Quantitative analysis of the methane gas emissions from municipal solid waste in India

Increased emissions of greenhouse gases have altered the global ambient temperature and adversely affected global climatic conditions. The municipal solid waste (MSW) generated by households is considered the third largest anthropogenic source of methane (CH₄) emissions, constituting 11% of all global CH₄ emissions. The current study derived total MSW CH₄ emission estimates using the IPCC default method (DM), modified triangular method (MTM) and first order decay method (FOD). The estimated CH₄ emission was higher for the DM than the other methods, and was comparable to estimates from other studies. This study observed that the net annual emission of CH₄ from landfills in India increased from 404 Gg in 1999-2000 to 990 Gg and 1084 Gg in 2011 and 2015, respectively. We also found that CH₄ emissions were highly correlated (R² = 0.8) with the gross state domestic product (GSDP) of states and the gross domestic product (GDP) of the country, which is an indicator of human well-being. The MSW management policy of India needs to be reviewed in a current policy context, as the management and efficient utilization of MSW technologies might help increase the use of CH₄ as an energy source and thereby improve its sustainable and cost-effective management.