Canopy Justice: Trees' Role in Addressing Racial Inequality and Urban Heat Islands
How can urban tree plantings mitigate the disparities in racial minorities in redlined neighborhoods from the urban heat island effect?
Background Information
With the effects of climate change rapidly increasing in intensity, racial minorities are facing these effects head-on.
Historical Redlining
The discriminatory practice of redlining in the United States can influence what neighborhoods racial minorities can live in. These neighborhoods are often the heavily industrialized areas of a city with little natural features. Because of redlining, racial minorities are often stuck in neighborhoods where the urban heat island effect is the most severe due to the lack of natural features (Jesdale et al., 2013).
Urban Heat Islands
Urban heat islands occur in areas of cities that replace natural land with impervious surfaces that absorb high temperatures. These surfaces contain a dense concentration of concrete, asphalt, and other features that retain heat. These areas are significantly hotter than outlying natural areas. This heat difference can have adverse effects on how the human body can tolerate this environment (Cetin, 2020).
Trees
Natural areas have systems that occur to regulate these increasingly intense temperatures. One of these natural features of focus for this proposal is trees. Trees provide shade, regulate the temperature, and purify the air (Morakinyo et al., 2020). These are all things that will help mitigate the urban heat island effect.
This proposal seeks to address how urban tree plantings can mitigate the disparities of racial minorities in redlined neighborhoods from the urban heat island effect.
Literature Review
The following literature review gives context on how this phenomenon developed. Historical redlining practices, the urban heat island effect, and tree utilization as a mitigation tactic are all discussed. Historical redlining is being discussed to reveal the discriminatory practices in the 1930s and how today’s inhabitants are negatively affected by them. Often, one negative trait of a redlined neighborhood is the urban heat island effect. This is discussed to show how this effect contributes to negative impacts on human health and well-being of the current inhabitants. Tree utilization is discussed to show how trees are an incredibly impressive mitigation tactic for the urban heat island effect.
Redlining Practices
The Home Owners’ Loan Corporation (HOLC) used language such as “Heavy concentration of foreigners” and “Negro concentration” to describe the perceived detrimental influences of a neighborhood (Nelson, 2023).
Individuals living in redlined neighborhoods today experience less interaction with green spaces (Nardone et al., 2021), higher temperatures (Hoffman et al., 2020), worse air pollution (Lane et al., 2022), and lower life expectancy (Huang & Sehgal, 2022).
Urban Heat Islands
Urban heat issues are intensified by global warming contributing to a higher frequency and intensity of heat waves in urban areas (Alcoforado & Andrade, 2008).
High temperatures contribute to heat-related deaths and illnesses like heat strokes, exhaustion, and respiratory illness (Heat & Health, 2018) and it affects one's thermal comfort (Cetin, 2020).
During the summer months, people of color are disproportionately impacted by the intensity of the urban heat island effect across major U.S. cities (Hoffman et al., 2020).
Tree Utilization
The utilization of urban tree plantings is especially effective due to their shading and cooling capacity (Morakinyo et al., 2020).
The greatest warming is found on streets with no trees or little amount of trees, over surfaces such as asphalt, and in general unshaded areas (Hertel & Schlink 2019).
Methods
Geographic Information System (GIS) will be utilized to analyze relevant geodata. Overlaying the geodata will provide insight to come to critical conclusions/discussions about how trees can be implemented in redlined neighborhoods to address disparities from the urban heat island effect. The geodata relevant to this proposal include a tree point layer, tree canopy raster layer, neighborhood temperature polygon layer, and historical redlining boundary polygon layer. All of these geodata compiled together and presented with GIS will provide a unique perspective in this discussion on tree utilization. I hope that these layers reveal a potential strategy or method to plant trees in redlined neighborhoods to reduce the urban heat island effects.
References
Alcoforado, M. J., & Andrade, H. (2008). Global Warming and the Urban Heat Island. In J. M. Marzluff, E. Shulenberger, W. Endlicher, M. Alberti, G. Bradley, C. Ryan, U. Simon, & C. ZumBrunnen (Eds.), Urban Ecology (pp. 249–262). Springer US. https://doi.org/10.1007/978-0-387-73412-5_14
Cetin, M. (2020). Climate comfort depending on different altitudes and land use in the urban areas in Kahramanmaras City. Air Quality, Atmosphere & Health, 13(8), 991–999. https://doi.org/10.1007/s11869-020-00858-y
Hertel, D., & Schlink, U. (2019). Decomposition of urban temperatures for targeted climate change adaptation. Environmental Modelling & Software, 113, 20–28. https://doi.org/10.1016/j.envsoft.2018.11.015
Hoffman, J. S., Shandas, V., & Pendleton, N. (2020). The Effects of Historical Housing Policies on Resident Exposure to Intra-Urban Heat: A Study of 108 US Urban Areas. Climate, 8(1), 12. https://doi.org/10.3390/cli8010012
Huang, S. J., & Sehgal, N. J. (2022). Association of historic redlining and present-day health in Baltimore. PLOS ONE, 17(1), e0261028. https://doi.org/10.1371/journal.pone.0261028
Jesdale, B. M., Morello-Frosch, R., & Cushing, L. (2013). The Racial/Ethnic Distribution of Heat Risk–Related Land Cover in Relation to Residential Segregation. Environmental Health Perspectives, 121(7), 811–817. https://doi.org/10.1289/ehp.1205919
Lane, H. M., Morello-Frosch, R., Marshall, J. D., & Apte, J. S. (2022). Historical Redlining Is Associated with Present-Day Air Pollution Disparities in U.S. Cities. Environmental Science & Technology Letters, 9(4), 345–350. https://doi.org/10.1021/acs.estlett.1c01012
Morakinyo, T. E., Ouyang, W., Lau, K. K.-L., Ren, C., & Ng, E. (2020). Right tree, right place (urban canyon): Tree species selection approach for optimum urban heat mitigation - development and evaluation. Science of The Total Environment, 719, 137461. https://doi.org/10.1016/j.scitotenv.2020.137461
Nardone, A., Rudolph, K. E., Morello-Frosch, R., & Casey, J. A. (2021). Redlines and Greenspace: The Relationship between Historical Redlining and 2010 Greenspace across the United States. Environmental Health Perspectives, 129(1), 017006. https://doi.org/10.1289/EHP7495
Nelson RK, Winling L,Marciano R, Connolly N, et al. Mapping Inequality.n.d. In: Nelson RK, Ayers EL, eds. American Panorama[Internet] .Richmond: University of Richmond Digital Scholarship Lab. Available from: https://dsl.richmond.edu/panorama/redlining/#loc=11/39.293/-76. 808&city=baltimore-md.
World Health Organization. (2018). Heat and health. World Health Organization. https://www.who.int/news-room/fact-sheets/detail/climate-change-heat-and-health
