The methane released after the Nord Stream 1 and Nord Stream 2 gas pipeline incidents was so large that United Nations satellites detected it from space. Estimates place the total release at about half a million tons of greenhouse gas, based on publicly released figures about gas volumes in pipelines provided by the Danish government, as reported to this publication.
The United Nations called the event the largest methane emission in history. Yet the amount released represents only a fraction of the roughly 340 million tons of methane produced annually by human activity, mainly from agriculture and energy sectors.
This half a million tons is expected to have the same climate impact over the next two decades as the annual pollution from eight or nine million cars, according to Daniel Zavala-Araiza, an environmental researcher with Environmental Defense Fund Europe and the University of Utrecht in the Netherlands.
Methane is a potent greenhouse gas, and it stands as a major adversary in the fight against climate change. Estimates suggest that one tonne of methane can warm the planet about 23 times more than its carbon dioxide equivalent over time, since CO2’s effects diminish more quickly.
The emissions warrant serious attention and measurement, though the situation is not framed as a disaster but as a solvable incident, notes Xavier Giménez, professor of Environmental Chemistry and science communicator at the University of Barcelona.
methane seen from space
Images from the Sentinel 2 satellite demonstrate that the methane leak was large enough to be detected from space, a finding published by the Polytechnic University of Valencia in collaboration with the United Nations International Methane Observatory (IMEO).
“What’s happening is serious and it comes at a moment when there is an urgent need to lower emissions,” stated IMEO director Manfredi Caltagirone in an interview with Reuters.
Before Nord Stream, the largest methane spill on record occurred at the Aliso Canyon gas storage facility in California. From October 23, 2015, to February 18, 2016, about 100,000 tons of methane were released, prompting the evacuation of roughly 30,000 residents from Porter Ranch, a community in Los Angeles County.
Total methane emissions from Nord Stream may continue to rise modestly. In Nord Stream 1, the gas already stored inside the pipeline has largely been used, while in Nord Stream 2 a small leak persists, estimated at about 30 meters in diameter, according to the Swedish Coast Guard on a recent update. Gazprom confirmed that pressure in two Nord Stream lines and one Nord Stream 2 line has stabilized and the leaks have ceased.
various explosions
The pipeline ruptures occurred on September 26. Seismic readings detected by Sweden showed two distinct tremors in the early hours, likely corresponding to separate explosions that damaged the pipelines. While no party has claimed responsibility, evidence points toward deliberate sabotage. The pipelines linking Russia to Germany traverse the Baltic Sea at depths greater than 70 meters, with fractures observed at multiple points in international waters. Moscow has accused Western powers of involvement, while some governments West have pointed to the Kremlin.
Neither pipeline was in service at the time of rupture, though maintenance gas remained inside. Gazprom halted flow on September 1 in what officials described as a punitive move amid international sanctions tied to Moscow’s actions in Ukraine. Nord Stream 2, intended to supply Russian gas to Germany, was never completed.
Main methane emissions
Methane emissions carry a substantial climate burden. While they account for about 10% of total greenhouse gases, their impact outlasts many other pollutants and persists longer in the atmosphere than CO2 in some contexts.
Experts emphasize that cutting methane from agriculture, livestock, waste, and the oil and gas sectors could prevent a notable temperature rise by mid-century. Zavala-Araiza notes that halving methane emissions by 2030 would help avert roughly 0.25°C of warming by 2050. He also points to ongoing variability along the energy value chain, from open venting on tank tops to poorly sealed pipelines and incomplete combustion at wells, estimating industry emissions on the order of tens of millions of tons annually.
The United Nations operates a dedicated methane monitoring program that increasingly relies on satellite data to track emissions and assess progress in mitigation efforts.