Context: NITI Aayog’s report “Scenarios Towards Viksit Bharat and Net Zero – Sectoral Insights: Waste” identifies the waste sector as a methane-intensive emissions source. Although it contributes a small share of India’s overall greenhouse gas emissions, its climate impact is significant due to methane’s high warming potential. The report outlines strategies to decarbonise waste systems and support India’s long-term Net Zero pathway.
Waste Sector Emissions Profile
The waste sector contributes only about 2.56% of India’s total GHG emissions, yet it remains disproportionately damaging because of methane dominance. Methane (CH₄) has a global warming potential nearly 25 times higher than CO₂, making its control crucial for near-term climate gains.
A key finding is that nearly 74% of waste-sector emissions originate from wastewater systems, highlighting gaps in sewage collection, treatment infrastructure, and anaerobic decomposition management.
Under the Net Zero Scenario (NZS), waste-sector emissions are projected to decline by around 95.9%, reaching only 10.9 MtCO₂e by 2070, provided aggressive methane mitigation and circular waste management are implemented.
Strategic Pillars for Waste Sector Decarbonisation
NITI Aayog proposes multiple transformation pillars:
1. Universal Methane Recovery
Achieve 100% methane recovery by 2040, especially from industrial wastewater. Sewage treatment should prioritise anaerobic processes integrated with energy recovery systems to prevent methane leakages.
2. Decentralised Circularity
Biodegradable waste should be processed through bio-methanation and Bio-CNG production, stabilising per capita waste generation while converting waste into clean fuel.
3. Wastewater Reuse Expansion
Sewerage coverage should expand towards 85% national coverage, along with large-scale reuse of treated wastewater in agriculture, industry, and urban services.
4. Legacy Waste Remediation
India must accelerate scientific closure of open dumpsites and shift towards engineered sanitary landfills, reducing methane release from decaying organic waste.
5. IoT-Based Monitoring
A unified national waste-data architecture using IoT-enabled sensors can support real-time monitoring, transparency, and regulatory compliance.
Aerobic vs Anaerobic Treatment
- Aerobic treatment uses oxygen and produces mainly CO₂, with relatively lower methane emissions.
- Anaerobic treatment generates methane, but if methane is captured, it enables biogas recovery and higher energy efficiency.
Thus, anaerobic systems are preferable only when paired with strict methane capture mechanisms.
Key Challenges
- Weak segregation and only 75–78% collection efficiency
- Sewage generation of 72,000 MLD, but treatment capacity only 31,000 MLD
- Presence of 3,000+ dumpsites, continuously emitting methane
- Infrastructure gaps in STPs, landfills, and scientific processing systems
Way Forward
NITI Aayog recommends methane recovery expansion through schemes like SATAT, improving segregation via SBM (Urban) 2.0, scaling STPs under AMRUT, and strengthening rural circular economy models through GOBAR-dhan.
Conclusion
Waste sector decarbonisation is a high-impact climate strategy for India. Methane mitigation through wastewater reform, circular bioenergy systems, and scientific dumpsite remediation can deliver rapid emission cuts and support the Net Zero vision.
