Scientists speculate the recent Nord Stream leak could be one of the worst ever, with over 400,000 metric tons of methane escaping into the atmosphere with a significant climate risk.
The initial leak was reported on September 26, followed by reports of additional leaks soon after. Swedish authorities have reported a fourth leak today.
The exact cause is not yet known, but accounts from seismologists of underwater blasts before the leaks emerged have raised suspicions of sabotage, with Bjorn Lund of Sweden’s National Seismology Centre confirming there was “no doubt that these were explosions.”
Russia has been accused by the European Union of using gas supplies as a weapon in retaliation for the West’s support for Ukraine. These latest reports have done nothing to change that view.
It is “very obvious” who is behind the damage, said the head of the International Energy Agency (IEA), Fatih Birol, without elaborating on the comment.
Ursula von der Leyen, head of the European Commission, said that deliberate disruption would meet “the strongest possible response”. Additionally, Norway – which is not in the EU – has said that it would deploy its military to protect oil and gas installations.
While this is certainly another blow to East-West relations, the bigger concern may lie with the long-term damage this will cause the climate.
The exact amount of methane that was leaked is still unknown, but the Danish Energy Agency estimates that the pipelines contained a total of 778m cubic metres of natural gas. This is twice as much as scientists originally thought and would make estimates of methane leaked to the atmosphere much higher at around 400,000 tonnes.
Methane has around 84 times the warming power of carbon dioxide during its first 20 years in the atmosphere, which means that based on the latest estimate, the leak could create 10,000,000 tonnes of carbon dioxide equivalent.
The term ‘CO2 equivalent’ is a way of comparing the emissions from different greenhouse gases by converting the amounts of other gases to the amount of CO2 with the same global warming potential.
According to the U.S. Environmental Protection Agencies emission equivalence calculator, that amount of CO2 would have the same climate effect as the yearly emissions of 25 natural gas-powered power plants or 2.1 million cars.
Kristoffer Bottzauw, head of the Danish Energy Agency, said that the methane emissions would account for around 32% of Denmark’s annual greenhouse-gas discharges and that the remaining gas from the pipe is expected to be gone by Sunday.
The challenge of accurately measuring the impact
Estimating the exact amount of methane that has escaped into the atmosphere is challenging. Events like this are often captured by satellite imagery when they occur over land-based pipelines or fossil-fuel production sites. As these leaks have taken place under a significant amount of water, capturing accurate data is challenging as light reflects off the surface.
Furthermore, the Nord Stream 1 pipeline was halted in August, and the Nord Stream 2 pipeline had never even started, but both contained an amount of pressurized natural gas. While estimates suggest around 778m cubic meters of natural gas, details about the exact contents of the pipes are not available.
Looking at the global scale
While the Nord Stream leaks are a disaster for the climate, some scientists claim that they still pale in comparison to daily discharges from gas infrastructure globally. According to Piers Forster, a professor of climate physics from the University of Leeds in the UK, around a tenth of the fossil fuels industries supply is leaked into the atmosphere.
“The most direct effect of these gas leaks on climate is the extra dollop of the powerful greenhouse gas methane,” said Dave Reay, executive director of Edinburgh Climate Change Institute. “That said, this is a wee bubble in the ocean compared to the huge amounts of so-called ‘fugitive methane’ that are emitted every day around the world due to things like fracking, coal mining and oil extraction.”
The expulsion of methane comes at a time when increased public awareness of its effects on the climate is growing. The EU is also in the process of legislation that would raise the obligation on companies to reduce flaring of the gas, conduct regular inspections to stem leaks and boost transparency of leaks associated with imports.
With COP 27 scheduled for November, this event will likely leave a lasting impression and generate discussion around fossil fuel use throughout the conference.
