For the millions of people who come to Munich for the annual alcoholic drinks festival, the Oktoberfest celebrates beer, bands and bratwurst.
But while the dust settles for another year on the largest popular festival in the world, e die Bierleichen back in the land of the living, environmental scientists released the first analysis of methane emissions from the 16-day party.
Researchers from the Munich Technical University walked and cycled around the perimeter of the festival last year with mobile sensors at the top. The tools revealed that the event issued almost 1,500 kg of methane – 10 times the amount that spread off Boston, Massachusetts, over the same period.
Scientists attribute the majority of Oktoberfest emissions to incomplete leaks and combustion in cooking and heating appliances. Although an appreciable part of the increase in gas, around 10%, has been attributed to flatulence and burping of revelers.
"Methane concentrations observed cannot be explained solely by biogenic sources," said Jia Chen, who studies greenhouse gases in urban environments. "We have strong indications that the emissions of methane from fossil fuels by gas grills and heating appliances are the main sources."
After carbon dioxide, methane is the second most common greenhouse gas emitted by human activity. Although short-lived, it is more effective than carbon dioxide in the warming of the atmosphere and accounts for about 20% of global warming due to anthropogenic greenhouse gas emissions since 1750. Atmospheric gas levels have increased over the past years for reasons that scientists cannot fully explain.
Having noticed a peak in Munich's methane levels during the Oktoberfest in previous years, Jia Chen and her colleagues decided to monitor the event to see if the major festivals made an important contribution to greenhouse gas emissions . Over six million people visit the Oktoberfest every year and make their way through over seven million liters of beer, 100,000 liters of wine, half a million chickens and a quarter of a million sausages.
To Chen's surprise, on average, every square meter of the Oktoberfest 2018 released 6.7 micrograms of methane per second. It is estimated that less than a tenth comes from the same festival participants in the form of flatulence and burps, according to a paper presented to the newspaper Chemistry and physics of the atmosphere.
Chen believes the work can help festival organizers develop policies to reduce their methane emissions. The study concludes that methane emissions are high enough to allow major festivals to be considered sources of greenhouse gases in local emission inventories.
"Festivals of large dimensions but limited in time, such as Oktoberfest, are sources that have not been taken into account in existing emission inventories, although, as we have seen, methane emissions are significant," he said. Chen at the Guardian. "Inaccurate or incomplete emission inventories are a problem, because many decisions
are based on this data. "
With people traveling to Oktoberfest from over 50 countries, methane leaks from the Theresienwiese site are not the main environmental concern. But improving gas appliances to reduce methane emissions still makes sense, said Chen. "Small steps can bring us closer to achieving global climate goals".