Civil aviation and the environmental challenge

In the coming century, the impact of air travel on the environment will become an increasingly powerful influence on aircraft design. Unless the impact per passenger kilometre can be reduced substantially relative to today’s levels, environmental factors will increasingly limit the expansion of air travel and the social benefit that it brings. This essay considers the three main impacts, noise, air pollution around airports and influence on climate change. Of the three, impact on climate change is taken to have the greatest long-term importance and is discussed at the greatest length. It is argued that, of the three main contributors to climate change from aircraft – CO 2 emissions, NO X emissions and the creation of persistent contrails – it is the last two which are the most promising targets. Ways of reducing the impacts of these two are discussed and it is noted that, in each case, the best environmental result is likely to entail some increase in CO 2 emissions. It follows that regulatory or economic measures to reduce impact on climate should be framed so as to do just that. Measures framed purely in terms of CO 2 emissions are likely to be counter-productive. Nevertheless, the design of aircraft to reduce fuel burn and hence CO 2 emission remains a key long-term objective; the essay considers the potential offered by new technology and new design concepts in this arena.