Impacts of Future Weather and Climate Extremes on United States Infrastructure: Assessing and Prioritizing Adaptation Actions

The strength of US infrastructure is the foundation of its economic strength and position in the world and depends on various critical systems for its maintenance and longevity. Implementing adaptation options for climate change into civil engineering design is complicated by the traditional approaches premised on empirically derived probabilities of risk to characterize functionality, durability, and safety. This book aims to synthesize the available research on individual sector vulnerabilities to disruptive weather and climate and to consider the possible fragility of these systems, given the anticipated changes in climate and adaptation activities. This chapter provides an overview of these key concepts.

This chapter explores some of the challenges associated with attributing specific meteorological and hydrological extreme events to global warming. The direct impact of higher temperatures on such critical infrastructure as increased energy demand for cooling purposes, damage to roads and railways, and degraded water quality is reviewed. Details are provided on some of the effects of such extreme upward movements in temperature on other meteorological and hydrological factors that can in turn have substantial impacts on civil engineering infrastructure. These include precipitation, stream flow and runoff, frequency and intensity of droughts and fires, storm tracks, frequency and intensity of tropical cyclones, sea levels and surface temperatures, storm surge, ocean acidity, sea ice extent, frequency of atmospheric icing events, ocean wave height and duration, snow pack duration and depth, and the frequency and cost of natural disasters. The projected influence of global warming on many of these factors is discussed.

Damages from extreme weather events demonstrate current urban infrastructure vulnerabilities. Major stressors that will have the greatest impact on critical infrastructure include more frequent and intense precipitation events, heat waves, coastal flooding, and wildfires. The US energy and transportation systems are major sectors affected by such stressors. These sectors have therefore been organized into the following groups: energy transmission, storage, and distribution infrastructure; transportation; transit and aviation; drinking water and wastewater; flood protection infrastructure; and navigation/ports and harbors. Each sector is examined with respect to potential impacts of climate change, the status of sector resiliency in terms of current needs and climate change adaptation, potential adaptation response or actions to increase sector resiliency, and dependencies and influences on other sectors that may lead to cascading failure.

Many prioritization schemes are based on analysis of the relative merits and drawbacks of improvements or the tangible impacts of failure. This chapter discusses some of the constraints faced by decision makers, followed by an analysis and examples of the possible ways to frame a prioritization scheme. Decision steps are presented that were developed to assist in creating a sector- or location-specific prioritization framework. These decision steps are informed by the United Nations Environment Programme Multi-Criteria Assessment for climate change prioritization tool, and include: understanding the decision context; identifying options for adaptation; identifying criteria and indicators; scoring, weighting, and interpreting results; and conducting a sensitivity analysis.

Much of the existing infrastructure in the United States was designed for the climatic conditions of the twentieth century, and most current engineering minimum design standards have not been updated to address the impact of recent and future climate change. This chapter focuses on the threats posed by future weather and climate extremes to US infrastructure, and provides an assessment of the infrastructure that will benefit most broadly from preventing a cascade of negative impacts. Methodologies are examined that may be used to prioritize adaptation measures to achieve the greatest benefits when time and financial resources are limited. The following overarching groups are considered with respect to their specific vulnerability issues: energy transmission, storage, and distribution; transportation; drinking water and wastewater; flood protection infrastructure; and navigation/ports and harbors.