Work out your long-haul economy flights emissions
= 2.57 tonnes CO2e in 2026 (Scope 3)3.12 tonnes including well-to-tank
Each passenger km × 0.11704 kg CO2e, the 2026 UK government (DESNZ) factor.
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Long-haul economy flights emission factor by year
| Year | Scope 3 (kg CO2e per passenger km) | Well-to-tank | Full figure | Change |
|---|---|---|---|---|
| 2026 | 0.11704 | 0.024610 | 0.14165 | 0.0% |
| 2025 | 0.11704 | 0.024610 | 0.14165 | -41.5% |
| 2024 | 0.20011 | 0.024610 | 0.22472 | +0.0% |
| 2023 | 0.20011 | 0.024610 | 0.22472 | +35.3% |
| 2022 | 0.14787 | 0.016190 | 0.16406 | 0.0% |
| 2021 | 0.14787 | 0.016190 | 0.16406 | +1.2% |
| 2020 | 0.14615 | 0.016000 | 0.16215 | -2.4% |
| 2019 | 0.14981 | 0.016410 | 0.16622 | – |
Total kg CO2e for the seven greenhouse gases, from the official DESNZ files for each year. 2026 factor ID: 21_316_3170_11_1. Where a factor jumps sharply between two years, it is usually because DESNZ changed its method or data source, not because the activity itself changed.
Worked example
Take one return economy trip from London to New York, about 11,000 km each way. 22,000 passenger km × 0.11704 kg CO2e = 2.57 tonnes CO2e, reported as Scope 3, category 6 (business travel). Adding well-to-tank brings the full figure to 3.12 tonnes CO2e; the extra 0.54 tonnes are Scope 3 category 3.
How to report it
Long-haul is any flight to or from the UK beyond about 3,700 km. Economy seats take the least space, so they have the lowest factor per passenger.
The factor shown includes radiative forcing, the extra warming caused by emissions at altitude, which the government recommends including for business travel.
Where the data comes from
You'll usually find it in your travel booking system or expenses, as journeys you then convert to distance. Keep the source documents: anyone checking your Carbon Reduction Plan or SECR report may ask how each figure was worked out.
Read more about how the factors change each year in our guide to the 2026 conversion factors, or see how we apply them in our methodology.
Related emission factors
- Long-haul premium economy flights: 0.18726 kg CO2e per passenger km
- Long-haul business class flights: 0.33940 kg CO2e per passenger km
- Long-haul flights: 0.15282 kg CO2e per passenger km
- All UK emission factors