A new report by the Centre for Science and Environment (CSE) has urged India to conduct a nationwide study to accurately estimate methane emissions from legacy waste dumpsites and organic waste processing facilities. The report also recommended that India urgently phase out biodegradable waste disposal in landfills.
The report titled 'Methane Emissions from Open Dumpsites in India: Estimation and Mitigation Strategies' also stressed the importance of creating robust markets for reduced-emission products generated from organic waste processing and promoting carbon credits for biomining projects.
The unreliability and inconsistency of data related to municipal solid waste and methane emissions were the key concerns raised in the report. To address this issue, the report suggests using the first-order decay (FOD) method, which relies on field data and primary research to more precisely estimate methane emissions from landfill sites.
In its report, the environmental think tank has emphasised the need to phase out the disposal of biodegradable waste in landfills and advocated for robust policies to incentivise waste diversion through source separation and the development of critical infrastructure for biodegradable waste treatment.
Large-scale anaerobic digestion facilities are highlighted as a necessity to keep biodegradable waste out of landfills, reducing the burden on downstream mitigation technologies. The report also highlighted the need to promote carbon credits for biomining projects and mandates estimating methane potential from capped landfills and dumpsites.
The CSE has also advocated for afforestation on reclaimed bioremediation land, emphasising its role as a carbon sequester to mitigate emissions.
"Afforestation should be promoted in the reclaimed bioremediation land — recovered after biomining of legacy waste dumpsites. The green cover developed on the reclaimed land will act as a carbon sequester." "According to BUR-3 (third biennial update report) submitted by the Government of India, forest and tree cover sequestered 331 million tonnes of CO2 in 2016, which is around 15 per cent of the total CO2 emissions in the country," it said.
Compared to carbon dioxide (CO2), methane is a powerful GHG with a significantly larger potential for global warming. Over the past two centuries, its atmospheric concentration has more than doubled mostly as a result of human activity. Methane only stays in the atmosphere for around 12 years, which is not very long.
However, it has a 25 times greater global warming potential (GWP) than CO2, making it the second-leading contributor to climate change during the industrial period. GWP measures a gas's capacity to trap heat in the atmosphere.
After oil and gas systems and agriculture, landfills are the third-largest source of methane emissions worldwide. In 2016, it was estimated that landfill waste handling produced 1.6 billion tonnes of CO2e (CO2 equivalent) globally.
According to a report by the World Bank, this number is expected to reach 2.6 billion tonnes of CO2e (number of metric tonne of CO2 emissions) by 2050.
Notably, as per India's third biennial update report (BUR), the country's methane emissions in 2016 (excluding land use and land-use change and forestry) stood at 409 million tonnes CO2e. Of this, 73.96 per cent came from the agriculture sector, 14.46 per cent from the waste sector, 10.62 per cent from the energy sector and 0.96 per cent from the industrial processes and product use sector.