Fast Fact Library

Urban greenery can play a significant role in absorbing atmospheric carbon dioxide. According to a Columbia University study, trees, shrubs, flowers, herbs, and grasses in the five boroughs of New York City...

Wei, Dandan, Andrew Reinmann, Luke D. Schifer, and Roisin Commane. High resolution modeling of vegetation reveals large summertime biogenic CO₂ fluxes in New York City. Environmental Research Letters 17, 12 (2022). https://doi.org/10.1088/1748-9326/aca68f.

Street trees can reduce non-accidental and cardiovascular mortality. In a study of street trees planted in Portland over 30 years, planting 11.7 trees annually in each census tract was associated with 15.6 fewer non...

Donovan, Geoffrey H., Jeffrey P. Prestemon, Demetrios Gatziolis, Yvonne L. Michael, Abigail R. Kaminski, and Payam Dadvand. “The association between tree planting and mortality: A natural experiment and cost-benefit analysis.” Environment International 170 (2022). https://doi.org/10.1016/j.envint.2022.107609.

A statistical analysis of a 3D model of a Columbus, Ohio neighborhood estimated that if the neighborhood's trees were all mature, surface temperatures would be lowered by 3.48° F. 20 additional mature trees would...

Park, Yujin, Jean-Michel Guldmann, and Deshen Liu. “Impacts of Tree and Building Shades on the Urban Heat Island: Combining Remote Sensing, 3D Digital City and Spatial Regression Approaches.” Computers, Environment and Urban Systems 88 (2021): 131. https://doi.org/10.1016/j.compenvurbsys.2021.101655.

Greening in and around schoolyards can improve academic achievement. A study of 450 public schools in Washington state showed positive relationships between school greenness and academic achievement in sixth graders...

Kuo, Ming, Samantha E Klein, Matthew HEM Browning, and Jaime Zaplatosch. “Greening for academic achievement: Prioritizing what to plant and where.” Landscape and Urban Planning 206 (2021). https://doi.org/10.1016/j.landurbplan.2020.103962.

A cross-sectional study of almost 47,000 Australian residents showed that higher percentage of tree cover within one mile of their residence was associated with lower prevalence of diabetes, hypertension, and...

Thomas Astell-Burt, and Feng, Xiaoqi. “Urban green space, tree canopy and prevention of cardiometabolic diseases: a multilevel longitudinal study of 46,786 Australians.” International Journal of Epidemiology 49, Issue 3 (2020): 926–933. https://doi.org/10.1093/ije/dyz239.

Trees with small leaf size and high leaf complexity and trees with long "in leaf" periods like evergreens generally make the most effective barriers against roadside pollution and offer the most air quality benefits...

Barwise, Yendle, and Prashant Kumar. “Designing vegetation barriers for urban air pollution abatement: a practical review for appropriate plant species selection” npj Climate and Atmospheric Science 3, no. 12 (2020). https://doi.org/10.1038/s41612-020-0115-3.

Tree cover may improve academic performance. A study of 624 Illinois public high schools showed that tree cover density within a 1-mile radius of schools was positively associated with better ACT scores and college...

Li, Dongying, Yen-Cheng Chiang, Huiyan Sang, and William C. Sullivan. “Beyond the School Grounds: Links between Density of Tree Cover in School Surroundings and High School Academic Performance.” Urban Forestry & Urban Greening 38 (2019): 42–53. https://doi.org/10.1016/j.ufug.2018.11.001

A study of the 30 largest metropolitan areas in the United States found that walkable urban places (places developed for walkability and without prioritizing automobiles), perform better economically than sprawling...

Hadden Loh, Tracy, Christopher B. Leinberger, and Jordan Chafetz. Foot Traffic Ahead. New York: Smart Growth America and the George Washington University School of Business, 2019. https://smartgrowthamerica.org/resources/foot-traffic-ahead-2019/?download=yes&key=46188795

A study of 9,186 U.S. nursing homes found that increased tree canopy cover is associated with fewer depressive symptoms. This association did not vary by race or socioeconomic status of nursing home residents.

Browning, Matthew H.E.M., Kangjae Lee, and Kathleen L. Wolf. “Tree cover shows an inverse relationship with depressive symptoms in elderly residents living in U.S. nursing homes.” Urban Forestry & Urban Greening 41 (2019): 23-32. https://doi.org/10.1016/j.ufug.2019.03.002

At least 40% canopy coverage is needed to achieve the maximum cooling effect of trees in offsetting the urban heat island effect at the scale of a typical city block, according to this University of Wisconsin...

Ziter, Carly D., Eric J. Pedersen, Christopher J. Kucharik, and Monica G. Turner. “Scale-Dependent Interactions between Tree Canopy Cover and Impervious Surfaces Reduce Daytime Urban Heat during Summer.” Proceedings of the National Academy of Sciences 116, no. 15 (2019): 7575–80. https://doi.org/10.1073/pnas.1817561116