The gas pipelines contained approximately 778 million cubic meters of methane gas, according to information provided by the company Nord Stream to the Danish Energy Agency.
In Sweden, the Swedish Environmental Protection Agency has in turn calculated the effects of the leaks on the climate.
- When I calculated it, I realized that it is a large amount of emissions, says Mats Björsell.
The calculations show that the leaks correspond to 40 million tonnes of carbon dioxide over a 20-year perspective.
This can be compared with the whole of Sweden's combined climate emissions last year of 48 million tonnes.
- In total, the emissions will be on a par with Sweden's total emissions over the course of a year.
Worse in the short term
Methane is a more powerful greenhouse gas than carbon dioxide, but breaks down faster in the atmosphere.
Over a 100-year horizon, methane causes 28 times greater warming than carbon dioxide, while over a 20-year horizon, it is 84 times more powerful.
It is decisive for how the emissions are to be assessed.
- It has become increasingly urgent to reduce emissions quickly.
It is therefore relevant in the eyes of many to make calculations on a shorter perspective such as 20 years, says Mats Björsell.
Christophe Duwig, professor of chemical engineering at KTH, has made similar calculations on the size of the release and arrived at approximately the same results as the Swedish Environmental Protection Agency.
He takes the leak seriously.
- The climate is greatly affected, there is a very large leak and large amounts of methane are released.
It has a significant effect, he says.
Both Duwig and Björsell emphasize that the calculations are uncertain, above all depending on conflicting information about how much gas was in the lines.
Nord Stream's data may be exaggerated.
- There are big uncertainties, we don't know how much the pipes contain, it depends on what pressure you have had, says Mats Björsell.