As a fourth leak has been reportedly found on the Nord Stream gas pipelines in the Baltic Sea, climate scientists have warned the unexplained natural gas leaks will have a “significant” environmental effect, estimating up to half a million metric tons of methane has been released into the sea.
Methane makes up the majority of natural gas flows, and given its potency as a greenhouse gas, the leaks –– whether deliberate or not –– have been branded a “tragedy and very perplexing” situation by climate experts.
Experts say the leaks will add short term impact to greenhouse gas emissions but the effects to marine life should be “minimal.”
“This is indeed a tragedy and very perplexing. The natural gas that is escaping will contribute to short-term greenhouse gas emissions, but this is hard to quantify unless we know the volumes in the pipeline, and gas flow should have been turned off,” Grant Wach, professor of geoscience at Dalhousie University in Canada, told MarketWatch.
Stanford University climate scientist Rob Jackson and retired chemical oceanographer David Hastings have estimated roughly half a million metric tons of methane was released from 778 million cubic meters of gas, calculated using official worst case scenario estimates provided by the Danish government.
For reference, the Aliso Canyon disaster in 2015 released 90,000-100,000 metric tons of gas.
Andrew Baxter, a methane expert at the Environmental Defense Fund, told Barrons that just one of the pipelines could release emissions equating to the annual emissions of two million cars.
One of the biggest leaks is a 700 meter-wide (766 yards) gas bubbling pool in the Baltic Sea. The Danish military said the leaks, which are visible by satellite, range from 200 meters to 1 kilometer in diameter.
Doug Weir, research and policy director at The Conflict and Environment Observatory says the local effects of the leaks should be “minimal.”
“While this situation and the context are highly unusual and the volume of the methane released is significant, in our view any localized environmental effects on the marine ecosystem should be minimal,” he told MarketWatch.
“Unless there were lighter oils or condensates mixed with the natural gas there should be limited effects to marine life,” Wach added.
On Thursday, the Swedish coast guard told Swedish outlet Svenska Dagbladet it found another leak on Nord Stream 2 earlier this week, meaning each pipeline has two gas leaks each, in both Swedish and Danish waters.
The disaster began on Monday when ruptures were found after a pressure drop built up in the Nord Stream 1 and 2 pipelines. On Tuesday, Swedish seismologists reported a number of explosions around the pipelines between Russia and mainland Europe.
The leaks found were met international uproar. European leaders say they were a result of sabotage, though no concrete evidence has been found yet.
Weir added that deliberate attacks to commodities are not new.
“The deliberate weaponization of the environment in conflict settings does happen. For example Iraq setting alight oil wells in Kuwait in the 1991 Gulf War and, more recently, Islamic State setting fire to oil wells in Iraq in 2016,” he said.
“It could be argued that Russia has already demonstrated a willingness to hold the environment hostage through its occupation of the Zaporizhzhia nuclear power plant in Ukraine. Nevertheless, it’s unfortunately the case that the climatic cost of the pipeline attacks was probably not a priority in the mind of the perpetrator,” he added.