This article has been updated on Sept. 30, 1 p.m.
Leaks in two Russian gas pipelines have been reported to be releasing greenhouse gas emissions, largely methane, in the Baltic Sea.
The pipelines are currently not in operation, however, both contain natural gas, a major component of which is methane – a greenhouse gas that, in the short-term, far exceeds the planet-warming qualities of CO2 – more than 80 times.
In fact, methane is widely considered to be the second biggest culprit after carbon dioxide in the climate crisis and scientists around the world have been calling on governments to curb emissions.
So far, it is still unclear what the extent of the damage is and what the reasons for it are, but experts fear that in the event that the “pipelines fail”, they may have dire, unprecedented consequences for the climate.
There are many uncertainties surrounding factors that would make it difficult to determine the size of the leak, such as the temperature of the natural gas in the pipeline and how much of it would be consumed by microbes before it can reach the surface.
Relevant: Investigation Reveals Massive Methane Leaks In Europe
Some conservative estimates based on existing data say that combined, the Russian pipelines leaks were likely to be releasing over 500 metric tons of methane per hour after the breach.
That is ten times the flow rate of the 2016 Aliso Canyon gas leak in the United States, which was leaking methane at a rate of 50 tons per hour at its highest point.
A spokesperson for the Nord Stream 2 pipeline, operated by Gazprom, shared that this week it held 300 million cubic meters of natural gas.
If all of that amount were to be released into the atmosphere, that would amount to roughly 200,000 tons of methane emissions.
Most governments have so far avoided pointing fingers at who is to blame for the leaks. The EU said it believes the leaks are due to sabotage but did not name a specific culprit. Fatih Birol, head of the International Energy Agency (IEA), said it was “very obvious” who is responsible but did not clarify any further.
The Russian government denied allegations of Kremlin responsibility and Putin said the incident is an “act of international terrorism.”
“We have materials that point to a Western trace in the organization and implementation of these terrorist acts,” Sergei Naryshkin, the director of Russia’s Foreign Intelligence Service (SVR) said on national television in Russia.
The U.S. denied it was responsible for the leaks and said a full investigation is needed to establish who damaged the pipelines.
Read more: Methane Emissions From Natural Sources Are Rising, Leading To A More Warming Earth
