BLACKBURG, Va. — A 2020 Burger King ad was pulled after agriculturalists decried its message insinuating the “farts, burps and splatters” of methane produced by cows are a major contributor to climate-warming emissions.
Farmers objected to the perception that animal agriculture is a villain in the climate change narrative, said American Farm Bureau President Zippy Duvall. Parent company Restaurant Brands International has since pledged to consult with industry experts in future farming-related marketing campaigns.
But how much does animal agriculture contribute to greenhouse gas emissions?
Enteric fermentation is a natural part of the digestive process in ruminant livestock. Microbes decompose and ferment food in the digestive tract, producing methane as a byproduct.
While agriculture consistently represents just 10% of total U.S. greenhouse gas emissions when compared to other major economic sectors, enteric fermentation makes up a chunk of that contribution at 28%, according to a 2020 Environmental Protection Agency emissions inventory.
For more context—the U.S. currently produces 18% of the world’s beef with just 8% of the cattle, contributing 3% of overall greenhouse gases, Duvall added. And dairy cattle are thought to contribute less than 1% of total emissions.
“This is a big reason we get so riled up when we’re misrepresented,” he said.
The largest source of U.S. agricultural emissions is soil management, including fertilizer applications or tillage practices, making up 5% of overall emissions. The transportation sector has the biggest overall U.S. greenhouse gas impact, contributing 27.2%, followed closely by electricity generation and other industries.
“Animal agriculture is the industry’s largest component in Virginia,” noted Virginia Farm Bureau Federation President Wayne F. Pryor. “The sector is making recognized advances to reduce its environmental impact.”
Robin White, an associate professor in the Virginia Tech School of Animal Sciences, explained that enteric methane emissions are an important target of the animal agriculture industry moving toward carbon neutrality.
“Because molecules like methane and nitrous oxide have greater capacity to trap radiation and re-emit it back to earth, they have greater warming potential than less impactful greenhouse gases like carbon dioxide,” she said.
Carbon dioxide “sticks” in the atmosphere, and landowners must implement best management practices to sequester it. While methane has greater warming potential, it has a shorter life, metabolized quickly in the atmosphere. To reduce methane emissions, farmers can feed their animals methane-mitigating diets, or optimize farm population dynamics.
“If we can decrease the size of the atmospheric methane pool, we have an immediate positive impact on warming,” White said. “As we work toward climate change targets, this is one of our best strategies.”
–Virginia Farm Bureau