An important goal is to create the scientific basis for a sustainable development of global aviation and to identify and assess the corresponding technological options. This requires the climatic impact of the entire air transport system to be quantified for given emission scenarios.
To reach this interdisciplinary goal, the DLR-project „Climate-optimized Air Traffic“ (duration 2008-2011) develops and assesses such options for the air transport system for the first time. The focus will be on measures to reduce fuel consumption but also ozone production from NOx emissions and cloudiness triggered by condensation trails and soot particles. It will be investigated whether the climate impact of condensation trails can be mitigated by selecting higher or lower cruising levels based on weather prediction, among others, constrained by concomitant effects on ozone and climate via NOx emissions. Reducing such short-lived effects potentially reduces the climate impact of aviation more effectively than reducing long-lived CO2 emissions. Measures that can be influenced within about 10 years should be studied with high priority. Therefore, options involving the existing fleet and technology will be studied first. The climate impact of new aircraft and routing concepts are a subject of future studies.
Options to reduce the climate impacts will be developed and assessed using scientific criteria. For the first time, the climate impacts will be determined including technical and operational aspects of air frame technology and air traffic management. Ultimately, the potential of several options thought to be suited to reduce the aviation climate impact will be assessed. Studies to realize the best options and targeted investigations leading to reduced uncertainties will follow.
Simulations of air traffic scenarios and their climate impact are at the heart of these studies. New tools to analyze aircraft and their missions will be developed across the programmatic themes and their climatic consequences will be assessed. The assessment of options addressing flight planning will initially be based on a conceptual level building on existing knowledge about aircraft and mission planning. Technology factors (e.g., the use of alternative propulsion concepts and fuels, energy scenarios, air traffic management) will be considered in a simplified manner.
At the same time, existing uncertainties in assessing the climate effects of global air traffic or individual missions will be successively reduced with dedicated research. This effort will be based on the results of the DLR-project “Particles and Cirrus Clouds” (ending 2007). Innovative research will be carried out within the HGF alliance (e.g., the junior research group AEROTROP) and with international partners (e.g., the FAA, NCAR and NOAA in the USA, and in the EU), mainly focussing on cirrus clouds and ozone chemistry. To this end, a combination of model simulations covering many spatial scales, airborne measurements with the DLR research aircraft FALCON and HALO and remote sensing will be employed.
The project integrates 11 DLR groups and further external partners. With the project, DLR investigates the prerequisites for a sustainable and environmentally friendly development of aviation.