Are Cow Farts Destroying the Planet?
This article is a partial excerpt from the book, Sacred Cow: The Case for (Better) Meat, by Diana Rodgers and Robb Wolf. To support the Sacred Cow project, click here.
It’s repeated over and over again: cow farts are ruining our planet! (Perhaps a pedantic bit of hairsplitting, but cattle don’t really fart methane; they mostly belch it as a part of their digestive process.) We’re told by mainstream media livestock are worse than all of transportation. However, please allow me to explain why this is a lie.
This is one of several misleading graphics vilifying livestock and meat, available for free on the Meatless Monday website.
Where Do Methane Emissions Come From?
Methane emissions come from anaerobic breakdown of organic materials (like your composting kitchen scraps), and in the case of food production, some from ruminant digestion. Although (as we will see) there are many contributors to methane production, oddly, the villains in the popular story are grazing animals. And we’d like to make the case that getting worried about methane production from any biological process is reductionistic (and rather alarmingly silly). Why? Because methane produced via biological process is part of a system, provides no net inputs to the system, and perhaps most importantly, is caused by living organisms! Let’s take a closer look.
Thank you Smiling Tree Farm for the inspiration for this graphic
As you can see from this illustration, it’s critical to understand that the methane emitted from cattle are part of the natural, or “biogenic” carbon cycle, whereas fossil fuels are not. Fossil fuels come from “ancient” carbon that has been locked underground for millions of years, and when it is extracted, it’s adding new carbon to the atmosphere, which lasts thousands of years. In the case of cattle, they are transforming existing carbon, in the form of grass and other fibrous materials, into methane as part of their digestive process. Methane is then belched out and after about 10 years, is broken back down into water and carbon dioxide molecules. The CO2 and H2O are cycled back to grow more grass and the cycle continues.
Industrial animal production, with its manure lagoons, is indeed a significant source of methane, but these are largely from the pork, egg, and dairy industries. Beef feedlots generally do not use manure lagoons. And although cattle do burp methane, this is simply a natural byproduct of their digestive process. Some of this breakdown and methane production would happen even if it weren’t inside a bovine digestive tract, and as we’ll explore later, cattle are up-cycling nutrients. They’re converting grass and other plants that are of little nutrient value to humans into high-quality protein while improving the quality of our soil.
Concentrated animal feces from factory farms are a much different environmental issue than scattered cattle poop, urine, and hoof across grasslands in a natural system. In well-managed systems without a lot of antibiotics or drugs given to the animals, large dung beetle populations are re-established. These dung beetles help break down manure, and recent studies found they help to mitigate methane emissions from it. (source) How do they do this? Methane thrives in low-oxygen environments. As they tunnel through manure, dung beetles provide ways for oxygen to circulate, preventing methane formation.
Let’s also not forget that prior to the mid-1800s, there were an estimated 30-60 million bison, over 10 million elk, 30 to 40 million Whitetail deer, 10 to 13 million Mule deer, and 35 to 100 million pronghorn and caribou roaming North America.(source) Yet nobody seems to acknowledge this when citing current “devastating” herbivore numbers. According to a paper published in the Journal of Animal Science, in pre-settlement America, methane emissions were about 84% of current emissions.(source)
In fact, moose produce large amounts of methane and the Green Party in Sweden is now proposing that citizens should “shoot as many moose as possible and reduce the number of cattle”, for the sake of the climate. (source) A myopic view of methane production is now casting doubt on the utility, if not sanity, of promoting more life on this planet, vs less. The misunderstanding of this topic coupled with fear are so potent that seemingly credible people are suggesting we should have less life on earth…so we can protect the other life on earth, and all to reduce the perceived danger of biologically sourced methane (which is a process that has occurred since the earliest days of life on earth). In one case this is impacting the view of the natural state of grasslands and grazing animals, in the other it deals with lynchpin organisms on the seafloor.
So where do all of these exaggerated methane claims against cattle come from? Why does the Meatless Mondays campaign have memes saying that livestock production causes more GHG emissions than the entire transport sector? It all comes from a terribly flawed analysis from 2006 by the Food and Agriculture Organization of the United Nations (FAO), called Livestock’s Long Shadow. The report stated that livestock produce 18% of all GHG emissions, which was more than the transportation sector.
This number is circulated by the media constantly, even though the researchers have conceded it was an unfair assessment and have since reduced that figure. When UC Davis animal scientist Frank Mitloehner analyzed how the data was gathered, he found a striking methodological error. In the case of cattle, a full Life Cycle Analysis was done on the industry. This means they looked at the feed production, transport of the feed, processing, transport to stores, etc. All the way from what the animal ate to how it ends up in a consumer’s meal. There’s a lot more going on here than cow burps.
More damningly, the same cradle-to-grave assessment was not conducted on the transportation sector. Only direct emissions from burning gasoline were calculated. Many other factors in the transportation industry contribute to GHG production, like how the cars or planes were made, how the metal was extracted, the energy required to run the factories, to transport and refine the oil, etc. So, while they did a full Life Cycle Analysis on livestock, they did not do the same for transportation, unfairly leading the public to think that animal agriculture is worse than the transportation industry.
There is no full life cycle assessment on the total impact of the transportation industry worldwide. In the 2013 report, the FAO calculated that worldwide, all of human activities (including fossil fuels) is about 6.9 gigatons a year, about 14.5% of all emissions, and that direct emissions from livestock were 2.3 gigatons, about 5% of global GHG emissions.
In the United States, the number might be lower than that worldwide figure. According to the EPA, all livestock only represents 3.9% of GHG emissions. Within the livestock category, beef cattle only represent 2% of total GHG emissions. (Another recent study put GHG emissions from cattle, including the production of feed, at 3.3 percent of greenhouse gas emissions in the U.S.(source) This number is slightly higher than the EPA’s.) Clearly, there are a lot of moving pieces here that make computing the actual percentages a challenge, but in any case the number is far lower than the 18% - 51% (source) that many plant-based advocates report. The largest source of GHG emissions in the US comes from energy and transportation. These numbers are looking at emissions only for all industries and do not take into account any of the potential sequestration or net ecological benefit that cattle have to the land.
Why are the US livestock GHG emission numbers a smaller percentage contributor than the global numbers? A few reasons. We have more advanced agricultural practice here than in many other countries. Our cattle are also much more efficient at producing meat and milk than other countries. In the US, one dairy cow can produce about 20,000 pounds of milk a year. In Mexico, you would need five cows to produce that much and in India, you need 20 cows.(source) Also, in less developed countries for example, there are more animals compared to cars and energy production, so the percentage of emissions from animals will be higher simply because there is less transportation and industry.
To further complicate this whole story, a new study was published showing that fertilizer plants emit 100 times more methane than the industry previously reported.(source) Once this is folded into the GHG emissions data, it will be even clearer that synthetic chemical driven industrial mono-crop agriculture that brought us high yields at the expense of soil loss, ecosystem destruction, and intense GHG emissions will no longer be acceptable as we move into the future.
This is all technical, sometimes counterintuitive material that is clearly hotly debated. One point that is perhaps more universal is that it may be important to develop and expand smart methods to extract carbon out of the atmosphere and store it somewhere.
How Can Cattle Help to Sequester Carbon?
We can build expensive contraptions to capture carbon, but the energy required to produce and operate these seems exorbitantly high. This is not dissimilar to the misguided promise of “sustainable lab grown meat.” With innovation, we may in fact develop industrial methods of extracting and storing vast sums of atmospheric carbon in a manner that makes sense with regards to energy inputs (if you need to burn a “lot” of fossil fuels to try and sequester carbon, they may not pencil out as a net win). But what if there is a simpler, more elegant way of tackling this problem, one that favorably addresses many issues at once? To this end, we’d like to explain how cattle can be part of the solution.
When discussions of climate change emerge it is often overlooked that healthy soils (which are part of a dynamic interaction between plants and animals) store carbon. Lots of it. Despite this fact, the current narrative on climate change implicates animals that emit GHG, and specifically cattle. It may be prudent to consider that holistically managed livestock are critical to systems that can build healthy soil and produce healthy food.
According to a paper in the Journal of Soil and Water Conservation, most agricultural soils have lost 30% – 70% of their soil organic carbon (SOC), which has led to a decrease in food production.(source) The majority of the damage when it comes to agricultural GHG emissions is due to plowing up fields for crop production, not belching cattle, and most of the opportunity for improvement in this area comes from no-till cropping practices. One paper that looked at the impacts agriculture has had on the Great Plains illustrates that the plowing of native grasslands peaking in the 1930 was the most devastating when it comes to carbon emissions. The researchers estimate that if only 25% of producers switch to no-till practices, there would be a 25% improvement in GHG emissions. If 100% switched, the improvement increased to a whopping 80% improvement.(source) And what if they also incorporated grazing animals into the mix? Now we’re getting somewhere!
The earth holds approximately 3170 gigatons of carbon (a gigaton is 1 billion metric tons). About 2700 GT, or eighty percent of this is found in soil. All of the plants and animals on earth is only 560 GT. Soil holds 4 times more carbon than trees and about 3 times more carbon than the atmosphere itself.(source)
Some estimates suggest that reversing climate change would require the removal of about 700 gigatons of carbon.(source) It would be impossible to plant enough trees to do this, and the oceans seem to suffer with more carbon, becoming more acidic. Our biggest opportunity is to sequester carbon in soil, which actually benefits biodiversity, and can feed us with nutrient dense food. Another important point is that the carbon in soil is actually the driving facilitator of helpful work—the cycling of nutrients.
Some exciting new research is being done looking at the impact and carbon cycle of well-managed cattle. In one recent study, researchers from Michigan State University tracked carbon in the soil in two different systems of raising beef cattle over four years, comparing the traditional feedlot system to a new method known as adaptive multi-paddock (AMP) grazing, where the cattle finished on grass were moved frequently to allow plants to recover and protect the soil. And although the feedlot system produced less total emissions (in terms of cow burps), the AMP system resulted in a net GHG sink. The emissions in the finishing stage were more than completely offset by the amount of carbon sequestered in the ground. And not just a little bit of carbon, it was a significant amount: 3.59 Mg of Carbon per hectare, per year.(source)
Another study looked at the entire lifecycle of 100% grass-fed beef at a farm in Georgia, showing that the net total emissions were -3.5 Kg Co2-eq per Kg of fresh meat. This is significant because not only is it better than conventional beef, pork and chicken, but it’s better than the claims of Beyond Burgers and soybean production. (source)
To see how this is possible, consider this diagram adapted from White Oak Pastures, a farm that uses regenerative agricultural practices:
Through the right practices, this farm’s example illustrates that net carbon reduction and even sequestration is possible—and the key is healthy soil. In fact, you’d need to eat one of their grass-fed burgers in order to offset the emissions created from eating a Beyond Burger or an Impossible Burger.
Another meta-analysis looking at carbon sequestration in soils from livestock grazing in several South American countries showed that grazing lands not only sequester carbon, but that amount sequestered could partially or totally offset urban emissions. The researchers concluded that “the potential of grazing lands to sequester and store carbon should be reconsidered in order to improve assessments in future GHG inventory reports.”(source) In other words, it’s wrong to take a reductionist view and blame grazing cattle for methane emissions. Instead, we need to consider the full picture and realize their impact is helping to sequester carbon.
There are several more papers coming out about how cattle can be a net carbon sink. The Savory Institute and other organizations are also starting to document other ecological outcomes from grazing animals, like water filtration rates, increase in plant diversity, decreases in bare spots in pastures, and the return of pollinators, birds and other wildlife. None of this is happening in the industrial monocrop system.
Maybe you’re still not convinced. You may be thinking, “But if we’re trying to eliminate all of this methane, shouldn’t we eliminate all animals from our food system?” One study looked at the nutritional and environmental consequences of eliminating all livestock from the US food system. In this scenario, GHG emissions would decrease by only 2.6 percent, and the impact on our nutrient availability would be devastating. (source) Because animals are more nutrient-dense than plants, we’d need to eat a lot more to get the same nutrition. Overall calories would increase, our grain consumption would increase by 10 times, and we’d be deficient in calcium, vitamins A and B12, and EPA, DHA, and arachidonic acid.
In short, we’d have more nutrition-related diseases. The researchers concluded, “When animals are allowed to convert some energy-dense, micronutrient-poor crops (e.g., grains) into more micronutrient dense foods (meat, milk, and eggs), the food production system has enhanced capacity to meet the micronutrient requirements of the population.” (source) What we take away from this is that even typical beef is a net win for our food system nutritionally, and if we improve our production and finish cattle in a well-managed system on grass, which helps dramatically reduce emissions, then it can benefit the environment, as well.
If we’re sincerely interested in cutting down on our GHG emissions, the solution is not to eliminate all animals from our food system. Livestock just needs to be managed in a better way. (source)
It’s not the cow, it’s the cars.
This article is a partial excerpt from the book, Sacred Cow: The Case for (Better) Meat, by Diana Rodgers and Robb Wolf, coming in the summer of 2020. To support the Sacred Cow Film, click here.