The ongoing debate over the impact of the animal agriculture communities on greenhouse gas emissions is nothing new. Cows have been condemned for climate change effects time and time again – oftentimes unfairly with overstated figures and exaggerated claims. But even now, as anti-animal agriculture activists rally this cause as an excuse to reduce or even eliminate the consumption of meat, milk, poultry, and eggs, farmers and ranchers have countered their claims with a continued commitment and action toward reaching solutions. Enter: carbon sequestration.
How much do livestock contribute to carbon emissions?
The fact is animal agriculture does contribute to greenhouse gas (GHG) emissions, just not as much as critics want you to believe. According to the Environmental Protection Agency, agriculture accounts for less than 10% of U.S. GHG emissions, while livestock production is only 4%. As a direct result of the farming and ranching communities’ unparalleled dedication to stewardship and commitment to conserving natural resources, American dairy and beef production only contributes around 3.3% of all U.S. GHG emissions.
Reducing production and consumption of meat, milk, poultry, and eggs is often touted as a simple solution to reversing climate change. However, in truth, if we were to eliminate all dairy cattle from U.S. agriculture, the country would only see a reduction of 0.7% in GHG emissions according to a 2020 Virginia Tech study. Not only would this have a minimal impact on the environment, it would also lead to a tremendous nutritional gap as many beloved dairy items would disappear from supermarket shelves. Regardless of these facts, there are still opportunities for the agriculture and forestry communities to decelerate the effects of climate change that other GHG-emitting sectors do not have: they are the only two sectors that hold the potential for “net-zero” carbon emissions – or removing as much carbon from the atmosphere as it produces. The irony is that the world’s primary scapegoat for environmental degradation now holds the only hope for a sustainable solution.
Carbon sequestration and the biogenic cycle
Carbon is an essential element that is ubiquitous in nature. It is the basic building block in our bodies required to build carbohydrates, proteins, and fats. It is also a component in the air we breathe as carbon dioxide. Carbon is stored in oceans, rocks, fossil fuels, and even the cornfields that we pass by on the highway. The carbon cycle is the natural flow of this element between the atmosphere and these various places. Atmospheric carbon dioxide is captured by plants during the process of photosynthesis. That carbon is then either stored, or sequestered, in the plant’s tissues as sugar or released back into the air. When the plant dies, all the carbon sequestered in its tissues is released into the soil, where microbes release a portion of that carbon back into the atmosphere during the decomposition process.
Cows have a similar biological cycle to that of carbon known as the “biogenic cycle.” This cycle is a natural process that sustainably destroys methane at a similar rate as it is being created by the ruminant digestive system. To begin, cattle have a unique and useful ability to digest cellulose, an important structural component of plant matter that humans are not able to digest. Ruminant digestion involves a four-chamber stomach, where each one plays its part in breaking down tough plant material and byproducts that would otherwise go to waste. This rigorous digestive process requires that a portion of the carbon in the cellulose be transformed and emitted as methane, which cannot be held in the stomach for too long without having to escape via burping. The biogenic methane is released into the atmosphere where it stays for 12 years. After this period of time, it naturally undergoes a chemical reaction known as hydroxyl oxidation and is converted back to carbon dioxide—the very same carbon dioxide that was in the air prior to being consumed by the animal. As plants photosynthesize, the carbon dioxide begins the biogenic cycle again. These flow gases emitted by the biogenic cycle are not the same as the harmful stock gases emitted by fossil fuels, which are not recycled or transformed in the atmosphere.
Despite being innocent for the buildup of stock GHGs in the air, farmers and ranchers are seeking ways to further expunge cattle of their blame. As the pressure builds for the animal agriculture community to hit “net-zero” emissions, farmers and ranchers are working to offset even more methane emissions by increasing the amount of carbon sequestered in the soil. So, how are they doing it?
Restoring what was lost
The idea is to incorporate more practices that stimulate carbon sequestration, or, in other words, stimulate plant growth. The more plant matter in your pastures, the more atmospheric carbon dioxide that is being absorbed for photosynthesis. But how can cattle actively encourage plant growth if they are removing plant matter by grazing it every day? The answer is proper grazing management. Integrating livestock into rotational grazing systems has been proven to provide many beneficial services to the ecosystem. Rotational grazing, which allows cattle to be moved between a series of small pastures for shorter intervals of time, allows longer periods for plants to recover from grazing and stimulate new growth. Grazing also suppresses weeds from getting out of control, allowing dormant or repressed plant species to thrive and enhance local biodiversity. Not to mention, cattle can also improve soil health. As cattle walk through the pasture, they trample the ground with their hooves and break up hard crusts on the soil surface. Their manure is spread and incorporated into the soil to feed microbe populations via trampling, insects, and other wildlife. All these regenerative practices can be integrated into a modern grazing management plan. Crop farmers can play a role too in sequestering carbon by leaving leftover plant materials on the soil surface after harvest, incorporating reduced or no-till practices, and planting cover crops.
Leaving a Smaller Hoofprint
One thing is for certain: cattle play an irreplaceable role in the natural sequestration of carbon from the atmosphere. Instead of scapegoating the beef and dairy communities for climate change, we should be encouraging farmers and ranchers and providing access to the information they need to continue implementing these climate-friendly practices. Incorporating regenerative practices will not only aid in “clearing the air” but also has the potential to dramatically improve soil health and restore fertility to inarable or overworked land. By doing this, we make actual progress in reaching climate goals instead of being diverted by unfounded and exaggerated claims. Through mindful management and keeping science at the forefront of stewardship, cattle can become the primary mechanism of change in the movement toward reaching net-zero emissions in the agriculture community.
All posts are the opinion of the author and do not necessarily represent the view of the Animal Ag Alliance.
