True scope of Nord Stream pipeline leak revealed
A major leak of a greenhouse gas from the Nord Stream pipeline was far more significant than first realised, according to new research.
An international team of 67 researchers, including four from the School of Earth and Environment, has now revealed the true scope of the leak in 2022 – the largest single release of methane ever recorded.
Emissions from the pipeline which transports natural gas from Russia to Germany under the Baltic Sea were nearly double some initial estimates, with approximately 465,000 metric tons of methane released into the atmosphere – the equivalent of eight million cars driven for a year.
The results of the research are published today (15 January 2025) in the journal Nature.
The study, led by the United Nations Environment Programme, used state-of-the-art estimates of the leaks based on a range of scientific methods, combining new estimates from pipeline release models, models of the ocean and atmosphere, and a range of observations of the methane released into the atmosphere.
Understanding and reducing methane emissions will have a large benefit in limiting the extent of climate change.
The team at the University of Leeds used a 3D chemistry transport model called TOMCAT to track satellite-based measurements of the methane plume back to its source and produce an observation-based estimate of the leak rate from the pipelines. TOMCAT uses meteorological data, such as winds and temperatures, to simulate the transportation of chemicals through the atmosphere.
By combining data from the Leeds scientists with other sources, the international team was able to provide a more holistic and accurate estimate of emissions.
Study co-author Dr Chris Wilson who is a research scientist for the UK's National Centre for Earth Observation (NCEO) and the School of Earth and Environment at Leeds, said: “This event released a huge amount of natural gas into the atmosphere and one satellite instrument that we used was able to track a plume of very high methane concentrations over the North Sea for several days afterwards.
“The team here at Leeds used these observations to quantify the leaks, and our atmospheric model provided one of the vital strands of evidence for the robust estimate provided in this new study.”
Previous estimates of the Nord Stream leak varied widely as they told part of the story from a different perspective. The researchers believe that by combining them they have provided a coherent and accurate view of the emissions and that this underscores the importance of integrating diverse but complementary methods of measurement.
Fellow co-author Professor Martyn Chipperfield of the National Centre for Earth Observation, added: "Methane is a very potent greenhouse gas and second only to carbon dioxide in its importance for causing climate change.
“Moreover, because of its relatively short atmospheric residence time, understanding and reducing its emissions will have a large benefit in limiting the extent of climate change.
“This unexpected test case has confirmed our ability to quantify methane sources from a variety of sources."
Further information
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For media enquiries, please contact Kersti Mitchell in the University of Leeds press office via k.mitchell@leeds.co.uk
