Consider the following: 1. Rice fields 2. Coal mining 3. Domestic animals 4. Wetlands Which of the above are sources of methane, a major greenhouse gas?

1. Methane (CH4) is a potent greenhouse gas. 2. Rice fields: Anaerobic decomposition of organic matter in flooded rice paddies is a significant anthropogenic source of methane. 3. Coal mining: Methane trapped in coal seams is released during mining operations. 4. Domestic animals: Enteric fermentation (digestion) in ruminant livestock like cattle and sheep, as well as manure management, produces substantial amounts of methane. 5. Wetlands: Natural wetlands are the largest natural source of methane globally, produced by anaerobic decomposition. 6. All four listed (Rice fields, Coal mining, Domestic animals, Wetlands) are recognized sources of methane.