(Reuters) – Unexplained leaks in two Russian gas pipelines in the Baltic Sea are giving off greenhouse gas emissions, raising fears the disruption could cause a climate catastrophe – although it is not yet clear to what extent.
Neither pipeline was in service, but both contained natural gas – which is largely composed of methane, a potent greenhouse gas that is the second biggest cause of climate change after CO2.
“There are a number of uncertainties, but if these pipelines fail, the impact on the climate will be disastrous and could even be unprecedented,” said atmospheric chemist David McCabe, who is the lead scientist. principal of the non-profit organization Clean Air Task Force.
Mr McCabe and other emissions experts told Reuters it was not yet possible to assess the extent of the leak, given the uncertainties surrounding factors such as the temperature of the gas in the pipeline, the the speed at which it leaks and the amount of gas that would be absorbed by the microbes in the water before reaching the surface.
But as the two Nord Stream pipelines contain mostly methane, “the potential for a massive and very damaging emission event is very worrying,” Mr McCabe said.
Over a period of 20 years, methane has a global warming power more than 80 times greater than that of carbon dioxide, and about 30 times greater over 100 years. According to scientists, a sharp reduction in methane emissions over the next few years will be an essential lever to curb climate change.
DIFFICULT TO QUANTIFY
Jasmin Cooper, an associate researcher at Imperial College London’s Sustainable Gas Institute, said it would be difficult to quantify exactly how much of the gas is reaching the atmosphere – not least because there is little data on leaks from subsea pipelines. .
“Gazprom will probably have an estimate based on gas flows, but in terms of how much gas/methane is put into the atmosphere…now they have to send a team to measure and monitor,” she said, referring to the Russian state-owned gas company.
A “conservative estimate” based on available data suggests that the entire leak was releasing more than 500 metric tons of methane per hour during the first breach, with pressure and flow decreasing over time, Jean-Franois Gauthier said. Vice-President of Measurements of the commercial satellite methane measurement company GHGSat.
By comparison, the massive Aliso Canyon gas leak in the United States in 2016 spewed around 50 tonnes of methane per hour at its peak. “So it would be an order of magnitude higher,” said Gauthier.
A spokesperson for Nord Stream 2 – one of the leaky pipelines that never started operating and was shelved by Germany just before Russia invaded Ukraine – said that week that the system contained 300 million cubic meters of gas.
The release of this quantity into the atmosphere would result in the emission of around 200,000 tonnes of methane, said chemical engineer Paul Balcombe of Queen Mary University of London.
German nonprofit Deutsche Umwelthilfe gave a similar estimate of the pipeline’s potential emissions.
This amount of methane would have roughly the same global warming potential over a 100-year period as about 6 million tonnes of carbon dioxide, according to Reuters calculations based on IPCC conversion factors. This roughly corresponds to the amount of CO2 released in an entire year by medium-sized cities like Havana, or Helsinki or Dayton, Ohio.
How much gas is leaking from the Nord Stream 1 pipeline network is less clear, with a pipeline spokesperson declining to say how much was left in the network when it was taken out of service for maintenance a few weeks ago.
Stefano Grassi, head of the cabinet of the European Commissioner for Energy, said Tuesday that the leaks risked becoming “a climatic and ecological disaster”.
“We are in contact with [les tats membres de l’UE] to investigate what happened and find the quickest way to stop the leaks and prevent further damage,” Grassi said in a tweet.
EU countries are among around 100 countries, including the United States, Brazil, Pakistan and Mexico, which pledged last year to reduce their combined methane emissions by 30% by 2030 , to help avert disastrous levels of climate change.
ENVIRONMENTAL RISK
While oil spills can immediately affect and ultimately kill wildlife, authorities say gas leaks from the pipeline pose a limited threat to surrounding plant and animal life.
Germany’s environment minister said the leaks would not pose a significant threat to marine life, but Greenpeace on Tuesday raised concerns that fish could be caught in the gas plumes, which could interfere with their breathing.
The Danish Energy Agency told Reuters it was too early to say who would be investigating the Nord Stream 2 leak and that no one had yet been to examine the pipeline.
She added that the leaks will likely continue for several days and possibly even a week.