465,000 tons of methane have escaped into the air from the sabotaged Nordstream gas pipelines in the Baltic Sea. It is by far the largest leak of the greenhouse gas methane to date. Scientists have that calculated in a study the one in Nature has been published.
On September 26, 2022, three of the four Nordstream pipelines transporting natural gas from Russia to Europe ruptured via an explosives attack. Although the pipelines were not operational at the time, they were full of pressurized gas. In the following days, a lot of gas escaped into the air, recognizable by violent bubbling on the sea surface. An international group of 68 scientists collected all kinds of data to make the best possible estimate of the amount of escaped gas.
Peak in concentration
For example, they simulated the rupture of the pipelines in a computer model. They also collected data from measurements taken from the sea, from ships and aircraft, from measuring towers in Norway and Sweden, among others, and with satellites. This allowed them to find out that only a small part of the escaped gas had dissolved in the sea and had spread through wave action and wind. In a separate, simultaneously published publication Five of the researchers calculate that in 14 percent of the Baltic Sea the methane concentration temporarily peaked and was up to five times higher than normal.
By far the most methane escaped into the air. The researchers arrive at a quantity of 465,000 tons. That is by far the largest methane leak to date. The previous record was 131,000 tons of methane, which was released in the second half of 2023 after an accident at an oil and gas field in Kazakhstan, near the Caspian Sea.
Although the attack on the Nordstream pipelines released a huge amount of methane in a short period of time, the researchers put the leak into perspective by comparing the volume escaped with the total man-made methane emissions in the year 2022. had a share of 0.1 percent.
Livestock and landfill
Leaks from oil and gas pipelines are a major cause of the increased concentration of methane in the air, in addition to, for example, a growing livestock population and an increasing number of landfills. In 2021, the United States and Europe, among others, agreed that global man-made methane emissions must be 30 percent lower by 2030 than in 2020.
The now published, extensive analysis comes remarkably close the first rough estimate which three Cypriot researchers published in iScience in January 2024. They processed data about, among other things, gas pressure, gas content of the pipes, size of the cracks in a model and arrived at a leak of 478,000 tons. According to them, the climate effect of the escaped greenhouse gas can be compared to the amount of CO2 which would be released during the production of the cement for building 27 copies of the 828 meter high Burj Khalifa tower in Dubai.