Modern parks were not built by accident. The pride of many cities, from New York to Minneapolis to Houston, the best-maintained and most desirable parks have, in many cases, been set aside for richer, whiter, neighborhoods.
This systemic racism has many origins, ranging from historic minority underrepresentation in environmental groups like the Sierra Club to redlining, the racist practice of denying goods and service to Black communities, like park upkeep.
Now, researchers are finding that generations of racial inequality have made their mark on city ecosystems. A review of current literature published Wednesday in Science details both the ecological and evolutionary consequences of systemic racism in urban environments.
Filled with concrete and cars, it’s easy to forget that cities, just like everyone else on Earth, are biomes with their own flora and fauna. Some elements of these biomes are natural, like rats or weeds, while others are artificial. Humans can manage these biomes effectively, or at least hem them in — for example, while no city in history has ever successfully removed rats, they’re more likely to appear in some neighborhoods than others.
“Strong positive correlations exist between urban tree cover and household income for 7 major US metropolitan areas,” the study team, led by Christopher J. Schell of the University of Washington, Tacoma writes. Looking further into two, Los Angeles and the Chicagoland area, the authors point to recent research that suggests a correlation between the age of a house and the state of its surrounding environment.
Older houses in well-established neighborhoods are more likely to be linked to greater biodiversity in the types of trees around the neighborhood. Different types of trees attract different types of animals, thus leading to a neighborhood with greater biodiversity in general.
It might not be surprising that wealthier neighborhoods have more access to biodiversity; the “luxury effect,” as researchers call it, can often be self-evident when moving between neighborhoods.
The distribution of heat — What's less understood is how this biodiversity can affect the way a neighborhood feels. Not just a person’s mental state, although trees help with that too, but also in the feeling on a person’s body as they step outside during a hot summer. As temperatures increase due to global warming, getting relief from the heat is more crucial than ever.
Researchers call these cities “urban heat islands” because of their ability to make temperatures rise. Through a process called transpiration, plants in rural areas are able to release water vapor back into the atmosphere, creating what NASA calls “nature’s air conditioner.” Cement and glass-filled cities often lack the green spaces to transpire on a large scale.
Not all urban heat islands are created equally. “Heat is unevenly distributed in a city, where temperatures are typically greatest in lower-income compared to higher-income neighborhoods,” the researchers write. The cause? “Low-income neighborhoods have reduced tree and vegetation cover and increased impervious surface cover,” they write, meaning there is less shade and transpiration and more cement reflecting heat back into people’s faces. There is also less public space to escape.
The inequalities don’t stop with heat. The paper’s authors point to pollution as well, noting that “air pollution sources are often co-located near low-income neighborhoods and consequently, low-income residents often have higher risk and vulnerabilities to air pollutants.”
Stemming from cars, factories, and construction sites, lower-income neighborhoods also often get more than their fair share of nitrogen dioxide, both outside and indoors. That has serious health consequences, ranging from asthma to heart attacks.
Cities are not wild environments — they are planned. Thus, the authors write, “we cannot generalize human behavior in urban ecosystems without dealing with systemic racism and other inequalities.” They mention plans like the Green New Deal and the Paris Climate Accords as potential solutions, but caution that “the insidious white supremacist structures that perpetuate racism throughout society compromise both public and environmental health, solidifying the need to radically dismantle systems of racial and economic oppression.”
These struggles are interconnected, the authors argue. And if there’s going to be a serious solution to one, there needs to be a serious solution to all of the above.
Abstract: Urban areas are dynamic ecological systems defined by interdependent biological, physical, and social components. The emergent structure and heterogeneity of the urban landscape drives the biotic outcomes observed, and such spatial patterns are often attributed to the unequal stratification of wealth and power in human societies. Despite these patterns, few studies effectively consider structural inequalities as drivers of ecological and evolutionary outcomes, instead focusing on indicator variables such as neighborhood wealth. We explicitly integrate ecology, evolution, and social processes to emphasize the relationships binding social inequities, specifically racism, and biological change in urbanized landscapes. We draw on existing research to link racist practices - including residential segregation - to the observed heterogeneous patterns of flora and fauna observed by urban ecologists. As a result, urban ecology and evolution researchers must consider how systems of racial oppression affect the environmental factors driving biological change in cities. Conceptual integration of the social and ecological sciences has amassed considerable scholarship in urban ecology over the past few decades, providing a solid foundation for incorporating environmental justice scholarship into urban ecological and evolutionary research. Such an undertaking is necessary to deconstruct urbanization’s biophysical patterns and processes, inform equitable and anti-racist initiatives promoting justice in urban conservation, and strengthen community resilience to global environmental change.