Methane emissions from U.S. dairies in decline

U.S. dairy and livestock trends point to a decline in methane emissions. While the greenhouse gas has been used by climate change activists to clobber animal agriculture, science points to a different trend.

Methane as a greenhouse gas has long been the Achilles’ heel for activists to attack animal agriculture. That appears to be shifting as scientific discovery suggests a reduction in atmospheric methane over the United States.

Frank Mitloehner, a professor and air quality Extension specialist with the University of California and scientific colleagues from across the globe are helping to change the narrative on methane. In an address to a virtual meeting of the Animal Agriculture Alliance, Mitloehner said methane does not accumulate in the atmosphere like carbon dioxide but is part of a cycle that starts and ends as carbon.

While methane is still linked to a warming climate and is said to be 28 times more potent than carbon dioxide as a greenhouse gas, the science behind how it is created also reveals that it is a short-lived gas that is destroyed through biological processes. The term Mitloehner used is "atmospheric removals."

That was effectively the "take-home" message from his presentation. Methane, while rightly worrisome to climate scientists because of its ability to raise global temperatures, is a short-lived climate pollutant that can be managed. It is also important to note, according to Mitloehner, that the accumulation of atmospheric methane is flat or declining in developed countries as livestock herd numbers, particularly in the United States, are declining.