Contrail Avoidance: A Strategic Assessment of Technological Readiness and Adoption

Abstract The warming from contrails is comparable to the warming from all aviation CO2 emissions. Contrail avoidance through flight path deviation will likely be necessary to achieve aviation climate neutrality, yet the specifics of a global contrail avoidance system are not well understood. To address this, a realistic contrail avoidance strategy is identified from the literature, and first order modelling is used to estimate the achievable climate forcing reduction by 2050. The strategy targets all persistent contrails and employs vertical flight path deviations with consideration for air traffic conflicts. A neural network-based system that uses satellite imagery is assumed to predict contrail formation. At full adoption, the strategy is 51% effective (estimated range: 37-64%). Despite the uncertainty, contrail avoidance has the potential to achieve over twice the cumulative forcing saving of sustainable aviation fuels by 2050, which would make it the fastest and most effective means for aviation warming mitigation.