Emissions
Air traffic causes various emissions that mix in the atmosphere and affect the climate and environment.
Emissions and immissions
Emissions are substances released by a source, such as an aircraft engine. These substances are well mixed into the atmosphere. Immissions, on the other hand, are the concentration of substances in the atmosphere measured at a particular measuring station.
CO2 and non-CO2 emissions produced by aviation
The Federal Council's long-term climate strategy addresses both CO2 and non-CO2 emissions.
Contrails
Under certain atmospheric conditions, visible trails form behind aircraft in the sky. These condensation trails, or contrails, mainly consist of water in the form of ice crystals and are created by the combination of atmospheric humidity and low temperatures at cruising altitude.
Overall climate impact of aviation
The FOCA records emissions from Swiss air traffic. The data is included in the FOEN's greenhouse gas inventory and shows the overall climate impact.
Recording and measuring
Part of the FOCA’s statutory duties is to calculate Swiss civil aviation’s emissions inventory each year. The total amount of combustion products and pollutants emitted during a year is calculated. The issue of boundaries is relevant to all cross-border modes of transport: up to which point is a cross-border rail service or flight classified as ‘Swiss’? In aviation, two methods are used for classification purposes – the territorial principle and the point-of-sale principle.
