The average distances travelled by tourists are increasing, especially since flying has become widely used for vacation travel (Peeters et al., 2007). The availability of low-cost air fares has brought many distant destinations within reach and inside acceptable time periods and cost constraints (Knowles, 2006). Lower fares and provision of many new direct flights have together resulted in a higher proportion of the tourist population visiting distant places, with future projections of yet more growth and more distant travel (Peeters, 2007). Unfortunately longer travel generates more greenhouse gas emissions. Although tourism is currently only responsible for about 5 per cent of global greenhouse gas emissions, both its absolute and relative contributions are growing while other industries are reducing their emissions (UNWTO-UNEP-WMO, 2008).