Felix Johnson was stunned when he saw the turnout for a local tree planting last fall. He’d woken up at dawn to dig holes and prepare tree tags at a nearby park in Ruston, Louisiana, where every summer brings record-breaking heat waves and more than 36% of the community lives below the poverty line. At noon, neighbors started showing up in droves. Around 150 volunteers planted 38 trees that day.
“Not a lot of areas have shade in our neighborhood,” Johnson, 28, said. “It was nice to be out there in nature, digging holes with my hands, and showing kids how to properly plant trees that will provide shade.”
That one day of tree planting took three months of planning. It began with local urban forester Darrell Street meeting with the mayor, city council members and the local school board to present the findings of the Tree Equity Score Analyzer, a tool that analyzes census, building density and tree coverage data to calculate tree canopy goals in any neighborhood in any U.S. city. The officials learned that the Ruston areas that scored “highest priority” in need of more trees were in low-income communities of color.
“They realized, ‘Wow, there really is a tree inequity issue in their community,’” Street said.
Though it makes fewer headlines than hurricanes and tornadoes, heat is the leading cause of death from extreme weather in the United States. Rising temperatures disproportionately affect lower-income communities of color, which have 33% less tree canopy and are on average 13 degrees hotter than predominantly white neighborhoods.
The nonprofit American Forests launched the Tree Equity Score Analyzer in 2020 to capture these green space inequities. Benita Hussain, the program’s chief officer, said that as cities embraced the growing tree equity movement, they needed direction. “We knew that in order to define this as a critical issue of our time, we had to demonstrate that there was data out there showing who was impacted the most,” she said.
So far, American Forests has mapped the tree canopy of 2,600 urban areas across the country along socioeconomic and racial census tracts, pinpointing which neighborhoods in a city score the lowest. The Tree Equity Score Analyzer has provided even more in-depth analysis at the block level in 12 cities. Though it’s too early to calculate tree canopy increase, the tool has already catalyzed Detroit, Milwaukee, Boston, El Paso, Denver and more to allocate tree planting funds to the hottest areas with the least tree density.
Hussain said the tool came at a critical time when cities began rapidly shifting their attention to urban greening and climate resilience. “We not only need to take action on the climate crisis, we need to make sure that the members of our community aren’t disparately impacted by health impacts like extreme heat and air pollution,” she said.
The value in mapping tree equity
Tree inequity can be traced back to historically discriminatory policies.
A 2021 study published in Nature highlights the impact of redlining, a mid-20th century federal policy that designated neighborhoods inhabited by low-income people of color risky for mortgage lending. The study found that even 60 years after redlining was outlawed, 37 formerly redlined areas still had half the tree canopy of majority-white areas. These neighborhoods had “poor quality housing and higher exposure to noise and other pollution from nearby industries.” Their higher population densities and greater number of paved roads attracted heat and decreased the space available to plant new trees. In contrast, majority-white neighborhoods “directed municipal investments into street tree plantings, creating public parks with trees, and invested their own resources into trees on their private lands.”
The benefits of tree coverage are clear: Trees have the potential to cool the area underneath them by as much as 45 degrees Fahrenheit, and studies have found trees can reduce cooling load — or the amount of heat needed to be removed from a space to reach a desired temperature — in a home by more than 50%. Green spaces also bring mental health benefits to communities.
When the Biden administration earmarked $1.5 billion of the Inflation Reduction Act for urban greening projects last year, American Forests received $50 million to work with cities to advance tree equity. Joshua Simon, senior manager of community engagement at American Forests, said this brought an unprecedented influx of resources and attention to the movement. “Urban forestry has never gotten this amount of funding,” he said.
Hussain said that to receive funding from American Forests, mayors must demonstrate a commitment to deploy the dollars and use tools like the Tree Equity Score Analyzer to improve greening in underserved neighborhoods. “Political commitment came from cities that are both small and large, with red mayors and blue mayors,” she said. “This is really a nonpartisan issue because they need to make sure their people are not dying of extreme heat.”
Cities like Columbus, Ohio, are applying the Tree Equity Score Analyzer to determine which areas to prioritize for tree planting. The city’s goal is to go from 22% to 40% tree canopy by 2050. But, to reach Columbus’s tree canopy goal, planting needs to expand beyond parks and public properties. Often, planting “street trees,” or trees along roads and sidewalks, means working with limited space because of overhead wires or lack of soil.
As a workaround, Columbus has started to look at planting on private property, particularly properties that serve the larger community. A pilot project in a low-scoring neighborhood in south Columbus was able to plant dozens of trees on church land. “If we can get into yards and have more access to growing space, we can plant larger trees,” said Rosalie Hendon, Columbus’ city forester. “Since the church owns about dozens of properties, it opens up dozens of yards to increase tree canopy.”
A critical part of establishing tree equity is working with local businesses, schools and churches to ensure that those who have long been neglected have a place at the table. Carly Weidman, a vice president of stakeholder engagement at Keep Indianapolis Beautiful, partners with the Tree Equity Score Analyzer to make sure neighborhood organizations have input and buy-in on tree plantings. “We’ve been able to put the tool in the hands of community members so they can view the heat challenges they’re facing as a neighborhood,” Weidman said. “Oftentimes, they’re empowered to advocate for tree plantings themselves.”
Going beyond tree planting
Greening cities doesn’t just stop at tree planting; trees take about two to three years to develop strong roots. They also require maintenance and need increasing amounts of water amid rising temperatures. “The trees we’ve planted are for 20 years out, so we need to maintain the trees we already have,” Hendon said. Both Columbus and Indianapolis have developed local employment pipelines for watering and mulching trees by hiring students and community members to care for the green spaces.
Last September, American Forests launched the Tree Equity Catalyst Fund & Initiative to provide technical assistance to cities and create an urban forestry workforce. “Trees aren’t going to thrive without gardeners, horticulturists and tree trimmers,” Hussain said. “We need to create a labor pipeline from underserved and underemployed neighborhoods to feed into the next generation of urban foresters.”
Until then, cities are doing their best to maintain the trees they already have and keep them healthy as temperatures rise.
Johnson recognizes that the trees he planted in his local park 10 months ago still won’t provide shade anytime soon. “We might not be able to reap the benefits of it, but future generations will,” he said. “You plant a tree now, and wait for it to grow, and these parks will become more and more abundant.”
