Name the gas released from landfills, decaying organic matter under shallow water in marshes, flooded paddy fields, by ruminant animals & termites, and by the burning of biomass. A molecule of this gas has 21 times more global warming potential than a molecule of CO2.

Methane (CH4) is produced in all the listed sources: landfills, anaerobic decomposition in marshes and paddy fields, by ruminant animals during digestion, and by termites. It is also released during biomass burning. Methane has 21-25 times more global warming potential than CO2 over 100 years, making it a potent greenhouse gas.