How India’s trash mountains are contributing to climate change

Ghazipur landfill, Delhi. (Photo via Wikimedia Commons)

Last month, a fire broke out at Delhi’s Ghazipur landfill. It is one of the national capital’s three trash mountains, and a dumpsite for wet, dry, biomedical, sanitary and even electronic waste. The landfill exceeded its capacity in 2002, but continues to receive new trash every day.

Periodically, it catches fire, causing dangerous heat and toxic fumes. Landfills also release gases. Methane is the biggest component of landfill gas, and it is adding to India’s growing climate challenges.

“Organic waste is typically covered and compacted in landfills. This removes oxygen and causes anaerobic breakdown, resulting in methane gas formation. Methane is the second-most abundant greenhouse gas after carbon dioxide and more than 25 times as potent as CO2 at trapping heat in the atmosphere,” says Tanmay Karnik, independent consultant and researcher, solid waste management.

Record growth

In the last 200 years, methane levels in the atmosphere have more than doubled, largely due to human activity, according to the United States Environmental Protection Agency. This potent greenhouse gas alone is now responsible for 30 per cent of global warming since the Industrial Revolution in the 18th-19th century. Its concentration in the atmosphere also continues to increase at a record pace, with about 580 million tonnes of the greenhouse gas emitted in 2022 from both industrial and natural processes.

In the US, oil and gas is the top methane emitter. In other countries, agriculture and livestock are major sources. In India, studies show that 74 per cent of methane emissions come from livestock and rice farming. But garbage is also a big contributor.

According to the Centre for Science and Environment (CSE), India has over 3,000 waste mountains containing 1.3 billion tonnes of legacy waste. “Although the term ‘legacy waste’ has not been defined in any official government document in India, it typically refers to old municipal solid waste in landfills or dumpsites. There is no set standard to define how old waste qualifies to be called legacy waste,” said Atin Biswas, programme director, solid waste management unit, CSE, at a national symposium on legacy waste management and dumpsite remediation.

Landfill waste generates around 15 per cent of the country’s methane emissions. India, incidentally, creates more methane from landfill sites than any other country, according to GHGSat, which monitors emissions via satellites. In a study published in 2022, high-resolution satellite images snapped in 2020 showed high methane levels over cities in the country. When scientists tried to zero in on the source, they found that methane was coming from upwind landfills in Mumbai and New Delhi. In Mumbai, for instance, a landfill was emitting about 9.8 tonnes of methane per hour according to the study.

Cause for concern

Methane is a short-lived greenhouse gas with an atmospheric lifetime of about 12 years, but it is much more potent than carbon dioxide. It can also lead to ground-level ozone and methane leaks, which can be dangerous to human life.

India does want to lower its methane output, but it has not yet signed the Global Methane Pledge. This pact, which was launched at COP26, commits countries to collectively reduce methane emissions by at least 30 per cent by 2030 from 2020 levels. Scientists estimate that this reduction could help to cut global warming by 0.2 per cent, which would be a significant step towards limiting global warming to 1.5 degrees Celsius.

India’s Ministry of Environment, Forests and Climate Change has said, in reply to a Parliament question, that the Global Methane Pledge shifts the burden of CO2 reduction to methane reduction, which has a lifetime of just 12 years. It also pointed out that agriculture was excluded in the country’s pre-2020 voluntary commitments on emission intensity, and including it could impact exports and the economy.

Environmentalists, however, argue that reducing methane emissions is one of the most effective ways to slow climate change in the near term. It can have a rapid impact on global warming.

India is aware of the problem, and is taking steps to address it by focusing on legacy waste. As part of the Swachh Bharat Mission 2.0, which aims on making urban India garbage-free, cities with a population of less than one million must clear legacy waste sites by March 31, 2023, and cities with a population of over one million to reclaim the lost land by March 31, 2024.

It earmarked as much as Rs 1,41,600 crore for this phase, which includes the cost of dumpsite remediation. “There is also more focus on creating a sustainable solid waste management plan and ensuring that no fresh waste finds its way to these landfills,” says Karnik. These efforts will reduce methane emissions. It will also improve air quality and could also help the world lower its greenhouse gas emissions.