Food · emission factor
The Carbon Footprint of Milk
320 g CO₂e / 100g
Cow's milk carries a footprint of roughly 320 g CO₂e per 100g — about 3.2 kg CO₂e per litre once you scale it up. That puts milk well below beef, lamb, and cheese, but several times higher than plant-based alternatives like soy or oat drinks. Because many people consume dairy daily, milk is one of the quieter but steadier contributors to a typical diet's emissions.
Why milk has the footprint it does
Most of milk's emissions come from the cow itself. Cattle are ruminants: their digestion produces methane through enteric fermentation, and methane traps far more heat than CO₂ over a 20-year horizon. Manure management adds more methane and nitrous oxide. On top of that, dairy cows need feed — often grain and soy whose cultivation involves fertiliser (a source of nitrous oxide) and sometimes land-use change. Livestock as a whole account for roughly 14-15% of global greenhouse gas emissions according to the FAO, and dairy is a meaningful slice of that. Milk's saving grace is efficiency: a dairy cow produces thousands of litres per year, so the animal's emissions are spread across a large volume of product — unlike beef, where the whole footprint lands on the meat.
How milk compares to other foods
At 320 g CO₂e per 100g, milk sits in the middle of the food spectrum. It is roughly a tenth of beef (2,990 g) and about a quarter of cheese (1,350 g) — cheese is concentrated milk, which is why its footprint multiplies. Milk is also lower than chicken (620 g) or fish (550 g) per 100g, though people typically consume milk in larger quantities. Compared with plant foods, dairy is still heavy: tofu comes in at 200 g, beans at 100 g, and vegetables at 50 g per 100g. Peer-reviewed data from Poore and Nemecek (Science, 2018) shows plant milks — soy, oat, almond — typically emit around a third of dairy milk's greenhouse gases per litre, while also using far less land and water.
The daily-habit effect
Milk's footprint per glass is modest, but frequency changes the math. A 250 ml glass every day adds up to nearly 300 kg CO₂e over a year — comparable to a 1,300 km trip in a petrol car at 231 g per passenger-km. Milk in coffee, cereal, and cooking accumulates the same way. This makes dairy a good example of where small, repeated choices matter more than occasional ones: swapping even part of your regular milk consumption has a larger annual effect than cutting a rare indulgence. It also means partial changes count — you don't need to eliminate dairy to meaningfully shrink this slice of your footprint.
How milk compares
How to reduce this footprint
- ✓ Swap dairy milk for oat or soy drink in coffee and cereal — plant milks emit roughly a third as much per litre.
- ✓ Buy only what you'll use: wasted milk carries the full farm footprint with none of the benefit.
- ✓ Treat cheese as the bigger lever — at 1,350 g CO₂e per 100g it concentrates milk's footprint about four-fold.
- ✓ Track your dairy intake for a couple of weeks to see how daily habits add up over a year.
Frequently asked questions
Is milk bad for the environment compared to plant milk?
Dairy milk emits about 320 g CO₂e per 100g, roughly three times more than typical soy or oat drinks per litre, according to the Poore and Nemecek 2018 dataset. It also uses substantially more land and freshwater. That said, dairy is still far lower-impact than beef or cheese.
Why does milk have a lower footprint than cheese if cheese is made from milk?
It takes around 10 litres of milk to make 1 kg of hard cheese, so cheese concentrates milk's emissions. That's why cheese comes in at about 1,350 g CO₂e per 100g versus milk's 320 g — the same dairy footprint packed into a smaller product.
How much CO₂ does a glass of milk produce?
A 250 ml glass of cow's milk produces roughly 800 g CO₂e. Drunk daily, that's close to 300 kg CO₂e per year — similar to driving well over 1,000 km in a petrol car.
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Sources & methodology: see Research & scientific references. Figures are averages used by the Decarbonr app; real-world values vary by production system, country, and occupancy.