Which of the following gases is released from rice fields in the most prominent quantities ?

Rice fields are a significant source of methane (CH4) emissions, primarily due to the anaerobic conditions created by continuous flooding. In these submerged environments, methanogenic bacteria decompose organic matter in the absence of oxygen, releasing methane as a byproduct [c1, t4]. Research indicates that rice paddies contribute approximately 10% to 12% of global methane emissions and account for nearly 48% of greenhouse gas emissions from agricultural land [t1, t4, t8]. While rice cultivation also involves minor emissions of nitrous oxide (from fertilizers) and carbon dioxide (from residue burning), methane is the most prominent gas released directly from the flooded soil during the growing process [t2, t5]. This makes rice paddies the leading agricultural source of methane after livestock operations [t3, t5].

Sources

1. [1] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 7: Climate Change > 2. greenhouse gases > p. 11
2. [2] https://www.sciencedirect.com/science/article/abs/pii/S0167880924001737
3. [3] https://blogs.worldbank.org/en/eastasiapacific/greening-rice-we-eat
4. [4] https://www.cbo.gov/system/files/2025-08/61467-ghg-agriculture.pdf