Flying and trees
Travel opens the world, and planes are part of life. Here is what a flight really emits, what helps most, and why a tree for every trip is a lovely habit to start.
£5 per tree, VAT included
of CO2e per passenger-kilometre on a domestic flight in economy, including the extra warming of emissions at altitude.
UK Government factors 2022, via Our World in Dataper passenger-kilometre by national rail. A short-haul flight is 151 g and a petrol car 170 g.
UK Government factors 2022, via Our World in Dataof CO2e for a long-haul flight of 6,000 km each way: 12,000 km × 148 g.
Our calculation from the UK factorsThe UK Government publishes emission factors that companies use for their reporting, and Our World in Data compares them across ways to travel. Per passenger and kilometre in economy class, a domestic flight comes to 246 g of CO2-equivalents, a short-haul flight 151 g and a long-haul flight 148 g. A petrol car is 170 g, and national rail 35 g.
The flight figures include the extra warming that planes cause high in the sky, such as contrails, which is why they are given as CO2-equivalents. Real numbers vary with the aircraft, the route and how full the plane is, and other countries have their own factors, but the picture stays the same.
A city break 1,500 km away is 3,000 km there and back. By plane that is about 450 kg of CO2e (3,000 × 151 g). The same distance by rail would be about 105 kg (3,000 × 35 g), although train emissions depend on how the trains are powered.
A long-haul holiday 6,000 km away is 12,000 km there and back, or about 1.8 tonnes of CO2e (12,000 × 148 g). That is more than a third of what the average person in the world emits as CO2 from fossil fuels and industry in a whole year: 4.7 tonnes in 2024.
The emissions of a flight happen on the day you fly. A tree stores carbon slowly, as it grows over decades. To hold 1.8 tonnes of CO2, a tree needs about a tonne of dry wood (1,776 ÷ 3.67 ÷ 0.47, using the IPCC factors), and a seedling takes a long time to get there. That is why we never say a tree cancels a flight, and why we don't promise CO2 per tree.
Fly a little less often and stay a little longer. Take the train for trips you can make in a day by rail. Choose one long holiday over several short ones, and look at the train before you book a short flight.
When you do fly, plant a tree. Not as an eraser, but as a habit: a small thank-you to the planet each time you see a new place. Every tree becomes part of a new forest on former grassland, and with the same name and e-mail your trees add up into one row on our leaderboard.
Book the trip, plant a tree. Easy to remember, easy to keep.
Every tree becomes part of a forest that did not exist before.
Each trip adds a tree to your row on the leaderboard.
One for this trip, or one for every flight this year. Each costs £5.
It goes on our leaderboard, or stays hidden if you prefer.
We plant in the next season and report on how it grows.
No honest number exists. A flight emits on the day you fly, while a tree stores carbon slowly over decades and every site grows differently. We see a tree for every flight as a good habit and a contribution to new forest, not as a way to cancel the flight.
Yes. The UK factors add the extra warming that planes cause at altitude, which is why they are given as CO2-equivalents (CO2e).
In the UK figures, national rail is 35 g per passenger-kilometre against 151–246 g for flights. Trains elsewhere depend on how they are powered and how full they are, but for trips you can make in a day by rail, the train is usually far lower.
Yes. Use the same name and e-mail each time and your trees add up into one row on the leaderboard.
