You might feel good buying grass-fed, free-range beef, touted as better for the environment than conventional beef from factory farms. But you're "being misled," says Bard College geophysicist Gidon Eshel, author of one of the first studies to compare the carbon footprint of grass-fed and feedlot cattle, while also taking into account the role of pastures in sequestering carbon, per Euronews. In the study published Monday in PNAS, researchers used newly available US data to analyze how much carbon was stored underground in undisturbed grassy areas and in grazing areas managed to increase the amount of carbon stored in the soil, adding this information to the overall carbon footprint of grass-fed beef. Even then, feedlot cattle had a smaller carbon footprint.
The average cow produces 220 pounds of planet-warming methane annually, roughly half the emissions of an average car, per the Washington Post. But feedlot cattle, quickly fattened on grains, are slaughtered at a younger age than grass-fed cattle who are slower to gain weight, meaning they have less time to burp methane into the atmosphere. Grass-fed cattle also don't get as large as grain-fed cattle, "so it takes more of them to produce the same amount of meat," per Euronews. However, some ranchers, conservationists, and researchers have challenged the notion that grass-fed beef is worse for the planet, saying it ignores the benefits of soil sequestration, or the management of land to increase the amount of carbon stored in the soil.
Yet even the most efficient grass-fed beef operations had 10% to 25% higher emissions per kilogram of protein than factory farms, per the Post. This isn't to say there aren't other drawbacks to factory farms. Air and water pollution, accusations of animal cruelty, and the potential to spread diseases are just a few. Some advocates also make the case that grain-fed beef is less healthy—more fatty and containing fewer antioxidants and vitamins—than grass-fed beef. For consumers struggling to make a choice, Eshel suggests they avoid making beef "a habit." With climate change posing the biggest threat to the world, raising beef is unlikely to prove "environmentally, genuinely wise," he tells Euronews. Most plant and animal alternatives are far less carbon intensive. (More carbon emissions stories.)