In 2012, researcher Brian Stone of the Georgia Institute of Technology conducted a study of 50 large cities across the country to analyze the gradual increase in U.S. temperatures.
He discovered that Louisville’s temperature increased by 1.67 degrees over time, with Phoenix showing the second most notable difference at 0.8 degrees.
The primary reason for this increase was the city’s tree canopy, which stood at a dismal 38 percent and was predicted to decrease to as low as 21 percent in the coming decades if no action was taken.
A robust tree canopy includes the number of trees, shade and greenery in an area. The presence of more trees in a community leads to a decrease in pollution, prevention of flooding, provision of food and shelter for wildlife, reduction of energy bills and enhancement of physical and mental health.
“A healthy tree canopy is around 45 percent,” said Mayor Greg Fischer in response to the issue. He established the Louisville Metro Tree Advisory Commission to research and propose solutions. Cindi Sullivan, executive director of TreesLouisville, said, “By 2015, TreesLouisville had been established.”
Sullivan explained that TreesLouisville operates on several pillars. The first is public education and awareness. “People need to understand the importance of trees for the community,” she said. “Even though Louisville appears green, there is a significant disparity in neighborhoods. Some areas in south and south-central Louisville have a mere 28 percent tree canopy.”
By simply planting a tree, communities can amplify the benefits for neighborhoods and residents. TreesLouisville has developed programs to support specific areas, including free tree plantings and other initiatives.
Advocacy is another core mission for TreesLouisville. Volunteers collaborate with government leaders to enhance the protection and preservation of trees in the city.
Canopy gains and losses can be substantial. Sullivan noted that when developers clear 100 acres of trees, it is considered a significant event. Volunteers then plant a 2-inch tree that grows for 10 years to replace a single lost tree.
Recently, the city passed an ordinance amending building code language to preserve 20 percent of trees under certain development circumstances—a result of the advocacy and educational efforts of TreesLouisville.
Apart from development, trees face threats from invasive pests, severe storms and limited life expectancy, underscoring the importance of planting more trees than are lost.
Sullivan highlighted a collaboration with the Kentucky Transportation Cabinet to plant trees alongside roads, dispelling concerns related to buses. She emphasized that trees along roads reduce accidents and lower traffic speeds.
Encouraging citizens to contribute to the mission is a key focus for TreesLouisville. Sullivan said, “We can only work on 30 percent of public land, with the remaining 70 percent privately owned.” Partnerships with businesses and entities like Jefferson County Public Schools have been vital in planting trees and nurturing their growth.
To support these efforts, the Canopy Core, a group of trained volunteers dedicated to planting and caring for trees, has been established. These volunteers engage in regular maintenance activities to ensure the well-being of trees in the area.
Sullivan stressed the importance of selecting the right tree species for specific areas, considering factors such as growing conditions and property characteristics. TreesLouisville offers resources and advice to aid residents in choosing and caring for trees effectively.
For TreesLouisville, the focus is not solely on trees but on people’s well-being. Planting roadside trees to intercept gases improves air quality and leads to utility savings during the summer months.
The organization’s efforts have shown positive results, with an updated study in 2022 by the University of Vermont revealing an improvement in the city’s tree canopy.
Since 2015, TreesLouisville has successfully planted and distributed nearly 20,000 trees, with additional trees planted by residents and community partners. The public can engage in programs such as a rebate program for approved trees, attending tree adoption events or signing up for the NeighborWoods program.
Residents in areas with a low tree canopy percentage—ZIP codes 40210, 40211, 40212 and 40216—can partner with TreesLouisville for a free tree planting. Sullivan noted that Smoketown, an area with a 14 percent tree canopy, is a prime location for tree restoration efforts.
For more information on TreesLouisville, visit treeslouisville.org.
