"When it comes to climate change, we know where the most important warming agent — carbon dioxide — is coming from. Most of it is coming from the burning of fossil fuels, with additional contributions from deforestation and other causes.
But the second-most potent greenhouse warming agent — the hard-hitting, if short-lived, gas known as methane — presents more of a mystery. There has clearly been an alarming uptick in atmospheric methane in recent years, following a flattening of concentrations from 2000 to around 2007. But the cause of this particular pattern has been hotly debated, with some blaming the fracked natural gas boom (natural gas is primarily composed of methane) and others pointing to causes such as agriculture.
Now, new research published Thursday in the journal Carbon Balance and Management by three scientists with the Joint Global Change Research Institute, a center of the University of Maryland and the Pacific Northwest National Laboratory, point the finger at agriculture once again. And more specifically, at cattle and other livestock."