Among the leading contributors to anthropogenic greenhouse gases responsible for global warming are cattle who, through natural digestive processes, release large quantities of methane into the atmosphere. And while much of it is released via burping and flatulence, a portion of this methane is emitted from cow pats, which, a new study shows, may be partly neutralized by beetles found living in these dung heaps.
"Cow pats offer a prime food for a large number of organisms," Atte Penttilä, who took the study on while study at the University of Helsinki, said. "In fact, there are probably as many beetle species living in dung as there are bird species on this planet."
Knowing that these beetles are helping to reduce methane emissions tied to cattle production is important, the researchers explain, when calculating the overall climatic effects of dairy and beef farming.
"We believe that these beetles exert much of their impact by simply digging around in the dung," Penttilä said. "Methane is primarily born under anaerobic conditions, and the tunneling by beetles seems to aerate the pats. This will have a major impact on how carbon escapes from cow pats into the atmosphere."
This, according to Tomas Roslin, head of the research team, is because in addition to how much carbon is released, is the question of what form it is released in.
"If carbon is first taken up by plants as carbon dioxide, then emitted in the same format by the cows eating the plants, then the effect of plants passing through cattle will be small in terms of global warming," the researcher explained. "But if in the process the same carbon is converted from carbon dioxide to methane -- a gas with a much higher impact on climate -- it is then that we need to worry."
The news, however, is not overwhelmingly positive, according to Eleanor Slade, a researcher who worked with teams examining dung beetles in both Helsinki and Oxford.
"When you combine the current increase in meat consumption around the world with the steep declines in many dung beetle species," she explained "overall emissions from cattle farming can only increase."