Issue #12: Climate Change and the Meat Industry
Let's Wade into the Kiddie Pool of Industrial Controversy
First things first, I’m not going to debate whether climate change is real. I’m not even going to debate whether the livestock industry contributes to it. It is, and it does, respectively. Indeed, this debate is now so urgent it is seeping into national press; both the New York Times and Bloomberg published articles this week about needing new business models that more responsibly address climate issues in the meat industry and industry denialism, respectively.
From Bloomberg:
Mainstream climate science has long presented a much more grim arithmetic. Cows burp out large quantities of heat-trapping methane. As a result, beef causes vastly more emissions than most other foods—more than five times as much as an equivalent amount of chicken or pork and at least 15 times more than lentils and other plant-based proteins, according to data from the University of Michigan.
As we’ll see in a bit, beef’s carbon-equivalent footprint is about 3 times higher than sheep/lamb.
But, let’s start at the beginning with the Environmental Protection Agency (“EPA”).
According to the EPA, Agriculture contributes about 10% of the United States’ total greenhouse gas emissions. There are two things to note about this that will become important later. First, this 10% does not include the emissions as a result of the supply chain - that is part of the “Transportation” sector’s 29% of greenhouse gas emissions. Second, it also does not include the 12% net reduction in greenhouse gas emissions as a result of Land Use and Forestry.1
It might be helpful to know what counts as a “Greenhouse Gas.” The EPA basically tracks 4: Carbon Dioxide (CO2), Methane (CH4), Nitrous Oxide (N2O), and miscellaneous fluorinated gases.
CO2 is not, largely, associated with agriculture. Of course, agriculture uses electricity which is generated by fossil fuels that are a major producer of CO2. And, of course, transportation of agricultural products uses gasoline and contributes to CO2 production. In our pie chart above, though, both of those are captured by “electricity” and “transportation,” respectively.
The agricultural industry is a major contributor of both Methane (CH4) and Nitrous Oxide (N2O). Enteric Fermentation and Manure Management, both explicitly connected to the livestock industry, together account for 36% of methane gas emissions in the United States. While methane is only 10% of greenhouse gas emissions (CO2 being 80%, all of the others being the other 10%), it is a far more intense greenhouse gas than CO2.2
CH4 is more efficient at trapping radiation than CO2. Pound for pound, the comparative impact of CH4 is 25 times greater than CO2 over a 100-year period.
Nitrous Oxide is also a greenhouse gas byproduct of human agriculture. It is even more intense than Methane: “The impact of 1 pound of N2O on warming the atmosphere is almost 300 times that of 1 pound of carbon dioxide.” The vast majority of Nitrous Oxide emissions in the agriculture is related to application of fertilizers (75%), and manure management (4%).
Of the major greenhouse gases, the agricultural industry plays a significant role in Methane and Nitrous Oxide in particular, and also a role in CO2. Beef from dedicated beef herds are (by far) the largest contributor to climate change, globally. Followed by lamb and mutton. Then cheese, and beef from dairy herds. It turns out that farming operations, land management, and production of animal feed play the largest role. Processing and transportation are a very distant 3rd and 4th place, respectively.3
What is important to note, is that farming operations and production of animal feed are directly related to the “Agriculture” industry statistics that we quoted above from the EPA; it is where the Methane and Nitrous Oxide in the “Agricultural Industry” is generated. Thus, the vast majority of the greenhouse gas emissions related to the meat industry are related to farming operations (either for the livestock themselves or the feed needed to keep said livestock alive).
Processing and transportation together account for approximately 1/12th (8.3%) of total greenhouse gas emissions for lamb/mutton.4 This portion of the greenhouse gas contribution is predominately carbon dioxide in the range of 2(ish) kilograms of CO2 equivalent per kilogram of product. Or, stated differently, for every kilogram of lamb, the equivalent of 2 kilograms of CO2 is emitted as a result of processing, transportation, retail, and packaging.
On the other hand, farming operations generate mostly methane and nitrous oxide as their principle greenhouse gas emissions and are the great bulk of greenhouses gases emitted by sheep-based meat production. Methane is produced by farming operations through enteric fermentation and manure management. And Nitrous Oxide is produced through the use of fertilizers and also manure management.5 Together, these account for almost 21 kilograms of CO2-equivalent per kilogram of lamb. Or, again stated differently, for every kilogram of lamb, the equivalent of 21 kilograms of CO2 are emitted as a result of farming operations.
It might make sense for a moment to appreciate scale. Each kilogram of lamb is responsible for approximately 24 kg of CO2-equivalent greenhouse gases. This is a little more than 1/3 of the CO2-equivalent greenhouse emissions for 1 kg of dedicated-herd beef-cattle. It is about double that of a kilogram of farmed prawn and roughly equivalent to cheese, beef from dairy herds, and chocolate.
To put it in even sharper perspective, it would take 24.5 kilograms of lamb to equal the same CO2-equivalent emissions as one roundtrip flight from Madison, Wisconsin to Los Angeles, California per person (588.6 kg CO2-equivalent).6 Or, stated differently, each person that flies from Madison to Los Angeles causes the same level of greenhouse gas emission as 1.2 lambs’7 worth of meat.
So, with that perspective in mind, what about farming operations is so bad for the environment? There are three culprits: fertilizer used for growing animal feed, manure management, and enteric fermentation.
You may note that the graph above8 is slightly different from the EPA numbers and this is because this particular graph includes CO2-equivalent emissions as a result of transportation and land-use, which the EPA treats separately. As a quick aside (this post is already long enough, so might as well take a quick diversion…), land-use emissions are significantly higher for beef than for, say, sheep because in other parts of the world (not, generally, the United States), cattle ranching is displacing forests thus not only adding greenhouse gases, but simultaneously removing the antidote to greenhouse gases.9 Whereas, as we’ll see in a future post, sheep are usually taking advantage of already existing pasture.
Feed production is a significant source of greenhouse gas emissions in two principle ways. First, intensification of farming results in decreased soil quality and increased greenhouse gas emissions; second, the use of inorganic fertilizers also impacts long-term soil quality and increased greenhouse gas emission.10
Tilling and farming intensification in the modern era has caused soil in farming areas to lose between 30% and 75% of its soil organic carbon; annual soil losses are more than three times the yields from the corn, soybeans, and hay combined. As a result, surface water runoff is greater than ever, soil erosion is exacerbated, and reservoirs and bodies of water are being inundated with farm silt. This is a double-whammy because not only does it mean that there is greater reliance on fertilizers, but it also means that loss of soil carbon and carbon carrying capacity reduces the earth’s best natural defenses against greenhouse gases.
Simultaneously, use of inorganic fertilizers and other modern crop practices like tilling between plantings have caused reduced soil ecosystem function by 90%. These same chemicals also interact with water bodies to cause emissions of methane, nitrous oxide, and ammonia. Additionally, both methane and nitrous oxide from fertilizers are released from the disturbance of soil in crop tilling.
The next major climate impact from farming operations is related to manure management. This concern is particularly acute in concentrated animal feeding operations (“CAFO”s) because the manure generated by having an extraordinarily large number of animals far outweighs (literally!) the manure-as-fertilizer needs of the land.11 This concentration of manure itself contributes methane and nitrous oxide in incredibly high doses in addition to poisoning ground water and seeping into water tables causing pollution of community water sources. Sheep are smaller than cows (obviously) and generate slightly less manure; 1000 pounds of sheep generate 2/3rd of the manure as 1000 pounds of beef cattle.12 You learn something new every day!
Finally, there is the issue of enteric fermentation in ruminants as a result of feed digestion.13 AKA: cow farts (and belches, but mostly farts).
“Ruminant animals (cattle, buffalo, sheep, and goat) produce CH4 as part of their digestive process. In the rumen (stomach), microbial fermentation breaks down carbohydrates into simple molecules that can be digested by the animals. Methane is a byproduct of this process. Poorly digestible (i.e., fibrous) rations cause higher CH4 emission per unit of ingested energy.”14
Imagine thousands of cows standing in a feed lot at a CAFO15, each of them belching and farting. They are belching and farting methane. Now imagine thousands of these farms spread around the world. This is the reality of where most of the world’s beef comes from. Now, don’t get me wrong, all ruminants contribute - sheep included; there are about 512 million sheep on the planet16 - all of them farting methane to some degree or another.
Well, the bad news is that SubStack is telling me I am near the limit for words on an email. The good news is we’re done with the bad news! We’ll be back in another post to talk about potential solutions.
Just eyeballing the chart seems to imply that approximately 2/24ths of the total output is red + blue. We can even add in the remainder of the supply chain in retail and packaging and these factors are still largely CO2 emitting and barely add to our 8.3%; we can round up and call it 8.5% or even 9% if you want to get “optimistic” about CO2 contributions.
It shouldn’t be surprising that animal shit is toxic. If you’ve spent any time around animals (including humans) this is obvious.
You may recall from Issue #10 that each lamb is approximately 80 pounds live weight, or 44 pounds hanging weight; 24.5 kilograms is approximately 53 pounds, or about 1.2 lambs.
Teague, et al. The Role of Ruminants in Reducing Agriculture’s Carbon Footprint in North America. Journal of Soil and Water Conservation. Vol 71, No. 2 (March/April 2016). https://www.jswconline.org/content/jswc/71/2/156.full.pdf
Hribar, Carrie. Understanding Concentrated Animal Feeding Operations and their Impact on Communities. National Association of Local Boards of Health. (2010). https://www.cdc.gov/nceh/ehs/docs/understanding_cafos_nalboh.pdf
Can you tell I’ve been reading a lot of scientific literature?
Gerber, et al. Tackling Climate Change Through Livestock - A Global Assessment of Emissions and Mitigation Opportunities. Food and Agriculture Organization of the United Nations (FAO), Rome. 2013. https://www.fao.org/3/i3437e/i3437e.pdf