Today's global cities are hyper-connected, transcend borders and impact international agendas. Within the context of global change, cities' perpetual adaptability, reflexivity and responsiveness, have legitimized their growing role within the global governance architecture. Nevertheless, the increased mismatch between the role cities are expected to play at the global level and their place within global governance structures hinders the collective ability to address planetary challenges. This thesis compares three global city case studies (Abu Dhabi, Geneva, Los Angeles) through my Sustainability-Oriented Innovation Index for Airports©, with regards their international airport's capacity to align sustainability strategies through three unique lenses of environmental, social, and technological innovation. The objective of this thesis is to demonstrate how the collaborative responsiveness, reflexivity, and adaptability of a city and its respective airport breeds the kind of legitimacy called for by citizens and solidifies the role of cities in today's global governance architecture as a main actor.