Nord Stream pipeline has leaked methane into the atmosphere New Scientist

Satellite measurements should provide information about how much of the greenhouse gas methane has escaped the Nord Stream pipeline. Current estimates speak of hundreds of millions of cubic meters.

Huge amounts of the potent greenhouse gas methane have leaked from the Nord Stream pipeline. According to one estimate, the emissions are comparable to the annual emissions of the city of Paris.

Nord Stream 1 and 2, important connections for gas transport from Russia to Europe, were damaged several times in a short time last week. European leaders speak of sabotage, because it is unlikely that the pipelines in several places at the same time were damaged unintentionally. However, they do not name names. Russia points to the United States and its allies.

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explosives

The Nord Stream pipelines at the bottom of the Baltic Sea have been the source of diplomatic tensions since the start of the war in Ukraine.

The governments of Denmark and Sweden, the countries closest to the pipelines, have submitted a report to the United Nations. In it they state that just before the gas leaks, explosions were observed that correspond to the ignition of hundreds of kilograms of explosives. Speculation about how the explosives were placed range from submarine to diver scenarios. It is also possible that the pipeline has been damaged from the inside, by vehicles that usually drive through it for inspections.

Both Nord Stream 1 and 2 consist of two pipes. It is suspected that both pipes of Nord Stream 1 were damaged, in addition to one of the pipes of Nord Stream 2. On October 3, Sweden sent a diving vehicle to investigate the gas leaks. The Swedish Coast Guard then reported that Nord Stream 1 was no longer leaking. But gas from Nord Stream 2 is still bubbling up, though not as quickly as immediately after the blasts: At that point, the bubbles covered an area a kilometer in diameter.

Methane from the Nord Stream pipeline bubbles to the surface of the Baltic Sea. Image: Swedish Coast Guard.

Satellites

The European research network that tracks greenhouse gas emissions, the Integrated Carbon Observation System (ICOS), stated on September 30 that a “huge amount” of methane had escaped. ICOS estimates that this is comparable to the annual emissions of a city the size of Paris, or a country the size of Denmark.

Cloud cover obstructed the view of ICOS satellites at the time. But Swedish, Finnish and Norwegian ground stations reported that the leaked gas was traveling north, first towards Finland, then Sweden and Norway.

Director of ICOS Alex Vermeulen says in a response: ‘Later we may be able to confirm the amount of gas leaked. Several ICOS scientists are now discussing the possible options.’ The United Nations International Methane Emissions Observatory (IMEO) has also confirmed the gas leak by means of satellites.

valves

According to the pipeline’s owner, the Russian company Gazprom, the undamaged Nord Stream 2 pipeline can be commissioned, despite the size of the gas leaks and the difficult accessibility of the pipelines. Bill Caram, deputy director of the Pipeline Safety Trust oversight body, says he has seen damage to pipelines more than once. But that case was about minor sabotage or accidental damage from stray bullets, not the gas leaks of this magnitude.

The damage can be repaired, he said. ‘It involves highly specialized technology. But you can take out the damaged part, install a new piece and weld it together underwater.’

He also says multiple valves at regular intervals could have reduced the amount of gas leaked. “It appears that there are no valves in this pipeline at all. I was amazed when I heard that. I’ve never heard of a pipeline like this without valves.’

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