiotemporal distribution of CEI and further applied the Theil index and Shapley decomposition method to evaluate CEI inequality and its influencing factors. The results revealed that: (1) Enteric fermentation constituted the primary source of CE at 61.41 %, with cattle contributing the largest proportion (56.47 %), followed by pigs (23.43 %) and sheep/goats (16.09 %) (2) From 2006 to 2022, CEI declined from 3.09 t/10⁴ yuan to 1.39 t/10⁴ yuan, with an average annual decline of 5.1 %. (3) Low CEI values were concentrated in economically developed regions east of the Hu Line (a population density demarcation), while high CEI values were clustered in the west. The center of CEI shifted from southwest to northwest. (4) The Theil index showed a marked increase from 0.535 to 0.651, primarily driven by intra-regional inequality. Ruminant CO₂ emission was the dominant contributor to CEI inequality (67.6 %), while environmental regulations had the greatest impact in the northwest and southwest regions. These findings provide insights for strengthening regional coordination and promoting carbon justice.