The carbon footprint of a cup of coffee (it's mostly the milk)
A black coffee carries roughly 0.05 kg of CO₂e; a large latte can be 0.3–0.55 kg — up to ten times more. The gap isn’t the coffee. It’s the milk.
Where a coffee’s footprint comes from
| Cup | ~kg CO₂e |
|---|---|
| Black coffee / espresso | ~0.05 |
| Coffee with a splash of dairy milk | ~0.1 |
| Flat white / cappuccino | ~0.2–0.35 |
| Large latte (lots of dairy) | ~0.3–0.55 |
| Same, with oat or soy milk | ~0.1–0.15 |
Dairy is the driver because milk comes from cows — the same ruminant problem that makes beef an outlier. Switching a latte from dairy to oat or soy milk roughly halves or thirds its footprint. The beans, the cup, and the machine are comparatively minor (though a daily disposable cup adds up as waste, if not much as carbon).
Does it add up?
One dairy latte a day is on the order of 100–150 kg CO₂e a year — not nothing, but a rounding error next to a flight. It’s a fine place to make an easy swap (plant milk), not a place to agonise.
The honest framing
Coffee is the perfect small example of a big rule: animal products dominate food footprints, even in a drink. If you take milk, the plant-milk swap is the single highest-leverage change to your cup — and it’s the kind of low-stakes decision worth automating so you can save your attention for the tonnes elsewhere. CO2Mate logs the milk, not just the coffee.
Sources: Our World in Data on the carbon footprint of milk and plant-based alternatives; Poore & Nemecek (2018) dairy emission factors; BBC/University of Sheffield analyses of coffee’s footprint.