German municipal gas pipe leaks cause more than 1 mio t CO2 emissions

Methane leaks in municipal gas pipe systems produce an estimated 1.3 million tonnes of CO2 equivalents annually in Germany, according to Der Spiegel, which cites a new study by an international team of researchers, including scientists from the University of Utrecht and the Environmental Defense Fund (EDF). The study, which reports that a lot of methane escapes into the atmosphere from city gas networks, comes as data from the World Weather Organization (WMO) show the methane concentration in the atmosphere has reached a new high. Methane damages the climate far more than carbon dioxide.

In their study, the researchers say methane emissions can be reduced easily by detecting small leaks in municipal gas pipe networks. According to the study, Hamburg alone leaks some 286 tonnes of methane into the atmosphere annually, corresponding to about 24,600 tonnes of CO2 equivalents if the climate impact of methane is considered over a 20-year period. Using air analyses, the scientists examined methane emissions from several European cities’ gas networks. "We discovered elevated methane concentrations at 145 points in the Hamburg city area,” said Stefan Schwietzke, EDF scientist and the study’s co-author. “For two-thirds of these, leaks in the gas network are the cause. Biogenic sources such as wastewater or waste storage are responsible for the remaining third."

Some gas network operators are already making efforts to find and close leaks. The municipal company Gasnetz Hamburg, which is responsible for the city’s pipelines, employs eight "gas trackers". Every year they examine around a third of the 7,900-kilometre-long network with highly sensitive probes, according to the company. More methane emissions escape during the production and transport of natural gas and not from local gas networks, according to a 2019 study by thinktank Energy Watch Group, which estimates that up to 2.5 percent is lost in the process – a similar order of magnitude to imported US liquefied natural gas. This potentially makes natural gas even more harmful to the climate than coal, although less CO2 is released when natural gas is burned.

Environmental Action Germany (DUH) said this month that it was suing to stop the controversial Nord Stream 2 natural gas pipeline from going into operation and demanding a fuller accounting of the project’s potential greenhouse gas emissions.