This policy brief summarizes the main findings of the E-CONTRAIL project, which aimed to provide a stronger scientific basis for aviation policy and climate mitigation. The project's goal was to systematically detect, classify, and assess the climatic impact of contrails using artificial intelligence and satellite data. The primary challenge is quantifying the "hidden climate impact of contrails". Current policies focus on CO2 , which overlooks non-CO2 contributors like contrails that cause substantial warming but remain "largely invisible to policymakers" and unaccounted for in most emissions inventories. This omission makes it impossible to monitor the real impact of non-CO2 agents or evaluate the effectiveness of mitigation strategies like routing optimization. The E-CONTRAIL project demonstrates with high confidence that night-flight contrails significantly contribute to climate warming, an effect most pronounced in winter, while summer contrails are often neutral or cooling. This warming impact is geographically concentrated, with a high occurrence over the Atlantic Ocean. These complex findings provide a clear basis for targeted mitigation but also underscore the urgent need for further investment in fundamental research to refine predictive models. In light of these results, we propose the following policy actions: Prioritize mitigation actions for flights occurring at dark (or mostly at dark) Prioritize contrail mitigation actions during Winter months. Focus special attention on oceanic Flights. Invest in fundamental contrail research to close knowledge gaps. To align aviation policy with climate reality, we must act on this knowledge. By leveraging AI-powered detection, adjusting flight scheduling practices, and incorporating non-CO₂ impacts into regulatory frameworks, we can take immediate, practical steps toward reducing aviation’s warming effect.