Trip CO2 Emissions by Transport Mode

CO₂ emissions per trip by transport mode

How much CO₂ falls on each passenger comes down to the mode and how full it is. Here are some reference factors (g CO₂/passenger-km): domestic flight ~250; international ~150, since longer hops run more efficiently; car ~200 alone, dropping to ~50 once you've got 4 people aboard; intercity bus ~70; electric train in Brazil ~30; Eurostar ~6, thanks to France's clean grid; and a cruise ship ~250 per pax/km. To put numbers on it, a São Paulo-New York round-trip lands at roughly 1 tonne CO₂/passenger, while 1,000 km solo in a gasoline car is 200 kg. Aviation answers to CORSIA (ICAO), and corporate emissions to the EU CSRD from 2024 on. Voluntary offsetting through schemes like Carbono Neutro Eu Concordo, Gold Standard or Verra usually runs $5-25/tonne.

Applications

Sizing up a personal carbon footprint, deciding train versus plane on a European trip, buying voluntary offsets for flights, putting together ESG reports on corporate travel, filing CSRD scope 3 disclosures, or running ANTT freight transport audits.

FAQ

Why are short flights worse per km? Takeoff and the climb out burn far more fuel than cruising does. Stretch the hop out and the per-km factor gets better, even though the total emissions go up.

Is a full car worse than a train? Not really. Four people in a car sit around ~50 g/pax-km, on par with a diesel train, and that beats a domestic flight by 5×.

Does offsetting actually work? Don't treat it as a replacement for cutting emissions in the first place. That said, solid standards like Gold Standard and Verra VCS do fund avoided-deforestation and reforestation projects where the additionality can be measured.