Trajectory Optimisation to Minimise the Combined Radiative Forcing Impacts of Contrails and CO₂

Multi-objective trajectory optimisation (MOTO) is part of an initiative to modernise air traffic management (ATM). The successful implementation of MOTO in next-generation avionics and ATM systems takes into account various objectives, such as fuel consumption, flight time, pollutant emissions, and the associated radiative impact of such pollutants and contrails. This chapter presents the mathematical models for integrating radiative forcing (RF) of contrails and of carbon dioxide (CO₂) into a MOTO software algorithm. In particular, these models were used to define cost functions in a MOTO case study accounting for an international flight from Paris to Beijing. The case study involves optimal trajectories that minimise the RF of flight trajectories. The results of this study demonstrate the feasibility of MOTO in generating RF-minimal trajectories with respect to contrails and CO₂, and show that not all contrail-persistent regions should be avoided.