Efficacies of individual components contributing to aviation climate impact

Aviation climate impact consists of a number of quite different individual components, with non-CO2 contribution being at least as important as the contribution of CO2 emissions from fuel burning. Usually the components have been quantified and intercompared in terms of their radiative forcing (RF), or by climate impact metrics derived from RF, like the global warming potential. However, it has to be ensured that all the components have the same, or at least similar, efficacy before such an RF based treatment can be taken as appropriate for determining the sum of effects, or tradeoffs between the effects, or assessing mitigation measures that limit one component at the expense of another one. In this paper the results of individual equilibrium climate change simulations dedicated to the contributing RFs are presented and the respective efficacy parameters are discussed. Phsical reasons are given to explain the differences in efficacy between, e.g., the CO2 impact and the contrail impact