7th Framework Programme
     About     04 May 2010


Despite significant progress has been made in reducing the specific emissions of aircraft, in particular CO2, the absolute emissions have been increasing rapidly during the recent decades and are projected to continue to grow. Furthermore, aviation substantially impacts upon climate from non-CO2 effects such as ozone formation and methane destruction from aviation's NOx emissions, the formation of contrails and contrail cirrus, the emission of H2O at high altitudes, emission of aerosols (e.g., soot) and aerosol precursors (e.g., SOx), which are directly radiatively active and which modify cloudiness and cloud micro-physical and radiative properties.

Current flight planning is performed with the objectives of achieving maximum punctuality or minimizing the operational costs, whereas the target of minimal fuel consumption, minimal CO2 emissions or minimal climate impact has a lower priority.

Impact of aircraft non-CO2 emissions on the atmospheric composition and on climate depends on the altitude and location of the emissions. Therefore climate impact via NOx, contrails and contrails cirrus can be reduced e.g. by flying lower and by avoiding contrail regions. On the other hand this results in a higher fuel burn and hence in higher CO2 emissions.

The project REACT4C will perform an optimisation approach for alternative or environmental flight planning in order to assess the potential for reducing fuel consumption, CO2 emissions and climate impact from aviation.


In order to reduce aviation's emissions and improve its environmental compatibility, the project REACT4C will address those inefficiencies which exist in the aviation system with respect to fuel consumption and emissions by investigating the potential of alternative flight routing for lessening the atmospheric impact of aviation.

Hence the main objectives of REACT4C are

  • to explore the feasibility of adopting flight altitudes and flight routes that lead to reduced fuel consumption and emissions, and lessen the environmental impact;
  • to estimate the overall global effect of such ATM measures in terms of climate change.
The objective of REACT4C is to demonstrate that environmentally friendly flight routing is feasible, but does not address the operational implementation of such advanced ATM procedures. The latter would require much more time than is available during the present project. However, REACT4C will deliver substantial scientific foundation and operational specification for novel ATM procedures, which might be explored in a later phase of the SESAR JU. Analogously, REACT4C will deliver fundamental concepts of aircraft that are better suited for environmentally flight routing, which will have the potential to enter the Clean Sky JTI in a later phase.

Work Packages

Graphical presentation of project structure, showing work packages and interaction.