Uneven Ground: The Complexities of Urban Greening and Equitable Access

Written by: Nicole Fassina

Terms to Know

Green Space: Designated vegetated open areas, either within or outside cities, including plant life, water, and various natural elements. These areas are typically accessible to the public but can also be privately owned. Examples include parks, open fields, beaches, community gardens, and hiking trails (Mehhdi et al., 2017).

Urban Green Space: Green spaces that are specifically within cities and urban areas. These spaces are typically designed to provide ecological, recreational, and aesthetic benefits to urban residents. Examples include public parks, green roofs, urban forests, and street trees (Lee et al., 2015).

Urban Greening: The process of creating, maintaining, and enhancing green spaces within urban environments through intentional design, implementation, and management. This involves incorporating greenery into urban infrastructure through various methods, such as planting trees, creating green roofs and walls, and developing parks and community gardens (Mehhdi et al., 2017).

Green Infrastructure: A network of connected green spaces and pathways that offer environmental benefits like managing stormwater and improving air quality. It differs from urban greening in that it is purposefully designed to create a system that integrates these spaces to enhance environmental and community well-being in urban and rural areas (Mehhdi et al., 2017).

Introduction

As the world’s population increases and urban areas become denser, the importance of green spaces for promoting physical and mental well-being, preserving biodiversity, mitigating urban heat island effects, and fostering a greater sense of community and connection with the environment has become increasingly evident. As our cities grow and become more crowded, green spaces will become an efficient tool in transforming urban areas into healthier environments to live in.

Proponents of urban greening play a crucial role in elevating the overall quality of life and supporting ecosystem services within cities. Urban green spaces offer a range of benefits not only to the environment, but also to individuals and their well-being. Some of those environmental benefits include mitigating greenhouse gas emissions and managing stormwater (Lee et al., 2015). Furthermore, green spaces also offer significant health benefits by mitigating the effects of urban heat islands and by providing a space for physical activity and social interaction, which enhance both physical and mental well-being (Lee et al., 2015).

Green Spaces and the Environment

Urban greening plays a crucial role in mitigating environmental challenges in urban areas. Firstly, it significantly contributes to offsetting carbon emissions. Trees and plants absorb carbon dioxide during photosynthesis, thereby reducing the amount of this greenhouse gas in the atmosphere (Ai & Yan, 2024). By incorporating more green spaces into cities, we can create carbon sinks that help counteract and decrease the effects of urban carbon emissions. Trees and plants also act as natural air purifiers, trapping dust, smoke, and other pollutants, and releasing oxygen into the air, thus improving air quality (Nowak et al., 2014, EPA, 2024). This process not only makes cities more pleasant to live in, but enhances public health by helping to mitigate respiratory health problems such as allergies (Lee et al., 2015).

Furthermore, green spaces mitigate extreme heat by moderating temperatures through shade and evapotranspiration, which occurs when water in or on a plant is evaporated (EPA, 2023). This process on trees and other vegetation creates a cooling effect, which counteracts the urban heat island effect, or the phenomenon in which cities are significantly warmer than their rural surroundings due to human activities and infrastructure, like tarmac, that absorbs heat (EPA, 2024). By lowering temperatures, urban greening helps alleviate the strain on energy use for cooling and decreases heat-related illnesses (EPA, 2024).

In addition to these benefits, urban greening can also effectively reduce noise pollution. Trees, shrubs, and plants can act as natural sound barriers, absorbing unwanted sounds and creating a quieter, more peaceful environment (Khan et al., 2024). Strategic placement of green spaces and green infrastructure, such as green belts around roadsides, can prevent noise from reaching residential and recreational areas, offering both aesthetic and practical advantages. This noise reduction not only improves the quality of life but also contributes to a healthier community by reducing stress and sleep disturbances linked to excessive noise (Khan et al., 2024). Furthermore, by integrating these noise-reducing green elements into urban planning, cities can enhance overall environmental resilience and create more sustainable, livable spaces. The combined environmental benefits of air purification, temperature regulation, and noise reduction highlight the multifaceted value of urban greening in creating healthier urban environments.

Green Spaces and Health

Green spaces play a pivotal role in improving physical health in several ways. Firstly, they provide opportunities for physical activity, such as walking, jogging, cycling, or playing sports, which are essential for maintaining cardiovascular health, muscle strength, and overall health (Marques da Costa and Kállay, 2020). Regular physical activity in green spaces can help reduce the risk of many chronic illnesses, and studies have shown a link between green space exposure and decreased blood pressure, cholesterol, and incidence of stroke, asthma, diabetes, and heart disease (Twohig-Bennett and Jones, 2018). Specifically in regards to cardiovascular health, a study done in urban areas located in Ontario, Canada, showed an association between more green space and lower risks of heart attacks, heart failure, and death from any cardiovascular cause (Chen et al., 2020).

Access to natural environments also has the potential to improve one’s overall mental health. Beyond providing recreational opportunities, green spaces can offer relief from urban stressors and can contribute to improved mental health outcomes. One study revealed that individuals residing in areas with abundant green spaces experienced lower levels of stress in response to life events compared to those in less green surroundings (Van den Berg et al., 2010). This suggests that urban green spaces can provide emotional relief to individuals and can even decrease the burden of stressful life events. Furthermore, access to usable green spaces has also been associated with reduced counts of anxiety and mood disorder treatments, suggesting that the active component in the interaction between individuals and natural environments is especially important in regards to how green spaces benefit mental health (Nutsford et al., 2013). Moreover, urban greening has a notable impact on reducing noise pollution. Vegetation helps absorb and deflect sound waves, particularly from traffic and industrial activities, thus creating quieter and more tranquil urban environments (Khan et al., 2024). This reduction in noise pollution contributes to improved well-being and quality of life for city dwellers.

Green spaces also offer a space for people to socialize and enhance their sense of community and belonging with each other. Moreover, green spaces play a crucial role in fostering social connections and combating feelings of loneliness, and research indicates that people who live in neighborhoods with more green spaces feel less lonely and experience more social support (Maas et al., 2009). The mere presence of green spaces in one’s living environment enhances community cohesion through strengthened place attachment and identity, promoting social connectedness and a sense of belonging (Maas et al., 2009). Overall, the presence of green spaces has been revealed to provide many benefits to one’s mental well-being through different mechanisms, specifically by relieving stress, anxiety, and promoting social connectedness.

Urban Greening in San Diego

Urban greening in San Diego has become a cornerstone of the city’s sustainability efforts, reflecting its commitment to environmental stewardship and community well being. There have been numerous initiatives implemented to enhance green spaces, improve air quality, and promote biodiversity. These initiatives include supporting habitat restoration or urban canyons, increasing tree planting in communities of concern, supporting the expansion of urban tree canopy in parks, and more (City of San Diego, 2022). Moreover, San Diego boasts an impressive array of green spaces, with approximately 45 percent of the total land area in San Diego County designated as green space (SD Foundation, 2010). These include expansive parks like Balboa Park or Mission Bay Park, numerous small neighborhood parks, and community gardens. These green spaces offer residents and visitors places for recreation, relaxation, and socialization and also provide essential ecosystem services like improving air quality, reducing urban heat island effects, and supporting local biodiversity (SD Foundation, 2010). .

However, the benefits of urban greening in San Diego are not equitably distributed across all communities. For example, California schoolyards are a prime example of how many communities lack access to green space. Schoolyards are often considered “mini urban heat islands” due to the extensive use of asphalt, impermeable surfaces, and a general lack of tree canopy (Green Schoolyards America). In order to quantify and track the distribution of tree canopy across California’s K-12 public school campuses, a California Schoolyard Tree Canopy Equity Study is being conducted in order to track changes to tree canopy on campuses over time. The visual data from this study is available on an interactive map, so everyone can access information about the extent and distribution of tree canopy in school campuses across California (Green Schoolyards America, 2024).

Moreover, despite the abundance of green spaces in our region, disadvantaged communities often face barriers to accessing these natural resources or find that fewer are available close to them. Within all jurisdictions of San Diego County, a minimum of 48 percent of residents live within a 10-minute walking distance from a park (The Nonprofit Institute, 2023). Yet, this percentage fluctuates significantly depending on the area. In cities like Del Mar and Coronado, 93 percent and 82 percent of residents, respectively, are within this distance from a park, while in Vista and Carlsbad, the proportion drops to 50 percent and 48 percent (The Nonprofit Institute, 2023). However, in San Diego, residents in low-income neighborhoods have 56 percent less park space than residents in high-income areas, who have 203 percent more access to park space comparatively (Trust for Public Land, 2024). And neighborhoods that are predominantly people of color have 73% less park space compared to predominantly White neighborhoods in San Diego (Trust for Public Land, 2024). This highlights the need for ensuring equitable access to green spaces and how it remains an essential goal for future well-being and environmental justice.

The map above illustrates San Diego’s park score equity index and demonstrates park accessibility between communities of color and White communities, and between low income and high income communities. (Trust for Public Land, 2024)

Case Study: Tree San Diego

Tree San Diego is a nonprofit dedicated to expanding and enhancing the region’s urban forest. Their mission focuses on benefitting all communities and improving the environment through tree planting initiatives in order to mitigate the effects of climate change. They prioritize underserved areas through tree planting, community education, and workforce development, aiming to get more people involved in urban forestry work in different ways. Mandy Conry, Program Coordinator at Tree San Diego, emphasizes the intersectional impact of Tree San Diego’s work, highlighting how it benefits both people, communities, and the environment.

Tree San Diego offers a variety of programs, which allow community members to get involved with urban forestry work in many different ways. Key programs and projects include:

Leafing Our Legacy: A 10-year celebration program aimed at distributing 1,000 trees to San Diego residents throughout 2024 by holding monthly tree distribution events in order to foster community engagement and education on urban forestry. The program has already distributed 600 trees and plans to distribute an additional 100 trees this year.
Tree Treks: Monthly tree walks led by arborists in different parks, focusing on tree identification, benefits of trees, and park history. The program is designed for families and children, but welcomes those of all ages, and aims to foster a sense of community interest in local flora by providing forestry education in a casual and local setting.
Treejectory+ : A workforce development program that offers paid training in urban forestry. Participants learn about urban heat islands, tree care, and the benefits of trees. Additionally, this program provides career pathways in urban forestry and environmentalism.
Plan and Plant: An urban forestry master plan that allows for county-wide evaluation of tree planting processes. The goal is to plant 1,500 trees over the next few years, prioritizing people, communities, and their needs.
Tree Steward Certification Program: A certification program open to anyone interested in learning about tree benefits and care. Volunteers are trained and certified to preserve and enhance neighborhood trees, contributing to community improvement.

Programs like the ones offered at Tree San Diego illustrate the profound impact urban forestry initiatives can have on communities, and the importance of community education and engagement in urban greening efforts. A key aspect of many of these initiatives is community education, which is crucial for the success of environmental projects. Through educational events, tree planting, and volunteer opportunities, Tree San Diego fosters a sense of community and empowers members to actively participate in environmental stewardship. This unification and education of the community are essential for mitigating the effects of climate change using an environmental justice approach – by ensuring that community members, especially those in underserved areas, have the knowledge and resources to benefit from and contribute to a healthier environment.

However, despite all the benefits from programs like these, everything comes with its challenges, especially when it comes to environmental work and community engagement. One challenge to urban greening that Mandy identifies is in planting and maintaining urban trees. Tree San Diego can organize tree planting initiatives, but the question of who will maintain and care for the trees once they have been planted can often be unclear. Ensuring community collaboration for maintenance, such as watering and pruning, has its challenges because every community functions differently. There is also the challenge of balancing native and non-native trees. On one hand, introducing non-native trees can negatively impact the environment, but on the other, it can also enhance biodiversity and resilience to environmental stressors. Additionally, the need to focus on shade trees to reduce urban heat and the importance of planting drought-resistant tree species in our arid region (especially in a changing climate) can often be difficult to balance.

Image credit: Tree San Diego

Challenges and Considerations for Urban Greening

Urban greening has a variety of benefits, such as improved air quality, reduced urban heat island effects, enhanced aesthetic appeal, and increased biodiversity. While greening can offer numerous environmental and social benefits, it can also reflect and exacerbate existing social inequities, as access to green space is not uniformly distributed across different communities. In many cities, affluent neighborhoods boast well-maintained and abundant green spaces, while low-income and disadvantaged communities struggle with limited access to these amenities. Research indicates that urban vegetation is generally linked to traditional markers of privilege in major U.S. cities, revealing a widespread “green inequity” (Nesbitt et al., 2019). Affluent, well-educated, and predominantly white neighborhoods typically enjoy better access to green spaces and resources, while visible minorities, lower-income groups, and those with less education frequently face significant deprivation (Nesbitt et al., 2019). This disparity is a critical environmental justice issue, as green spaces provide essential benefits such as cooler temperatures and opportunities for physical activity and social interactions. Without equitable access to green space, residents in underserved areas are deprived of these health and social advantages, further entrenching systemic inequities.

Another social issue related to urban greening is “green gentrification,” which can occur when city planners implement green amenities in an area with the intention of improving environmental conditions and community aesthetics, without accounting for the unintended side effect of increased property values and the displacement of low-income, often marginalized, residents (Chen, 2021). Additionally, the transformation of neighborhoods through new parks and green spaces often attracts middle- or upper-class residents, leading to higher housing costs (Chen, 2021). The increase in rent and shift in local businesses can create an unaffordable environment for long-standing residents and cause displacement of these individuals, who are typically working class. This displacement results not only in the physical migration of residents but also contributes to the loss of community identity, culture, and values (NCRC, 2019).

Despite these challenges when it comes to urban greening, it is certainly not a reason to do away with introducing green spaces to communities that need them, especially since there is extensive data showing that areas with more natural vegetation, fields, and flowers experience higher levels of community well-being, including improved mental health and reduced mortality for many different causes of death (Van den Berg et al., 2015). This abundance of benefits can seem troubling; however, when one considers that low-income neighborhoods generally have less access to green spaces, parks, and gardens compared to wealthiest neighborhoods, and therefore, have less access to these benefits. The current approach to community revitalization through urban green space implementation needs to be reconsidered in order to be more equitable. It is crucial to adopt fair policymaking practices that involve community participation and prioritize environmental and housing justice in order to create more green and equitable spaces for everyone.

Conclusion

The integration of urban green spaces into cities is essential for promoting environmental sustainability, public health, and community well-being. As urban areas expand, the development and maintenance of green spaces offers numerous benefits, such as mitigating climate change effects, providing recreational opportunities for communities, and contributing to physical and mental health. However, ensuring equitable access of these green spaces remains a challenge, with disadvantaged communities often lacking access to such vital resources. Addressing these challenges requires thoughtful planning and community involvement.

When community members are actively involved in decision-making processes, they are more likely to take ownership of green spaces, leading to improved maintenance and care (Rahtz et al., 2023). This involvement ensures that green spaces meet the specific needs and preferences of local residents, making them more effective and utilized. Additionally, fostering a sense of connection among residents through the availability of green spaces enhances social cohesion and collective responsibility for the local environment (Jennings & Bamkole, 2019). Education and awareness efforts through community engagement empowers individuals with the knowledge and skills to advocate for and contribute to environmental stewardship. Moreover, prioritizing community input helps address potential concerns related to green gentrification, as residents can work together to find balanced solutions that benefit all. By adopting inclusive and equitable policies, cities can create healthier, more resilient, and connected urban environments for everyone.

Sources

Header image caption: An image of the Botanical Building at Balboa Park, one of San Diego’s expansive parks that makes up green spaces in the region. (Souce: Getty Images)