Climate Change and Infrastructure, Urban Systems, and Vulnerabilities

This Technical Report on Climate Change and Infrastructure, Urban Systems, and Vulnerabilities has been prepared for the U.S. Department of Energy by the Oak Ridge National Laboratory in support of the U.S. National Climate Assessment (NCA). It is a summary of the currently existing knowledge base on its topic, nested within a broader framing of issues and questions that need further attention in the longer run. The report arrives at a number of assessment findings, each associated with an evaluation of the level of consensus on that issue within the expert community, the volume of evidence available to support that judgment, and the section of the report that provides an explanation for the finding. Cross-sectoral issues related to infrastructures and urban systems have not received a great deal of attention to date in research literatures in general and climate change assessments in particular. As a result, this technical report is breaking new ground as a component of climate change vulnerability and impact assessments in the U.S., which means that some of its assessment findings are rather speculative, more in the nature of propositions for further study than specific conclusions that are offered with a high level of confidence and research more » support. But it is a start in addressing questions that are of interest to many policymakers and stakeholders. A central theme of the report is that vulnerabilities and impacts are issues beyond physical infrastructures themselves. The concern is with the value of services provided by infrastructures, where the true consequences of impacts and disruptions involve not only the costs associated with the clean-up, repair, and/or replacement of affected infrastructures but also economic, social, and environmental effects as supply chains are disrupted, economic activities are suspended, and/or social well-being is threatened. Current knowledge indicates that vulnerability concerns tend to be focused on extreme weather events associated with climate change that can disrupt infrastructure services, often cascading across infrastructures because of extensive interdependencies threatening health and local economies, especially in areas where human populations and economic activities are concentrated in urban areas. Vulnerabilities are especially large where infrastructures are subject to multiple stresses, beyond climate change alone; when they are located in areas vulnerable to extreme weather events; and if climate change is severe rather than moderate. But the report also notes that there are promising approaches for risk management, based on emerging lessons from a number of innovative initiatives in U.S. cities and other countries, involving both structural and non-structural (e.g., operational) options. « less