Your grass-fed burger isn’t better for the planet, new study finds
Grass-fed beef has no climate benefit — even when taking into account that healthy pastureland can trap carbon, according to a new study.
The Washington Post, March 18, 2025
by Anna Philips
For years, ranchers and some conservationists have argued that grass-fed beef is better for the planet than conventional cattle.
But a study published Monday in the Proceedings of the National Academy of Sciences challenges that idea, finding that cattle raised only on pastures do not have a smaller carbon footprint than feedlot cattle, which are quickly fattened on corn and other grains.
This held even when the researchers took into account that healthy pastureland can help capture more carbon by pulling it out of the air and storing it in roots and other plant tissues.
“Until now, with this study, there’s really been no rigorous analysis that combines these two pieces of the puzzle,” said Daniel Blaustein-Rejto, director of food and agriculture at the Breakthrough Institute, a think tank, who was not involved in the study.
Cattle are a major source of methane, a potent greenhouse gas that presents a growing threat to the world’s ability to confront climate change. The average cow produces about 220 pounds of methane per year, or about half the emissions of an average car. According to the United Nations’ Food and Agriculture Organization, cows are responsible for about 62 percent of global livestock emissions.
In the United States, very little beef is purely grass-fed. Most cattle are raised on pasture until they are weaned from their mothers and are then moved to industrial-scale feedlots, where they are fattened on grain.
Past studies have found that feedlot systems tend to have lower greenhouse gas emissions because grain-fed cattle gain weight faster than grass-fed cattle and are slaughtered at a younger age. Their shorter lives means feedlot cattle burp less planet-warming methane into the atmosphere than grass-fed cattle.
But some ranchers, conservationists and researchers have pushed back against these studies, saying that valuing feedlots for their efficiency ignores the role that carefully managed grazing can play in fighting climate change. They say healthier ranchland can have a big effect — if done on a large enough scale. By storing carbon underground instead of releasing it into the atmosphere, where it contributes to climate change, pastureland can act as a carbon sink.
Measuring the effect of soil-improving practices is complicated. In the study, the researchers used newly available data from the United States comparing pasture where cows were grazing to grass that had been left undisturbed, excluding land that had clearly been overgrazed and degraded. They factored the effects of soil sequestration into the overall carbon footprint of grass-fed beef operations and compared this with feedlot systems’ emissions.
They found the emissions per kilogram of protein of even the most efficient grass-fed beef operations were 10 to 25 percent higher than those of grain-fed U.S. beef — and many times higher than those of plant and animal alternatives.
“Accounting for soil sequestration lowers the emissions, and makes grass-fed beef more similar to industrial beef, but it does not under any circumstances make this beef desirable in terms of carbon balance,” said Gidon Eshel, an environmental studies professor at Bard College and the study’s lead author. “That argument does not hold.”
A 2023 study by Blaustein-Rejto that looked beyond the emissions from cow burps and feed production found the comparison is even more unfavorable for grass-fed beef because of the amount of land it uses. When he factored in the opportunity cost of converting natural landscapes in 16 countries to cow pasture, he found grass-fed beef’s carbon footprint was 42 percent higher than that of grain-finished cattle.
“It really cuts against this common notion that ‘natural’ is best,” Blaustein-Rejto said. “That is a very uncomfortable idea for many people, that actually more technological systems, more intensive systems, more confined systems can have environmental benefits.”
Feedlots do have well-documented environmental drawbacks, including air and water pollution from thousands of steers living in close quarters, generating huge quantities of manure. In some rural communities, people living near these large-scale operations have accused them of harming their health. Animal rights activists largely view them as inhumane.
Some grass-fed advocates also suggest there’s a health advantage, in part because grass-fed beef has less fat overall. It can have higher concentrations of some nutrients, including antioxidants, some vitamins and omega-3 fatty acids — the fats found in fish. But evidence for its long-term health benefits is limited.
The controversy over whether grass-fed or grain-fed beef is better for the environment is primarily an American debate, said Timothy Searchinger, a senior fellow at the World Resources Institute and Princeton University researcher. That’s because outside of the United States, cattle are mostly grass-fed. The best chance to lower carbon emissions in major beef-producing countries such as Argentina and Brazil is from improved grazing practices that help cattle put on weight faster, Searchinger said.
“The strange thing is, even though feedlots are actually, unfortunately, better for climate in the U.S., feedlots are not the solution in most of the world.”
Researchers have developed ways to lower methane emissions from cattle by adding seaweed, oregano or garlic to their diets. Last year, the Food and Drug Administration approved an emissions-reducing food additive called Bovaer for use in dairy cows in the United States. Other scientific research aims to change cows’ microbiome itself. But most of these efforts have yet to reach American farms and ranches.
“There’s a number of things going on at the moment that would reduce the emissions quite substantially,” said Ermias Kebreab, a professor of animal science at the University of California at Davis. “Those solutions are coming.” [Yeah, that’s what you Big Beef supporters keep promising, Ermias. Why not just give up eating cows altogether, since dairy & “beef” are probably the most inefficient and ecologically destructive human food on the planet – TreeSpirit]
READ THE FULL Washington Post ARTICLE: https://www.washingtonpost.com/climate-environment/2025/03/17/grass-fed-beef-health-emissions/?commentID=54770785-fa25-4a79-af54-875ebc4d7aa8