What Drives Adaptation?
Evidence from Sea Level Rise Planning in the Southeastern United States
Andrew Grandage (Western Carolina University), Robert E. Hines (The University of North Carolina, Charlotte), Katherine G. Willoughby (University of Georgia), Mathew E. Hauer (Florida State University)
While coastal local governments are accustomed to managing disruptions and uncertainty, they will face a pronounced challenge from sea level rise (SLR). SLR has the potential to reshape coastal communities through enhanced coastal flooding, saltwater intrusion, and the eventual loss of habitable land. In the long term, SLR could lead to migration away from low-lying coastal areas, reductions of tax revenue, demand for new infrastructure, and costly damages from extreme weather events, but even today recurrent high tide flooding is already delaying commuters in coastal areas. SLR’s potential impacts will be worse if adaptive actions are not taken over the short and long run. In the United States, local governments have taken the lead on SLR planning, given the localized impacts and lack of consensus among the federal and some state governments in proactively addressing climate risks. Our research examines how local governments across the southeastern United States are planning for SLR and factors serving as barriers and drivers to local SLR planning.
We study the 85 counties stretching the coastline from North Carolina to Louisiana, a region with a rich diversity of political environments and coastal archetypes. To understand how southeastern counties are planning for SLR, we collected governmental documents, including counties’ comprehensive plans, financial reports, and land use plans and developed a dataset containing each county’s documented SLR practices. We then categorized the SLR planning practices to identify the focus areas in which governments are planning for SLR, the types of SLR risks experienced, and the tactics governments were using to adapt to SLR. Overall, our results provide a snapshot of SLR planning activity as of 2018.
At the summary level, we find that most counties are in the initial stages of SLR planning, having addressed SLR in their planning documents. However, relatively few have conducted comprehensive analysis of risk across their portfolio of infrastructure assets and service areas. Figure 1 shows the number of tactics used by each county to address SLR. Most often, counties identify general SLR risks to their communities with some going further by identifying specific threats and broader implications for the natural environment and local economy. Tactics for managing SLR typically involve the issuance of policy statements that provide guidance for long-term planning. However, some counties evidence more concrete actions, including intensive information gathering, regulations on land use and building codes, and investments in adaptive projects. As Figure 1 shows, heavily populated areas, such as New Orleans and South Florida, have taken several steps to address SLR. Of course, they each face unique risks given their different coastal archetypes, such as the subsiding delta in Louisiana and porous Floridian areas.
Figure 1: Count of Tactics Used by County
After describing SLR practices, we shift our focus to quantifying barriers to SLR planning. Previous research has described barriers to SLR planning, such as lack of financial resources and unsupportive political environments, which prevent local governments from conducting vulnerability assessments and committing to adaptive measures. However, much of this research has been conducted by using case studies of metropolitan areas, with relatively few studies covering wider geographic areas. Furthermore, many studies rely on surveys which ask participants to rank barriers, without taking measures of planning activity and relating these to local conditions. Our work examines the barriers to SLR planning by providing a snapshot of a well-defined geographic region based on documented SLR policies.
We tailored our research questions based on the literature review. For instance, the literature strongly indicates that areas with greater populations and financial resources are more likely to pursue adaptive measures. Therefore, we focused on quantifying the relative size of these barriers and the way in which they inhibit planning. In contrast, the impact of risk exposure and political environment were less certain, so we emphasized substantiating their relationship to SLR planning.
We find that financial resources, population size, and future risk exposure each significantly increase the likelihood of planning for SLR. Among these, we found that financial resources had the largest impact, followed by population size and risk exposure. An important nuance in our findings is that future risk exposure matters more than historic flood damages. Specifically, we find that the percentage of the population expected to annually experience a flood by 2050 significantly predicted SLR adaptation whereas historic flood claims per capita did not. This implies that prospective, rather than retrospective, measures of risk exposure may better predict SLR adaptation.
Although political environment did not have a significant impact on whether a county engaged in SLR planning, we find that the political environment impacted how much planning was done. Among counties planning for SLR, those with higher shares of democratic votes tend to plan across a greater number of focus areas, identify more risks, and develop more tactics for addressing SLR. While results indicate that a county’s political environment is not necessarily a barrier when it comes to planning for SLR, it may be a driver of more comprehensive planning practices.
Because adaptation to climate change is characterized by multiple sustainability objectives that are often led locally, examining context specific issues facing local governments remains critical for improving our understanding of adaptation to climate change. Ultimately, our results align with previous research on adaptation to climate change and offer new insights for SLR planning in particular. Climate risk management involves two key initial hurdles – merging risk assessments with existing management plans for different service areas and then determining how to use this information. Our results indicate that, in the case of SLR, financial resources, population size, and future risk exposure contribute to the incorporation of climate risks into local government planning. However, among local governments addressing SLR, their distinct political environments contribute to greater use of this information.
Of course, because our research represents a snapshot of planning practices as of 2018, we are planning future research to examine how SLR planning has evolved, and welcome comments from local governments on their SLR planning journeys.
Andrew J. Grandage, PhD, is an assistant professor at Western Carolina University. He conducts research on public administration, capital budgeting, and project management.
Robert E. Hines, PhD, is an assistant professor at University of North Carolina at Charlotte. His research focuses on public administration, budgeting, and climate change, with special attention to sea level rise.
Katherine G. Willoughby, PhD, is the Margaret Hughes and Robert T. Golembiewski professor of Public Administration and Policy at The University of Georgia where she also serves as the director of the PhD Program in Public Administration and Policy. She conducts research on public administration, budgeting, and performance management.
Mathew E. Hauer, PhD, is the Charles B. Nam associate professor of Sociology at Florida State University and a faculty affiliate in the Center for Demography and Population Health. His research focuses on the intersection of demography, migration, population projections, and climate change.