The air transport system is a major industry with a global impact of 2.7 trillion dollars. However, the growth of air transport is leading to increasing climate concerns. The main emitters are CO2, NOx and contrails. Regulators have taken initiatives to reduce emissions in line with the 1.5°C target of the Paris Agreement. IATA is aiming for net zero emissions by 2050, with 65% of the emissions reduction to be achieved through SAF and 13% through new technologies. However, there are many uncertainties as to how these targets can be achieved. This book analyses different scenarios and transition pathways to assess the impact of new technologies, policy measures and production delays. Different policies and technologies were tested through a system dynamics model that integrates airlines, demand, fuel producers and regulators. The results show that ambitious targets can only be achieved through a strong combination of measures. While electric and hydrogen aircraft remain challenging in the short-haul segment, SAF can play a key role in the long-haul segment. However, this requires close coordination between all stakeholders.