CO2 and non-CO2 emissions produced by aviation

A closer look

Aircraft emit CO2 and other exhaust gases during the fuel combustion process. CO2 contributes to global warming. In line with its fuel consumption, aviation accounts for 2–3% of global greenhouse gas emissions. Non-CO2 emissions both warm and cool the atmosphere, and contribute to additional global warming overall.

Overview: Climate-impacting emissions and the differences between them

  CO2 emissions non-COemissions


CO2 is a greenhouse gas

Other main climate-impacting emissions from aviation are not greenhouse gases

Amount depends on the type of fuel and is proportional to consumption

Amount not proportional to CO2 and depends on the engine and environment


Contrails: Almost entirely produced from water vapour in the atmosphere


Always warming

Warming and cooling

Persistent contrails strongly warming at night, cooling during the day

Can be calculated accurately

Cannot be calculated accurately

Once emitted, impact continues for hundreds of years

Impact lasts minutes, hours

For nitrogen oxides a maximum of several decades

Impact increases even when emissions remain the same

Impact does not increase although emissions remain the same

Impact does not depend on the location, time of day or weather conditions

Impact depends on the location, time of day and weather conditions

Further information

Last modification 19.06.2024

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