According to their findings, published in the journal Nature Sustainability
, the extent of these secondary costs depends more on the structure of the production and supply networks for a particular city than on its geographic location. Regional cities that are dependent on their urban network for industrial supplies — and that have access to relatively few suppliers— are most vulnerable to these secondary impacts. Larger, global cities such as New York and Beijing, meanwhile, are more insulated from risks.
“Cities are strongly connected by flows of people, of energy, and ideas — but also by the flows of trade and materials,” said Chris Shughrue
’18 Ph.D., lead author of the study which is based on his dissertation work at Yale. He is now a data scientist at StreetCred Labs in New York. “These connections have implications for vulnerability, particularly as we anticipate cyclones and other natural hazards to become more intense and frequent as a result of climate change over the coming decades.”
The paper was co-authored by Karen Seto
, a professor of geography and urbanization science at F&ES, and B.T. Werner, a professor from the Scripps Institution of Oceanography.
“This study is especially important in the context of climate impacts on urban areas,” Seto said. “Whereas we tend to consider a city’s vulnerability to climate change as limited to local events, this study shows that we need to rethink this conceptualization. It shows that disasters have a domino effect through urban networks.”
Using a simulation coupled with a global urban trade network model — which maps the interdependencies of cities worldwide — the researchers show how simulated disasters in one location can trigger a catastrophic domino effect.
The global spread of damage was particularly acute when cyclones occurred in cities of North America and East Asia, largely because of their outsize role in global trade networks — as purchasers and suppliers, respectively — and because these regions are particularly susceptible to cyclone events.