Explained: Scientists release findings on possibly the second biggest man-made methane leak, ever

A drilling incident at the exploration well in Kazakhstan caused a fire that raged between June and December 2023 and released 127,000 tonnes of methane into the atmosphere. Here is a look at what happened and what the incident's environmental impact is likely to be.

Manfredi Caltagirone, head of the UN's International Methane Emissions Observatory, said that the magnitude and the duration of the leak were “unusual” and “extremely big”. (Representational image/Wikimedia Commons)

Recently, scientists revealed that a drilling incident, which took place last year at an exploration well in the Mangistau region of southwestern Kazakhstan, led to one of the worst methane leaks in history. It was possibly the second biggest man-made methane leak ever.

Methane is a potent greenhouse gas — it traps heat in the atmosphere and adds to global warming. Leaks from fossil fuel operations are the biggest source of methane emissions. About 40% of human-caused methane emissions come from such operations.

Here is a look at what happened in Kazakhstan and what the incident’s environmental impact is likely to be.

What happened?

The drilling incident at the exploration well caused a fire that raged between June and December 2023 and released 127,000 tonnes of methane into the atmosphere. Plumes of gas could be seen from space, which is how scientists behind five satellite instruments detected the leak 115 times during the six months. The leak has now been stopped and the well is currently being sealed with cement.

Manfredi Caltagirone, head of the UN’s International Methane Emissions Observatory, said that the magnitude and the duration of the leak were “unusual” and “extremely big”, according to the BBC, which first reported the incident.

French geoanalytics firm Kayrros investigated the leak and released its findings last month. The firm had the results reviewed by the Netherlands Institute for Space Research in Leiden, and the Polytechnic University of Valencia, Spain.

Also in Explained | Meet MethaneSAT, a satellite which will ‘name and shame’ methane emitters

The BBC said the owners of the well, Kazakhstan-based Buzachi Neft, would be fined more than 350 million tenge ($774,000).

Story continues below this ad

What will be the environmental impact of the Kazakhstan leak?

According to the US Environmental Protection Agency’s Greenhouse Gas Equivalency Calculator, “the environmental impact of such a leak is comparable to that of driving more than 717,000 petrol cars for a year,” the BBC reported.

Methane is one of the biggest drivers of climate change, second only to carbon dioxide. Its concentration in the atmosphere has more than doubled in the last couple of centuries and is responsible for around 30 per cent of the rise in global temperatures since the Industrial Revolution.

The Kazakhstan methane leak is the latest addition to the long list of such leaks from the oil and gas sector. The UN Environment Programme said that “massive methane leaks, known as super-emitter events, have been taking place at oil and gas fields all over the world, from the US to Turkmenistan”. Most of these leaks are due to equipment failure.

Notably, 2023 witnessed the highest levels of greenhouse gas concentrations ever in the atmosphere. Methane concentrations increased by 11 parts per billion (ppb).

Story continues below this ad

According to the International Energy Agency (IEA), rapid and sustained reductions in methane emissions are needed to limit near-term warming and improve air quality. The average global temperature has already risen at least 1.2 degree Celsius above pre-industrial times.

To ensure that the planet doesn’t breach the 1.5 degree and 2 degree Celsius thresholds set by the 2015 Paris Agreement, countries urgently need to implement certain steps, including curbing greenhouse gases like methane and carbon dioxide.

Dipanita Nath

Dipanita Nath is a Senior Assistant Editor at The Indian Express, based in Pune. She is a versatile journalist with a deep interest in the intersection of culture, sustainability, and urban life. Professional Background Experience: Before joining The Indian Express, she worked with other major news organizations including Hindustan Times, The Times of India, and Mint. Core Specializations: She is widely recognized for her coverage of the climate crisis, theatre and performing arts, heritage conservation, and the startup ecosystem (often through her "Pune Inc" series). Storytelling Focus: Her work often unearths "hidden stories" of Pune—focusing on historical institutes, local traditions, and the personal journeys of social innovators. Recent Notable Articles (December 2025) Her recent reporting highlights Pune’s cultural pulse and the environmental challenges facing the city during the winter season: 1. Climate & Environment "Pune shivers on coldest morning of the season; minimum temperature plunges to 6.9°C" (Dec 20, 2025): Reporting on the record-breaking cold wave in Pune and the IMD's forecast for the week. "How a heritage tree-mapping event at Ganeshkhind Garden highlights rising interest in Pune’s green legacy" (Dec 20, 2025): Covering a citizen-led initiative where Gen Z and millennials gathered to document and protect ancient trees at a Biodiversity Heritage Site. "Right to breathe: Landmark NGT order directs PMC to frame norms for pollution from construction sites" (Dec 8, 2025): Reporting on a significant legal victory for residents fighting dust and air pollution in urban neighborhoods like Baner. 2. "Hidden Stories" & Heritage "Inside Pune library that’s nourished minds of entrepreneurs for 17 years" (Dec 21, 2025): A feature on the Venture Center Library, detailing how a collection of 3,500 specialized books helps tech startups navigate the product life cycle. "Before he died, Ram Sutar gave Pune a lasting gift" (Dec 18, 2025): A tribute to the legendary sculptor Ram Sutar (creator of the Statue of Unity), focusing on his local works like the Chhatrapati Shivaji statue at Pune airport. "The Pune institute where MA Jinnah was once chief guest" (Dec 6, 2025): An archival exploration of the College of Agriculture, established in 1907, and its historical role in India's freedom struggle. 3. Arts, Theatre & "Pune Inc" "Satyajit Ray, Ritwik Ghatak were not rivals but close friends, says veteran filmmaker" (Dec 17, 2025): A deep-dive interview ahead of the Pune International Film Festival (PIFF) exploring the camaraderie between legends of Indian cinema. "Meet the Pune entrepreneur helping women build and scale businesses" (Dec 16, 2025): Part of her "Pune Inc" series, profiling Nikita Vora’s efforts to empower female-led startups. "How women drone pilots in rural Maharashtra are cultivating a green habit" (Dec 12, 2025): Exploring how technology is being used by women in agriculture to reduce chemical use and labor. Signature Style Dipanita Nath is known for intellectual curiosity and a narrative-driven approach. Whether she is writing about a 110-year-old eatery or the intricacies of the climate crisis, she focuses on the human element and the historical context. Her columns are often a blend of reportage and cultural commentary, making them a staple for readers interested in the "soul" of Pune. X (Twitter): @dipanitanath ... Read More