Grass-fed beef packs a punch to environment

April 8, 2010


First it was slow. Then local, then organic. Now it is firmly grass-fed.

As a rare geophysicist studying diet’s environmental consequences, I am asked daily by my colleagues – a bit bemused by my new field yet quantitatively astute and environmentally concerned – about the latest claim made about impacts of food production on the physical environment.

In this role, I get to keep a sensitive finger on the envirofood pulse. Unambiguously, grass-fed beef is all the rage now. Even the New York Times Op-Ed page featured a recent piece extolling the virtues of grazing cattle.

Depending on your guiding environmental objectives, grass-fed beef may indeed be the greatest thing since Guns n’ Roses or the environmental equivalent of entrusting former Secretary of Defense Donald Rumsfeld with military preparedness.

Yet on reasonably balancing the main geophysical dimensions of dietary choices, grass-feeding loses most of its touted allure, relegating its role in a rational food production system to the margins.

To be sure, the flesh of a healthy, thriving animal is clearly nutritionally superior to the biochemically compromised, microbiologically teeming ecosystem that is the bulk of the nation’s meat supply.

Grass-feeding is also biogeochemically sensible. Unlike mammals, bacteria in the ruminants’ digestive system can decompose cellulose, the sugar-based rigid structure into which most of the solar energy the biosphere absorbs is converted.

This decomposition converts the otherwise unavailable energy locked in the cellulose structure into metabolically readily available glucose. If it weren’t for the absorption of glucose liberated by bacteria mediated cellulose breakdown inside ruminant bodies, most of this energy would have bypassed the animal kingdom altogether.

These demonstrated virtues, however, pale in comparison to overwhelming environmental liabilities.

To begin with, there is greenhouse gas emissions, the argument most often invoked to promote grass-feeding. Yet grass-fed meat is more, not less, greenhouse-gas intensive.

In this, simple chemistry is the Draconian ring master, dictating that every decomposing carbon-containing molecule ends up as methane if the decomposition is anaerobic, as it is in the largely oxygen free rumen, and as carbon dioxide if the decomposition occurs in the presence of oxygen, as befalls most cellulose not digested by ruminants.

Since grazing animals eat mostly cellulose-rich roughage while their feedlot counterparts eat mostly simple sugars whose digestion requires no rumination, the grazing animals emit two to four times as much methane, a greenhouse gas roughly 30 times more powerful than carbon dioxide.

This, and the faster weight gain by feedlot animals, result in significantly higher greenhouse gas emissions per pound of meat by grass fed animals than by feedlot ones.

This is true, to variable a degree, for organic and non-organic, large- and small-scale grazing operations in the U.S. and overseas.

Then there is land. Upward of a quarter of the entire U.S. surface area is pasture or grazeland.

Grazing animals produce at most a quarter of the calories per acre typical plant based production systems do. While these facts are well established, they are often dismissed as irrelevant to the grass feeding question on the (partly correct) grounds that much grazing occurs on land that would otherwise produce no human destined calories.

But do we need more calories?

In recent decades, the U.S. has been consistently producing 3,800 kcal per person per year, almost twice the average person’s needs.

Given biodiversity declines due to dwindling, fragmented, wilderness, allocating all this land to inefficiently producing needless calories is foolhardy.

Even if you irrationally consider those extra calories indispensable, because of corn’s unrivaled caloric yield it makes more sense to produce them as a corn derivative on a fraction of the land, and still have some left for species protection.

Grazing cattle also compromise river systems in the fragile arid and semi arid environments in which they are disproportionately ubiquitous, and accelerate soil erosion.

Because they eat much more dry matter then feedlot animals, they also pressure dwindling local water supplies exactly where they are most vulnerable.

While some of those adverse impacts can be minimized by adequate management, most rigidly reflect cattle biology and north American geography.

Grass-feeding produces unnecessary low-quality calories at ostentatious environmental costs while displacing threatened wildlife.

While some grass-feeding may be reasonable on marginal lands near population centers in the rainy eastern U.S., the logical number of grazing cattle in the western U.S. is zero.

What we need is not grass fed cattle, but quantitative sophistication that readily distinguishes elixirs like grass feeding from actual environmental solutions.


Cows feed on grass as they roam the hills near Pleasanton, California March 23, 2007. REUTERS/Mike Blake


We welcome comments that advance the story through relevant opinion, anecdotes, links and data. If you see a comment that you believe is irrelevant or inappropriate, you can flag it to our editors by using the report abuse links. Views expressed in the comments do not represent those of Reuters. For more information on our comment policy, see

My only problem with organic and grass-fed beef is the price, which is totally out of my price range. It’s easier for me to avoid meat entirely, then it would be to keep it straight which kind is best for me and best for the environment.

Posted by veggiehead | Report as abusive

The writer of this article totally missed the point of eating grass feed beef. Animals finished at feed lots on grains have much much higher levels of omega 6 fat saturation and lower amounts of omega 3. When consumed this leads to inflammatory markers in the human body leading to an array of disease pathologies ranging from heart disease to arthritis. Wild animals have higher levels of omega 3 (anti-inflammatory) compared to omega 6 (inflammatory). These animals are leaner and strictly eat what nature intended for them. I would rather eat an animal feed on all different types of live plants than a fat obese, almost diabetic cow feed corn. Lastly, the writer didn’t take into account the amount carbon emission needed to produce and provide all that grain at feedlots. Man I wish people would wake up and do some research for themselves than listen to idiots like this writer.

Posted by LionMan | Report as abusive

The answer is to stop eating meat, end of story! The sooner America realizes this, and the disgusting industry based on quarter-pounders and triple heart bypass burgers the better off the entire nation will be. Cows will go back to eating grass because no one will care what their eating when we don’t have to eat them!!!

Posted by jwakeman | Report as abusive

Who funded the beef study? Grass fed beef is much better for your health. You are what you eat.

Posted by jb510 | Report as abusive

[…] Grass-fed beef packs a punch to environment | Analysis & Opinion | Reuters. April 9th, 2010 in Climate & Energy, Food & […]

Posted by » Blog Archive » Grass-fed beef packs a punch to environment | Analysis & Opinion | Reuters | Report as abusive

[…] Grass-fed beef packs a punch to environment | Analysis & Opinion | Reuters. previous« Washington to host major economies meeting on climate | Reuters […]

Posted by Grass-fed beef packs a punch to environment | Analysis & Opinion | Reuters « Action 2030 news | Report as abusive

Thanks for the great article. There’s one more reason to second guess what we’re eating.

Posted by JaneMcC | Report as abusive

The question is not “grass fed or corn fed?”, it’s “beef or other sources of protein entirely?”

Posted by rimu | Report as abusive

Are you aware you’re discrediting hundreds of millenias of natural cattle diet and making it seem like it’s bad for the planet? You fool.

Posted by PrimalLover | Report as abusive

It is disturbing that factual information like this seems to have no impact on changing people’s minds on their personal habits. If they want to eat beef, they will– and environmental destruction doesn’t matter. Scientists say we are entering a “great extinction” where we may lose half or more of all species, sea level will rise inundating our coastlines, and we will continue to get more and more intense storms. The article didn’t touch on the fact that a whole foods plant based diet is much healthier for people– a way to reverse heart disease and linked with less cancer and diabetes. Check the work of Drs. Colin Campbell and Caldwell Esselstyn. I am not sure whether even hearing that would get people to change their minds, unless currently faced with a medical emergency.

Posted by Leda_Beth | Report as abusive

[…] fed, pampered, manicured, blissfully happy animals are even more environmentally unsound than intensively farmed […]

Posted by The Paleo Diet. SIIIGGHHH. Alright, Let's 'Ave It. | Vegan Coach | Report as abusive