Since September 26, mysterious leaks appeared in the underwater Nord Stream gas pipelines—which run from Russia to Germany—close to the Danish island of Bornholm in the Baltic Sea. his More likely to be the largest emission event ever detected, climate scientists are yet to determine its actual impact on the environment.
On September 26, Nord Stream 2 pipeline’s operators saw a sudden pressure drop from 105 bar (which is 105 times atmospheric pressure) to just 7 bar. Soon after, a 1-kilometre-wide area of the Baltic Sea’s surface was bubbling with the escaping gas. This pipeline has been shut since Russia’s invasion of Ukraine. However, it is still full of gas, which is assumed to be around 90% methane.
NORD STREAM; METHANE
Some reports quoted Germany’s Federal Environment Agency as saying that about 3,00,000 metric tons of methane entered the atmosphere as a result of the releases. That amount of the gas would have roughly the same climate impact over a 20-year period as the annual emissions from about 5.48 million US cars, the agency said.
Meanwhile, Danish Energy Agency calculations show that the leaks from the Nord Stream 1 and 2 pipelines in worst case will emit approximately 778 million standard cubic meters of natural gas. The leaked gas volume amounts to greenhouse gas emissions of approximately 14.6 million tons of CO2-equivalent (CO2e). In comparison, Danish CO2e emission totalled approximately 45 million tons of CO2e in 2020. The climate effect of the leaks thereby corresponds to 32 per cent of Danish greenhouse gas emissions in 2020.
NORD STREAM; EXPEDITION
University of Gothenburg researchers claim that the methane levels near the leak were about 1,000 times higher than normal. After five days at sea, the research vessel Skagerak carrying the scientists reached home in Gothenburg with huge samples.
Marine chemist at the University of Gothenburg, and coordinator for the expedition Katarina Abrahamsson, said that they had 20 different measurement locations at intervals of approximately 9–18 kilometres to map the spread of methane in water. The team also had researchers and equipment from the Alfred Wegener Institute in Germany, who have the knowledge to separate the pipeline methane from what occurs naturally.
Katarina Abrahamsson said that they saw methane levels were up to 1,000 times higher than normal. “The distribution pattern of the methane from the leak was complicated and difficult to explain. A reason for this could be that we couldn’t measure the entire discharge, because the vessel was only permitted to go in Swedish waters. We simply didn’t have time to seek permission from Denmark,” the researcher said.
NORD STREAM; MARINE LIFE
Marine biologist at the University of Gothenburg Carina Bunse noted that it was unclear what kind of effect these high methane levels could have on marine life.
“It’s autumn now, and soon it will be low season for phytoplankton and zooplankton. It could affect the food web locally if these methane-eating bacteria grow at the expense of other plankton species. But we can’t foresee the results. Before we can draw any conclusions, we have to make DNA analyses of the content in the water samples,” said Carina Bunse.