Longer-term aircraft fleet modelling: narrative review of tools and measures for mitigating carbon emissions from aircraft fleet

Abstract

Aviation industry stakeholders such as International Air Transport Association (IATA) agreed on ambitious goals and a basket of measures for mitigating aircraft emissions. Determining the emissions mitigation potentials (EMPs) of these measures requires the use of a set of assumptions or longer-term forecasts in an integrated modelling environment. However, the results of longer-term forecasts are only as reliable as the reliability and consistencies of their assumptions and methods with industry trends, as well as their compatibility with other dominating external developments. In this article, nine approaches to modelling aircraft fleet development were reviewed. Each of the first eight approaches used a unique fleet development model, while the last approach combines two additional models with one of the eight models. Therefore, ten global and regional longer-term aircraft fleet development models were reviewed and compared. The review focus was on their individual methods used for aircraft addition to and disposal from the fleet. Where available, the EMPs of individual measures were compared in order to create an overview of the EMPs of the measures. Furthermore, methods used for fleet development modelling in the studies were compared with the airline industry trends and practices for fleet planning in order to identify opportunities for research. This study is useful to policy-makers in knowing the expected emissions mitigation benefit of proposed environmental policies related to the IATA basket of measures. Aviation stakeholders like aircraft manufacturers and airlines would also have an overview of expected emissions savings of individual and combined measures. Lastly, researchers can also understand state-of-the-art modelling methods and scenario assumptions for the purpose of duplication studies, as well as identify unexplored areas for research.