This report looked at ways in which aviation CO2 emissions could be mitigated, and how far the mitigation potential of each measure got us towards various ‘goals’ for the reduction of international aviation emissions of CO2. ‘Goals’ tend to be focused on achieving an emissions target by a certain date. However, this approach does not factor in the physics of CO2 – namely the accumulative nature of CO2, its long lifetime in the atmosphere and its consequent effect on climate. The emissions’ pathway by which a goal is achieved over time matters more than simply achieving the goal itself. This work conducted over 11,000 complex calculations to rank the ‘best’ mitigation strategies, both as individual measures and combined strategies, in terms of their climate impacts – calculated as radiative forcing and global mean temperature response.