We recommend the following steps when offsetting flights:

Step 1: Is the flight really necessary? A quick check.

Check again quickly: Is this flight really necessary? Are there holiday destinations that I can visit without flying? Is there another way of attending a meeting or conference, e.g. via an online meeting? Are there alternative travel options, such as (overnight) trains, that are reasonable in terms of time and cost?

Step 2: Quantify the climate impact

If the flight is necessary, then its climate impact can be quantified using online calculators. However, different calculators use different methods to calculate the climate impact. Make sure that the calculator considers not just CO₂ emissions, but the total climate impact of the flight. It is also important that emissions from the upstream chain of fuel supply are taken into account. The calculators offered by Atmosfair, Klima-Kollekte and PRIMAKLIMA, for example, can be used for this purpose.

However, the calculation of the climate impact of flights differs among providers and organizations, especially in respect of the indirect climate effects beyond CO₂:

• Klima-Kollekte and PRIMAKLIMA use Klimaktiv’s CO₂ calculator. This applies a uniform factor of 2.7 for all flights to account for the climate impact of non-CO₂ effects. This value is based on a report by the Intergovernmental Panel on Climate Change from 1999.

• Atmosfair has developed its own detailed methodology for estimating the climate impact. Since this impact strongly depends on the flight altitude, the typical flight altitude is taken into account, which in turn depends on the flight distance. Above an altitude of 9 kilometres, a factor of 3 is applied to account for the non-CO₂ effects. Since some flights do not reach this altitude at all, and some emissions are always emitted by the remaining flights below 9 kilometres (during takeoff and landing), the calculated average factor for all flights worldwide is approx. 2.7. According to this more precise calculation, short- and medium-haul flights have a somewhat lower climate impact than is the case with Klimaktiv’s calculator, while long-haul flights have a higher climate impact.

• Some organizations such as the International Civil Aviation Organization (ICAO) or the UNFCCC Secretariat’s website Carbon Neutral Now only take into account the CO₂ emissions and not the total climate impact of the flight. The use of these calculators is therefore not recommended.

There are online tools for comparing different modes of transport; ecopassenger can be used for passenger transport and ecotransit for freight transport.

Step 3: Carbon offsetting or “climate responsibility”?

Choose between carbon offsetting or climate responsibility. With carbon offsetting, you purchase carbon offsets in the next step, which are used to offset the climate impact of your flight. With climate responsibility, you calculate a climate budget that you invest in innovative climate protection projects. For this, you multiply the emission impact of the flight by a higher CO₂ price.

Step 4: Select providers and climate investment

In the market for voluntary carbon offsets, a wide range of very different projects are offered by a variety of organizations. This does not make the choice easy. We do not recommend individual projects or specific providers here; rather, we want to support you in your choice by providing tips and recommendations.

The following paths are possible:

1. Purchase from the provider without selecting a project: You purchase carbon offsets from a provider you trust without selecting a specific project. In effect, you support the provider’s project portfolio.

2. Purchase of carbon offsets from a specific project: You select a specific climate protection project on the provider’s website. Your purchase of carbon offsets then helps to finance this specific project.

3. Following the concept of “climate responsibility”: Under this concept, you select initiatives with a transformative impact, which you support financially. This support can lead to further decisive breakthroughs in the necessary transformation processes in the medium and long term.