In some cases, such as in Alaska, the need to adapt has already  become a reality. Roads and Bridges, Wastewater Management Systems, and NASA Centers Are Vulnerable to Changes in the Climate

According to NRC and USGCRP assessments, changes in the climate  have been observed in the United States and its coastal waters and are  projected to grow in severity in the future, thereby increasing the  vulnerability of infrastructure such as roads and bridges, wastewater  management systems, and NASA centers. Storm surge, combined with sea level rise, is projected to generate a wide  range of negative impacts on roads and bridges. Collectively, Louisiana State Highway 1 currently supports 18  percent of the nation’s oil supply. Flooding of this road effectively closes  the port. However,  within 15 years, NOAA anticipates that the at-grade portions of Louisiana  State Highway 1 will be inundated by tides an average of 30 times  annually even in the absence of extreme weather. Due to past problems with sewer overflows, the Milwaukee Metropolitan  Sewerage District in Wisconsin significantly increased the capacity of its  sewer system. Key factors that enabled these decision makers to  undertake such measures and overcome the challenges that have  deterred others from integrating climate change into infrastructure  planning were that (1) their local circumstances were conducive to  addressing climate-related risks, (2) they learned to use available climate  information, (3) they had access to local assistance, or (4) they  considered climate impacts within existing planning processes in the  same context as other potential risks. Access to local assistance was instrumental to decision makers’ ability to  undertake climate adaptation efforts at the sites we visited. Improving Infrastructure Decision Makers’ Access to and Use of Available Information

According to relevant studies, local decision makers from our site visits,  and other stakeholders, future federal efforts to improve access and use  of available climate-related information could better focus on the needs of  local decision makers. While coordinating available climate-related data is a first step in making  more informed adaptation decisions, another key step is to ensure  decision makers have access to the best available data. Considering Climate Change in Existing Planning Processes

Notwithstanding the limited federal role in planning for transportation and  wastewater infrastructure, several emerging federal adaptation efforts  could help local infrastructure decision makers consider climate change in  existing processes, according to studies, local site visit decision makers,  and other stakeholders. Planning for transportation and wastewater infrastructure in this country  remains largely within the domain of state and local governments, but  emerging federal efforts are under way to facilitate and enable more  informed decisions about adaptation. Specifically:
Federal agencies and academic institutions collect a vast array of  climate-related data, but local infrastructure decision makers face  difficulty identifying, accessing, and using them, because as noted by  a 2010 NRC study, this information exists in an uncoordinated  confederation of networks and institutions. According to the 2010 NRC report, the  end result of this information not being easily accessible is that people  may make decisions—or choose not to act—without it. Recommendations for Executive Action

To improve the resilience of the nation’s infrastructure to climate change,  we are making the following four recommendations:  that the Executive Director of the United States Global Change  Research Program or other federal entity designated by the Executive  Office of the President work with relevant agencies to identify for decision makers the “best available” climate-related  information for infrastructure planning and update this information  over time and clarify sources of local assistance for incorporating climate-related  information and analysis into infrastructure planning, and  communicate how such assistance will be provided over time;  that the Chairman of the Council on Environmental Quality finalize  guidance on how federal agencies can consider the effects of climate  change in their evaluations of proposed federal actions under the  National Environmental Policy Act; and that the Secretary of the U.S. Department of Transportation and the  Administrator of the Environmental Protection Agency work with  relevant professional associations to incorporate climate change  information into design standards. They did  not provide official written comments but instead provided technical  comments, which we incorporated, as appropriate. Appendix I: Objectives, Scope, and Methodology

This report (1) describes what is known about the impacts of climate  change on the nation’s infrastructure, specifically roads and bridges,  wastewater management systems, and National Aeronautics and Space  Administration (NASA) centers; (2) analyzes the extent to which potential  climate change impacts are incorporated into infrastructure planning; (3)  identifies the factors that enabled certain decision makers to integrate  climate change impacts into infrastructure planning; and (4) analyzes  federal efforts to address the adaptation needs of local infrastructure  decision makers and describes potential opportunities for improvement  identified by studies, local decision makers who integrated climate  change into infrastructure planning, and other stakeholders.
Why GAO Did This Study

The federal government invests billions of dollars annually in infrastructure, such as roads and bridges, facing increasing risks from climate change. Adaptation--defined as adjustments to natural or human systems in response to actual or expected climate change-- can help manage these risks by making infrastructure more resilient.
GAO was asked to examine issues related to infrastructure decision making and climate change. This report examines (1) the impacts of climate change on roads and bridges, wastewater systems, and NASA centers; (2) the extent to which climate change is incorporated into infrastructure planning; (3) factors that enabled some decision makers to implement adaptive measures; and (4) federal efforts to address local adaptation needs, as well as potential opportunities for improvement.
GAO reviewed climate change assessments; analyzed relevant reports; interviewed stakeholders from professional associations and federal agencies; and visited infrastructure projects and interviewed local decision makers at seven sites where adaptive measures have been implemented.

What GAO Found

According to the National Research Council (NRC) and others, infrastructure such as roads and bridges, wastewater systems, and National Aeronautics and Space Administration (NASA) centers are vulnerable to changes in the climate. Changes in precipitation and sea levels, as well as increased intensity and frequency of extreme events, are projected by NRC and others to impact infrastructure in a variety of ways. When the climate changes, infrastructure-- typically designed to operate within past climate conditions--may not operate as well or for as long as planned, leading to economic, environmental, and social impacts. For example, the National Oceanic and Atmospheric Administration estimates that, within 15 years, segments of Louisiana State Highway 1-- providing the only road access to a port servicing 18 percent of the nation's oil supply--will be inundated by tides an average of 30 times annually due to relative sea level rise. Flooding of this road effectively closes the port.
Decision makers have not systematically considered climate change in infrastructure planning for various reasons, according to representatives of professional associations and agency officials who work with these decision makers. For example, more immediate priorities--such as managing aging infrastructure--consume time and resources, limiting decision makers' ability to consider and implement climate adaptation measures. Difficulties in obtaining and using information needed to understand vulnerabilities and inform adaptation decisions pose additional challenges.
Key factors enabled some local decision makers to integrate climate change into infrastructure planning. As illustrated by GAO's site visits and relevant studies, these factors included (1) having local circumstances such as weather-related crises that spurred action, (2) learning how to use available information, (3) having access to local expertise, and (4) considering climate impacts within existing planning processes. As one example, the Milwaukee Metropolitan Sewerage District managed risks associated with more frequent extreme rainfall events by enhancing its natural systems' ability to absorb runoff by, for instance, preserving wetlands. This effort simultaneously expanded the sewer system's capacity while providing other community and environmental benefits. District leaders enabled these changes by prioritizing adaptation, using available locallevel climate projections, and utilizing local experts for assistance.
GAO's report identifies several emerging federal efforts under way to facilitate more informed adaptation decisions, but these efforts could better support the needs of local infrastructure decision makers in the future, according to studies, local decision makers at the sites GAO visited, and other stakeholders. For example, among its key efforts, the federal government plays a critical role in producing the information needed to facilitate more informed local infrastructure adaptation decisions. However, as noted by NRC studies, this information exists in an uncoordinated confederation of networks and institutions, and the end result of it not being easily accessible is that people may make decisions--or choose not to act--without it. Accordingly, a range of studies and local decision makers GAO interviewed cited the need for the federal government to improve local decision makers' access to the best available information to use in infrastructure planning.

What GAO Recommends

GAO recommends, among other things, that a federal entity designated by the Executive Office of the President (EOP) work with agencies to identify for local infrastructure decision makers the best available climaterelated information for planning, and also to update this information over time. Relevant EOP entities did not provide official comments, but instead provided technical comments, which GAO incorporated, as appropriate.