Which one among the following is a source of methane emission into the atmosphere ?

Methane (CH4) is a potent greenhouse gas emitted from both natural and anthropogenic sources. Wetlands are the single largest natural source of methane globally, contributing approximately 30% of total emissions [3]. In these environments, methane is produced by anaerobic bacteria during the decomposition of organic matter in waterlogged soils where oxygen is absent [2]. While human activities like coal mining [1], livestock farming [2], and leaks from natural gas systems [3] are significant contributors, wetlands remain the primary natural reservoir. Although incomplete combustion in automobiles and industrial processes can release trace amounts of methane, they are not categorized as primary sources compared to the massive biogenic output of wetlands. Scientific assessments highlight that wetland emissions are highly sensitive to temperature and moisture changes, making them a critical component of the global methane budget [3].

Sources

1. [1] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 17: Climate Change > 17,3.3. Methane > p. 256
2. [3] https://svs.gsfc.nasa.gov/4799
3. [2] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 7: Climate Change > 2. greenhouse gases > p. 11