The sabotage of the two Nord Stream pipelines is likely to be releasing five times the amount of methane into the atmosphere as the largest greenhouse gas release in US history.
The leaks are pumping huge amounts of methane into the Baltic Sea and atmosphere, which is likely to be the largest release on record, and much larger than the Aliso Canyon disaster.
According to a Danish official, it is the equivalent of a third of Denmark's total annual greenhouse gas emissions.
The dual pipes run from Russia to Germany, providing much needed gas for heating and industry. They were decommissioned by Russia for several weeks.
A number of explosions were registered in Denmark, Norway and Finland shortly before the leaks were discovered.
The leaks, which will push up energy prices, have been accused of being caused by the Kremlin.
The person who ordered this should be prosecuted for war crimes and go to jail, according to Stanford University climate scientist Rob Jackson.
Two scientists looked at the official worst-case scenario estimates provided by the Danish government -- 778 million cubic meters of gas - for The Associated Press.
Professor Jackson and the retired chemical oceanographer David Hastings of Gainesville, Florida, each calculated that would be the equivalent of about half a million metric tons of methane.
In October 2015, the Aliso Canyon disaster released 100,000 metric tons of natural gas into the atmosphere. Methane is the largest component of natural gas. Andrew Baxter, a chemical engineer who formerly worked in the offshore oil and gas industry and now at EDF, thought the Danish estimate was too high.
He had a more conservative estimate, but it was still more than double the Aliso Canyon disaster.
The Danish Energy Agency chief Kristoffer B tzauw said emissions from the three leaks on the underwater Nord Stream 1 and 2 pipelines were equivalent to about 32 per cent of annual Danish carbon dioxide emissions.
In 2020, Danish emissions were about 45 million tons of CO2.
The methane seen in the ocean surface was an indication of a strong upward flow according to Imperial College London's Paul Balcombe, a member of the engineering faculty in the department of chemical engineering.
He said that the loss of pressure in the pipes likely meant a large amount of gas had already been lost.
The effects were likely to be significant, according to Balcombe.
Even if it released a portion of this, it would have a very large environmental and climate impact, he said.
Methane is a major contributor to climate change and is responsible for much of the current climate disruption.
It is 82.5 times more potent than carbon dioxide at absorbing the sun's heat and warming the Earth.
On Sunday, Mr B tzauw said half of the gas had now leaked from one of the two pipes.
He said we are talking about a huge spill of several million cubic meters of gas.
As long as there is gas, it is dangerous to be there, according to Mr B ttzauw.
He did not say when experts would be able to see the pipes, which lie on the seabed between 70 and 90 metres deep.