This paper investigates the potential of LH(2) (Liquid Hydrogen) as an alternative fuel for achieving more sustainable long-term development of large airports in terms of mitigating their air pollution For such purpose, a methodology for quantifying the potential of LH2 IS developed it consists of two models the first model enables the estimation of the fuel demand and the specification of the fuel production and storage capacity needed to satisfy that demand at a given airport under given conditions, the other model enables assessment of the effects of introducing LH2 on mitigating air pollution at that airport The main inputs for the methodology are scenarios of the long-term growth of air traffic demand at the airport in terms of the annual number of ATM (Air Transport Movements), I e. flights and related LTO (Landing and Take-Off) cycles and their time characteristics, the aircraft fleet mix, characterized by the aircraft size and proportions of conventional and cryogenic aircraft, the fuel consumption per particular categories of aircraft/flights, and specifically, the fuel consumption and related emission rates of particular air pollutants by these aircraft during LTO cycles The output from the methodology includes an estimation of the long-term development of demand at a given air-port in terms of the volume and structure of ATM, which depend on the scenarios of traffic growth and introduction of cryogenic aircraft, the required production and storage capacity of particular fuel types, the fuel consumed, and the quantities of related air pollutants emitted during LTO cycles carried out during the period concerned The airport planners and policy makers can use the methodology for estimating, planning, design, and managing the fuel production and storage capacity, as well as for setting a cap on the air pollution depending of the circumstances (C) 2009 Professor T Nejat Veziroglu Published by Elsevier Ltd All rights reserved.