The explosion of Russia's natural gas pipeline Nord Stream occurred in 2022. As a result of the incident, energy prices rose across Europe, leading to an international economic issue. Three years after the incident, analyses have emerged indicating that the event had a catastrophic impact not only on the economy but also on the marine ecosystem.
A research team led by Stephen Harris, a researcher at the United Nations Environment Programme (UNEP), announced on the 16th in the international journal "Nature" that 465,000 tons of methane leaked into the sea due to the Nord Stream explosion in 2022.
Nord Stream is an underwater gas pipeline connecting Russia and Germany. Nord Stream 1 and Nord Stream 2 were constructed separately, with each pipeline consisting of twin pipes. Nord Stream 1 began operations in 2011, and Nord Stream 2 started in 2021, transporting a total of 55 billion cubic meters of natural gas annually, establishing itself as a key facility for Europe's energy supply.
In 2022, during the ongoing war between Russia and Ukraine, the explosion of Nord Stream occurred. As a result of the incident, European countries reliant on the pipeline for energy, including Germany, faced disruptions in natural gas supply, leading to soaring energy expenses. This led to severe inflation and an economic crisis, with Ukraine being pointed to as a possible perpetrator behind the incident.
The research team created simulations to determine the environmental impact of methane leakage due to the damaged gas pipeline and calculated the amount of methane leaked. As a result, it was revealed that methane leaked from four damaged locations of Nord Stream totaled 465,000 tons. This is the largest emission of methane from a single incident recorded to date.
Methane is considered one of the primary culprits of global warming, having a greenhouse effect 81 times stronger than that of carbon dioxide. However, the impact of the incident on the climate is expected to be minimal. This is because the amount of methane leaked from the incident is only a tiny fraction compared to the total methane emitted from industrial sources. According to the research team, the 465,000 tons of methane released represents merely 1.2% of the total natural gas emitted in the industrial sector, and about 0.3% of emissions from agriculture.
The UNEP research team noted, "It seems that methane was released into the atmosphere in the form of large bubbles after the Nord Stream explosion," and added, "Some methane is expected to have dissolved in seawater and remain in the sea according to the structure of the seawater."
However, there are concerns that methane not released into the atmosphere but dissolved in the sea could have significant impacts on the marine ecosystem. A research team led by Martin Mohrmann, a researcher at the German Aerospace Center (DRL), announced their findings in the international journal "Nature Communications," calculating the amount of methane that has dissolved in the sea from Nord Stream.
As a result, it was found that 14% of the Baltic Sea area where Nord Stream was located has seen a fivefold increase in methane concentration compared to normal levels. It is estimated that this will have a significant impact on the ecosystems of 23 marine protected areas in the Baltic Sea region. However, further research is needed to determine what effect the increased methane concentration may have on marine ecosystems.
The DRL research team stated, "There is a need for a long-term analysis of the impact of methane concentration on the ecosystem," and added, "It is likely that the initial explosion of Nord Stream adversely affected marine mammals."
Researchers analyzing the Nord Stream explosion incident argued that it is essential to establish a real-time monitoring system to prepare for similar incidents in the future. This study could only estimate the extent of the damage more than two years after the incident due to the absence of a real-time monitoring system.
The DRL research team emphasized the necessity of establishing a real-time monitoring system that can accurately track the impact of large-scale incidents on the sea and atmosphere, stating, "A system that can be utilized in atmospheric and marine environments should be introduced to respond quickly to incidents."
Reference materials
Nature (2025), DOI: https://doi.org/10.1038/s41586-024-08396-8
Nature Communications (2025), DOI: https://doi.org/10.1038/s41467-024-53780-7
Nature Communications (2025), DOI: https://doi.org/10.1038/s41467-024-53779-0