What is our assessment?

Based on our analysis, grass-finished beef production has higher emissions of enteric methane and emissions from land use conversion than does conventional beef production, and would increase risks of biodiversity loss if scaled to meet current demand. Therefore, it is "Not Recommended" as a climate solution.

What is it?

Grass-finished beef production involves raising cattle exclusively on available pasture for their entire lives, eliminating the need for feed crops and associated resources. All cattle begin life on pasture; however, in conventional beef production, the animals spend their final four to six months in high-density feedlots, often called concentrated animal feeding operations (CAFOs). In these systems, cattle are fed high-calorie, mostly grain-based-energy feeds to gain weight quickly. The animals put on one-third to one-half of their total weight during this time, to reach slaughter weight by ~18 months. In contrast, grass-finished beef production requires ~24 to 28 months for animals to reach market weight on forage alone. 

Cattle raised entirely on grazing with no other feed inputs provide only about 1% of global protein. Using broader definitions of grass-finished that allow supplementary forage increases the global beef that would qualify to roughly one-third of global production (about 2–3% of global protein). Grass-fed cattle often receive supplementary feed in pasture-based systems in places such as Brazil, Ireland, and Australia, particularly during seasonal feed shortages.

Does it work?

Deploying grass-finished beef is not an effective climate mitigation strategy. Grass-finished cattle eat a more fibrous diet that produces higher methane emissions per unit of energy intake, and they take longer to reach market weight, resulting in higher lifetime methane emissions per animal. One widely cited study found that forage-fed cattle produce around four times more methane per unit of digestible energy intake than those fed corn- and grain-based diets. In addition, slower weight gain and longer production time require more grazing land, which would likely increase emissions from deforestation and other land use change. Life-cycle assessments consistently show higher emissions per kilogram for grass-finished beef than for grain-finished beef. Even the most efficient grass-finished systems produce 10–25% more emissions per kilogram of protein than grain-finished U.S. beef, and three to over 40 times more than a wide range of plant and animal protein alternatives.

Why are we excited?

Interest in grass-finished beef reflects a broader effort to reduce the environmental harms of industrial livestock systems and improve land stewardship. In limited local contexts, if grass-finished and feedlot grain–finished cattle could gain weight equally, this could alleviate the need for crops destined for feedlot. A recent estimate found that, globally, 34% of crops grown on recently converted natural ecosystems went to animal feed instead of feeding people directly. While grass-finished beef has a higher total water use, it can reduce water risk by shifting from irrigated feed crops for cattle feedlots to rain-fed pastures.

From a human health standpoint, grass-finished beef may contain slightly higher omega-3 fatty acids and vitamin E, but the differences are small and unlikely to meaningfully affect health outcomes. It is often slightly leaner, which can reduce total fat and saturated fat somewhat, but beef in general remains higher in fat than most food options, which increases the risk of heart disease. Within the broader category of red meat, it is still a Group 2A probable carcinogen, according to the World Health Organization. 

Another human health consideration is that grass finishing requires less antimicrobial use. Antibiotics and other antimicrobials are often used in large quantities in confined livestock systems, and cattle account for over half of antimicrobial use among cattle, chickens, and pigs. This use increased by 43% between 2010 and 2020, raising concerns about accelerating antimicrobial resistance and making infection treatments in humans less effective. This may be the strongest case for grass-finished beef, particularly within a global demand reduction scenario.

From an animal welfare perspective, pasture-based systems allow natural behaviors such as walking, socializing, and grazing freely. However, animals are still slaughtered at a young age (before 3 years old) relative to their natural lifespan of 20 years.

Why are we concerned?

Beef production is already the largest single land use globally and the most emissions-intensive food option. Shifting to grass-finished systems would further increase this footprint. Beef is inherently protein-inefficient, requiring large amounts of feed and land. While grass-finished systems were historically the norm, the rise of grain-finishing feedlots after the 1950s modestly improved efficiency by shortening cattle lifespans and reducing per-kilogram land use. Land is a key limiting factor in any expansion of grass-finished production. In the United States, pastureland could support only approximately 27% of current beef production under grass-finished systems. Maintaining current output would require roughly 30% more cattle and 270% more land and would result in a 43% increase in associated methane emissions.

Such land expansion would pose serious biodiversity loss risks. Animal-sourced foods are the leading driver of biodiversity and habitat loss globally. Ruminant meat is disproportionately responsible, causing extinction risks ~340 times higher than grains by mass and ~100 times higher than legumes both by mass and when adjusted for protein, according to a 2025 study.

Last, many government and commercial “grass-fed” certifications are not well enforced and often include cropland-grown forage, which still results in slower weight gain, more methane emissions, and often land carbon leakage. As a result, there are concerns about greenwashing as major fast-food chains market grass-fed beef as environmentally friendly.

While there will likely continue to be an appeal to consumers to choose grass-finished beef, it does not meaningfully change the environmental reality of producing it.