By: Ennio Cantergiani – Académie du Café

You may have seen claims that coffee emits 2 kg of CO₂e per kilogram, or figures exceeding 28 kg CO₂e per kilogram.
On a per-cup basis, estimates range from around 50 grams to more than 250 grams of CO₂e.

So which number is correct?
All of them — depending on what is being measured.

  • 1) System boundaries: what’s included?

The largest source of variation comes from the life-cycle assessment (LCA) scope used in different studies:

Farm gate only: cultivation and primary processing

Roasted coffee delivered: adds transport, roasting, and packaging

Cup footprint: includes brewing energy and waste

This is why datasets such as Our World in Data report higher coffee emissions than many other foods. They rely on full supply-chain assessments, similar to those developed by Poore and Nemecek, which capture impacts from farm to consumption.

  • 2) Origin dominates the footprint

At the farm level, origin often accounts for 40–80% of total emissions. Key drivers include:

Use of nitrogen fertilizers, which generate nitrous oxide emissions

Land-use change and deforestation

Low yields, which increase land and input intensity per kilogram

Energy use in wet processing and drying

Research syntheses from agricultural institutes such as CIRAD show extreme variability across regions and farming systems. Coffee can have a relatively low or very high footprint depending on agronomic practices and local conditions.

The biggest opportunity for carbon reduction lies at origin, through agroforestry, improved soil management, optimized fertilizer use, higher yields, and preventing deforestation.

  • 3) Brewing method matters more than expected

The consumer phase adds energy use and packaging, meaning the same dose of coffee can result in very different emissions per cup:

Instant coffee (small dose, no machine): ~50–80 g CO₂e

Filter or moka (simple heating): ~80–170 g CO₂e

Espresso machines (electricity and standby losses): ~110–220 g CO₂e

Capsules (packaging and waste): ~120–250 g CO₂e

Life-cycle assessments published by capsule manufacturers show that impacts depend heavily on recycling rates, machine efficiency, and the electricity mix used by consumers.

  • Where can we really save CO₂?

Highest leverage actions:

Origin: deforestation-free + better fertilizer/yield systems

Transport: avoid air freight

Consumer: reduce energy waste (standby), use efficient brewing

Packaging: bulk beans/ground coffee; recycle capsules properly

Same beverage. Different impact.

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