Amber Chessa
In Los Angeles, the intensity of the heat increases the risk of mortality, even when it is not the direct cause. The most significant increase in deaths was observed among Hispanic individuals. On a summer day, direct exposure to the sun can make the temperature feel up to 20 degrees higher than in the shade. A properly planted tree can lower the internal temperature of a building by 18 degrees compared to a situation with full solar exposure.
You can die from heat, but this threat does not affect everyone equally. A powerful reminder of the urban challenges and environmental injustices that Alejandra Borunda tells us through the eyes of Miguel in her article (1) “Los Angeles confronts its shady divide”.
Miguel remembers perfectly when he first understood the value and power of the shadow. He was at school in Los Angeles, running around a neglected soccer field in Huntington Park, under a blazing sun. Heatstroke caused his vision to blur and his heart to pound. Confused, he stumbled under the only visible tree in the camp. In that shelter, Miguel’s symptoms eased. His heart slowed. He recovered, reinvigorated by the cool, dense shade of that tree. He later discovered, while working on tree planting, that that simple blessing is abundant only in the affluent areas of Los Angeles. In black and Hispanic neighborhoods like Huntington Park, where Hispanics make up 97 percent of the population, finding shade is extremely rare (1).
Los Angeles experiences extremely high temperatures, a condition that can occur any time of year (2). It is known that the city has always placed great importance on sunlight, and Southern California has seduced individuals from every corner of the country with the promise of perpetual sunshine and extraordinary light. Even urban architecture was designed to optimize solar radiation; municipal construction directives have imposed precise restrictions on the extent of shadows produced by buildings, with the aim of preventing areas such as internal courtyards, green areas or terraces from remaining too much in the shade. But it wasn’t always like this. When Spanish colonizers arrived in the Los Angeles Basin, they encountered an area carefully tended by the Tongva natives, characterized by abundant ecological diversity and shade provided by oak forests. The Spanish modified this landscape, cutting down trees for lumber and replacing the natural shade of trees with artificial shade from buildings. In the following centuries, settlers arriving from the east of the country again distorted the landscape and introduced new crops and, in the 20th century, the importation of water transformed Los Angeles into an “urban forest” (1,3).
After World War II, the American dream materialized in the image of a house with a garden, made even more idyllic by a lush tree and a car in the driveway, symbols of prosperity and well-being. This aspiration led to a significant increase in tree density in Los Angeles, which grew 150 percent from 1920 to the early 2000s, with over 10 million trees dotting the city (1). But, urban forests grow on money, the distribution of which has never been uniform. In fact, until recently, nearly 20 percent of the trees were concentrated in just five census blocks, where only one percent of the population lived (4). Il redlining – discriminatory practice adopted by banks and financial institutions which involves the refusal or the application of increased costs for services such as loans or insurance, based on the race or income of the individual – in the first half of the 20th century it had denied many people of color mortgage financing for the American Dream and had caused a significant reduction in investments in public infrastructure, including trees.
To this day, the disparity persists. In the current context of climate change, can the Los Angeles sun still be considered an unconditional advantage?
In Los Angeles, the intensity of the heat increases the risk of mortality, even when it is not the direct cause. The record 10-day heatwave in September 2022 saw an increase in the overall mortality rate of 5%, with 395 more deaths than expected. The most significant increase in deaths was observed among Hispanic individuals (5). On a summer day, direct exposure to the sun can make the temperature feel up to 20 degrees higher than in the shade. A properly planted tree can lower the internal temperature of a building by 18 degrees compared to a situation of full solar exposure (6). Thus, shade helps keep the environment cool, a fact that the hot city is starting to capitalize on.
In Italy the issue of shadow and environmental justice take on particular contours, considering the historical, cultural and climatic context of the country. A survey conducted in Europe and disclosed by The Lancet (7) in 2022 also examined the case of three Italian metropolises – Rome, Naples and Milan – revealing a variability in the density of urban greenery, with average percentages of 9%, 13 respectively % and 6.4%. The cities examined were on average 1.5 degrees warmer than neighboring rural areas. According to the same research, approximately 6,700 deaths linked to urban heat islands could have been prevented by increasing tree cover to 30% in cities, which would have required a doubling of existing trees.
Christopher Hawthorne in Los Angeles proposes an integration of shade into urban planning policies, shifting attention from the traditional valorization of the sun to projects that offer protection from heat. “It’s time to turn off the sun” (8). This idea is also taking hold in Italy, moving towards solutions that improve both the quality of the air and the liveability of cities, helping to reduce inequalities in access to green and shaded spaces. Hawthorne suggests the importance of recognizing a “right to shade” as a crucial factor for well-being in urban areas.
To Miguel, the boy with the color stroke and now a tree planter in Los Angeles, this message will sound like a familiar echo. Miguel knows well the value of a moment of shade. He knows that he matters even more to the abuelitas in his neighborhood than he does who goes into the summer heat to pick up their grandchildren; for domestic workers walking towards the bus stop in the hot summer; for everyone – and those who do not have the privilege of living in a well-insulated home.
Miguel has a long-term vision “This is a commitment that takes time. The effects will not be immediate, not this year, not next, perhaps not even in ten years. Future generations will benefit from it.” But, as the poet R. Tagore stated, “he who plants trees knowing that he will never enjoy their shade has understood the true meaning of life”.
Ambra Chessa, medical resident Geneva University Hospital, Geneva
Columbia University, New York
BIBLIOGRAPHY
Longcore, T., & Turner, V. K. Los Angeles Confronts Its Shady Divide. Institute of the Environment and Sustainability at UCLA. Natural Resources Agency. Los Angeles Region – Climate Resilience. American Heritage Commission. Gabrielino (Tongva) Nation. Retrieved from StoryMap by Esri. Department of Public Health. (2022). Excess Mortality During the September 2022 Heat Wave in California. Different Group. Ambiente. The Lancet. Retrieved from T. (2019, December 1). Los Angeles Tries to Shade Itself from a Warming Climate. The New York Times. https://www.nytimes.com/2019/12/01/us/los-angeles-shade-climate-change.html