Methane Emissions from Waste in India

Context

Recent satellite-based observations suggest that methane emissions from Waste in India are significantly under-estimated in official inventories. At several major landfill sites, actual emissions are found to be many times higher than model-based estimates, raising concerns for climate action and waste management policy.

What is Methane and Why Does It Matter?

• Methane (CH₄) is a greenhouse gas released during the decomposition of organic matter in oxygen-poor conditions, such as landfills.
• Key features:
  • It is 84 times more potent than carbon dioxide over a 20-year period.
  • It contributes to landfill fires, air pollution, and climate change.
  • It can also be captured and used as fuel for cooking, vehicles, and power generation.
• In India:
  • About 15% of methane emissions come from the waste sector.
  • Unlike agriculture or energy, waste-sector methane can be reduced quickly through targeted interventions.

Why Waste-Sector Methane Is a Key Opportunity for India?

1. Waste management offers immediate climate gains, unlike long-term energy transitions.
2. National frameworks like the Swachh Bharat Mission already exist.
3. Reducing landfill methane improves urban safety, public health, and climate outcomes.
4. However, effective action requires accurate identification of emission hotspots.

How Methane Emissions Are Traditionally Estimated?

• Historically, India has relied on model-based estimates, which:
  • Use incoming waste volumes
  • Apply standard emission factors
  • Depend on aggregated, infrequently updated data
• Limitations:
  • Lack of granular, site-specific information
  • Difficulty in identifying individual high-emission landfills
  • Especially unreliable in developing country contexts
• Ground-based monitoring is also difficult due to:
  • High costs
  • Maintenance requirements
  • Limited scalability in large cities

How Satellite Monitoring Changes the Picture?

• Advances in satellite technology now allow direct observation of methane emissions.
• Two types of satellite data:
  • Regional monitoring: Tracks broad trends over large areas
  • High-resolution monitoring: Pinpoints emission hotspots down to specific landfill sites
• India’s progress:
  • ISRO-led research (2023 data) mapped anthropogenic methane emissions
  • Identified major landfill hotspots in Ahmedabad, Mumbai, and Delhi
  • Findings triggered National Green Tribunal (NGT) action for ground verification
• Global platforms such as ClimateTRACE and WasteMAP combine satellite data with traditional models to improve accuracy.

What the New Data Reveal (Key Discrepancies)

• Satellite observations show that:
  • Actual landfill methane emissions can be 8 times higher globally than model estimates
  • In India, discrepancies are even sharper due to outdated State-level data (mostly from 2018)
• Illustrative patterns:
  • In some cities, one or two landfills emit almost as much methane as the entire city’s estimated waste sector
  • Engineered landfills assumed to be efficient are sometimes emitting far more than expected
  • This suggests leakages, system failures, or faster methane generation
• These gaps indicate that India does not yet know the true scale or location of its methane problem.

Why Are These Findings Important?

• Hidden methane emissions mean missed climate mitigation opportunities.
• Policies may target the wrong sites or underestimate urgency.
• Without accurate data, hazards remain unaddressed simply because they are invisible.
• Satellite data now makes it possible to:
  • Measure the true magnitude of emissions
  • Identify exact leakage points
  • Design targeted, cost-effective solutions

How Satellite and Ground Action Must Work Together?

• Satellite data alone is not sufficient due to:
  • Cloud cover
  • Weather interference
  • Urban complexity
• The solution lies in a feedback loop:
  • Satellites detect methane hotspots
  • Ground teams investigate causes (poor waste cover, gas system failure, illegal dumping)
  • Ground data improves satellite accuracy
  • Refined data guides further action
• Different landfill types need different data:
  • Open dumps: Track dumping and reclamation patterns
  • Engineered landfills: Assess gas collection infrastructure
• Cities with advanced waste systems, like Bengaluru, can integrate these datasets effectively.

Institutional and Policy Integration Needed

• Current challenges:
  • Urban Local Bodies (ULBs) and State Pollution Control Boards work in silos
  • Lack of standardised national data-sharing systems
• Opportunities:
  • Revised municipal waste rules already propose a centralised data portal
  • This can be expanded for methane tracking
  • Bodies like CAQM (NCR) can oversee regional monitoring
  • Swachh Bharat Mission can integrate methane reduction targets
  • Schemes like GOBARdhan show methane’s potential as an energy resource (e.g., Bio-CNG plants)

Implications

1. Stronger alignment with India’s climate commitments
2. Improved urban safety and air quality
3. Better utilisation of methane as a clean energy resource
4. Data-driven governance replacing assumptions
5. Faster, cheaper climate mitigation compared to energy-sector reforms

Challenges and Way Forward

Conclusion

Methane from waste is one of India’s most underestimated climate challenges. By combining satellite monitoring with ground-level action and institutional coordination, India can turn invisible emissions into measurable, manageable, and economically useful climate solutions.