Debates about environmental issues – particularly global environmental issues – are often framed within broader debates about sustainable development (Adams 2009). This has occurred with the ascendancy of the concept of sustainable development, which came to prominence as a result of several high-profile United Nations summits, including the United Nations Conference on Environment and Development (UNCED) held in 1992 in Rio de Janeiro and the World Summit on Sustainable Development (WSSD) held in 2002 in Johannesburg. Sustainable development has rapidly become the central organising principle in debates about how to manage environmental impacts whilst at the same time ensuring that the development of human economies and societies occurs in an equitable way (Adams 2009; Baker 2006; Dresner 2008; Elliott 2006). Many definitions of sustainable development have been proposed; most of them include the idea of balancing the economic, social and environmental costs and benefits of development, both for present and future generations. Thus proponents of sustainable development argue that economic development and environmental protection are not mutually-exclusive goals but should occur together in an integrated manner. Whilst such a view is attractive and seemingly benign, achieving such a reconciliation of economic, social and environmental concerns is far from easy and raises thorny problems of governance, power and justice. Ideas of sustainable development, then, are intrinsically political and cannot be divorced from considerations of participation, representation, transparency and accountability (Jacobs 1995; Redclift 1984). Notions of sustainable development also contain myriad assumptions – and often many contradictions – that ideally should be acknowledged and analysed critically. In relation to air transport and sustainable development, a central question is whether the growth of air transport should be constrained in order to keep aviation environmental impacts within acceptable limits, or whether that growth should be allowed and its intensifying environmental impacts justified on other (economic

and social) grounds. That question is about values, attitudes and beliefs far more than it is about technologies and operating practices, important as those factors are. Moreover, it is a question that legitimately concerns many more people than those directly involved with the air transport industry.