2.1 Conceptualizing adaptation measures

A wide range of different adaptation measures are typically considered in planning for coastal climate adaptation sea level rise [8]. Preventative adaptation measures include grey infrastructure, such as sea walls and dams, and green infrastructure, which uses methods like wetlands and marshes to create a buffer [9]. Natural and nature-based features (NNBF) along with hybrid approaches that combine natural elements with engineered structures are innovative solutions increasingly acknowledged for their capacity to bolster coastal resilience and serve as effective climate mitigation and adaptation strategies, while also providing additional social and ecological benefits, such as constructed wetlands, maritime forests, reefs, breakwater islands, channel shallowing, ecologically enhanced bulkheads, revetments, and living shorelines [10]. Some examples of smaller-scale adaptation strategies that focus on infrastructure and human systems rather than environmental include raising homes, drainage, and alarm systems [11]. Managed retreat is another adaptation strategy that relocates people to higher ground or further inland through political strategies such as a buyout program in areas that are high risk for recurring flooding events [12]. While effective in removing people from physical risk, managed retreat often carries deeper social implications, particularly around social equity. The uneven distribution of benefits and burdens within these approaches highlights a critical dimension of climate adaptation: the role of social equity in shaping outcomes for different communities.

The purpose of this literature review is to synthesize existing scholarly discussions on social equity within coastal climate adaptation planning. This review focuses on key themes and debates regarding the conceptualization of social equity, challenges in its implementation, and the role of case studies in highlighting unique community-specific opportunities and obstacles.

2.2 Defining and measuring social equity in adaptation

The critical aspect of coastal climate adaptation measures lies in their impact on social equity, which requires a nuanced understanding and careful consideration. While social equity has increasingly become an important component in assessing the effectiveness of adaptation strategies, there can be significant tradeoffs, and the differential impacts of these strategies on different communities are not well understood [3,13]. The impact on social equity in adaptation planning partly depends on how stakeholders define and measure social vulnerability and identify disadvantaged populations [14]. Despite recent efforts by government agencies to hire diversity, equity, and inclusion officers and develop relevant indices, achieving a shared definition of social equity remains challenging, especially in the context of coastal adaptation planning, where vulnerabilities vary across communities and no standardized metrics exist to assess vulnerability.

Equity has been characterized by two elements: horizontal and vertical categories [15,16]. Horizontal equity is when an individual or group has their needs met through access to the same resources as other communities. Vertical equity is when an individual or group has their needs met by varying amounts of resources proportional to their needs and vulnerabilities.

One approach to defining social equity is through the use of vulnerability assessments, which identify populations that are at risk of being disproportionately impacted by climate change [17]. Many studies have identified the need to consider social vulnerability, or the susceptibility of different groups to harm from climate impacts, in adaptation planning [18,19]. For example, in a study of the Gulf Coast region, researchers used vulnerability assessments to identify vulnerable populations and developed strategies for enhancing social equity in climate adaptation planning [20]. Some researchers have proposed using specific indicators, such as income, race, or access to healthcare, to measure social vulnerability [21].

Due to the differential impacts that climate change risks have on different communities, there has been a call for more inclusive and equitable approaches to coastal resilience planning and project implementation. Flooding and severe storm events disproportionately affect low-income communities and communities of color, which may lack the resources to prepare for and recover from such events [19]. One study revealed that while urban climate change adaptation planning aims to reduce vulnerability and fosters new collaborations and coordination, it often overlooks equity issues, social vulnerability, and the influence of non-climatic factors [22]. One such approach that does explicitly account for social equity is the Resilience Adaptation Feasibility Tool (RAFT), which seeks to incorporate equity into coastal resilience planning [23]. The authors argue that a more inclusive and equitable approach to resilience planning can lead to more effective and sustainable outcomes that benefit all communities.

2.3 Addressing maladaptive solutions

But simply advocating for participation is insufficient to ensure inclusive governance. Issues such as tokenizing, misrepresentation, and extractive engagement can exacerbate social inequities within ostensibly inclusive adaptation planning. Recognizing these challenges is crucial for designing participatory processes that genuinely empower marginalized communities.

Practical challenges such as time constraints and institutional barriers can hinder the integration of diverse knowledge systems, limiting meaningful participation in adaptation planning [7]. Inadequately planned adaptation strategies may even worsen vulnerabilities, highlighting the need for careful, context-sensitive planning [24]. For example, high-cost adaptation actions often benefit certain groups at the expense of marginalized communities, necessitating a nuanced approach that considers social and temporal dimensions [25].

Robust, flexible, and equitable approaches in urban planning and municipal governance are important to effectively manage climate risks and enhance citizen participation [26,27]. This includes the need for clear objectives and guidelines to navigate uncertainties and ensure fair outcomes. Multi-stakeholder partnerships, while potentially transformative, require careful management of knowledge uncertainties, value conflicts, and complex decision-making processes [28]. The inclusion of diverse stakeholders is essential for equitable adaptation planning, yet it must be approached with an understanding of inherent challenges and potential pitfalls. Climate adaptation solutions can further the resource divide and exacerbate social inequities.

One prominent example is the managed retreat buyout programs in the United States (U.S.) which have tended to favor whiter communities over communities of color, as evidenced in the aftermath of Hurricane Sandy where collective action among white neighborhoods facilitated buyouts, contrasting starkly with Black communities’ resistance, perceiving them as a guise for displacement. This dichotomy, detailed in the nationwide analysis "Racial Inequities in the Federal Buyout of Flood-Prone Homes," underscores the need for a nuanced approach to climate adaptation that conscientiously addresses and mitigates entrenched racial disparities [29]. The social justice implications of managed retreat buyout programs in the U.S. can perpetuate social inequalities and displacement, particularly for low-income and marginalized communities [30]. There is a pressing need for a transformative approach to managed retreat that addresses social injustices associated with climate change and promotes community participation and empowerment [31]. Such an approach calls for policy interventions and support to ensure that managed retreat is socially just and equitable for vulnerable communities.

The lack of standardization and clarity on how equity is defined and measured in adaptation research hinders efforts to promote equitable outcomes [13]. There is a need for more precise and context-specific definitions of equity and greater participation from marginalized communities in the decision-making process to address systemic inequities in adaptation planning and implementation. Another significant gap in research is a limited conceptualization of equity, resulting in several barriers to promoting equity in urban adaptation planning [14]. More research is needed on the intersection of equity and urban climate adaptation, as well as more inclusive and participatory approaches to planning and implementation that address the multiple dimensions of equity.

A study in Hampton Roads, Virginia highlights the importance of recognizing the subjective and value-laden nature of adaptation decision-making in the context of climate change. The study emphasizes the need for critical engagement with power dynamics and the inclusion of diverse perspectives in the decision-making process to promote equitable outcomes in adaptation planning [32]. Considine et al.’s (2017) case study of Hampton Roads, Virginia, emphasizes the importance of incorporating local knowledge, promoting cross-sectoral collaboration and adaptive governance structures, and fostering social learning and innovation to build resilience to sea level rise and climate change impacts [33]. In Coastal Virginia, low-income and minority communities are more vulnerable to climate change impacts and there is a need for more equitable and inclusive approaches to climate adaptation that prioritize vulnerable communities and promote social justice and resilience [34]. These findings underscore broader challenges in climate adaptation planning, pointing to key gaps in research and practice that must be addressed to promote more equitable and inclusive outcomes.

2.4 Research needs and focus

Overall, the literature on social equity in coastal climate adaptation research highlights several key gaps and research needs: 1) lack of standardization and clarity on how social equity is defined and measured in the context of adaptation planning; 2) the need for more research on assessing the effectiveness of different adaptation strategies in promoting equity and ensuring that they do not perpetuate social inequalities; 3) the need for more inclusive and equitable approaches to climate adaptation that prioritize social justice and resilience to ensure the needs and perspectives of vulnerable communities are taken into account; and 4) the need for more localized case studies in climate adaptation research, particularly in the context of vulnerable coastal communities, to provide valuable insights into the context-specific social, economic, and cultural factors that could influence the outcomes of climate adaptation strategies. In light of the identified gaps and research needs, our study aims to contribute to the understanding of social equity in coastal climate adaptation by examining the definition and application of social equity in government decision-making, focusing on localized case studies, and promoting inclusive and equitable approaches to better address the unique challenges and opportunities faced by vulnerable coastal communities.

3.1 Case study design

In this study, we chose the City of Norfolk in southeast Virginia as the representative case study due to its combination of challenging climate-related issues and stressors, including rapidly increasing relative sea-level rise and increased intensity of rainfall patterns, alongside an overdeveloped urban environment experiencing the heat island effect [35–37].

Norfolk’s demographic profile, as summarized in Table 1, reveals a diverse population with 40.7% Black or African American, 8.7% Hispanic or Latino, and a substantial portion of the population being under 18 (20.3%) and over 65 years old (12.3%). With a median household income of $60,998, about 16.9% of its residents live in poverty, highlighting the socio-economic challenges faced by a significant segment of the population. This demographic snapshot, combined with a 44.8% owner-occupied housing rate and a median housing value of $254,200, underlines the potential vulnerability of Norfolk’s community to the socioeconomic impacts of climate adaptation and managed retreat policies. Given Norfolk’s proactive stance on coastal climate adaptation, this detailed demographic understanding enriches the examination of how managed retreat buyout programs could influence social equity within urban, coastal settings, thus amplifying the need for policies that are sensitive to the nuances of the community’s socio-economic fabric [38].

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 1. Key demographic and socioeconomic characteristics of Norfolk City, Virginia [38].

https://doi.org/10.1371/journal.pclm.0000516.t001

Norfolk has a unique socioeconomic context that is characterized by high levels of poverty, disability, and uninsured citizens, and a history of neglect towards vulnerable populations in public policy considerations, offering a rich backdrop for exploring the intertwining of climate adaptation and social equity [38].

Fig 1 displays the National Risk Index, a visualization of social vulnerability and community resilience across Norfolk, Virginia. This figure helps identify areas with higher exposure to various risk factors based on comprehensive boundary and exposure data. It is overlayed with key economic hubs nearby coastal areas.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Fig 1. FEMA national risk index map for Norfolk, Virginia.

The Risk Index leverages available source data for natural hazard and community risk factors to develop a baseline risk measurement for each United States county and Census tract. This figure was created by the authors using ArcGIS Online, based on FEMA’s National Risk Index, updated May 26, 2023 [39].

https://doi.org/10.1371/journal.pclm.0000516.g001

Norfolk has been proactive in coastal climate adaptation planning [34] and therefore can serve as a useful case study to other urban, coastal communities facing similar concerns. Norfolk’s participation in the National Flood Insurance Program provides flood insurance options for its residents and businesses, complemented by local regulations aimed at mitigating flood risks. Despite these efforts, the looming threat of sea-level rise and other slow-onset and sudden natural disasters necessitates further action [40].

Fig 2, sourced from FEMA, shows the annual flood risk areas overlayed with economic hubs near the coast, highlighting regions most vulnerable to flooding and the potential impact on Norfolk’s critical infrastructure.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Fig 2. FEMA flood Hazard Areas from FEMA’s flood insurance rate map, displaying special flood Hazard Areas in Norfolk, Virginia.

This map displays Special Flood Hazard Areas where flooding risk is significant, especially near the coast. This map was created by the authors using ArcGIS Online, adapted from FEMA data [41].

https://doi.org/10.1371/journal.pclm.0000516.g002

3.2 Stakeholders interviews and ethical considerations

Our primary data collection method was semi-structured interviews, which included human subjects and involved approval from the University of Virginia (UVA) Institutional Review Board for the Social and Behavioral Sciences (IRB-SBS). The IRB-SBS approved our protocol number 4396 (S2 Appendix) originally in July of 2021 but then additionally amended and approved in January 2022 to add additional researchers. Participants were given consent letters to sign. Then consent was additionally requested verbally before starting the interview and again on record when the interview began. All participants were allowed to withdraw at any time. The interviews were conducted from August 30^th, 2021, until January 5^th, 2022. To comply with our IRB protocol, all direct quotes in this paper are cited with the date of the interview (MM/DD/YY) and the interviewee’s organization type.

The stakeholder interviews aimed to understand the role and impact of different stakeholders in coastal climate adaptation policymaking in Norfolk (Research Question 1), identify points of conflict or reinforcement among different stakeholder groups (Research Question 2), and assess how stakeholders incorporate social equity into their decision-making processes (Research Question 3). The interviews included a diverse array of influential stakeholders, such as representatives from environmental and economic development non-governmental organizations (NGOs), academic research institutions, and various government agencies. These stakeholders play significant roles in climate change adaptation and mitigation efforts in coastal Virginia. Our research specifically targeted individuals directly involved in policymaking and implementation for coastal resilience, allowing us to delve into the complex mechanisms behind adaptive strategies.

To ensure relevance and richness of data, stakeholders were carefully selected, and each interview was tailored to the unique work and expertise of the interviewee. We contacted 110 people within different stakeholder groups and conducted a total of 42 interviews were conducted. The breakdown of interviewees by sector is as follows: 13 from environmental NGOs, 3 from economic development NGOs, 5 from academic research institutions, 10 from local government, 2 from regional government, 7 from state government, and 2 from the federal government. While we acknowledge the importance of including local businesses, utilities, residents, and marginalized groups for a more comprehensive perspective, this initial study intentionally focused on the foundational climate adaptation policy landscape, reflecting institutional and practitioner viewpoints rather than those of residents or marginalized communities.

Initial participants were strategically identified based on their leading roles in both local and state government sectors, directly involved in coastal climate adaptation efforts. Recognizing the crucial input of NGOs in shaping Norfolk’s climate adaptation policies, we compiled a list of NGOs actively engaged in this area. Our focus remained on interviewing leadership figures (e.g. directors, chiefs, and executives), as their insights provided the most authoritative perspectives. To refine our selection and ensure we engaged with the most influential figures in Norfolk’s climate adaptation policymaking, we employed a snowball sampling method. This involved asking our initial interviewees to identify other key stakeholders they viewed as significantly impacting local climate adaptation strategies. This iterative process enabled us pinpoint individuals pivotal to Norfolk’s coastal climate adaptation planning. The repetition of certain names across interviews confirmed the centrality of certain entities and individuals in the policymaking process. The saturation point for the data occurred when information in interviews became redundant [42].

Reflexivity was central to our ethical approach. We recognized our positions and biases as researchers, reflected on how our backgrounds could influence the research process and the questions posed. We did not hold any authority over our participants, and no conflicts of interest arose during the study. Access to the community was facilitated through newly established relationships, ensuring that participation was voluntary and informed. We communicated via email that participation was entirely voluntary, and that no compensation would be provided. We actively addressed power dynamics between researchers and participants by fostering an environment of mutual respect. Participants were assured of their confidentiality, and we committed to generalizing their descriptions by sector rather than identifying specific roles or institutions. This approach was crucial in eliciting candid responses.

Interviews were conducted with careful consideration of safety and accessibility due to the COVID-19 pandemic. All interviews were carried out virtually via Zoom to adhere to health guidelines, ensuring the safety of both participants and researchers. The pandemic’s influence on the research process was minimal; we had planned to record the interviews and conduct them remotely regardless of the pandemic. However, scheduling conflicts arose due to the election year and the impending release of the Coastal Resilience Master Plan, which reduced participation from certain agencies with overlapping responsibilities and deadlines.

4.1 The exclusion of historically marginalized groups

There is an inherent tension when interviewing decision-makers about their choices on behalf of disadvantaged populations. Specific marginalized groups, such as people without homes, those with disabilities, and the elderly, were notably absent from these discussions. The discussions below highlight the challenges in reaching disadvantaged communities both in participation, representation, and resource capacity.

An environmental NGO stakeholder highlighted, “A lot of our work developing adaptation strategies for neighborhoods and communities takes place in low to moderate-income areas. Early on, we recognized that people with means can get out of the way or access policymakers to take care of themselves. But disenfranchised folks and limited resource communities, especially in rural areas, will have a harder time. Rural areas are significantly disadvantaged, and we’re just now figuring out how to help develop capacity there. Social equity is predominant in our actions; we prioritize those who need our resources more than those who can hire a contractor.”

A different environmental NGO interviewee explained, “Providing a stipend could be the difference of getting childcare, and that mom being able to attend a meeting,” highlighting the importance of financial support for volunteers from low-wealth and marginalized backgrounds. Additionally, the same interviewee acknowledged the existing gaps in representation within their organization: “Most of our membership in Virginia are white middle class or more affluent and middle aged. What I recognize is that there’s a lot missing from our constituency. I would love to have more younger mothers, BIPOC [Black, Indigenous, and People of Color] mothers, and mothers from low wealth, geographical areas.” Furthermore, they emphasized the importance of considering practical equity implications in policy decisions: “For instance, one team was considering pursuing their county in banning plastic shopping bags. I asked the question, what might that mean to someone who, all of a sudden, now has to pay for their bags? When we pursue this, how might we do it in a way where we’re taking something away, but we’re also providing something?” These insights underscore the necessity of addressing the practical needs and concerns of marginalized communities to ensure that participation in adaptation planning is both meaningful and realistic.

A state government employee we interviewed discussed the participation of tribal communities in climate adaptation policymaking. “Tribes are a challenge. They all need to be treated separately as individuals. And it’s just really hard to do that because they’re overwhelmed with their federal responsibilities, the ones that are federal tribes now…it’s just very difficult to make those connections. The state has struggled to come to terms with how to deal with federal tribes. It didn’t have federal tribes until the Pamunkey in 2015, and the other six since 2018. It’s a whole new world to deal with having seven of them, plus state recognized tribes. But the federal tribes are independent. They’re basically governors, they are states. And they’re the equivalent of the governor, their chief. I don’t think by and large that the broader Commonwealth views them that way. But that is how they are. That’s how the federal government views them.”

A local government interviewee discusses the historical nature of city council wards. “The City of Norfolk moved to a ward system in the early 90s after a lawsuit suggested there wasn’t representation of minorities on the council. We have five single wards, and two superwards that are very racially gerrymandered. Neighborhoods that are historically Black, which should be part of [a certain] superward, are literally drawn out. The lack of infrastructure investment and the resulting flooding typically happens in [a different] superward.”

There’s an obvious omission of specificity when discussing social equity, environmental justice, and how disadvantaged communities are included in the conversation in a meaningful way. To focus this, we asked the interviewees how they define social equity.

4.2 Stakeholders’ definition of social equity

When discussing social equity, the following key themes emerged from the stakeholders’ interviews: “environmental justice”, “sustainability”, “diversity, equity, and inclusion”, “resilience”, and “sustainability”. However, some interviewees did not provide a clear definition for social equity, while others discussed related issues without providing a clear definition. Table 2 presents a small sample of direct responses from the interviewees. We found that the stakeholders in Norfolk’s coastal climate adaptation planning have diverse perspectives on social equity. The most frequently used words within their definitions included opportunity, support, ability, resources, voices, different, and vulnerable. Specifically, the definitions highlighted the following aspects: providing equal opportunities and awareness; ensuring voice and control; understanding vulnerability and historical factors; reaching traditionally underserved communities; enabling equitable responses to challenges; addressing past wrongs; ensuring post-disaster recovery for low-income communities; and considering the fair distribution of impacts and benefits. While most interview participants agreed that fairness, equal opportunity, and justice are key components of social equity, only a few identified systemic vulnerabilities as a factor. These diverse viewpoints emphasize the importance of a multifaceted approach to social equity in coastal climate adaptation planning.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 2. Definitions for social equity provided by the interviewees by sector.

https://doi.org/10.1371/journal.pclm.0000516.t002

4.3 Metrics for social equity assessment

When asked how they incorporate social equity into their objectives, stakeholders provided a range of responses. Some gave concrete examples, such as helping people vote, using relatable language, focusing on mixed-income communities, and providing equitable volunteer support. One stakeholder even shared an acronym they use to incorporate equity and inclusion into their program goals: SMARTIE goals. “SMART goals are Specific, Measurable, Achievable, Realistic, and anchored within a Time frame, but with the addition of ‘I’ for inclusion and ‘E’ for equity, they become SMARTIE goals” (10/07/21, Environmental NGO).

Metrics are essential for assessing progress and determining whether objectives have been met. By providing quantitative and/or qualitative measures, metrics can help establish clear criteria for success and enable the accurate evaluation of the effectiveness of the project. Stakeholders were asked how they measure social equity. Some admitted that they do not measure it at all, while others mentioned using social vulnerability metrics and tools. This indicates a gap between recognizing the importance of social equity and being able to measure progress towards achieving it.

Several sources were repeatedly identified as useful tools by the stakeholders interviewed for assessing social equity in coastal climate adaptation planning. These were: Social Vulnerability Index, Poverty Ratio, and Environmental Justice Tool. Notably, none of these resources were specifically developed for Norfolk. The VIMS Social Vulnerability Index, a statewide tool developed by the Virginia Institute of Marine Science, uses various socio-economic and demographic variables to evaluate social vulnerability and resilience to hazards [48]. The Poverty Ratio, a federal tool, assesses economic vulnerability by classifying individuals or families as impoverished based on diverse income [49]. The Environmental Justice Tool, another federal resource developed by the US Environmental Protection Agency, merges demographic and environmental indicators to assess equitable distribution of environmental policies and impacts [50]. While these tools offer valuable insights into social equity, they present limitations when used in local contexts like Norfolk, as they may not fully account for unique regional socio-economic and environmental characteristics that influence local social equity dynamics. Table A in the S1 Appendix presents a breakdown of these three tools, including their definitions as provided by the institutions that developed them, and an overview of their metric components.

One approach to measuring social equity, as shared by a local government stakeholder, focuses on analyzing the vulnerability of residents and considering all contributing factors that impact their ability to succeed or face vulnerability. Their climate adaptation strategy follows a multi-pronged approach, which begins with understanding the community’s vision for the future and documenting it, as in Norfolk’s Vision 2100. The community is divided into four distinct areas, and they have implemented tools within their zoning and floodplain ordinances to help realize their vision. The local government has also adopted a resilience quotient, which is a point system that encourages market participation in a voluntary exchange to reduce risk and improve flood and stormwater management. The community plays a significant role in this process, and the local government has incorporated these tools into their ordinances to ensure the community is invested in the success of their managed retreat efforts. However, the interviewee did not provide specific details on the zoning plan’s release or the community’s involvement in the process.

A federal government stakeholder emphasized that cost benefit analysis is a crucial factor in evaluating proposed solutions to protect against environmental challenges. They acknowledged the challenges of balancing economic benefits against costs, particularly when considering underserved low-income communities and social factors. However, they asserted that cost benefit analysis is a fair and consistent way to measure the effectiveness of proposed solutions. In their own words, “at the end of the day, it’s very much an engineering answer, which is not necessarily the right way, but, at least, it’s fair and consistent across the board, so it’s measurable, and we can go back and reproduce it” (12/14/21, Federal Government). The stakeholder mentioned that using cost benefit analysis can present challenges when considering underserved low-income communities and environmental justice issues. They acknowledged that financial damage prevented by expensive properties that would get flooded are given higher priority in the cost benefit analysis whereas damage prevented by low-income neighborhoods with low-value homes are minimal. The stakeholder also indicated that there is no quantitative number for social factors and analyses, making it more challenging to consider the impacts of cost benefit analysis on vulnerable communities. They acknowledged that this could make it difficult to justify building solutions that may cost a significant amount to protect a relatively small amount of property. Overall, the stakeholder recognized the challenges of balancing economic benefits with protecting vulnerable communities, particularly when using cost benefit analysis.

4.4 Connecting climate risks with social inequalities

As climate change poses an increasing threat to our cities, it is necessary to examine how the resulting risks are distributed among different communities and why. In this section, we explore the relationship between social inequalities and the primary climate risks confronting the City of Norfolk, as identified by the stakeholders, i.e., flooding, severe storms, and urban heat. To gain a deeper understanding of how these risks are perceived through the lens of stakeholders, we explore the narratives that connect climate change threats to socially vulnerable communities. Through this analysis we aim to highlight the intersections of climate change and social justice and identify potential solutions to mitigate the disproportionate impacts on marginalized communities.

4.4.2 Equitable tree canopy distribution and excessive heat in Norfolk.

Interviewees expressed concerns about excessive heat waves impacting communities that have been historically neglected in green development efforts, such as tree canopies. In the face of this growing threat, extreme heat remains a cause of preventable death in the US, with health risks expected to rise due to factors such as an increasing urban population, an aging population, and the presence of urban heat islands [55,56].

Urban heat islands are areas hotter than their surrounding communities due to a lack of natural land cover and a preponderance of urban infrastructure like pavement, buildings, and other heat-absorbing structures [57]. A recurring theme in the interviews was that heat is considered a neglected climate risk, often overshadowed by flood and storm adaptation efforts. A state stakeholder acknowledged that heat is a significant issue in places like Richmond, Virginia, but their primary focus is on flooding. They believe that heat, along with flooding, is a root cause of many climate-related problems in the Commonwealth.

An interviewee from an environmental NGO highlighted the issue of urban heat islands and the lack of investment in natural resources to address climate change. They noted that there is a partisan divide on how to prioritize and invest in disadvantaged communities and communities of color, which are disproportionately impacted by certain policy choices. The interviewee described the impact of unsustainable development practices on urban heat islands, stating, “when it can be 30 degrees, my neighborhood is 30 degrees cooler than an area that does not have trees, was not developed in a way that is sustainable. The type of plantings that were chosen to put in, we’re seeing those long-term health impacts of those policy choices” (10/06/21, Environmental NGO).

A local government stakeholder explained that historically redlined neighborhoods, usually populated by people of color or Jewish people, still face challenges such as higher temperatures due to fewer trees and increased energy burden. They emphasized the importance of heat resiliency and addressing energy burden by implementing measures such as home weatherization programs and other small adjustments to help residents cope with extreme temperatures, which are not mentioned in the Climate Action Plan.

The interviewees also discussed the impact of redlining on present-day neighborhood conditions, such as tree coverage and heat vulnerability. Redlining was a practice in the 1930s and 40s where banks and mortgage companies would decide not to give mortgages to neighborhoods deemed “bad,” often where people of color or Jewish people lived. These neighborhoods were considered “hazardous” or “definitely declining.” These antiquated maps have generational impacts and have created systemic oppressive housing practices.

To explore the contemporary implications of these historical inequitable practices, our study uses the Tree Equity Score (TES) developed by American Forests, a non-profit organization committed to the restoration of large forests in natural landscapes to enable their adaptation to the impacts of climate change [58]. The TES is a nationwide metric calculated at the neighborhood level (Census block group), ranging from 0 to 100, that measures the equitable distribution of tree benefits to communities, prioritizing areas with lower scores for tree planting based on the extent to which low-income communities, communities of color, and those disproportionately impacted by extreme heat and other environmental hazards currently access these benefits [59]. Achieving socially equitable tree canopy coverage is crucial for creating healthier and more resilient urban environments. This approach not only enhances ecosystem services but also facilitates benefits such as job creation and improved quality of life. Through the provision of necessary green infrastructure, especially in underserved areas, equitable tree distribution plays a pivotal role in mitigating environmental challenges while promoting community well-being and sustainability.

Fig 3, generated in ArcGIS, overlays the TES and Norfolk’s redlining map, offering a stark visual representation of how historical redlining correlates with current disparities in tree canopy coverage [58]. By illustrating the intersection between historical housing discrimination and current environmental challenges, we underscore the necessity of integrating equity-focused metrics like the TES into urban planning and policy decision-making. The different grades represent the Home Owners’ Loan Corporation’s (HOLC) judgement on a neighborhood’s risk level. Grade A (green outline) is “Best”, grade B (yellow outline) is “still desirable”, grade C (orange) is “definitely declining”, and grade D (red) is “hazardous” [60]. Fig 3 provides a visual representation of the disparities between neighborhoods and highlights the connection between historical redlining practices and current tree canopy coverage. A lower score of 44 corresponds to worse health outcomes, a larger population of people of color, unemployment, youth population, and poverty. The higher score of 94 has nearly met their tree canopy goal. The tree canopy goal is a target for equitable tree coverage that takes into account the population density of an area, adjusted from generalized natural biome baseline targets selected with the assistance of the United States Department of Agriculture Forest Service.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Fig 3. Comparison of two census block groups in Norfolk, Virginia, showing tree equity scores, score indicators, and historical redlining impacts.

This visualization highlights the disparities in urban greening relative to historical redlining practices. Data sourced from Tree Equity Score [58] and Mapping Inequality: Redlining in New Deal America [60], generated originally by the authors using ArcGIS Pro.

https://doi.org/10.1371/journal.pclm.0000516.g003

An academic stakeholder expressed their belief that investing in resilience to combat excessive heat is not a sustainable long-term solution and instead encourages migration away from high-risk areas. They argued that the costs of investing in resilience are immense and do not substantially reduce the risk of excessive heat. Another stakeholder highlights the importance of addressing heat-related issues and energy burden, which are often overlooked. They summarized their position by stating, "The bottom line is, there’s not enough money. And you have to rely on all of those sources and figure out wisely how to use them" (11/10/21, Academic Research Institution).