There are increasing concerns that aviation fuel burn exacerbates greenhouse gas emissions, making management of flights critical. Extra fuel is carried on flights for safety reasons. The amount of extra fuel needed is related to the distance that a flight has to go to reach its nominated alternative airport. If a curfew is imposed on the alternative airport, another airport has to be nominated. Following public concern about possible imposition of curfews on Christchurch International Airport, this dissertation investigates the resulting cost penalty for airlines in terms of energy, and the carbon footprint. Conclusions arising from the analysis indicate the necessity of keeping at least two international airports, Auckland and Christchurch, capable of handling large, inbound jet aircraft, open at all hours. Recommendations are made to local authorities to ensure that the airport is protected by maintaining the area around the airport free of residential development.