Sustainable air transport -: on track in 2050

In this paper three 'Images' of air travel on a sustainable path in 2050 are outlined. The method used is backcasting. A stabilization of the carbon dioxide concentration in the atmosphere at 450 parts per million is assumed to constitute a sustainable level. It is concluded that a refinement of the conventional turbofan aircraft is probably not sufficient to reach even the less demanding target level, even though a 40% reduction of fuel intensity may be achieved. The introduction of more radical aircraft configurations, e.g. the flying wing, probably has the greatest potential for reducing fuel consumption, but the development of such aircraft is uncertain. A less risky strategy is to opt for a high-speed propeller aircraft with a cruise speed which is 20-25% lower than for a conventional turbofan aircraft. This configuration entails a 56% cut of carbon dioxide emissions per passenger-kilometre compared to 2000. If this technology trajectory is combined with a development characterized by a weakened emphasis on economic growth together with less hectic lifestyles, it may be possible to reach even the most demanding of the target levels. Air travel per capita in 2050 would then be slightly higher than in 2000. If only the less demanding target level is to be reached global air travel per capita may be about 110% higher than in 2000. (c) 2004 Elsevier Ltd. All rights reserved.