Trajectory Optimization and climate change


Planing climate-aware trajectories

The strong growth rate of the aviation industry in recent years has created significant challenges in terms of environmental impact. Air traffic contributes to climate change through the emission of carbon dioxide (CO2) and other non-CO2 effects, and the associated climate impact is expected to soar further. The mitigation of CO2 contributions to the net climate impact can be achieved using novel propulsion, jet fuels, and continuous improvements of aircraft efficiency, whose solutions lack in immediacy. On the other hand, the climate impact associated with non-CO2 emissions, being responsible for two-thirds of aviation radiative forcing, varies highly with geographic location, altitude, and time of the emission. Consequently, these effects can be reduced by planning proper climate-aware trajectories.

Development of climate optimal aircraft trajectory planing

By taking into account the dependencies of non-CO2 effects in the aircraft trajectory planning, operational
mitigation towards climate optimized aircraft trajectories is possible. Thus, to consider the climate impact of aviation in the aircraft path planning, information on the climate-sensitive regions, i.e., regions where those non-CO2 effects are significantly enhanced, needs to be available. Moreover, aircraft dynamical models and the optimization approach are crucial factors affecting the performance and mitigation potential of the optimized trajectories. Studies differ, in the optimization algorithm, incorporation of climate impacts as the objective function, number of flights, and maneuvres. That is why our study aims to provide a comprehensive review of the state-of-the-art studies for the past two decades, i.e., 2000–2021, considering these factors, e.g., aircraft dynamical model, climate metrics, and optimization approaches.

Cover story of the paper “A Comprehensive Survey on Climate Optimal Aircraft Trajectory Planning”, published in the journal of aeronautics and astronautics Aerospace.
Network Level Climate Assessment

Aviation contributes to anthropogenic climate change through carbon dioxide (CO2) and non- CO2 emissions. Due to dependency on atmospheric conditions, the non-CO2 climate impacts can be mitigated using aircraft trajectory optimization. However, adopting independently optimized
trajectories may not be operationally feasible for the air traffic management system due to the associated impacts on the safety, demand, and complexity of air traffic. This study aims to explore the effects of employing climate-optimized trajectories on air traffic complexity in terms of the number of conflicts and propose a strategic resolution based on speed change to resolve the conflicts that arise. A scenario with 1005 flights is considered as the case study. The results indicate that the adoption of climate-optimal trajectories increases operational cost and the number of conflicts. Employing the proposed resolution algorithm, it is shown that the conflicts can be resolved by accepting slight increases in climate impact and cost.

Related projects

  • FlyATM4E↗ Flying Air Traffic Management for the benefit of environment and climate.
  • ALARM ↗ A prototype of a global multi-hazard monitoring and early warning system for natural hazards in aviation.
  • RefMap

Highlighted publications

  • Simorgh, A., Soler, M., González-Arribas, D., Linke, F., Lührs, B., Meuser, M. M., Dietmüller, S., Matthes, S., Yamashita, H., Yin, F., Castino, F., Grewe, V., and Baumann, S.: Robust 4D Climate Optimal Flight Planning in Structured Airspace using Parallelized Simulation on GPUs: ROOST V1.0, EGUsphere [preprint],, 2022
  • Dietmüller, S. Matthes, S., Dahlmann, K., Yamashita, H., Soler, M., Simorgh, A., Linke, F., Lührs, B., Mendiguchia Meuser, M. , Weder, C., Yin, F., Castino, F., Grewe, V. (2022): A python library for computing individual and merged non-CO2 algorithmic climate change functions: CLIMaCCF V1.0, Geoscientific Model Development (GMD). Under Review. In pre-print.
  • Conflict Assessment and Resolution of Climate Optimal Aircraft Trajectories at Network Scale. Fateme Baneshi, Abolfazl Simorgh, Manuel Soler. Transportation Research Part D: Transport and Environment. Volume 115, February 2023, 103592
  • A Comprehensive Survey on Recent Climate Optimal Aircraft Trajectory Planning. Abolfazl Simorgh *, Manuel Soler, Daniel González-Arribas, Sigrun  Matthes, Volker Grewe, Simone Dietmüller, Sabine Baumann, Hiroshi Yamashita,  Feijia Yin, Federica Castino, Florian Linke, Benjamin Lührs, Maximilian Meuser. Aerospace2022, 9(3), 146;