Livestock methane emissions contribute more to global warming than previously thought. A new study by three scientists with the Joint Global Change Research Institute revealed that this source resulted in 11 percent more methane than what scientists had calculated, meaning that this gas coming from animal poop and farts may be a major contributor the rise in the atmospheric budget over the 2000s to 2010s.
Cows, swine and other livestock release methane into the atmosphere as a result of the digestive process in the animal’s stomachs. The gas produced in this process – scientifically known as enteric fermentation – makes up most of the emissions from ruminants, as explained by the Environmental Protection Agency.
A natural byproduct of digestion, methane significantly contributes to the greenhouse effect and climate change by trapping heat within Earth’s atmosphere. Compared to carbon dioxide, the main contributor to global warming, methane is 85 times more potent to trap heat, but it breaks down faster.
Published Thursday in the journal Carbon Balance and Management, the study considers changes in the way people are handling the animals’ waste, as well as changes in manure management. A center of the University of Maryland and the Pacific Northwest National Laboratory were also part of the NASA-funded research.
Changes in the industrialization of agriculture contribute to global warming
Rob Jackson, a methane expert at Stanford University who was not part of the study, affirmed that from all human activities, agricultural emissions make up the largest source of methane. Rice paddies also emit significant amounts of this gas.
The methane expert said this research offers improved calculations of livestock emissions due to the inclusion of aspects such as the places where the cattle are located, their size and how humans manage their feed and waste, according to a report by The Washington Post.
Moreover, Julie Wolf, lead author of the study, explained that the livestock had been bred to be larger in the majority of developed regions, where this economic activity had become more productive and efficient, as reported by The Post. Larger animals release a massive amount of methane into the atmosphere, noted Wolf, who works at the Department of Agriculture at the Joint Global Change Research Institute.
Because livestock is larger than before and is, therefore, being fed more, people are managing their manure differently and often thrown to massive waste lagoons that release large volumes of methane into the atmosphere. This changes in the industry of agriculture led the researchers to update the guidelines the United Nation’s Intergovernmental Panel on Climate Change (IPCC) introduced in 2006 to estimate methane emissions.
The updated methodology allowed scientists to discover that, compared to research by the IPCC, global emissions released by enteric fermentation were 8.4 percent higher by 2011 and those coming from manure management were 36.7 percent higher.
“We believe our approach, because of its uniqueness, has helped provide some clarity on some of the changes that we see over the recent decade,” said Ghassem Asrar, study co-author and head of the Joint Global Change Research Institute, as quoted by The Washington Post.
Drew Shindell, a professor at Duke University involved in research about methane emissions, believes it might be possible to control the amount of gas being released by cattle. He said people could change the animal’s diet to reduce the effect of their waste.
Source: The Washington Post