Major Sources of Methane Emissions
Context:
With the world on track to warm above 2°C, curbing methane is seen as a critical quick win due to its high Global Warming Potential with 28–86 times that of CO2.
Methane from Paddy Cultivation:
Traditional rice farming involves continuous flooding (maintaining 4-5 cm water depth) to suppress weeds.
This creates an anaerobic (oxygen-free) environment where methanogenic microbes decompose organic matter, releasing methane
Mitigation:
Alternate Wetting and Drying (AWD)
It is a technique that involves periodically drying fields (for 12 days) to disrupt these microbes.
Studies show this reduces methane emissions by ~40% and water use by ~30% without reducing grain yield.
Other Sources of Methane:
Enteric Fermentation (Livestock Sector):
This is the largest agricultural source
Cattle and other ruminants produce methane during digestion.
Manure management also contributes significantly
Fossil Fuels:
It accounts for ~35% of anthropogenic emissions.
Sources include venting (deliberate release) and fugitive emissions (leaks) during oil/gas extraction and coal mining.
Waste Sector:
Landfills and sewage treatment plants generate methane through anaerobic bacterial activity in oxygen-deficit environments
Natural Sources:
Wetlands are a major natural source.
Thawing of Permafrost threatens to release vast stored carbon reserves as methane.