Building up the country’s green infrastructure can benefit people’s psychological and physical health, in addition to helping achieve decarbonization goals. Inequities in access to green spaces across the nation can be addressed with available tools.
Sunday, March 21 commemorated the ninth annual International Day of Forests. The value of “the woods” has been fully evident during this past year, as people have struggled to find relief in challenging times. Whether at a National Forest, in a local park, or on a neighborhood walk, trees and forests have provided comfort, a place to connect to others, and a space to breathe. Many of us have opened our eyes to how integral trees and forests are to the American landscape. But with this awareness has come the recognition of huge disparities in access to these spaces by low-income and majority-minority communities.
Our cities have long recognized the importance of trees in their infrastructure, which has led to the emergence of Tree City USA, a program supported by the Arbor Day Foundation that celebrates and nurtures the residential tree canopy. Currently, over 3,400 municipalities across the nation have met the program’s standards to become Tree Cities by achieving 40 percent canopy cover. For instance, Baltimore, Maryland, recently celebrated the planting of its 10,000th tree in October 2020 and has explicitly recognized the importance of providing green infrastructure in less wealthy neighborhoods.
City managers have recognized the need to invest in green infrastructure. Clear evidence demonstrates the health benefits of trees: research has shown that hospital patients recover more quickly when they see trees, gardens, and nature through hospital windows. And positive environmental outcomes sprout from forests: 100 healthy trees can capture 200,000 gallons of water, reducing stormwater runoff and lowering the cost of managing that water. Trees absorb air pollutants, improving ambient air quality. The increased interest in nature-based solutions to climate change has put a spotlight on the carbon sequestration potential of trees and helped lead to the Trillion Trees campaign, which promotes reforestation.
Urban spaces can contribute to achieving these goals, as studies show that urban trees store over 708 million tons of carbon and capture an additional 28.2 million tons of carbon per year in the United States (approximately 0.05 percent of U.S. annual emissions). The i-Tree calculator has been developed by the US Department of Agriculture Forest Service to better quantify these values and better inform city managers about the potential benefits of urban forests (Figure 1).
Figure 1. Quantifiable Benefits of Trees
But data continue to show that urban heat islands occur more often among low-income communities. While shade from trees can provide energy savings by cooling buildings in the summer and buffering winter winds, energy poverty afflicts people of color more often. We already have the tools to greatly expand tree cover and develop urban forests; what’s necessary is the political will to focus on underserved communities. Within a municipality, an urban forester can be most effective by working across departments—engaging managers who are involved with transportation, environment, water, and other areas—to incorporate planting trees and building green infrastructure as essential activities.
After a year of COVID, many of us feel compelled to take a break from the “four walls” of our home offices and crowded apartments, or from the pressures of serving as essential workers. The need for environmental equity and access to open space has become abundantly clear. Urban forests not only improve quality of life, but also have a measurable effect on reducing air pollution, reducing energy demand, and sequestering carbon. As we celebrate this year’s International Day of Forests, we need to fully embrace the value of growing trees in built environments.