Global methane emissions from rice paddies: CH4MOD model development and application

Qiwen Hu; Jingxian Li; Hanzhi Xie; Yao Huang; Josep G Canadell; Wenping Yuan; Jinyang Wang; Wen Zhang; Lijun Yu; Shihua Li; Xinqing Lu; Tingting Li; Zhangcai Qin

doi:10.1016/j.isci.2024.111237

Global methane emissions from rice paddies: CH4MOD model development and application

iScience. 2024 Oct 23;27(11):111237. doi: 10.1016/j.isci.2024.111237. eCollection 2024 Nov 15.

Authors

Qiwen Hu^{1

2

3

4}, Jingxian Li¹, Hanzhi Xie¹, Yao Huang^{5

6}, Josep G Canadell⁷, Wenping Yuan^{3

4

8}, Jinyang Wang^{9

10}, Wen Zhang⁶, Lijun Yu⁶, Shihua Li¹, Xinqing Lu¹, Tingting Li^{2

3

4}, Zhangcai Qin^{1

3

4}

Affiliations

¹ School of Atmospheric Sciences, Guangdong Province Data Center of Terrestrial and Marine Ecosystems Carbon Neutrality, Sun Yat-sen University, and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China.
² Key Laboratory of Atmospheric Environment and Extreme Meteorology, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
³ International Research Center of Big Data for Sustainable Development Goals, Beijing 100094, China.
⁴ Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China.
⁵ State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
⁶ LAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
⁷ Global Carbon Project, CSIRO Oceans and Atmosphere, Canberra, ACT 2601, Australia.
⁸ Institute of Carbon Neutrality, Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
⁹ Key Laboratory of Green and Low-carbon Agriculture in Southeastern China, Ministry of Agriculture and Rural Affairs, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China.
¹⁰ Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing, China.

Abstract

Rice cultivation constitutes a significant anthropogenic methane (CH₄) source and a crucial target for CH₄ mitigation. However, global and regional emissions remain poorly constrained. In this study, we validated a global-process-based methane model for rice paddies (CH4MOD), analyzed the sensitivity of major emission drivers, and simulated management scenarios involving four water regimes and three organic matter amendments. CH4MOD simulations achieved a correlation coefficient of 0.76 across 986 CH₄ flux observations globally, demonstrating its capability under different environmental conditions and management practices. The sensitivity analysis revealed water regime as the primary driver, followed by organic matter amendment and temperature. Under different crop management, CH₄ emissions varied significantly from 8 to 78 Tg CH₄/yr. This wide range of emissions demonstrates the need to use and improve rice-specific emission models and spatiotemporal data on rice distribution, water, and residue management for accurately assessing local to global emissions and their climate mitigation potential.

Keywords: earth sciences; methods in earth sciences; natural sciences.