How is the atmosfair offsetting contribution calculated?

There are two components that come together: first, the CO₂ emissions on a flight, and second, the costs to save this amount in a climate protection project.

The CO₂ emissions on a flight are calculated by the atmosfair emissions calculator. In addition to pure CO₂ emissions, other pollutants such as nitrogen oxides or soot particles that contribute to warming the climate alongside CO₂ are also included. For this reason, the values for a flight at atmosfair are usually higher than with other emission calculators.

The emissions calculator sets a price of 30 euros per ton of carbon dioxide. Currently, these 30 euros are needed to save one ton of CO₂ in high-quality climate protection projects in countries of the Global South. The following example illustrates how the price for saving one ton of CO₂ comes about:

On rooftops in an outskirts settlement of Cape Town in South Africa, all the hot water is usually heated with diesel stoves. This is emissions-intensive and also expensive. atmosfair agrees with a project operator in South Africa to install solar panels on the roofs of houses to directly heat the water. For the realization of 50 systems, the operator receives the necessary 30,000 euros from atmosfair. Over a ten-year contractual period, this is intended to save 40,000 liters of diesel annually and thus a total of 1000 tons of carbon dioxide (CO₂) from being emitted into the atmosphere. With 30,000 euros, atmosfair can thus save 1000 tons of CO₂ in this project. atmosfair concludes a contract with the project operator, according to which the operator receives 30 euros from atmosfair for each ton of CO₂ saved, and pays the first 15,000 euros as an advance so that the operator can start the project. Proof of successful CO₂ reduction must be provided by approved UN auditors, who are liable for errors.

The principle of avoiding emissions elsewhere is based on the economic insight that it is cheaper to avoid damage than to repair it. In other words, once a storm has destroyed a settlement, the costs of rebuilding are higher than the costs of climate gas avoidance that would prevent the storm from occurring in the first place. The emission contribution for a long-haul flight therefore does not reflect the costs of “repairing” the damage caused to the climate but rather the amount necessary to avoid these emissions elsewhere.

Why do even the shortest flights always cost at least 6 euros?

atmosfair sets a minimum price of 6 euros for one-way flights and 12 euros for round-trip flights for all flights so that the issue of “air travel and climate” is taken seriously. A lower contribution would suggest that short-haul flights are not problematic for the environment. However, they are, because even a flight from Berlin to Munich and back emits 300 kg of CO₂ per passenger. This already corresponds to three times the annual consumption of a refrigerator or one-fifth of a person’s climate-friendly annual budget. Moreover, flights over short distances can be easily shifted to rail transport. To stick with the example mentioned: Someone traveling the route from Berlin to Munich by ICE train causes only about one-fifth (around 60 kg) of the emissions generated by the flight there and back!

Why does the emissions calculator only make its calculations using carbon dioxide? Airplanes also emit other pollutants that harm the climate.

Carbon dioxide, nitrogen oxides, soot particles, and water vapor from aircraft engines affect the climate differently in terms of duration and intensity. However, since they all together form the greenhouse roof, atmosfair roughly converts them into carbon dioxide. In total, the various emissions in high altitudes of more than nine kilometers have a climate impact about three times as strong as just the carbon dioxide from a flight. To appropriately represent the climate impact of total flight emissions, the atmosfair emissions calculator therefore multiplies the CO₂ emissions emitted at altitudes of over 9 km by the globally averaged factor of 3. This factor arises when integrating the Global Warming Potential of all non-CO₂ effects over 100 years (UNFCCC Convention) and discounting it (David Lee et al., “Transport impacts on atmosphere and climate: Aviation”, in “atmospheric environment” (44), 2010).

Do short-distance flights cause more emissions than long-­distance flights?

In general, the longer a flight is, the more harmful its impact on the climate. This is because for every kilometer flown further, more fuel is consumed overall, resulting in more greenhouse gas emissions. However, when considering the relative consumption per 100 kilometers of flight distance, the ratio changes.

Airplanes on short-haul flights of up to about 400-600 kilometers distance operate in lower air layers where contrails and ice clouds do not form. Also, ozone formation from nitrogen oxides is lower here than at altitudes above about 9 kilometers. Additionally, the fuel tanks of an aircraft flying only 500 kilometers are much lighter than those of a long-haul flight. On the other hand, the fuel-intensive climb during a short-haul flight has a much greater impact than during an intercontinental flight, which is why it has the highest kerosene consumption per 100 kilometers. The relative consumption decreases up to a distance of about 3,000 kilometers. For longer flights, the heavy fuel tank causes the consumption per 100 kilometers of flight distance to increase again.

You can find detailed information on the topic “distances” in the atmosfair emissions calculator documentation.

Is it important whether I fly on a scheduled or a charter flight?

A charter aircraft usually seats more passengers than a similarly sized scheduled aircraft. Due to the higher occupancy rate of the charter aircraft, a package traveler causes less climate impact relative to an individual traveler.

You can find detailed information on the topic “capacity utilisation” in the atmosfair emissions calculator documentation.

Why can you specify Business or Economy? Does that make a difference?

In the Business class, the seats are wider, so fewer people can sit here compared to the same space in Economy class. Because fuel consumption per person decreases when more people are on the plane, the atmosfair contribution for a seat in Business class is on average higher than the emission contribution for a seat in Economy class. As a result, Economy class passengers donate slightly less, and Business class passengers donate slightly more than the average would suggest.

You can find detailed information on the topic “flight class” in the atmosfair emissions calculator documentation.

Do I need to know the aircraft type?

The more precise the flight data you enter into the emissions calculator, the more accurately the resulting per capita emissions can be calculated. However, if you do not know the aircraft type, the emission contribution can still be calculated using atmosfair’s approximation values. These are based on all aircraft types flying on a route and are averaged. However, specifying the aircraft type makes the calculation more accurate. The emissions calculator has consumption data for all commercial aircraft stored, covering the majority of civil air traffic. Because only certain models are used on each route, the emissions calculator combines them into a virtual average aircraft typical for the respective connection.

You can find detailed information on the topic “aircraft type” in the atmosfair emissions calculator documentation.

How exact are the results of the emissions calculator?

It’s clear that only the likely emission output of a flight can be calculated. If the airplane has to circle in holding patterns due to runway icing or if the occupancy is exceptionally high or low, the calculator cannot take this into account. Therefore, the result of the emissions calculator may not be as precise as a direct measurement on site. However, its results are generally expected to correspond well to reality due to the abundance and quality of the underlying data.

You can find a discussion of the methods and the accuracy of results in the atmosfair emissions calculator documentation.

How does the atmosfair CO₂ Event Calculator work?

The atmosfair CO₂ Event Calculator is a digital tool for calculating event emissions. It is based on the VDR standard and is freely accessible to calculate emissions from events of various sizes. This serves as both a benchmark for continuously reducing emissions and as a basis for compensating for previously unavoidable emissions. Further details about the calculator, methodology, and low-emission event planning can be found here.