Do “cow farts” cause global warming?
While it makes for endless dad jokes, it’s a myth that cow farts cause global warming.
Cows actually burp out methane as their complex ruminant digestive systems break down plant materials, explains Dr. Sara Place, an animal science professor at Colorado State University.
Activist groups often blame cattle emissions – or to put it bluntly, cow farts – for climate change. That’s because cows emit methane, a greenhouse gas linked to global warming.
Yes, cow farts make for great comedy. But in reality, climate change – and livestock agriculture’s role – are a lot more complex, Place says.
Cattle and other ruminant animals account for about 4% of U.S. greenhouse gas emissions, according to the U.S. Environment Protection Agency (EPA).
In comparison, our transportation system — including cars, planes and more — accounts for more than 25.3 percent of U.S. greenhouse gas emissions.
Even extreme dietary changes — such as switching to a vegan, all-plant diet — won’t have much impact on climate change and global temperatures, Place explains.
Research shows that removing all livestock and poultry from the U.S. food system would only reduce global greenhouse gas emissions by 0.36%, she notes.
Plus, studies have shown that if we eliminated all livestock from U.S. farms, our diets would be deficient in vital nutrients – including high-quality protein, iron and vitamin B12 – that meat provides, Place says.
“People want to act. I don’t doubt the good intentions. People want to make a positive difference,” Place says. “But if somebody does ‘Meatless Mondays,’ they are making no difference at all.”
How has U.S. cattle farming innovated to be more environmentally friendly?
Iowa farmers remain committed to continuous improvement to ensure the safety, nutrition and sustainability of the foods they grow for all.
Specifically, cattle farming in the United States is the most environmentally friendly and sustainable in the world, says Dr. Frank Mitloehner, an animal scientist and air quality specialist at the University of California-Davis.
For example, the U.S. dairy industry’s carbon footprint has shrunk by two-thirds since the 1950s, Mitloehner says.
Cows may still belch, but U.S. farmers are raising fewer cows. Today, there are about 9 million dairy cows in the United States, compared to 25 million dairy cows in 1950. That helps drive down potential greenhouse gas emissions like carbon dioxide and methane.
However, even with much fewer cows, U.S. dairy farms now produce 60% more milk than in 1950 thanks to improvements in farm animal care, sustainability and technology, Mitloehner says.
Also worth noting, while methane is a potent greenhouse gas, it rapidly decays in 12 years, Mitloehner says. In comparison, carbon dioxide – released by burning fossil fuels - lasts in the air for hundreds of years.
So if a cattle farm has existed for 12 years – and many cattle farms in Iowa have operated for generations - those established farms are carbon neutral and aren’t creating any new methane emissions, Mitloehner says.
Is beef a nutritious and sustainably produced food?
As for beef’s role in a sustainable diet, Place explains that cattle are natural “upcyclers.”
Cattle can consume plant material – such as grasses, corn stalks, cottonseed hulls, ethanol byproducts and more – that are inedible to humans because of cattle’s unique ruminant digestive system.
Without cattle, these plant materials would end up in landfills, Place says. And food waste in landfills is one of the biggest sources of greenhouse gas emissions in the United States, according to the Environmental Protection Agency (EPA).
“When you talk about nutrition and sustainability, cattle play a unique role as ruminants in the larger ag and food system,” Place says. “They are taking what we can’t consume and upgrading those resources into high-quality beef.”
Nutritionally, beef is an excellent source of many micronutrients, including B12, iron, zinc and high-quality protein, that are essential for human health, experts say.
The USDA also recommends lean beef as part of a heart-healthy diet in its MyPlate dietary guidelines.
To learn more about how Iowa farmers work to ensure meat quality, food safety and farm animal well-being, visit the “Real Farmers. Real Food. Real Meat” website.
This piece was originally published on April 2, 2019 and was updated on July 27, 2023.
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