Contrail avoidance (CICONIA)
CICONIA is a pioneering research initiative under the SESAR 3 programme, focused on mitigating the non-CO₂ climate effects of aviation—specifically those caused by contrails. These ice-crystal trails, formed when aircraft pass through cold, humid air masses, can evolve into cirrus clouds that trap heat in the atmosphere, contributing significantly to global warming. In fact, contrail-induced cloudiness is estimated to have a greater warming effect than aviation’s CO₂ emissions alone.
Led by Airbus and involving partners including NATS, Air France, Swiss, and easyJet, CICONIA brings together scientific and operational expertise to develop and trial innovative air traffic management (ATM) strategies aimed at avoiding the formation of warming contrails. These strategies include pre-flight planning, tactical rerouting, and airspace reservation methods, all designed to reduce the climate impact of flights over the North Atlantic.
NATS’ role in the project centres on designing and conducting operational trials, supported by computer simulations and human-in-the-loop experiments. These trials assess the feasibility of contrail avoidance in real-world scenarios, exploring the trade-offs between fuel burn, operational costs, and environmental benefits.
The project is funded by the European Union under SESAR 3 Joint Undertaking. It builds on years of NATS-led research into contrail formation and avoidance, and reflects our commitment to supporting the aviation industry’s transition to net zero emissions.
CICONIA exemplifies how operational improvements using today’s aircraft can deliver meaningful climate benefits now—without waiting for future technologies. By helping to avoid warming contrails, the project contributes to the global effort to limit temperature rise in line with the Paris Agreement.
