The carbon footprint of processed onions
Processed onions emits about 0.571 kg CO₂e per kg. Below is where that figure actually comes from — every stage of the chain, not a single headline number.
- Processing
- 0.5 kg
- 88%
- Turning the raw product into food: milling, refining, slaughter, curing.
- Transport
- 0.052 kg
- 9%
- Moving it from farm to processor to shop.
- Packaging
- 0.019 kg
- 3%
- Producing the packaging it reaches you in.
How it is grown changes the number by 97%
These are 5 separately assessed production systems for the same product. Emissions are farm-gate — the part the grower controls — and range from 0.045 to 1.725 kg CO₂e. A label on a shelf almost never tells you which one you are holding.
- Onion, long-day sown, conventional, at farm gatelowest0.045
- Onion, national average, at farm0.054
- Onion, short day sown, conventional, at farm gate0.054
- Onion, long-day planted, conventional, at farm gate0.122
- Onion sets, conventional, at production site1.725
kg CO₂e per kg, cradle to farm gate. Farm-gate figures exclude processing, packaging and transport, so they sit below the full total above.
Lower-carbon alternatives
Each emits less than half as much as processed onions.
Similar products
Common questions
- How much CO2 does processed onions produce?
- About 0.571 kg CO₂e per kg, measured across the supply chain. That is roughly the same as driving 3 km in an average petrol car.
- What drives the footprint of processed onions?
- Processing is the largest contributor at 0.5 kg CO₂e, about 88% of the total. Transport is only 0.052 kg — which is why what you eat matters far more than how far it travelled.
- Does how processed onions is produced change its footprint?
- Yes, substantially. Across 5 production methods in this dataset the farm-gate emissions range from 0.045 to 1.725 kg CO₂e — a difference of 97%.
- Where does this data come from?
- The WRAP UK Food & Drink Emission Factor Database v2.0, which aggregates peer-reviewed life-cycle assessments. This product's figures come from Frankowska et al..
Figures from the WRAP UK Food & Drink Emission Factor Database v2.0, which aggregates published life-cycle assessments; this product's data originates from Frankowska et al., for UK. Real values vary by farm, region and method — treat these as the shape of the problem, not a measurement of any one item on your shelf.
Shred what you can't cut
Diet is one of the biggest levers you control. For the rest, retire verified carbon credits — with the serial number to prove it.