Methane Emissions

Methane is a crucial fuel widely used for domestic and industrial purposes. However, when released in an uncontrolled manner—especially from landfills—it becomes a serious environmental hazard. Recent satellite-based evidence indicates that methane emissions from Indian landfills are significantly higher than official estimates, posing challenges to India’s climate commitments, urban environmental quality, and public health.

Key Findings on Landfill Methane Emissions

• Satellite observations reveal substantial underestimation of methane emissions from Indian landfills, indicating a major data and monitoring gap.

• Methane is a short-lived but highly potent greenhouse gas, with a global warming potential (GWP) 84 times that of CO₂ over 20 years.

• The integration of satellite monitoring, ground-level validation, and targeted policy interventions enables accurate identification of methane hotspots and supports effective waste management and energy recovery strategies.

What is Methane?

Definition and Composition

Methane (CH₄) is a chemical compound composed of one carbon atom bonded to four hydrogen atoms. It is the simplest alkane and the primary constituent of natural gas.

Physical Properties

Methane is colourless, odourless, tasteless, and lighter than air. Under complete combustion, it burns with a blue flame, producing carbon dioxide (CO₂) and water (H₂O) in the presence of oxygen.

Applications

• Methane constitutes 80–95% of natural gas, making it a major source of energy for cooking, heating, and electricity generation.

• It is an important industrial feedstock used in the production of hydrogen, ammonia, methanol, and other chemicals.

Methane Emissions: India’s Status

India is the third-largest methane emitter globally, after China and the United States.

• India emits approximately 31 million tonnes of methane annually, accounting for about 9% of global methane emissions.

• According to India’s Third Biennial Update Report (2016) to the UNFCCC, methane emissions (excluding LULUCF) amounted to 409 million tonnes of CO₂ equivalent.

• The waste sector contributes nearly 15% of India’s total methane emissions, primarily from landfills and wastewater treatment systems.

Major Sources of Methane

Natural Sources

• Wetlands, where organic matter decomposes under anaerobic conditions.

Anthropogenic Sources

• Agriculture:

  • Flooded rice paddies, which create oxygen-deprived conditions.

  • Enteric fermentation in livestock, especially cattle.

• Energy and Industrial Activities:

  • Fossil fuel extraction, processing, transportation, and combustion.

  • Fertilizer production and other industrial processes.

• Waste Sector:

  • Landfills and wastewater treatment plants, where organic waste decomposes anaerobically.

• Biomass Burning:

  • Burning of crop residues, firewood, and other biomass.

Global Warming Potential of Methane

Methane is a highly effective greenhouse gas due to its ability to absorb infrared radiation.

• Over a 20-year time horizon, methane is approximately 84 times more potent than CO₂.

• Over a 100-year period, its warming potential is 28–34 times higher than CO₂.
  This makes methane mitigation a high-impact, short-term strategy for climate change control.

Methane Cycle

The methane cycle refers to the natural processes through which methane is produced, released, and removed from the environment.

• Methane is produced by microorganisms under anaerobic conditions in wetlands, rice fields, landfills, and the digestive systems of ruminants.

• It is released into the atmosphere through both natural processes and human activities.

• Methane is removed primarily through oxidation in the atmosphere by hydroxyl (OH) radicals, and to a lesser extent by soil microorganisms.

Initiatives to Reduce Methane Emissions

India’s Initiatives

• Harit Dhara initiative to reduce methane emissions from cattle.

• Implementation of BS-VI emission norms to curb vehicular and fuel-related emissions.

• National Action Plan on Climate Change (NAPCC), which indirectly addresses methane through sectoral missions.

Global Initiatives

• Satellite-Based Monitoring: Missions such as CarbonMapper’s Tanager detect methane super-emitters, including major landfill sites like Ghazipur and Okhla.

• Global Methane Pledge (GMP): Launched at COP26 (2021), it aims to reduce global methane emissions by at least 30% by 2030 compared to 2020 levels. (India is not a signatory.)

• Global Methane Tracker (IEA): Focuses on reducing methane emissions from the energy sector.

• UNEP Initiatives:

  • International Methane Emissions Observatory (IMEO)

  • Oil and Gas Methane Partnership (OGMP)

Conclusion

Methane emissions from landfills represent a significant yet under-addressed climate challenge for India. Strengthening satellite-based monitoring, improving waste segregation and landfill management, and promoting waste-to-energy solutions can help India achieve rapid climate benefits while enhancing urban environmental health and supporting sustainable development goals.