Is Grass-Fed Beef Good for the Climate?

This blog post was written by Sylvia Black and edited by Anneke Hobson.

Whenever we talk about climate-friendly diets, one message that comes through again and again is the need to reduce our intake of meat from ruminant animals, which for many Canadians means less beef. But some advocates in the restorative agriculture movement argue that this messaging is too simplistic. They make the case that the real climate problem is with factory-farmed beef, while beef from grass-fed cows actually has environmental benefits.

For anyone interested in a deep dive into the research on this topic, we highly recommend the Food Climate Research Network’s excellent 2017 report (and animated video) “Grazed and Confused? Ruminating on cattle, grazing systems, methane, nitrous oxide, the soil carbon sequestration question – and what it all means for greenhouse gas emissions”. It goes into much more detail than we have space for here, but ultimately comes to the same conclusion: grass-fed beef isn’t a significant solution to climate change. For another overview of the various benefits, drawbacks, and confounding variables of grass-fed beef and dairy, Tamar Haspel wrote a great summary for the Washington Post back in 2015.

Let’s unpack some of the issues here.

What is grass-fed beef?

All calves start their lives on pasture, so in reality, all cows are “grass-fed” for at least part of their lives. However, most cattle are then “finished” in a feedlot where they’re fed corn and other grains to gain weight quickly before being sent to slaughter (1). In contrast, grass-fed (or “grass-finished”) cows spend their entire lives on pasture. 

What are the climate implications?

Most life-cycle assessments have found that feedlot beef has a lower carbon footprint than grass-fed beef. This is mostly because feedlot cows gain weight faster and are sent to slaughter younger, so they emit less methane over the course of their (shorter) lives (2). Grass-fed advocates argue, though, that these studies are misleading because they don’t account for the fact that cows raised on pasture help to increase the amount of carbon stored in the soil. 

Basically, as plants grow, they take in carbon from the atmosphere and store some of it in their roots, which (depending on environmental factors) may remain in the soil even after the plant dies. This is called carbon sequestration. Grazing animals like cows can help in this process by eating the plants, which can encourage more growth and more storage of carbon (2).

Big claims are made about the potential of carbon sequestration to partially or completely offset the greenhouse gas emissions associated with raising cows, including the claim that grass-fed beef can be carbon-neutral or even carbon-negative. Some proponents of regenerative grazing methods like Allan Savory even claim that his holistic grazing method, if applied on all the world’s grasslands, would single-handedly reverse climate change within a few decades (3).

The truth is more moderate: good grazing practices can help maintain the carbon that’s already stored in the soil, and in some cases it can help to store more, especially if the soil quality was poor to begin with (2). Findings from published research on this process range widely, with suggestions that carbon sequestration has the potential to offset 20% – 60% of average annual emissions from grazing animals (2). (And this will vary from place to place depending on a whole range of environmental and soil factors). Even under the best-case scenario, though, grass-fed beef would continue to be a significant source of greenhouse gas emissions. 

The more ambitious claims about the potential of carbon sequestration as a climate solution are usually made on the basis of anecdotal reports or small pilot studies. It’s not uncommon for a farmer to start using regenerative methods, measure the carbon in their soil, and find that after a year or two it’s much higher. But there are a few problems with jumping to big conclusions based on these observations.

First, high carbon sequestration rates in the first year or two after switching to a regenerative grazing method won’t stay at that high level over time. It’s important to remember that soil can’t keep storing more and more carbon forever. At some point, it will reach an equilibrium and it won’t be able to absorb any more (and soil that’s already in good condition may reach that point quite soon, or already be there to begin with) (2). At the same time, as long as cows (or other ruminant animals) are being raised on the land, they will continue to produce methane indefinitely (along with all the other greenhouse gas emissions associated with the ranching operation). Any potential that carbon sequestration has to offset emissions is at best temporary. 

Second, all sorts of factors, from overgrazing to drought, can result in stored carbon being released from the soil. For this reason, sequestration might be better thought of as a nice bonus where possible, but not a reliable long-term solution to climate change (2).

The last thing to know is that “regenerative agriculture” and “restorative farming” are not consistently defined by researchers, practitioners, regulatory bodies, or governments (4). This makes it hard to actually measure their benefits and downsides relative to conventional methods, and it makes the terms vulnerable to marketing hype. 

So does this mean grass-fed beef is bad?

Grass-fed beef isn’t going to solve climate change, but that doesn’t mean that we need to write it off. Well-managed grazing operations can be better for animal welfare, and may have some environmental benefits (independent of their effect on climate). Both of these things depend a lot on context, partly because “grass-fed” isn’t a regulated term in Canada, so there’s no standardization of exactly what it entails.

Grass-fed beef also tends to be higher in omega-3 and omega-6 fatty acids and some micronutrients like vitamin E (although the difference is small) (5). 

A climate-friendly diet can still include a small amount of beef for those who choose to consume it, and some people might prefer grass-fed over conventional for these or other reasons. But all beef is a significant source of greenhouse gas emissions, so from a climate perspective, the important thing is still to reduce consumption of all meat from ruminant animals, regardless of how they were raised. 

References

1. Is Grass-Fed Beef Really Better For The Planet? Here’s The Science (NPR).

2. Grazed and Confused? Ruminating on cattle, grazing systems, methane, nitrous oxide, the soil carbon sequestration question – and what it all means for greenhouse gas emissions (TABLE Debates [formerly the Food Climate Research Network])

3. Holistic management – a critical review of Allan Savory’s grazing method (Maria Nordborg) 

4. What is Regenerative Agriculture? A Review of Scholar and Practitioner Definitions Based on Processes and Outcomes (Newton, Civita, Frankel-Goldwater, Bartel, & Johns)

5. Is grass-fed beef really better for you, the animal and the planet? (The Washington Post)