International tourism is a huge industry, with the latest data indicating that around 975 million tourists travelled internationally between Jan - September 2023. This is 87% of the pre-pandemic level and puts the expected 2023 global tourism value at approximately 1.4 trillion USD. It’s estimated that business travel accounts for around 20% of annual global tourism expenditure, which is a sizeable chunk of the overall travel industry.
Whether travelling for business or leisure, it’s a significant contributor to CO₂e emissions, as air travel, cars, trains and buses are all primarily powered by fossil fuel-burning activity at present.
Taking a more sustainable approach to travel is increasingly important for many individuals and businesses, in order to minimise their own impact on the environment. Depending on where you live and where you’re travelling to, your options might be limited in terms of how you can travel to your destination. However, for situations where there is a choice, e.g. flying vs driving, it can be helpful to better understand the CO₂e emissions that these two common forms of travel generate.
In this article, we compare these two forms of travel in terms of carbon footprint and include some tips to help minimise CO₂e emissions when travelling by road or air.
The carbon footprint of flying
There are many variables involved in calculating the emissions generated by flying, including the size and type of aircraft, the distance travelled and the amount of time spent taxiing, taking off, cruising and landing, along with the number of passengers on board.
However, if we make some assumptions then it is possible to estimate the average CO₂e from fuel consumption per flight. Carbon Independent has calculated that for both short international flights and long-haul flights, the CO₂e is around 250kg (or ¼ tonne) per passenger for every hour of flying.
Shorter domestic flights tend to spend significantly less time in the air, but taking off and landing are considered more polluting than cruising. It’s been estimated that the emissions impact of a domestic flight in the UK in 2023 is equivalent to 270g of CO₂e for every km travelled by air.
As an example, a flight from Edinburgh to Gatwick (573km) would generate around 155kg of CO₂e for each passenger.
The carbon footprint of driving
As with flying, there are lots of variables that play into calculating the emissions generated by driving. The type, make and model of the vehicle, whether it uses petrol, diesel or is an electric vehicle (EV) or hybrid, the number of passengers and even the route taken and the driving style of the person behind the wheel, all play a role in emission levels.
Research indicates that an average petrol car in the UK in 2023 produces approximately 164g of CO₂e per km, while its diesel counterpart is responsible for around 170g CO₂e per km.
Taking the same journey between Edinburgh and Gatwick, the road distance of that trip is longer than the flight distance, so 705 km. Therefore, a petrol car making that journey would be responsible for emissions of approximately 116kg CO₂e.
However, if two or more people are making the car journey together, this figure is split between them, meaning that the emissions per person travelling becomes significantly lower.
Tips for reducing flight carbon emissions
Avoid domestic flights when possible
There can be circumstances when speed is of the essence, so taking a domestic flight may be necessary. However, if travelling for leisure, it’s well worth considering whether another form of transport might be a better option from a carbon footprint perspective.
Train travel, for example, has been calculated as generating 33g of CO₂e for each km travelled by a passenger. While the whole journey might not be possible by rail, even partially switching to a section of the journey being done on a train can make a positive difference to the carbon footprint of that trip.
Fly direct whenever possible
As taking off and landing generates more emissions than cruising during a flight, direct flights have a lower impact than those which take several legs to get you to the destination. The total distance travelled is usually also significantly less with a direct flight.
Sit in economy when flying
Air passenger emissions are determined partly on the amount of space that they take up on the flight. Business class seats, which take up considerably more space per passenger, therefore are responsible for up to double the emissions of those passengers in economy.
Keep your luggage as light as possible
Heavier planes need more fuel to get them to their destination. While having luggage that is slightly under the weight limit might not seem like it will make a difference, if every passenger does this, it really will. Packing light and leaving unnecessary items at home all helps in a small way.
Offset flight emissions
If you want to take steps for a greener future, you can choose to offset some or all of the emissions that a flight you’ve taken has generated. Find out more about offsetting flight emissions.
Tips for reducing driving carbon emissions
Carpool as often as you can
Depending on your reason for travel, taking on passengers for all or part of your trips could be a good way to help keep your personal carbon footprint as small as possible. You can join an official lift share scheme or community in your area which helps to match people travelling to the same place at the same time and many large employers have existing carpooling schemes you can join for those who commute by car. If you’re travelling to an event or concert, the chances are high that there will be other drivers nearby who would be happy to car share. Not only does it have emissions benefits, by reducing the number of vehicles travelling to the same destination, you can generally share petrol costs too, to save extra cash.
Consider the fuel you use
Depending on the age of your vehicle, deposits can start to build up in the engine, which reduces how efficiently it runs and can increase emissions. Some fuels available at forecourts have cleaning agents already added in, which helps to remove these deposits. Alternatively, you can buy bottles of cleaning agent, which you add directly to the fuel tank every few months yourself, that do a similar thing.
Get the car serviced regularly
Things such as oil changes and air filter changes can make a real difference to how efficiently your car runs, and problems can mean that emissions increase. Ensuring your car is serviced to the manufacturer’s instructions and that you check things like oil levels regularly will help to keep things running more smoothly.
Check your tyre pressures at least monthly
If your tyre pressure is too low, it increases your vehicle’s fuel consumption and CO₂e emissions. As well as sometimes being an indicator of something being wrong with the tyre itself, like a slow puncture, checking the pressures regularly also helps you to drive more efficiently, to minimise the car’s impact on the environment.
Make some adjustments to your driving style
Even some fairly minor changes to driving habits can make a tangible difference to your car’s efficiency and fuel consumption over time. Some of the small tweaks you can make include:
- Reduce your idling time - turn off the engine if you’re waiting at a standstill for more than 10 seconds
- Change gear slightly earlier and accelerate gradually
- Brake sooner and more gently
Offset driving emissions
You can take steps to reduce your personal carbon footprint by calculating and offsetting your car’s CO₂e emissions for a whole year or more at a time. Switch2Zero's Vehicle Emissions Calculator takes into account the make and model of your vehicle, along with the number of miles that you drive annually, will help to determine the most accurate measurement of CO₂e that you have generated through your travels by road.
A more sustainable future
Taking action to help reduce your own personal impact on the planet can be simple, and Switch2Zero is here to help.
You can choose to invest in projects that make the world a cleaner place, either as an individual or on behalf of your whole family, and track your impact to see the real difference that your subscription is making.
Find out more about personal CO₂e emissions offsetting.
