For many years, I’ve been a critic of cattle production. I have mainly focused on public land grazing because that is one area where citizens can have a voice in management. More recently, concern about livestock’s contribution to climate warming has garnered more attention. The punch line is that any kind of beef is bad for our climate, and one should avoid red meat whenever possible.
The average cow produces about 220 pounds of methane per year, or about half the emissions of an average car!
Many liberal, ecologically oriented folks prefer to buy “grass-fed” beef, believing that somehow this is environmentally friendly. Most land trusts and many conservation groups promote ranching as a “benign” or even good thing for the environment. Yet the overwhelming evidence suggests that, from a climate-warming perspective, grass-fed beef is far worse than CAFO (Confined Animal Feed Operation),
A study published Monday in the Proceedings of the National Academy of Sciences finds that grass-fed beef produces more methane than other livestock operations.
We know that CO2 and methane trap heat. In the most recent estimates, the atmospheric CO2 level was 51 percent above that of the pre-industrial era. In 2023, CO2 concentrations were at 420 parts per million (ppm), methane at 1,934 parts per billion, and nitrous oxide at 336 parts per billion.
The United Nations Food and Agriculture Organization estimates that cattle are responsible for 62 percent of global livestock emissions. One estimate finds that one cow yearly produces about 50% of the emissions of a typical car. Yet at least one World Watch article suggests that livestock production may contribute to as much as 51% of climate warming. The full report can be downloaded here.
Other sources conclude that livestock, particularly cattle, are somewhere in between, attributing 11 to 20% of all global GHG emissions to livestock. The U.S. EPA assigns one-third of anthropogenic methane emissions to livestock production—ahead of natural gas and petroleum systems as a source (Myers 2014).
The difference in various estimates concerns what is counted as emissions. For example, expanding cattle pasture land is responsible for 41 percent of tropical deforestation, but deforestation emissions are often counted under a separate category of land use, land-use change, and forestry (LULUCF)). Letting pasture return to forest would store far more carbon than any benefits from so-called “regenerative” agriculture.
Livestock apologists argue that grass-fed cattle are better than CAFO-raised livestock. But CAFO cattle are fed higher protein feedstock and tend to put on weight faster than grass-fed animals, thus ultimately producing fewer methane emissions before they are slaughtered.
Grass is nutritionally inferior and requires greater transit time in the cow’s rumen, resulting in anywhere from 2–4 times as much methane production. For instance, one study reported a 48% increase in methane production by cows feeding on natural grasslands (Grobler, S.M. et al. 2014). In another study comparing CAFO-farmed animals with natural pasture-fed cattle, the grass-fed beef had significantly greater methane emissions (Pelletier, N. et al. 2010).
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 mean feedlot cattle burp less planet-warming methane into the atmosphere than grass-fed cattle.
Further, to compensate for the slower time it takes for a cow to gain weight before slaughter while still producing the same amount of meat, a significant increase in pasture would be required.
A 2023 study demonstrated that the needed conversion of land to pasture grass-fed beef’s carbon footprint was 42 percent higher than that of grain-finished cattle.
One shouldn’t pretend that “grass-fed” beef is somehow environmentally superior to other forms of beef. All cow production is bad for our climate.
All of this suggests that eating beef—whether grass-fed or CAFO origins-is a bad idea. If you must consume meat, many other sources are available that do not contribute nearly as much to climate warming, including rabbits, chickens, and fish.
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