Nord Stream pipes leaked 'enormous' amount of methane into atmosphere

Huge volumes of the potent greenhouse gas methane have leaked and may have been damaged by someone. It is similar to the yearly methane emissions from a city as large as Paris.

Within hours of each other last week, there were large leaks on the Nord Stream 1 andNord Stream 2. European leaders have labelled the incidents as sabotage because of the low chance of near-simultaneous damage on pipes in different locations, without pointing to any culprit in particular.

TheNord Stream pipes, which run under the Baltic Sea, had at times been a focal point of diplomatic tensions. The countries closest to the leaks issued a report to the UN that claimed that blasts detected shortly before the leaks started were equivalent to the detonation of hundreds of kilograms of explosives. There are theories about the cause of these, including explosives planted outside the pipes or inside by robotic inspection vehicles.

Sweden sent a diving vessel to investigate whether or not the two pipes that make upNord Stream 1 are damaged, as well as one of the two pipes that make upNord Stream 2.

According to reports from the Swedish coast guard on 3 October, there is still gas bubbling to the surface, but it is at a lower rate than in the immediate aftermath of the leak.

There was an enormous amount of methane released by the Integrated Carbon Observation System. This is equivalent to a year's methane emissions for a city the size of Paris.

The observation satellites were not able to see the leak because of cloudy weather, but the ground stations in Sweden, Norway and Finland indicated that the gas had been blown north to Sweden and Norway.

At a later stage, we might be able to confirm and quantify the amount of gas leaking, and several ICOS scientists are currently discussing the various options for that.

The leak using satellites has been confirmed by the International Methane Emissions Observatory.

If the estimates of the leak are correct, the emissions could be equivalent to the annual methane emissions of 124,000 UK homes.

Even though the pipes are hard to reach on the sea bed and the leaks are large, the remaining operational pipe could be put into service.

Bill Caram at the independent watchdog says he has seen minor sabotage at protests and accidental damage involving stray bullets, but he has never seen the scale of the leaks. The pipes could be repaired. They can cut out the damaged section, install a new section and do underwater welding, even though it is very specialized.

The leak could have been mitigated by having more valves. The climate impact of this huge amount of methane is the most important thing. I was floored by the fact that there were no valves in the entire line. I haven't heard of a section like this before.