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Methane (CH₄) is a powerful greenhouse gas with a global warming potential 28 times that of carbon dioxide (CO₂). CH₄ is responsible for approximately 20% of the Earth's warming since pre-industrial times. Knowledge of the sources of CH₄ is crucial due to the recent substantial interannual variability of growth rates and uncertainties regarding individual sources. The prevailing paradigm is that methanogenesis carried out by methanogenic archaea occurs primarily under strictly anaerobic conditions. However, in the past decade, studies have confirmed direct CH₄ release from three important kingdoms of eukaryotes—Plantae, Animalia and Fungi—even in the presence of oxygen. This novel CH₄ production pathway has been aptly termed “aerobic CH₄ production” to distinguish it from the well-known anaerobic CH₄ production pathway, which involves catalytic activity by methanogenic archaeal enzymes. In this …