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Night Train vs. Flight: The Climate Case
How EcoPassenger calculates emissions — and why the numbers favour the train.
The methodology
TrainZzz uses emissions factors from EcoPassenger, a tool developed by the International Union of Railways (UIC). It accounts for energy consumption, load factors, and — for flights — the radiative forcing index (RFI), which captures the warming effect of contrails and NOx at altitude.
Typical numbers
European rail averages around 6 g CO₂ per passenger-km. A short-haul flight, including RFI, runs around 200 g CO₂ per passenger-km. On a Vienna–Amsterdam route (~1,270 km), that's roughly 8 kg CO₂ by train versus 254 kg by plane — about 30× less.
Caveats
Numbers vary by rail electricity mix, aircraft type, and cabin class. TrainZzz uses European average factors. Treat them as order-of-magnitude comparisons, not precise calculations.