Not all milk is the same. There can be worlds of difference between one milk and another. And we aren't talking about taste, fat content, or price here, but about its impact on our environment.
In our cafés, more than 70% of coffee drinks are prepared with milk. That is about six times more milk than coffee. For this reason alone, milk is just as much in our focus as coffee.
Are we allowed to drink milk? This question is enough to open up an extensive ethical discussion. This article is less about ethics, animal welfare, or nutritional physiology (you can find further leading links at the end of the article), but rather focuses primarily on the climate impact.
For this, we want to show two perspectives. One leads to the conclusion: Cows are climate killers. The other paints a different picture. But why does cow's milk have such a high social status in the first place, and why is the climate impact of cows so high in terms of global emissions?
What is milk?
Milk is always produced when a mammal has offspring. No offspring, no milk. When we drink milk other than breast milk, we are always drinking the milk of an infant. So, no lamb, no sheep's milk; no puppy, no dog's milk; no baby, no breast milk; and no calf, no cow's milk. Cow's milk is so important <1> that it is the only milk that does not need to specify the animal species. This is also anchored in law: In trade within the EU, only milk from cows may be labeled as “milk”.
After the weaning period, lactase production normally stops in all mammals. Without lactase, milk proteins can no longer be broken down, and therefore milk can no longer be processed by the body. Humans are the exception. We are the only mammals that can still consume milk and dairy products after infancy. About a third of the world's population today is still lactose intolerant. How did this come about?
A new study explains: Livestock farming began as soon as humans became sedentary. However, the milk was reserved for the offspring. Especially during famines, people were forced to fall back on animal milk. In times of malnutrition and shortages, intolerances usually led to death, and thus the “lactose-tolerant” prevailed. In this way, cattle gradually turned from working animals into livestock.
From the 1960s onwards, people began talking about factory farming as we know it today. At the time, the term promised supply security and had a positive connotation.
Today, there are about 950 million cattle <2>, of which about 260 million are dairy cows <3>. Per capita milk consumption in Germany in 2022 was 46.1 kg. (The trend is falling) <4>.
Status Quo
A look at the list of the most climate-damaging foods shows that the first three places go to the cow. Butter, beef, and dairy products (cream, milk, and cheese) are the culprits <5>. It is easy to conclude that a world without cows would be a better one.
The milk system
Conventionally produced milk (and dairy products) perform particularly poorly in climate assessments. This is because the cultivation of concentrated feed, most of which is imported from overseas, causes deforestation there and releases large amounts of stored carbon. The established monocultures require large amounts of fertilizer. Fertilizer production is resource-intensive, and large amounts of CO₂ are generated. When applying it, significant amounts of nitrous oxide can be produced. (Nitrous oxide is particularly harmful as it has 300 times the climate impact compared to CO₂). Transporting the feed to Europe creates further CO₂. With the transported plants, the stored nitrogen also comes to Europe and over-fertilizes the fields in the form of cow manure. This results in soil depletion in cultivation and over-fertilization in Europe. Both lead to measures that end up with more carbon dioxide in the atmosphere. A vicious circle for the soil and the climate.
In addition, the cow itself produces large amounts of methane during food processing (approx. 550 L per day, methane is in turn about 28 times more harmful to the climate than CO₂). This means that methane emissions from “the cow” are responsible for about 48% of agricultural emissions in Germany in 2022 <6>.
Depending on the form of husbandry, this results in 0.9 kg CO2e (ecological pasture farming, with allocation of meat sales) to 1.64 kg CO2e (conventional husbandry without pasture access, without allocation) in Germany <7>, although the global average is 2.4 kg CO2e per liter of milk <8>.
The emissions (global average) are roughly equal to the emissions generated by burning one liter of gasoline. (Tank-to-wheel view → meaning only combustion, without extraction)
Is 1 liter of milk as harmful as 1 liter of gasoline?
Are there solutions?
There are various approaches, ranging from increasing milk yields to feed additives that reduce methane emissions <9>.
One solution would be to increase milk yield while keeping methane emissions constant. 100 years ago, a cow's milk yield was about 2,000 liters per year; today, it is about 8,000 liters. (These are values for cows bred for milk production. For dual-purpose breeds, the values are lower. Our dairy farmer's cows, for example, give about 4,000L per year.) If you take the daily methane output of a cow, approx. 550 L (which in turn corresponds to ~400 g) and apply it to the annual milk yield*, the milk from 100 years ago had a footprint of 2.05 kg CO₂ equivalents, compared to 0.51 kg CO2e today. If you then add feed additives that promise a methane reduction of one-third, it would only be 0.34 kg CO2e. This would correspond to a reduction of almost 84%. However, a mistake is regularly made in this consideration: only the output is looked at.
The cow from 100 years ago very likely only ate grass from the pasture, whereas the cow today has to receive the concentrated feed described above to achieve such yields. The feed additives also have to be produced, processed, shipped, and added to the feed.
Is the cow from 100 years ago likely the more sustainable one? And does the solution perhaps not lie in technical progress, but in the form of husbandry?
The climate killer… or is it?
In many considerations, the cow is viewed as a milk machine, and its emissions are allocated to the final product just like those of machines. These machines can be optimized, output increased, and emissions reduced. All technical optimization for a living being. We would like to point out another perspective.
Changing perspectives
Every person emits CO₂, just like with the cow, we metabolize our food and emit CO₂ (and also methane). This may only be a small part (between 168 and 2040 kilograms of carbon dioxide per year; <10>).
Comparison of CO₂ equivalents of methane from dairy cows and CO₂ from humanity
Assumption 1: 8 billion people; each emits an average of 1.1 t CO₂ per year through breathing.
Assumption 2: 260 million dairy cows; each emits about 400 g of methane per day; the greenhouse effect of methane is 28x higher than that of CO₂. Thus, the average CO2e emission is 4.1 t CO₂ through methane excretion.
Accordingly, humanity emits 8.8 billion t CO₂ while dairy cows “only” emit 1.07 billion t CO2e through their methane output. (If you also add the cattle from meat production, the output would be 14.98 billion t CO2e)
(The breathing of cows and the methane output of humans is missing here)
Both our breathing and the methane output of cows are part of the carbon cycle. Methane decomposes into CO₂ and hydrogen. This CO₂ is absorbed by plants, which store the carbon and release oxygen back into the atmosphere.
Cows provide us with proteins and carbohydrates that would otherwise not be available to us. We can digest corn and soy ourselves, but not grasses.
Where do we get our milk?
We source our milk from Jonas Plattner. He has a small-scale organic dairy farm in Reigoldswil in Switzerland.
The farm
- Jonas lets his cows graze on 30ha of land
- He owns 15 cows and 1 bull
The cows
- The cows are a dual-purpose breed: they give less milk, but a bit more meat when they are old
- Jonas's cows are about 15 years old, which is very old in dairy production
- the bull is part of the herd
- the cows give milk twice a day, totaling about 10l per cow
- in a week, the cows produce about 900l
The food
- The cows eat exclusively grass, and hay in winter
- Concentrated feed like soy or corn is not used, and Jonas also avoids silage
Husbandry makes the difference - Regenerative agriculture
We all know that trees bind CO₂. But much more important for our climate are the soils: forest soils, meadows, and moors. Technical solutions in the fight against global warming mimic what nature has already solved.
With factory farming, more and more animals were kept on less and less land. This allowed the remaining area to be used for growing animal feed. As described, however, this leads to soil depletion in one place and over-fertilization in another.
But when the cattle return to the pastures, they can provide additional carbon sequestration and make these pastures, which are unsuitable as arable land, available for human nutrition. For ideal carbon sequestration, they must be kept in small pasture areas at short intervals so that they can graze and fertilize with cow manure in this small area (mob grazing). Afterward, this area remains at rest for a certain time to recover. This promotes root growth before the cattle are allowed to graze on it again.
No grassland without grazers.
If you factor in the carbon sequestration that can be created this way against the emissions, the overall balance of cows looks completely different. Unfortunately, there are few studies on this. One of them is from “White Oak Pastures” <11>, which concludes that for every kg of meat, approx. 1.6 kg of CO₂ is stored in the soil.
Conclusion
Back to milk. It's in our own hands; we can choose for our needs at home: do we support the status quo, do we reach for alternatives like oat, or do we take the regenerative option? Two out of three options tend to have positive climate effects. That sounds good. (The fact is, however, that the real share is (still) low.)
In Germany, there are about 100 farms that produce milk not only regeneratively but also in maternal-rearing systems. The special thing about this is that the calves grow up with the mother and are allowed to drink first, and humans take what is “left over”. The organic share of all produced milk is approx. 3.5%, of which approx. 2% is cow-calf rearing <12>.
As citizens we reject factory farming, but as consumers we do not yet.
Further links:
- TED Talk Allan Savory
-
TED Talk Bobby Gill
- Farm Rebellion on Disney+ - Trailer
- NDR Green Garage - Beef - enjoyment without a guilty conscience?
- The Milk System on Netflix - Trailer
- ARTE Documentary: What are we still allowed to eat?
Books
- Die Kuh ist kein Klimakiller! - Anita Idel
- Rebellen der Erde: wie wir den Boden retten - und damit uns selbst! - Benedikt Bösel
- Holistic Management Handbook - Allan Savory
Sources:
<1> cf.: statista.com, Milk - Germany, as of: 28.09.23
<2> cf.: https://de.statista.com/statistik/daten/studie/28931/umfrage/weltweiter-rinderbestand-seit-1990/, as of: 28.09.23
<3> cf.: agrarheute.de, Dairy farming XXL: Herd size is growing worldwide, as of: 28.09.23
<4> cf.: tagesschau.de, Why Germans drink less milk, as of: 28.09.23
<5> cf.: utopia.de, These 6 foods are the worst for the climate, as of: 28.09.23
<6> cf.: umweltbundesamt.de, Contribution of agriculture to greenhouse gas emissions, as of: 28.09.23
<7> cf.: umweltbundesamt, Making hidden environmental costs of agriculture visible using the example of milk production systems, as of: 28.09.23
<8> cf.: bauernverband.de, Methane emissions in cattle farming, as of: 28.09.23
<9> cf.: dsm.com, The proven solution for methane reduction, as of: 28.09.23
<10> cf.: co2online.de, What do humans exhale, as of: 28.09.23
<11> cf.: whiteoakpastures.com, Study: White Oak Pastures Beef Reduces Atmospheric Carbon, as of: 28.09.23
<12> cf.: ardmediathek.de, Content, as of: 28.09.23
