Urban forest inequity, also known as shade inequity or tree canopy inequity, [1] is the inequitable distribution of trees, with their associated benefits, across metropolitan areas. [2] This phenomenon has a number of follow-on effects, including but not limited to measurable impacts on faunal biodiversity and the urban heat island effect. [3] [4] Urban heat inequity occurs when intra-urban heat islands, with their associated negative physical and emotional health consequences, are more common and more intense in lower-income communities. [5] [6]
Potential solutions to urban forest inequity include but are not limited to investment in marginalized communities, tree-planting initiatives, and more. [7] Examples of urban forest inequity can be seen in various cities across the world. [1] [8] [9] [10] [11]
Urban forests are areas of land covered by trees or other vegetation located in and around places of intensive human influence, particularly metropolitan, urban areas such as cities. [12] Urban forests, though present on both public and private land, typically are found on public spaces due to the predominance of street trees noted by researcher Steven Strom. [12] Urban forests are recognized for their significant role in mitigating the impacts of climate change, exemplified by their role in mitigating heat and flood risks and their contribution to green infrastructure is seen as a nature-based solution for climate change adaptation and mitigation. [13] [14] Trees and vegetation absorb and store rainwater during heavy rainfall events, reducing flood risk, and capture carbon dioxide from the atmosphere as part of climate change mitigation efforts. [15] Additionally, urban forests are also important in maintaining the biodiversity of an urban area, particularly the avifauna (birds) of the area. [16] These characteristics of urban forests help contribute to the creation of healthy, resilient, and sustainable cities in a cost-effective manner. [17]
Urban forest inequity is a phenomenon in which the distribution of and access to trees and nature is inequitable in urban areas. [7] It is thought to be an example of environmental injustice, as it disproportionately impacts marginalized communities. [7] [18] Numerous studies, including a 2017 meta-analysis done by researchers Ed Gerrish and Shannon Lea Watkins, have found a positive relationship between income and urban forest coverage. [7] This introduces the concept of the luxury effects, which explains how the disparities in urban forest cover coincide with socio-economic and historical factors. [19] The luxury effect illustrates how wealthier areas tend to exhibit higher biodiversity, reflecting the influence of socioeconomic factors and education levels in shaping the quantity and quality of green spaces in a given area. [19] Moreover, inequitable distribution of greenery in urban areas may restrict an equal distribution of the benefits of urban forests, which include reducing stress and anxiety, cultivating a safe community, emotional fulfillment, mitigating the effects of global warming, and more. [18] For instance, canopy cover quantity in an area can diminish the urban heat island effect and increase carbon sequestration from the atmosphere. [2] Various historical, cultural, and institutional factors contribute to the perceived inequities in urban forestry management and inequitable distribution of urban greenery. [18] A 2022 paper published in the International Journal of Environmental Research and Public Health found that vulnerable residents of an urban area, particularly lower-income residents and those who live further from urban forests and green space, are particularly susceptible to the urban heat island effect. [9] There are examples of urban forest inequity in cities globally, some of which are listed below.
Environmental justice and spatial justice are two ideologies associated with the problems presented by urban forest inequity, and these ideologies seek to understand the disproportionate quality of life due to uneven environmental or spatial conditions and benefits. [1] [8] [11] [18] Problems commonly associated with urban forest inequity include but are not limited to the urban heat island effect, public health concerns, and the inequitable distribution of environmental benefits. [20] In a 2022 paper, socio-spatial inequalities specialist Bernard Bret and geographer Sophie Moreau described environmental justice and spatial justice as two concepts defined by an interconnectedness between geographical space and quality of life. [21] The U.S. Environmental Protection Agency has found that inequities are most often visible along the lines of “income, race, color, or national origin.” [22] For example, South Africa historically has treated minority populations unequally, particularly by means of racial segregation, perhaps most clearly evident in the South African apartheid that occurred for the greater part of the twentieth century. [23] Researchers in South Africa in a 2018 report found correlations between an increased risk of cancer and chemical poisoning, as well as of respiratory diseases like asthma, are of a much greater likelihood in marginalized communities that are negatively affected by environmental and spatial injustice, because individuals there may be more often be at risk of exposure to dangerous pollutants in water or in the air. [24]
The U.S. E.P.A. defines the urban heat island effect as a phenomenon where urban areas experience higher temperatures than surrounding areas. [25] Air temperature inside urban areas can be about 1–3°C or 1–7°F higher than rural or surrounding air temperatures, on average. [4] This is due to a variety of reasons, which include but are not limited to lower albedo on urban surfaces, anthropogenic heat released from buildings and vehicles, and reduced areas of evapotranspiration. [4] Asphalt and concrete, surfaces that are more common in urban areas, have a higher albedo than surfaces such as trees, grass, or snow. In addition, evapotranspiration is a powerful cooling process, [26] and the relatively reduced amount of greenery in urban areas compared to rural areas contributes to the urban heat island effect. Without urban forests, the cooling mechanisms of high albedo and evapotranspiration do not work to cool the geographic area. Additionally, the E.P.A. has found that lower-income communities and those of color are particularly susceptible to the phenomenon known as intra-urban heat islands, which is due, in part, to historical redlining. [20] As urban forests help combat urban heat islands and intra-urban heat islands, redlining contributes to this instance of environmental injustice.
Some cities have historically faced problems concerning urban forest inequity. They may have a disproportionate amount of green space in higher-income communities or face criticism from those who advocate for environmental justice. Beijing, China is one of those examples, demonstrated by the lack of accessibility to green spaces compared to gated communities. Research was published in the journal Environment and Planning B: Urban and City Analytics with data from the Beijing Green Spaces System Planning which found that higher-income gated communities had more access to green spaces than lower-income residential communities and that the urban planning was not meeting the demand for public parks and playgrounds in the densely populated regions of the city. [8]
New York City is another example of a city that has historically faced challenges with urban forest inequity. Because of the urban heat island effect, concrete in the city draws more heat and raises temperatures, so more shade coverage is needed to protect inhabitants. A 2023 editorial written for the New York Daily News found that many neighborhoods in the city lack shade protection and may subsequently face temperatures “20 to 45 degrees hotter than those with more shade,” and these are typically lower-income communities. [27] Moreover, researchers have often cited Chicago as another U.S. city facing difficulties in mitigating urban forest inequity. The city is actively trying to combat the lack of greenery and pollution they are facing through planting trees across different neighborhoods. [10]
In 2021, a paper published in the International Journal of Environmental Research and Public Health worked to identify which regions in Delhi, India were experiencing high levels of urban heat, and consequently if they had sufficient green space or areas with urban forestry of some kind. [9] According to the researchers, the results “documented how the spatial distribution of heat and greenspace relates to the spatial distribution of social vulnerability at the ward level in Delhi.” [9] Rafael Fernandez-Alvarez of Arizona State University conducted similar research on Mexico City, Mexico pertaining to the distribution of green public spaces for inhabitants. The researchers found that these spaces are often biased against marginalized populations. The evidence showed that they mostly exist in the wealthy areas of the capital city, while the more populated lower-income communities lacked green public spaces. [11]
Efforts to address urban forest inequity must effectively combat both environmental and spatial injustice in addition to urban heat islands. Some argue this may include activists and policymakers engaging directly with marginalized communities, [28] public investment in underserved neighborhoods, and tighter government restrictions regarding land use and pollution concerns. [29] A 2023 article published in the National League of Cities offered several potential solutions to combat urban heat islands, which included but are not limited to: increasing green space by planting trees along streets or sidewalks, converting existing roof spaces to green roofs, replacing normal pavement with sustainable alternatives, subsidies for planting trees, and active engagement of low-income communities, among others. [7] [30]
Furthermore, a potential solution to address this issue is the implementation of tree-planting initiatives. These initiatives aim to provide resources and support to historically underserved areas, thereby contributing to a more equitable urban environment. [15] However, it is important to recognize that simply planting trees in low canopy-covered areas may not be sufficient to combat this environmental inequity. Initiatives must adhere to specific practices aligned with urban forest management objectives to ensure the creation of an equitable urban environment. [15]
Moreover, it is important to consider the potential impacts of tree-planting initiatives before their implementation, as they may unintentionally contribute to environmental gentrification. [31] Studies have shown that within a 10-meter buffer of the newly planted street trees, properties tend to experience a notable increase in value, indicating a positive correlation between planting street trees and property values. [31] However, it is worth noting that the rise in property values may not always translate to benefits for underserved communities. [32] To counter eco-gentrification, there are some key practices for tree-planting initiatives to follow, which are described by Sousa-Silva et al. (2023) and Haffner (2015), including integrating initiatives with long-term management strategies, creating community engagement, and introducing changes gradually. [15] [33]
An example of a tree-planting initiative that is currently ongoing is the Million Tree Initiative. New York City is an example of a city who implemented this initiative in recent years. The city launched the MillionTreesNYC initiative in 2007, which is now recognized as one of the largest and greatest-funded tree-planting initiatives in the United States. [31] This initiative was a collaboration between the New York City Parks Department and the NY Restoration Project (NYPR), resulting in the successful planting of one million trees across five boroughs of New York City in less than a decade. [34] Guided by considerations of health and socioeconomic factors, the initiative targeted neighbourhoods with the greatest lack of trees, aiming to improve urban canopy coverage by 20%. [31] NYPR, a local non-profit organization, actively engaged the community in the planting and maintenance of the newly planted trees. [34] This initiative was supported by collaborations with external partners and had help from volunteers around the city. [34] After the initiative successfully planted one million trees across five boroughs, plans were made to update the street tree census and offer a user-friendly public map of trees to increase community involvement and create a culture of tree stewardship. [34] MillionTreesNYC serves as a notable example of effectively increasing canopy cover in historically underserved areas, inspiring similar efforts in other cities, including Los Angeles. [31]
Urban areas usually experience the urban heat island (UHI) effect, that is, they are significantly warmer than surrounding rural areas. The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak, under block conditions, noticeably during the summer and winter. The main cause of the UHI effect is from the modification of land surfaces while waste heat generated by energy usage is a secondary contributor. Urban areas occupy about 0.5% of the Earth's land surface but host more than half of the world's population. As a population center grows, it tends to expand its area and increase its average temperature. The term heat island is also used; the term can be used to refer to any area that is relatively hotter than the surrounding, but generally refers to human-disturbed areas.
The term built environment refers to human-made conditions and is often used in architecture, landscape architecture, urban planning, public health, sociology, and anthropology, among others. These curated spaces provide the setting for human activity and were created to fulfill human desires and needs. The term can refer to a plethora of components including the traditionally associated buildings, cities, public infrastructure, transportation, open space, as well as more conceptual components like farmlands, dammed rivers, wildlife management, and even domesticated animals.
Urban ecology is the scientific study of the relation of living organisms with each other and their surroundings in an urban environment. An urban environment refers to environments dominated by high-density residential and commercial buildings, paved surfaces, and other urban-related factors that create a unique landscape. The goal of urban ecology is to achieve a balance between human culture and the natural environment.
Urban agriculture refers to various practices of cultivating, processing, and distributing food in urban areas. The term also applies to the area activities of animal husbandry, aquaculture, beekeeping, and horticulture in an urban context. Urban agriculture is distinguished from peri-urban agriculture, which takes place in rural areas at the edge of suburbs.
Urban forestry is the care and management of single trees and tree populations in urban settings for the purpose of improving the urban environment. Urban forestry involves both planning and management, including the programming of care and maintenance operations of the urban forest. Urban forestry advocates the role of trees as a critical part of the urban infrastructure. Urban foresters plant and maintain trees, support appropriate tree and forest preservation, conduct research and promote the many benefits trees provide. Urban forestry is practiced by municipal and commercial arborists, municipal and utility foresters, environmental policymakers, city planners, consultants, educators, researchers and community activists.
A living street is a street designed with the interests of pedestrians and cyclists in mind by providing enriching and experiential spaces. Living streets also act as social spaces, allowing children to play and encouraging social interactions on a human scale, safely and legally. Living streets consider all pedestrians granting equal access to elders and those who are disabled. These roads are still available for use by motor vehicles; however, their design aims to reduce both the speed and dominance of motorized transport. The reduction of motor vehicle dominance creates more opportunities for public transportation.
An urban forest is a forest, or a collection of trees, that grow within a city, town or a suburb. In a wider sense, it may include any kind of woody plant vegetation growing in and around human settlements. As opposed to a forest park, whose ecosystems are also inherited from wilderness leftovers, urban forests often lack amenities like public bathrooms, paved paths, or sometimes clear borders which are distinct features of parks. Care and management of urban forests is called urban forestry. Urban forests can be privately and publicly owned. Some municipal forests may be located outside of the town or city to which they belong.
A sustainable city, eco-city, or green city is a city designed with consideration for the social, economic, and environmental impact, as well as a resilient habitat for existing populations. This is done in a way that does not compromise the ability of future generations to experience the same. The UN Sustainable Development Goal 11 defines sustainable cities as those that are dedicated to achieving green sustainability, social sustainability and economic sustainability. In accordance with the UN Sustainable Development Goal 11, a sustainable city is defined as one that is dedicated to achieving green, social, and economic sustainability. They are committed to this objective by facilitating opportunities for all through a design that prioritizes inclusivity as well as maintaining a sustainable economic growth. Furthermore, the objective is to minimize the inputs of energy, water, and food, and to drastically reduce waste, as well as the outputs of heat, air pollution. Richard Register, a visual artist, first coined the term ecocity in his 1987 book Ecocity Berkeley: Building Cities for a Healthy Future, where he offers innovative city planning solutions that would work anywhere. Other leading figures who envisioned sustainable cities are architect Paul F Downton, who later founded the company Ecopolis Pty Ltd, as well as authors Timothy Beatley and Steffen Lehmann, who have written extensively on the subject. The field of industrial ecology is sometimes used in planning these cities.
Sustainable drainage systems are a collection of water management practices that aim to align modern drainage systems with natural water processes and are part of a larger green infrastructure strategy. SuDS efforts make urban drainage systems more compatible with components of the natural water cycle such as storm surge overflows, soil percolation, and bio-filtration. These efforts hope to mitigate the effect human development has had or may have on the natural water cycle, particularly surface runoff and water pollution trends.
Inequality may refer to:
Green infrastructure or blue-green infrastructure refers to a network that provides the “ingredients” for solving urban and climatic challenges by building with nature. The main components of this approach include stormwater management, climate adaptation, the reduction of heat stress, increasing biodiversity, food production, better air quality, sustainable energy production, clean water, and healthy soils, as well as more anthropocentric functions, such as increased quality of life through recreation and the provision of shade and shelter in and around towns and cities. Green infrastructure also serves to provide an ecological framework for social, economic, and environmental health of the surroundings. More recently scholars and activists have also called for green infrastructure that promotes social inclusion and equity rather than reinforcing pre-existing structures of unequal access to nature-based services.
Greening is the process of transforming living environments, and also artifacts such as a space, a lifestyle or a brand image, into a more environmentally friendly version. The act of greening generally involves incorporating more environmentally friendly systems into one's environment, such as the home, work place, and general lifestyle.
In land-use planning, urban green space is open-space areas reserved for parks and other "green spaces", including plant life, water features - also referred to as blue spaces - and other kinds of natural environment. Most urban open spaces are green spaces, but occasionally include other kinds of open areas. The landscape of urban open spaces can range from playing fields to highly maintained environments to relatively natural landscapes.
Urban reforestation is the practice of planting trees, typically on a large scale, in urban environments. It may also include urban horticulture and urban farming.
Open spaces in urban environments, such as parks, playgrounds, and natural areas, can provide many health, cultural, recreational, and economic benefits to the communities nearby. However, access to open spaces can be unequal for people of different incomes. In California's two largest metropolitan regions, Los Angeles County in Southern California and the Bay Area in Northern California, access to green space and natural areas varies with the predominant races and classes of the communities. This also holds true in San Diego County in Southern California. Both expanding urbanization and diminishing funding for open space tend to widen these gaps in accessibility. Because open space is associated with various mental and physical benefits, a lack of access to it can pose health consequences. However, more research is needed to determine whether such environmental inequalities translate into long-term health inequalities, and, if so, how.
Environmental, ecological or green gentrification is a process in which cleaning up pollution or providing green amenities increases local property values and attracts wealthier residents to a previously polluted or disenfranchised neighbourhood. Green amenities include green spaces, parks, green roofs, gardens and green and energy efficient building materials. These initiatives can heal many environmental ills from industrialization and beautify urban landscapes. Additionally, greening is imperative for reaching a sustainable future. However, if accompanied by gentrification, these initiatives can have an ambiguous social impact. For example, if the low income households are displaced or forced to pay higher housing costs. First coined by Sieg et al. (2004), environmental gentrification is a relatively new concept, although it can be considered as a new hybrid of the older and wider topics of gentrification and environmental justice. Social implications of greening projects specifically with regards to housing affordability and displacement of vulnerable citizens. Greening in cities can be both healthy and just.
Stephanie Pincetl is an American academic specializing in the intersection of urban policy and the environment, particularly in California. She is the Director of the UCLA Center for Sustainable Urban Systems in Los Angeles.
Climate change vulnerability is a concept that describes how strongly people or ecosystems are likely to be affected by climate change. Its formal definition is the "propensity or predisposition to be adversely affected" by climate change. It can apply to humans and also to natural systems. Issues around the capacity to cope and adapt are also part of this concept. Vulnerability is a component of climate risk. It differs within communities and also across societies, regions, and countries. It can increase or decrease over time. Vulnerability is generally a bigger problem for people in low-income countries than for those in high-income countries.
Environmental racism is a form of institutional racism, in which people of colour bear a disproportionate burden of environmental harms, such as pollution from hazardous waste disposal and the effects of natural disasters. Environmental racism exposes Native Americans, African Americans, Asian Americans, Pacific Islanders, and Hispanic populations to physical health hazards and may negatively impact mental health. It creates disparities in many different spheres of life, such as transportation, housing, and economic opportunity.
Urban heat inequity, also termed thermal inequity, is an unequal distribution of heat in urban areas or neighborhoods within them, which causes disproportionate impacts to people living in those communities. Unequal threat of heat stress in urban environments is often correlated with differences in demographics, including racial and ethnic background, income, education level, and age. While the general impacts of urban heat inequity depend on the city studied, negative effects typically act on historically marginalized communities. The idea is closely tied to the urban heat island effect, where a major cause to urban heat inequity is increased urbanization.