Mystery still surrounds the cause of leaks in two Russian gas pipelines in the Baltic Sea – but there is little uncertainty about the impact on the environment of the spillages.
The release of methane – a potent greenhouse gas – into the atmosphere could be disastrous according to scientists, after the ruptures occurred in Nord Stream 1 and Nord Stream 2.
Stefano Grassi, head of the European Union Energy Commissioner’s Cabinet, said the leaks risked becoming ‘a climate and ecological disaster’.
‘We are in contact with (EU member states) to look into what happened and find the fastest way to stop leaks and avoid worse damage,’ Grassi said in a tweet.
Neither pipeline was in operation when the spillages were reported, but both contained natural gas, which is largely composed of methane, a greenhouse gas that is the second biggest cause of climate change after carbon dioxide, which exists in the atmosphere is much greater quantities.
‘There are a number of uncertainties, but if these pipelines fail, the impact to the climate will be disastrous and could even be unprecedented,’ said atmospheric chemist David McCabe, senior scientist at the non-profit Clean Air Task Force.
Difficult to Assess Damage
McCabe said currently it is not possible to assess the size of the leaks, due to uncertainties around factors such as the temperature of the gas in the pipeline, how fast it is leaking, and how much gas would be absorbed by microbes in the water before reaching the surface.
But he said: ‘The potential for a massive and highly damaging emission event is very worrisome.’
Current analysis suggests the leaks together released around 500 tons of methane per hour when first breached, but this could be slowly decreasing as pressure on the ruptured pipes lessen.
Jasmin Cooper, a research associate at Imperial College London’s Sustainable Gas Institute, said operators, Russian state energy company Gazprom, needs to act quickly to contain the possible environmental impact.
She said: ‘Gazprom will probably have an estimate based on gas throughputs. But in terms of how much methane is emitted into the atmosphere, they need to send out a team now to measure and monitor.
‘We know there are three explosions but we don’t know if there are three holes in the sides of the pipe or how big the breaks are. It’s difficult to know how much is reaching the surface. ‘But it is potentially hundreds of thousands of tonnes of methane, quite a big volume being pumped into the atmosphere.
‘It has the potential to be one of the biggest gas leaks. The climate risks from the methane leak are quite large. Methane is a potent greenhouse gas, 30 times stronger than carbon dioxide over 100 years and more than 80 times stronger over 20 years.’
According to its operators, Nord Stream 2 – which has never actually been used – its system held 300 million cubic metres of gas.
Releasing that amount into the atmosphere would result in around 200,000 tonnes of methane emissions, according to chemical engineer Paul Balcombe at London’s Queen Mary University.
This would have about the same global warming potential over a 100-year timeframe as six million tons of carbon dioxide – the same as the annual emissions of a medium sized global city.
The amount of gas leaking from the Nord Stream 1 pipeline system is less clear as operators are refusing to say how much it contains.
Gas leaks do not pose the same threat to marine life as oil spills, however Greenpeace has warned the methane could cause breathing problems for aquatic species.
Seismologists recorded what they think were explosions before gas began pouring out of the two Russia-to-Germany pipelines under the Baltic Sea last week.
Denmark’s Energy Agency said it is too early to say who will investigate the Nord Stream 2 leak, and no-one has been to look at the pipeline yet, but leaks will likely continue for up to a week.
Denmark’s Energy Agency said Wednesday that emissions from the gas leaks correspond to approximately one-third of the country’s annual greenhouse gas emissions.
The first leak was discovered on Nord Stream 2 around the Danish island of Bornholm. Hours later, two leaks were detected on separate sections of Nord Stream 1, reaching both the Danish and Swedish waters of the Baltic Sea. A possible fourth leak in Nord Stream 2 is currently (Thursday) under investigation.
Jean-Francois Gauthier, of the commercial methane-measuring satellite firm GHGSat, said it was a challenge to estimate the likely eventual impact of the ruptures.
He said: ‘There is little information on the size of the breach and whether it is still going on. If it’s a significant enough breach, it would empty itself.
‘It’s safe to say that we’re talking about hundreds of thousands of tonnes of methane. In terms of leaks, it’s certainly a very serious one. The catastrophic instantaneous nature of this one – I’ve certainly never seen anything like that before.’