Domestic flights (UK): carbon footprint per passenger-km (with RF)
Live factor value
0.22928 kgCO2e per passenger-km (with RF)
Source: UK DESNZ greenhouse-gas conversion factors, 2026 (revision 2). Factor set desnz-2026-r2.
Domestic flights have the highest per-km footprint of any flight category in the official DESNZ 2026 tables — shown live below with radiative forcing included — because take-off and climb, the most fuel-hungry phases, are spread over a short cruise.
That is why a London–Edinburgh flight emits several times more than the same journey by train, despite the shorter travel time. The factor applies the government-recommended radiative-forcing multiplier of 1.7 to account for altitude effects.
Worked example
London to Edinburgh flight (~534 km GCD + 8% ≈ 577 km): 577 × 0.22928 = 132 kgCO2e.
Measure your own with the free travel calculator.
Frequently asked questions
- Why are domestic flights the most carbon-intensive per km?
- Take-off and climb burn far more fuel than cruising. On a short domestic hop those phases dominate the whole flight, so the per-km average is higher than short-haul or long-haul international flights.
- How much lower is the train on the same route?
- National rail is 0.03092 kgCO2e per passenger-km in the same factor set — an order of magnitude below the domestic flight factor with radiative forcing.