CO2, NOX, water vapor, sulfur- and soot-particles are identified as climate-affecting emissions of air transport. In particular the chemical processes, which are triggered by the four last mentioned substances in the atmosphere, are very complex. The emission of these substances changes the methane and ozone level in the atmosphere and increasingly contrails and cirrus clouds are generated. %. According to current IPC estimates (2007) the contribution of international air transport to the global anthropogenic green house effect amounts to approx. 3% now.
Inclusion of Air Transport in CO2 Emission Trading (Download PDF)