A flight from Hamburg to Munich produces more CO2 per person than a month of commuting by car. That sounds dramatic – but is it true? The CO2 footprint calculator for travel makes the emissions of different modes of transport directly comparable. It uses current emission factors from Germany's Federal Environment Agency and accounts for special factors like the radiative forcing index (RFI) for flying, which amplifies the climate damage of emissions at altitude.
Step by Step: How to Use the CO2 Footprint Calculator
- Enter the distance: Enter the length of your journey – e.g. 600 km for the Hamburg–Munich route.
- Choose the mode of transport: Select car (petrol/diesel/electric), train, plane (short-haul/long-haul), coach or motorbike.
- Enter number of passengers: For car journeys: how many people are sharing the vehicle? With 2 people, the per-person emissions are halved.
- Read the result: The calculator outputs CO2 in kilograms per person – comparable across all modes of transport.
- Compare alternatives: Use the comparison function: train vs. plane vs. car for the same route, all at a glance.
Practical Examples
Example 1 – Hamburg to Munich (600 km): Car (petrol, 1 person): 600 × 0.150 kg = 90 kg CO2. Long-distance train (ICE): 600 × 0.032 kg = 19.2 kg CO2. Plane (short-haul, including RFI factor): 600 × 0.255 kg × 2 = 306 kg CO2 equivalent. The train is 15 times more climate-friendly than the plane.
Example 2 – Day trip with a car pool: 100 km drive, petrol car (diesel average 130 g/km), 3 people. Per person: (100 × 0.130) ÷ 3 = 4.3 kg CO2 – comparable to a coach ticket for the same route.
Example 3 – Long-haul flight Frankfurt–New York (6,300 km): Plane (long-haul, economy): 6,300 × 0.115 kg × 1.9 (RFI) = 1,376 kg CO2 equivalent. That's roughly equivalent to nine months of gas heating for a three-person household.
Calculate the CO2 Footprint of Your Journey
Emission factors: car (petrol) ~150 g CO2/km, train ~35 g CO2/km, plane (short-haul) ~255 g CO2/km, coach ~30 g CO2/km. Hamburg–Munich: car approx. 120 kg, train approx. 28 kg CO2.
Frequently Asked Questions (FAQ)
- What is the RFI factor for flying?
- The Radiative Forcing Index (RFI) accounts for the fact that aircraft exhaust gases at altitude have a stronger climate effect than at ground level. Water vapour (contrails), nitrogen oxides and soot particles at 9–12 km altitude amplify the greenhouse effect. The RFI factor ranges from 1.5 to 2.7 depending on the calculation method. The calculator uses a conservative value of approximately 1.9.
- How climate-friendly is an electric car really?
- It depends heavily on the electricity mix. With the German electricity mix (2024: approx. 380 g CO2/kWh) and an EV consuming 18 kWh/100 km: 180 × 0.380 = 68.4 g CO2/km – better than a modern petrol car, but still far from the European rail standard. With green electricity, the figure drops below 10 g CO2/km.
- Are vehicle manufacturing emissions included?
- No – the calculator computes only direct operational emissions (tank-to-wheel). Vehicle manufacturing (lifecycle emissions) is not included. For electric cars, production is more emission-intensive (especially the battery), which affects the overall lifecycle balance. Separate lifecycle assessment (LCA) tools are needed for that analysis.
