The sustainability of aviation fuels must be defined with clear and diverse criteria. Focusing exclusively on GHG reductions would not do justice to the complex ecological, economic and technological interrelationships of aviation. For this reason, aireg aims to incorporate the three pillars of sustainability – ecology, economy and social equity – into the overall value chain of aireg’s activities. We are also evaluating various feedstocks and conversion processes from a sustainability perspective and discussing regulatory approaches, both to improve the sustainability of aviation fuels and to bring them to market. One example is a book-and-claim crediting methodology for SAF, aireg’s discussion paper on this can be found here.