European scientific assessment of the atmospheric effects of aircraft emissions

The purpose of this report prepared on behalf of the European Commission is to review the current understanding of chemical and dynamical processes in the upper troposphere and lower stratosphere, and to assess how these processes could be perturbed as a result of current and future aircraft emissions. Specifically, perturbations in the atmospheric abundance of ozone and in climate forcing, as predicted by atmospheric models, will be presented. The goal is to compile and evaluate scientific information related to the atmospheric impact of subsonic and supersonic aircraft emissions and to review the state of knowledge concerning the various aspects of this problem. In Section 2, the issues and scientific questions relevant to the problem of aircraft perturbations will be presented. The key physical and chemical processes occurring in the troposphere and stratosphere will be discussed in Section 3. Estimates of air traffic and aircraft emissions will be given in Section 4. Section 5 and 6 will review the understanding of the atmospheric impact of aircraft emissions at small and large scale, respectively. The effect of aircraft emissions on climate forcing will be discussed in Section 7. Finally, conclusions will be provided in Section 8.