Mitigation potential of methane emissions in China's livestock sector can reach one-third by 2030 at low cost.

The mitigation of methane (CH 4 ) emissions from livestock production is crucial to China's carbon neutrality. Here we established a high-spatiotemporal-resolution dataset of the country's livestock CH 4 emissions from 1990 to 2020 using four large-scale national livestock greenhouse gas inventory surveys. We estimate CH 4 emissions to be 14.1 ± 2.0 Mt in 2020 and to increase by 13% until 2030 despite CH 4 intensity per kg animal protein having decreased by 55% in the past 30 years. Approximately half of the emissions come from 13% of all Chinese counties. The technical CH 4 mitigation potential is projected to be 36 ± 8% (4.4-6.9 Mt CH 4 ) in 2030, and reducing food loss and waste could mitigate an additional 1.6 Mt of CH 4 . Overall, most CH 4 mitigation could be achieved by increasing animal productivity and coverage of lagoon storage at carbon prices below US$100 tCO 2 e -1 , being more cost-effective than livestock nitrous oxide mitigation in China.