Rethinking the vulnerability of global cities to cascading events: evidence from volcanic ash clouds

Some recent evidence suggests that cascading disasters can be associated with the disruption of critical infrastructure and the escalation of secondary events. In this process, global cities can be seen as the bottlenecks... [ view full abstract ]

Some recent evidence suggests that cascading disasters can be associated with the disruption of critical infrastructure and the escalation of secondary events. In this process, global cities can be seen as the bottlenecks where local and global dynamics interact in the built environment. This paper aims to understand if the involvement of global cities could make the difference in the magnitude of possible cascading breakdowns triggered by natural hazards. First, we discuss the key features of global cities in terms of critical infrastructure, vulnerabilities and Interdependencies. Secondly, we frame their role in the current theory of cascading events. Thirdly, we provide a case study on volcanic ash clouds and flight disruption to show that, despite the recurrence of the phenomena, the involvement of global cities made the difference in the impact of the 2010 eruption of Eyjafjallajökull.Our conclusions suggest that the concentration of some categories of critical infrastructure in global cites could lead to a fast spreading of cascading breakouts, in particular when communication and transportation sector are hit. This could be potentially wider than what experienced until now, and requires the development of new buffering and vulnerability reduction strategies.

K words: Cascading events, global cities, vulnerability, critical infrastructure, globalization, interdependencies, volcanic ash clouds, natural hazards