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Climate-Conscious Ranching: Is Free-Range Really Better than Feedlots?
The issue of the livestock-climate connection has catalyzed a debate not only about whether and to what extent we should consume animal protein like meat and dairy, but what kind of system of livestock production is more sustainable from a greenhouse gas perspective if and when we do choose to continue consuming it.
For the carbon conscious consumer pained at the thought of giving up his or her Sunday roast or morning milk for coffee and cereal, what are the alternatives to an animal-free diet?
Sourcing meat, milk and eggs produced by grass-fed livestock have often been touted as an antidote to most of the environmental ills incurred by our mainstream system of feedlot agriculture.
Grass-fed (also known as ‘free range’ and ‘pasture-raised’) animal agriculture has even gotten some significant airplay as a method of production that can actually decrease carbon in the atmosphere, thereby reducing (and according to some proponents, reversing) climate change.
This assumption is based on a myriad of reports by agricultural scientists that conclude that grazing livestock on grass can sequester a substantial amount of carbon in the soils. In the past few years, the phenomenon on soil carbon sequestration has received prominent attention by the United State Department of Agriculture (USDA), the U.S. Environmental Protection Agency (EPA), and United Nation’s Food and Agricultural Organization (FAO), particularly in its landmark report Livestock’s Long Shadow.
Some supporters of grass-based agriculture have taken these findings several steps further in advocating it as a “silver bullet” against global warming. One notable proponent of this theory is Polyface farmer Joel Salatin, who was heavily featured in both Michael Pollan’s book Omnivore’s Dilemma and this summer’s documentary film, Food, Inc.
Salatin uses a form of holistic management where cattle are kept in close packs mimicking bison herds and are intensively grazed on alternate swaths of pasture from several hours to several days before switching to the next one, in a practice commonly referred to as ‘rotational grazing.’ Regarding questions of climate change and animal agriculture,
If every cattle producer in the United States used his methods of rearing, and poultry and pork production was in turn drastically reduced, “in less than 10 years, we would sequester all the carbon that’s been emitted since the beginning of the industrial age,” Salatin told Mother Earth News.
A Vermont-based collaborative known as the Carbon Farmers of America promotes a similar theory. It even offers training and consulting to farmers interested in building topsoil on their land and thus increasing carbon stock in their pasture, as well as “sell” carbon sinks to consumers interested in offsetting their emissions.
Co-founder Abe Collins states that he is not an avid fan of offsets, but is looking for proactive “public participation in the carbon cycle.” He also clarifies that he still believes we need to scale back considerably from burning fossil fuels in the future in order for soil sequestration to continue being effective means of mitigation.
Pasture-Raised Not a Panacea
The claims of Salatin and the Carbon Farmers of America seem to overlook many of the caveats raised by agro-ecologists about the limits of soil carbon sequestration. For instance, most experts agree that soil sequestration is only a temporary fix. In a best case scenario, newly converted pastureland can be projected to store carbon for a maximum of 50 years before it reaches a saturation point. More average estimates put this time limit at 25 to 30 years.
Pasture also has to be carefully managed and alternated. Otherwise, if done the wrong way, it can lead to overgrazing and desertification. Additionally, many regions and land types in the U.S. and abroad are not suitable for achieving sequestration through grazing. This includes some of the more arid lands in the American West and Midwest.
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Leaning in favor of pastured livestock
Laura, I haven't done the full degree of research you have, but even still there are a few points I think worth adding to the analysis that might lean conclusions in favor of properly managed pastured livestock.
First is the key point about that "properly managed" aspect. Everything I've read about livestock's impact makes clear that simply having animals on pasture does not begin to guarantee that their actions will be beneficial (e.g., lead to net sequestration of carbon dioxide-equivalent greenhouse gasses). If managed improperly, cattle (or other grazing livestock) will overgraze and/or undergraze pasture plants, resulting in poorer plant health and degraded soils. Only if managed properly (which will differ from location to location, climate to climate, soil type to soil type, grass type to grass type, etc) will the animals promote plant and therefore soil health, and therefore net carbon sequestration. In other words, while most of the writing on this subject pits a dichotomy of grain-fed vs. grass-fed, actually there are three distinct categories: grain-fed vs. standard grass-fed vs. holistically managed grass-fed. The impact of the third is as different from the second as it is from the first.
Second, when thinking about the difference between pastured and corn-fed cattle, and the question of how much meat would then be produced, note that the estimate you quote from Pimentel implies that only existing grazing land would be used to maintain the pastured animals. But in this hypothetical conversion of cattle production to all-pasture, recall that a bit over half of all corn grown in the US goes to animal feed (not only cattle, granted), plus a good chunk of other grains and soybeans. That means that a huge swath of land currently being tilled for corn and etc, with all the consequent top soil loss that Pimentel stresses, and all the associated greenhouse gas emissions (from fertilizers and oxidation of exposed top soils) need not be degraded in this way. Indeed, such land could be converted to perennial grassland pasture, opening up more acreage for pastured-cattle production that would be of lower-impact than the status quo of grain-fed cattle production. And if managed properly, these cattle would not be merely less harmful to the atmosphere and soil, they would actively improve the situation, helping to reproduce the billions if not trillions of tons of midwestern topsoil that have been lost over the past century and a half, and drawing down masses of atmospheric carbon in the process. And providing food supply as frosting on the cake. I don't know if the end result would mean more than, the same as, or less than the average amount of meat currently available, but it would be a higher ratio at least than the one provided by Pimentel.
A further thought: you talk about the inability to apply pastured livestock techniques to arid areas of the US, and Pimentel stresses problems of water shortage in the piece you link to. One of the arguments of those promoting proper management of pastured livestock is that, because of the soil promoting effect such animals can have, water conditions are greatly improved, specifically in arid regions. This is what Allan Savory emphasizes with his work through holistic management. As I've read about his experience in seasonally dry grasslands in Africa, as well as the experience of others in the US in similarly dry areas (such as New Mexico) utilizing Savory's holistic management methodology, increasing livestock density* has led to increased ground cover by perennial grasses, which has led to increased soil organic matter and improved water retention, which has led previously flash-flood prone, seasonally dry rivers to become year-round (or nearly so) waterways. This, in turn, enables the return of a wide variety of native species of plants and animals that had been driven off by desertification. Only through the use of dense herds of livestock has this desertification been reversed, meaning arid lands might indeed be the most important place to implement properly managed pastured livestock.
* When I mention "increasing livestock density" this probably sounds to most like a prescription for overgrazing. As Savory (most prominently) has been at pains to explain for years, overgrazing does not result from having too many animals on a given piece of land. It results from having animals of any number on a given piece of land for too long of a time. When not moved frequently, animals will repeated graze upon the same plants (as a previously grazed plant regrows, its new shoots are the tenderest and therefore preferred by the animals). This prevents the plant from being able to recharge its root-stores of energy, weakening the plant and eventually killing it. Only if the plant is given sufficient time to recover can it avoid overgrazing. On the other hand, too much time without being grazed is also harmful. Unlike trees, which can drop their leaves, perennial grasses rely on grazing animals to remove old growth and thus allow emergence of new, rejuvenating growth.
And finally, regarding the question of soil saturation, none of the advocates for soil sequestration (through pasturing livestock or other methods) that I have encountered suggest that this direction is sufficient to let fossil-fuel usage off the hook. We must certainly convert energy production to non-carbon technologies. However, even if we do that in short order, we are still stuck with the legacy load of excess atmospheric carbon produced both from fossil fuel usage as well as land use activities. This carbon has to be withdrawn from the atmosphere to limit the negative impacts of global warming. High-tech CCS can't do that--CCS only works at a smoke-stack to prevent ongoing additional emissions. Only biological methods of one sort or another can withdraw existing carbon from the atmosphere. And if the soils become saturated in 30 or 50 years, what of it? They will have done their job, so to speak. We don't need soils to perpetually remove carbon on balance. Once the atmosphere has returned to a safe level of carbon, under the now-famous 350ppm level or, ideally, back to the pre-industrial ~300ppm level, such "saturation" of carbon in the soils will represent a proper balance. That balance requires halting fossil fuel emissions and land-use emissions and sequestration. If the ranchers have figured out a way to sequester, which I'm increasingly convinced they have (or at least some few of them), let's encourage that.
bison
Hi Michael,
No, I haven't looked at bison in this context, though it's an interesting idea for a follow-up article. I imagine as a native species in their home region, this might work fairly well (better than ranching non-native domestic species) from an ecological standpoint, but I would need to look into it.
massive positive impact of changed grazing management
Hi from Australia. I agree with your comments above regarding industrial agriculture. I hope you will find the attached information of some interest in light of your comments regarding domesticated livestock. May I suggest that it is not the animals themselves that are the problem? Rather it is how we humans are managing them.
Could I ask you to look a little more into the massive positive impact changed grazing management could have. Please remember that some 2 billion people, the “bottom” third of our species, are almost totally dependent on domesticated livestock for their very existence. Domestic livestock are not just about feeding the affluent developed nations.
Methane is produced by bacteria in the rumen of all ruminant animals, a group which includes camels, wildebeest, alpacas, bison, mountain goats and 90+ species of antelope, as well as domesticated cattle, sheep and goats. This link http://www.abc.net.au/rural/vic/content/2009/08/s2649106.htm is to some very interesting (and to my way of thinking inherently logical and natural) research that shows that different bacteria in the soil under the cattle oxidize more methane in a single day than the cow emits in a whole year.
Professor Tim Flannery has stated that sequestering carbon into the soils of our grazing lands is one of the best means we have available to us for dealing with climate change. We have been raising awareness of the role of building soil carbon from a climate change perspective – but as you will see when you look through the presentation on our website the real outcome of changing management is three-fold – healthy environment, healthy financials, and healthy society.
grazing mgt.
Hello Tony,
I don't disagree that carbon sequestration from proper grazing can be an extremely useful tool in GHG mitigation. However, all of the literature I have reviewed (which I have extensively as it was a topic of my graduate research) maintains that this positive net effect is still temporary and limited by soil/region type. My article is intended mostly in the context of U.S. production. I do know that there are many pastoral communities that need livestock for their food and income and I do not begrudge these communities that necessity. Nonetheless, it should also be acknowledged that the U.S. citizen has the highest per capita consumption rates of animal protein in the world, three times the global average. Other Western countries aren't that far behind. These are the audiences my article targets, not pastoral communities in developing countries.
free range livestock
Laura
Did you find any significant difference in coarbon footprint if based on bison grazing on native prairie grasses, as is being proposed and tried by great plains ranchers and farmers?
Thanks
Thanks for the great summary
Thanks for the great summary - very useful and up to date!
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