Day trip flights and CO2.
The honest numbers.
We sell day trips, and most of them involve a plane. So here it is straight: flying isn't great for the climate. We'd like everyone who uses BudgetBro to think about the train first where there is one.
How much CO2 is a day trip flight?
London to Paris and back is about 87 kg of CO2e per person by plane, and about 8 kg by Eurostar. About a tenth.
For a short flight from the UK, roughly 87 to 190 kg of CO2e per person for the return trip, depending on how far you go. CO2e means carbon dioxide plus the other gases that warm the planet, counted as if they were all CO2.
Plane vs train vs car, return trip per person
London to Paris
Train about 8 kg. Car with 2, about 58 kg
London to Amsterdam
Train about 8 kg. Car with 2, about 61 kg
London to Edinburgh
Train about 33 kg. Car with 2, about 89 kg
| Route | Flight | Train | Car, 2 people |
|---|---|---|---|
| London to Brussels | about 88 kg | about 8 kg | about 58 kg |
| London to Frankfurt | about 164 kg | no day trip by train | about 108 kg |
| London to Geneva | about 190 kg | no day trip by train | about 125 kg |
| Manchester to Dublin | about 67 kg | no day trip by train | not counted |
| London to Manchester | about 112 kg | about 15 kg | about 41 kg |
Source: UK Government greenhouse gas conversion factors 2026 (Department for Energy Security and Net Zero, published 11 June 2026, revised 31 July 2026). Flights are economy short-haul (UK domestic flights use the average passenger figure), including the extra warming planes cause at altitude. Distances are straight lines between the cities. See the government figures.
How we worked these out
We took the straight-line distance for each route and multiplied it by the government's figure for each way of travelling. The government's flight figures already allow for planes not flying in a straight line, so we didn't add anything.
Trains and roads aren't straight, so the real train and car numbers will be a bit higher. Even if you add half as much distance again, Eurostar to Paris is still only about 12 kg and the train to Edinburgh about 50 kg. The train still wins easily. The car figures are for an average car and leave out the Channel crossing.
Why we count the extra warming from planes
Planes don't just burn fuel. At cruising height they also leave contrails, water vapour and other gases that add to warming. The government's figures with this included are about 40% higher than without. We use the higher figure because it's the more honest one. Without it, London to Paris would be about 52 kg and London to Edinburgh about 145 kg.
Is the train really better?
Yes, by a long way where a fast train exists. London to Paris by Eurostar is about 8 kg return, roughly a tenth of flying. London to Edinburgh by train is about 33 kg against about 245 kg by plane, because short UK flights have the highest footprint per mile of anything on this page.
A car with two people in it beats flying on every route here. On your own, a car is worse than flying to the continent, but still better than a UK domestic flight.
When to take the train instead
Paris, Brussels and Lille
About two hours. Quicker door to door than flying.
Amsterdam
About four hours each way. Doable, but a long day.
UK cities by train
Manchester, Edinburgh, York, Brighton and more.
If you do fly
We're not going to tell you never to fly. That would be a bit rich coming from us. But a few things make a real difference. Fly direct, because take-off and landing burn the most fuel, so one direct flight beats two with a change. Take carry-on only, less weight means less fuel. Do fewer trips rather than none at all: one great day out a few times a year beats lots of quick ones. If a train gets you there in about four hours or less, take it. And if you drive, take someone with you, because two people in a car halves the footprint each.
What we don't do
We don't sell carbon offsets and we don't call any trip green. Offsets are hard to check and we'd rather show you the real numbers than promise something we can't stand behind.
