Burst Pipelines in Baltic Sea May Be the Largest Methane Leak Ever

Earlier this week, three leaks sprang up in two natural gas pipelines that stretch from Russia to Germany. A huge amount of the potent greenhouse gas methane is now escaping into the Baltic Sea and atmosphere, writes Patrick Whittle of the Associated Press (AP).

The exact volume of gas that has burst from the pipelines is unclear. “It’s difficult to know how much [methane] is reaching the surface,” Jasmin Cooper, a research associate at Imperial College London’s Sustainable Gas Institute in England, tells the Guardian’s Karen McVeigh and Philip Oltermann. “But it is potentially hundreds of thousands of tonnes of methane: quite a big volume being pumped into the atmosphere.”

Methane is highly effective at trapping heat. According to the Environmental Defense Fund, the gas has over 80 times the warming potential of carbon dioxide during its first 20 years in the atmosphere. Methane released by human activity is responsible for at least one quarter of today's global warming. Over a 100-year timespan, this potent greenhouse gas is roughly 28 times stronger than carbon dioxide.

The recent bursts in the Baltic Sea pipes, called Nord Stream 1 and 2, have the potential to be the biggest leaks of methane on record. They could top the largest terrestrial release of methane in U.S. history: 2015’s Aliso Canyon disaster in Los Angeles, when a gas storage facility expelled 109,000 metric tons of the gas over 111 days.

Though the Baltic pipelines weren’t operational, both contained natural gas, according to Reuters’ Shadia Nasralla and Kate Abnett. Nord Stream 2 had yet to go into service, and Nord Stream 1 had been shut down since August, the New York Times’ Melissa Eddy reports.

Danish and Swedish seismologists registered two explosions near the leaks on Monday, according to NBC News’ Rhoda Kwan. Later, gas became visible on the surface of the ocean near the explosions, according to the Times.

The European Union’s top diplomat, Josep Borrell, said the leaks were caused by a “deliberate act,” according to NBC News. “There’s no doubt, this is not an earthquake,” Bjorn Lund, director of the Swedish National Seismic Network, tells the AP’s Monika Scislowska, Jan M. Olsen and David Keyton.

Though Borrell didn’t accuse anyone outright, other European officials have said Russia is likely to blame for the leaks. Still, some have urged people to hold off on pointing fingers until an investigation has taken place, per the AP. The leaks come during an energy battle between Russia and the West due to Russia’s invasion of Ukraine, writes the Times.

The Danish Energy Agency says that the amount of natural gas contained in the pipelines was equivalent to 32 percent of Denmark’s annual carbon dioxide emissions, per the Guardian. Kristoffer Böttzauw, head of the agency, said in a press conference that all of the gas will likely be out of the pipes by Sunday, according to the AP.

Grant Allen, an earth and environmental scientist at Manchester University in England, tells the Guardian that natural processes would likely not be able to absorb much of the escaped gas. “My scientific experience is telling me that—with a big blow-up like this—methane will not have time to be attenuated by nature. So, a significant proportion will be vented as methane gas,” he tells the publication.

German authorities have said the leaks pose little risk to nearby plants and animals, while Greenpeace says plumes of gas could affect fishes’ breathing, per Reuters.

For now, experts aren't exactly sure how much methane will escape from the pipelines. Two scientists calculated for the AP that the leaks would release five times the methane as the 2015 Aliso Canyon disaster, based on the Danish government’s worst-case scenarios.

But Andrew Baxter, director of energy strategy at the Environmental Defense Fund, says to the AP that the Danish estimate might be too high. Still, he thinks the leaks will emit more than double the methane that Aliso Canyon did.

“That’s one thing that is consistent with these estimates,” he tells the publication. “It’s catastrophic for the climate.”

Will Sullivan | | READ MORE

Will Sullivan is a science writer based in Washington, D.C. His work has appeared in Inside Science and NOVA Next.