They tower above Delhi like monstrous mountains, feasted upon by birds, flies, vermin and cows, and emitting an inescapable stench of rot. These “trash mountains” loom so large – several miles wide and more than 200ft (60 metres) high – that they are visible from across the city.
The rubbish dumps, located in the neighbourhoods of Ghazipur, Bhalswa and Okhla, are where more than 10,000 tonnes of Delhi’s waste ends up every day: everything from vegetable peelings to glass bottles, plastic packaging, batteries, broken toys and discarded clothes.
Delhi residents, who frequently breathe the world’s worst-quality air, widely view these dumpsites as apocalyptic places, dark monuments to the city’s failures to deal with the mounting problem of rubbish and pollution.
Yet the true menace of Delhi’s towering rubbish dumps is one that is largely invisible. Satellite data shared exclusively with the Guardian indicates that the landfills of India’s capital city have become a global hotspot for emissions of methane, a potent greenhouse gas that traps 82 times more heat than carbon dioxide over 20 years.
According to the data from Kayrros, an environmental intelligence agency, Ghazipur, Bhalswa and Okhla have been home to at least 124 methane “super emitter” leaks since 2020.
Due to the widespread culture of cooking using fresh produce, an unusually high proportion of the waste generated in India is “wet waste”, such as food scraps and vegetable peelings. More than 50% of the rubbish dumped daily in Ghazipur, Bhalswa and Okhla is biodegradable.
With no strictly implemented system of rubbish segregation in Delhi – a city of 32 million people – the wet waste is mostly unsegregated and left to rot. As it decomposes, it generates huge amounts of methane. At the Ghazipur, Bhalswa and Okhla sites, there is no system of gas capture, a method commonly used in developed countries, meaning the methane is free to rise into the atmosphere.
“Delhi has very poor waste segregation levels, especially for wet waste,” said Bharati Chaturvedi, founder and director of the Chintan environmental research and action group, which works on sustainable waste management issues in India. “As soon as it ends up on a landfill, the municipality is stuck: there’s nothing that can be done to stop it producing methane, which then causes all these fires and pollution.”
She added: “Even the simplest measures for reducing methane are not put in place in Delhi. We need to be composting this waste on a large scale but one big problem is that there’s no land to do it. There’s also no market for compost, so there’s no financial incentive to do anything other than dump organic waste.”
While the Delhi government has promised to clear the Ghazipur, Bhalswa and Okhla dumpsites by the end of 2024, authorities admitted that vast amounts of unsegregated rubbish still continued to arrive every day, and the deadline was deemed “unrealistic” by one official, who was not authorised to speak to the media. The Delhi state government, ruled by the Aam Aadmi party, declined to speak to the Guardian on the matter, despite months of requests for comment.
Methane from waste dumps, fossil fuel sites and livestock is responsible for 25% of global warming. Experts say that if countries such as India, with the largest population in the world and home to more than 1.4 billion people, cannot bring its methane emissions under control as its population continues to grow, then it could be one of the biggest threats to keeping global temperature rises below 1.5C above preindustrial levels.
Methane emissions from India’s thousands of dumpsites, the largest of which are in urban areas, have been surging in recent years, especially as the populations of cities such as Delhi continue to grow. Landfills and rubbish dumps account for more than 14% of India’s total methane emissions, the second highest contributor after agriculture.
The satellite data collated by Kayrros suggests that Ghazipur, Bhalswa and Okhla have probably become vast methane reservoirs. In Ghazipur, the data indicates the dumpsite has been the source of 37 major methane leaks since 2020, the worst in November 2021 when 156 tonnes an hour were recorded – the equivalent to CO2 from 24m running cars. An even larger leak was recorded in June 2019, when the site emitted 360 tonnes an hour, the equivalent carbon emissions of 57m running cars.
Okhla was found to have 19 major methane leaks since 2020, while Bhalswa had 19, including one in March 2023, when it was leaking 208 tonnes of methane an hour, emissions worse than 33m cars.
The environmental consequences of the methane leaks from these dumpsites have become doubly devastating in Delhi’s scorching summer months, when the highly flammable gas regularly catches fire, turning the trash mountains into toxic, burning infernos. The fires sometimes take weeks to put out, sending choking fumes into Delhi’s already highly polluted air.
Those living in areas close to the sites repeatedly described the summer months as “hell”. Mohammad Rizwan, 36, who owns a shop next to the Ghazipur dumpsite, said the nearby residents were the “unluckiest people in Delhi”.
“I have watched it grow from a small rubbish heap into that huge mountain over the past 20 years,” he said, pointing up at the looming wall of rubbish. “During the summer it catches fire every week because of all the gas and then it becomes even more disgusting here. It’s impossible to breathe and everyone gets sick because of the bad fumes and smoke we have to inhale. It feels so dangerous to live here but I have no choice, this is where my home and livelihood is.”
For Delhi’s thousands of ragpickers, who make a living climbing on to the trash mountains every day to find materials – plastic, glass, wires, metals – which they can sell for a few rupees, the methane fires can prove particularly deadly. Though it is illegal to enter the dumpsites, the archaic and dangerous practice continues. The Guardian met ragpickers as young as four working on the Ghazipur and Bhalswa sites, collecting and segregating rubbish.
Seven-year-old Rizwan Sheikh, dressed in muddy green pyjamas and with orange plastic sandals on his feet, said he climbed up on to the Ghazipur trash mountain – sometimes twice a day – to collect plastic and metals to sell, but he had to wade through a perilous wasteland of food waste, broken glass and used needles. On a good day, he said, he would make 150 rupees (£1.50), enough to buy himself biryani, his favourite meal, for dinner.
“In the summer it can be scary and very difficult because of all the fires,” said Rizwan. “Sometimes I don’t want to go up but I have to. My father died so I need to earn money.”
When the Guardian visited the village beneath the Bhalswa dumpsite, a funeral was taking place for a man in his 30s who had worked on the site and died recently from problems with his lungs and kidneys.
“It happens all the time here, people die young from health problems,” said Mohammad Insab, 32. “We know we are being poisoned by this rubbish dump but the government does nothing and the trash keeps on coming.”
Last March, the Delhi finance minister, Kailash Gahlot, made a promise that his government would see the “end of the mountains”, a pledge that was repeated by the chief minister, Arvind Kejriwal. However, the Municipal Corporation of Delhi (MCD), which manages the Ghazipur, Bhalswa and Okhla sites, said it would not close the sites until a system was in place to process and segregate 100% of Delhi’s waste – something experts consider to be a far-off prospect.
MCD said it had begun the process of removing legacy waste, such as aged plastic and metals, from these sites. In a written statement, it said it was “on schedule” to remove 3m metric tonnes of rubbish at Bhaslwa and Okhla by May this year, though admitted that it was lagging behind at Ghazipur.
But Dr Richa Singh, a programme manager at Delhi’s Centre for Science and Environment, said this biomining of old rubbish was still not dealing with the problem of new biodegradable waste and therefore “the vicious cycle of uncontrollable methane emissions will continue”.
“Fresh wet waste is still being dumped at these sites every day and that’s the main culprit for methane and air pollution from fires,” she said. “Removing legacy waste is not solving the larger problem: we need to end this culture of mixed waste dumping.”
There was also concern among environmentalists that the alternatives to landfills being offered were equally damaging, in particular a push for more waste-to-energy plants, where segregated waste is burned to produce heat – which in Delhi are opaquely operated, poorly regulated and have been repeatedly fined for excessively high pollution levels.
Singh was optimistic that the future for India’s waste lay instead in systems of segregation that were both sustainable and socially inclusive, ensuring that those millions in India who still make a living from sorting and selling waste could be part of the solution.
“We are still a developing country but I see a clear intention from the government that we want to make this country garbage-free,” she said. “If we are able to sustainably manage our waste, we will be able to reduce our methane emissions drastically.”
Hannah Ellis-Petersen and Aakash Hassan in Delhi www.theguardian.com