Cows vs. Cars – which is the real carbon emissions culprit?

March 10, 2025 / Julie Babis /

I have to admit to shouting at the TV the other evening, watching Mary Nightingale announce with absolute seriousness that we should all eat less meat and dairy to enable the country to comply with carbon emissions reductions targets.

I had to tell myself “don’t shoot the messenger, she’s just passing on the governement’s agenda with regards to trying to stir up some individual responsibility for one’s actions”. I don’t have a problem with taking individual responsibility per se. However, I do have an issue when the information is distorted to suit governments, lobbying groups and industry afactions. In my opinion, targeting meat and dairy is a facile and blatantly incorrect approach.

What’s the official agenda?

There are a number of reasons I say that.  These include:

  • The fact that the government has rowed back on targets to end the sale of petrol and diesel cars
  • Building a third runway at Heathrow is firmly back on the political agenda
  • The second proposed runway at Gatwick, whilst not actually given the go-ahead, is likely to be given the green light this autumn.
  • Additional runways will create – guess what – additional car use. One of the reasons for the delay to the Gatwick runway is that insufficient people travel there using public transport for the project to meet sustainability criteria.

What has that got to do with meat and dairy consumption? It has to do with the fact that carbon emissions are an issue that we need to address. However, if the government is going to reduce existing targets for cars and pretend that building extra runways can be carbon neutral (I suspect that bollocks, but that will entail a whole additional load of research), they have to been seeing to be targeting something. Food is an easy target, especially as farming does not have an effective lobby in parliament, and little money to spend on influencing opinion via advertising and social media.

Transport is highly polluting

It is indisputable fact that the carbon emissions from cars and planes are significantly higher than those of farm animals.  Take the headline figure from the news and extrapolate to emissions: if an additional runway at Gatwick would generate 100,000 extra flights a year, what is the knock-on effect on carbon?  Read on and I give you the information to calculate the effect that alone has on carbon emissions, and where consuming dairy fits into the bigger picture.

I think the results make interesting reading.

The campaign against real food

The mainstream media are quite happy to focus on the dairy and meat industries.  However, there is a lot of deliberate misinformation, and plant based eating is not necessarily angelic in terms of its environmental impact. Bear in mind that there are a lot of commercial interests behind the promotion of plant-based eating including the Kellogg Foundation (cereals), the Alpro Foundation (soy production) and big tech that supports the fake meat industry.

Milk

So, I’m starting with dairy.  Milk is nutritious.  There is no doubt about that.  It is an excellent source of protein with 6.8g per 250ml. It’s a source of fat and fat soluble vitamins.  I’m not going in to the ins and outs of why saturated fat is not the anti-nutrient we have been led to believe. However, I will point out that if you take the fat out of the milk, you are also taking out the fat soluble vitamins, including vitamin K2.

K2 is massively underrated. It acts in conjunction with vitamin D as the glue that binds calcium into your bones. At the same time, it reduces the affinity of calcium to bind  to thickened tissue in your blood vessels, and so reduces the risk of hardening arteries (Beulens et al., 2018). Whole milk contains a good amount of K2 (in the menaquinone -4 form) which is much more readily absorbed by the body than the K1 form (phylloquinone) found in plant based foods.

Whole milk provides approximately 37 micrograms (µg) per 100 ml of vitamin A.  This vitamin is essential for healthy vision, supporting immune function, and promoting skin health (USDA, 2020). Vitamin A from dairy sources is in its most bioavailable form, retinol, the active form of the ingredient that the body can readily use (Tanumihardjo et al., 2021).  Plant-based sources on the other hand provide provitamin A (beta-carotene), which has to be converted within the body to retinol.

We all know that milk contains calcium, which is essential for a number of functions within the body, including bone health, muscle contraction, and nerve signalling. Whole milk provides approximately 124 milligrams (mg) per 100 ml (Weaver & Heaney, 2020).  

Potassium plays a key role in regulating blood pressure, fluid balance, and muscle contractions. Whole milk provides around 162 mg per 100 ml (Houston et al., 2020). Dietary potassium is thought to support cardiovascular health and reduce the risk of hypertension.

Together, calcium and potassium act as signalling molecules, and allow for trace elements to enter into cells in the body, where they are utilised for energy production.

Milk further supports bone health by providing phosphorous phosphorus, another trace element involved in bone formation and maintenance. Whole milk contains around 99 mg per 100 ml (Calvo & Lamberg-Allardt, 2018).

It’s convenient to have all those nutrients together in one food stuff.  And I believe that there is no cause to ditch dairy in favour of alternatives in the name of ‘sustainability’. the greenhouse gas emissions argument, when put into context, doesn’t stack up.

Cows

It’s undeniable that livestock farming is a source of methane emissions. However, it is nowhere as massive a cause as the mainstream media, ITV included, seem to want us to think.  Methane is a greenhouse gas with a global warming potential (GWP) 28–36 times that of CO₂ over a 100-year period (IPCC, 2021). A single cow, depending on breed and diet, emits 70–180 kg of methane per year (FAO, 2013). But that figure needs to be put in a real context, not bandied about in a void.

Firstly, not all cattle are managed equally. It is important to take into account how the cows are reared. Commercially farmed dairy cattle, typically housed indoors and fed high-energy grain diets, emit 2.5–3.5 metric tons of CO₂e per year per cow.  This is due to increased gut fermentation and manure management (FAO, 2019).  All cows poop. The excrement from the one that is mostly stuck in a barn will be hosed out and likely into a giant septic tank known as a slurry pit.  There it continues to ferment and emit methane. Some enterprising farmers are exploring how this gas can be harnessed to burn as fuel to power the farm. Some spread it as fertiliser (or it is occasionally used as weapon by angry farmers!). Cows that are grazed year round poop out in nature, on the whole natural breakdown processes apply, it acts a nutrient for the soil, happy days.

Another point to remember is that grain in bulk is not a natural diet for cattle – they have to work harder to digest it, and those increased digestive processes result in a higher level methane produced than a cow that eats its natural diet of grass plus whatever other plants are growing in the meadow.

Organically grazed cattle – generally the rare and/or traditional breeds – which rely solely on pasture without supplemental feed, tend to emit 1.5–2.5 metric tons of CO₂e per year. On the flip side, although natural feeding patterns result in reduced methane production (Garnsworthy, 2004), milk production is lower. This results in more expensive milk (and meat). Intensively farmed Holstein dairy cows can produce 8,000–12,000 litres of milk per year, whereas rare breed pasture-reared dairy cows, such as Jerseys or Guernseys, typically yield 3,000–5,000 litres annually (DairyCo, 2012). Intensive farming systems maximize milk output per cow, but result in higher greenhouse gas emissions per animal because of the unnatural lifestyle of the cows.

When converted to CO₂ equivalent (CO₂e), per cow is in the range 2,000–6,500 kg of CO₂e annually. As you can see, this is quite a huge range. Where your milk fits into this range depends on whether you buy the cheapest supermarket milk, which is almost certainly from animals that are intensively farmed, or more expensive milk, where the price reflects the less intensive farming and lower yield.

But before you stress too much, consider this.  How much dairy do you actually consume? I’m not saying you shouldn’t care about the welfare of animals, but we’re looking principally about carbon emissions here. Unless you’re running a coffee shop, you’re unlikely to be consuming the entire milk output of a cow per year. My family of four consumes around 4 litres of liquid milk per week plus another couple of litres in yoghurt, kefir, cheese and butter.

So 6 litres milk per week, times 52 = 336 litres milk per year. So, conservatively, that’s a 10th of a rare breed cow’s production or 1/23 of the lowest range of output of a commercially reared cow.

That equates to a CO2 equivalent of 0.06 to 0.11 metric tonnes – a fraction of what my car emits (see below).  If you buy British milk, you’re also supporting a farmer, and depending on where you buy it, the food miles might be relatively small.

Cars

I drive a medium size petrol SUV. Not the best for the environment, I admit. Bizarrely, I can drive it into a ULEZ zone without penalty, but my husband can’t drive his diesel car into the same zone, despite a lower carbon impact. Go figure.

The SUV’s Carbon Footprint Compared to Cattle

Let’s have a look at what my SUV does for global warming. A petrol-powered SUV averaging 20 miles per gallon (mpg) and driven 12,000 miles per year produces around 5.33 metric tons of CO₂ (EPA, 2023). Diesel-powered models are slightly more efficient but still contribute nearly 4.88 metric tons annually.

Compared to the environmental cost of driving my car, the cow whose milk I drink is not doing anywhere near as much damage. And she also feeding between 9 and 22 other families.

Aircraft

What about air travel? I had some fun here working it out.

Aircraft are a massive source of emissions, particularly for long-haul flights. I chose to look at three particular types of aircraft for a closer approximation of accuracy, and different lengths of flight, which are consistent with the aircraft type.

Airbus A380 (London–Dubai, daily flights):

One of these superjumbos burns approximately 16,000 kg of fuel per flight, leading to an annual emission total of 18,469 metric tons of CO₂ (ICAO, 2021). When factoring in additional climate effects such as contrails and nitrogen oxides, the real impact may more than double  to around 37,000 metric tons CO₂e per year.

Now I live almost directly below the Heathrow flight path, and I know from personal observation that there are at least half a dozen of these flying in and out daily.  The Emirates ones I know fly between Heathrow and Dubai. The one that comes in at about 3pm is my school run reminder.

A320 (six intra-European flights daily):

A short-haul favourite of many airlines, the A320 emits on average 7.9 metric tons of CO₂ per flight, adding up to 17,301 metric tons annually. With climate multipliers included, this figure could reach 32,872 metric tons CO₂e per year.

So that lovely little city break in Barcelona? Assuming 180 passengers on the aircraft, your portion of the carbon emissions is a little over 0.4 metric tonnes each way. Again, significantly more than feasible individual annual milk consumption.

Boeing 787 Dreamliner (London–San Francisco, daily flights):

This is a long-haul jet, and it burns 24,000 kg of fuel per trip, emitting 27,667 metric tons of CO₂ annually—or approximately 52,567 metric tons CO₂e when non-CO₂ effects are included (ATAG, 2020).

Let’s put all that into context

While the emissions of a single intensively farmed cow and a car are comparable, flying producing significantly more not just CO2, but other equally damaging gases too. A single transatlantic flight on a Boeing 787 can produce as much CO₂ as hundreds of cars driving for a year or thousands of cows grazing.  But you’re not consuming the entire output of the cow. Yes, you’re not the only person on the plane either, but you are divvying up a massively larger amount of green house emissions between than you would be by sharing the cow’s milk.

What’s the solution?

I’m not going to tell you what you should and shouldn’t consume. But when the mainstream media is harping on about how we should be reducing our dairy and meat consumption to save the planet, don’t take what is said without putting it into context.

Milk alternatives are not necessarily a better choice, from an environmental perspective.  Let’s take almond ‘milk’ as an example.

Almonds

The vast majority of almonds used for almond milk in the UK are imported from California. So that means that whatever mode of transport got them here emitted a load of carbon. Additionally, almond trees are one of the thirstiest trees on the planet. The irrigation requirement for the Central Valley area of Caliornia, parts of which are vast monocultures where nothing else is allowed to grow, are vast. So vast that the ground over the whole area has dropped by up to 40m in places, because of decades of massive extraction of ground water.  That same water extraction is also thought to have contributed to the extreme aridity that has contributed to uncontrollable wildfires. Which also emit carbon.

Alongside this, single fruit monocultures are catastrophic for pollinators, because the crop flowers for about a fortnight once a year. Outside of that period, there is absolutely nothing for bees and other insects to eat.  They may as well be in the desert.  Eradication of all other plants is also an environmental disaster for mammals too. No food, no cover, nothing can live.

Conclusion

There is no such thing as a perfect food in terms of carbon emissions. In terms of nutrition, milk beats its alternatives hands down. Is it at the cost of the environment? Personally I don’t think so, especially if you opt for locally produced, minimally processed milk from pasture reared animals. Admittedly, this does come at a greater financial cost. However, I would argue that there is nothing to feel guilty about for buying British milk from the supermarket. It’s a perfectly valid choice.

One thing I have noticed in researching this is that the way any web search presents the data on cows vs. cars in terms of carbon emission is very much skewed towards playing up agricultural emissions and playing down transport ones. There’s something to ponder!

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References

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  • Calvo, M.S. and Lamberg-Allardt, C.J. (2018) ‘Phosphorus’, Advances in Nutrition, 9(5), pp. 651-653. doi:10.1093/advances/nmy042.
  • Goulson, D., Nicholls, E., Botías, C. and Rotheray, E.L. (2018) ‘Bee declines driven by combined stress from parasites, pesticides, and lack of flowers’, Science, 347(6229), p. 1255957. doi:10.1126/science.1255957.
  • Kremen, C. and Miles, A. (2012) ‘Ecosystem services in biologically diversified versus conventional farming systems: benefits, externalities, and trade-offs’, Ecology and Society, 17(4), p. 40. doi:10.5751/ES-05035-170440.
  • Marsh, J., Huth, M. and Lane, J. (2021) ‘Water usage in California almond production: A sustainability analysis’, Journal of Agricultural Water Management, 250, p. 106855. doi:10.1016/j.agwat.2021.106855.
  • Martínez Steele, E., Baraldi, L.G., Louzada, M.L.D.C., Moubarac, J.C., Mozaffarian, D. and Monteiro, C.A. (2017) ‘Ultra-processed foods and added sugars in the US diet: evidence from a nationally representative cross-sectional study’, BMJ Open, 6(3), p. e009892. doi:10.1136/bmjopen-2015-009892.
  • Meydani, S.N., Wu, D., Santos, M.S. and Hayek, M.G. (2018) ‘Antioxidants and immune response in aged persons: overview of present evidence’, The American Journal of Clinical Nutrition, 62(6), pp. 1462S-1476S. doi:10.1093/ajcn/62.6.1462S.
  • Richards, M., Jones, H. and Jenkins, C. (2022) ‘Sustainable water use in California agriculture: The case of almond production’, Environmental Research Letters, 17(3), p. 034011. doi:10.1088/1748-9326/ac4f7d.
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  • USDA (2020) ‘FoodData Central’, United States Department of Agriculture, Available at: https://fdc.nal.usda.gov/ (Accessed: 21 February 2025).
  • Weaver, C.M. and Heaney, R.P. (2020) ‘Calcium’, in Ross, A.C., Caballero, B., Cousins, R.J., Tucker, K.L. and Ziegler, T.R. (eds.) Modern Nutrition in Health and Disease. 11th edn. Philadelphia: Wolters Kluwer, pp. 234-250.
  • Calvo, M.S. and Lamberg-Allardt, C.J. (2018) ‘Phosphorus’, Advances in Nutrition, 9(5), pp. 651-653. doi:10.1093/advances/nmy042.
  • Goulson, D., Nicholls, E., Botías, C. and Rotheray, E.L. (2018) ‘Bee declines driven by combined stress from parasites, pesticides, and lack of flowers’, Science, 347(6229), p. 1255957. doi:10.1126/science.1255957.
  • Kremen, C. and Miles, A. (2012) ‘Ecosystem services in biologically diversified versus conventional farming systems: benefits, externalities, and trade-offs’, Ecology and Society, 17(4), p. 40. doi:10.5751/ES-05035-170440.
  • Marsh, J., Huth, M. and Lane, J. (2021) ‘Water usage in California almond production: A sustainability analysis’, Journal of Agricultural Water Management, 250, p. 106855. doi:10.1016/j.agwat.2021.106855.
  • Martínez Steele, E., Baraldi, L.G., Louzada, M.L.D.C., Moubarac, J.C., Mozaffarian, D. and Monteiro, C.A. (2017) ‘Ultra-processed foods and added sugars in the US diet: evidence from a nationally representative cross-sectional study’, BMJ Open, 6(3), p. e009892. doi:10.1136/bmjopen-2015-009892.
  • Meydani, S.N., Wu, D., Santos, M.S. and Hayek, M.G. (2018) ‘Antioxidants and immune response in aged persons: overview of present evidence’, The American Journal of Clinical Nutrition, 62(6), pp. 1462S-1476S. doi:10.1093/ajcn/62.6.1462S.
  • Richards, M., Jones, H. and Jenkins, C. (2022) ‘Sustainable water use in California agriculture: The case of almond production’, Environmental Research Letters, 17(3), p. 034011. doi:10.1088/1748-9326/ac4f7d.
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