Benefits of Trees to Cary Businesses and Residents


  • Trees in parking lots reduce asphalt temperature by as much as 36 degrees Fahrenheit, and car-interior temperatures by as much as 50 degrees Fahrenheit. [Note 2 {below}]
  • Shoppers in tree-lined and well-landscaped business districts are willing to pay more for parking, goods, and services. [Note 1]
  • Amenity and comfort ratings were about 80% higher for businesses located on a tree-lined sidewalk compared with those for a non-shaded street. Quality of products ratings were 30% higher in districts having trees over those with barren sidewalks. [Note 3]
  • People are more likely to shop and congregate in areas with tree cover than in sparse or barren areas. Stated simply in another way: The more trees, the more shoppers. [Note 1]

    Patrons prefer to park in shade, even though the cooler spaces are on unpaved crushed stone that is farther from the entrance. [Video taken at Cary VFW Post 7383 on May 18th when the temperature was 84 degrees.]

  • Trees reduce runoff and erosion from rain by about 7%, thus reducing the need for erosion-control structures. In urban areas with trees, the use of smaller drainpipes saves cities on materials, installation, and maintenance. [Note 4]
  • The net cooling effect of a young, healthy tree is equivalent to 10 room-size air conditioners operating 20 hours a day. [Note 5]
  • Trees properly placed around homes and commercial buildings as windbreaks save owners up to 25% each year on winter heating costs. [Note 6]
  • Properly positioned trees can save the average business and household up to 20% each year in air-conditioning costs. [Note 7]
  • Annual benefits provided by parking-lot trees in Sacramento, California, (8.1% tree shade) were valued at approximately $700,000 for improved air quality. By increasing shade to 50% in all parking lots in Sacramento, the annual benefits will increase to $4 million. [Note 8]
  • A home or business with healthy trees on its lot is valued at 5% to 10% more than a comparable one without. [Note 9]


  • Desk workers with and without window views of trees were surveyed. Those without views of nature, when asked about 11 different ailments, reported a 23% higher incidence of illness in the previous six months. [Note 10.]
  • When trees are killed by an invasive species of insect [or other agents], the rate of human death in the affected areas from cardiovascular disease and respiratory ailments increases. [Hear Dr. David Strayer describe the study published in the American Journal of Preventive Medicine:

  • Hospital patients recovering from surgery who had a view of a grove of trees through their windows required fewer pain relievers, experienced fewer complications, and left the hospital sooner than similar patients whose views did not include trees. [Read the fascinating article here.]
  • Symptoms of Attention Deficit Hyperactivity Disorder (ADHD) in children are relieved after contact with nature. Specifically, ADHD kids are better able to concentrate, complete tasks, and follow directions after playing in tree-rich settings. The greener the setting, the greater the relief. [Note 11]
  • The rate of children aged 0 to 14 who spend time in the hospital because of asthma increased 278% in Wake County in the last 20 years. This is the rate, not the number of children. The number of children who spend time in hospital has increased commensurate with the rise in population times the increased rate. And this statistic is only for children who spent time in hospital – the number of children who suffer from asthma but who haven't had to go to the hospital is, of course, greater. [Note 12]
  • Conditions of chronic heart disease, obesity, stress, and poor mental health are significantly reduced in those living among healthy trees, regardless of income level, race, or education, and regardless of whether the countries in which they reside are rich or poor ones. Science has NOT yet proved a casual link between the phenomena. The anecdotal evidence is, however, overwhelming. [Note 29]


  • Trees deflect and muffle sound waves. Belts of trees on the sides of a roadway reduce noise significantly. Trees in the medians of boulevards with trees on both sides reduce noise by a factor of four. [Note 13]
  • Views of nature reduce the stress response of both body and mind when stressors of urban conditions are present. [Note 14]
  • Trees reduce crime. Apartment buildings with high numbers of trees had 52% fewer crimes than those without trees. Buildings with medium numbers of trees had 42% fewer crimes. [Note 15]
  • Americans travel about 2.3 billion miles per day on urban freeways and highways. Studies show drivers who have a view of roadside trees had a greater ability to cope with driving stresses. [Note 16]
  • Distinctive trees planted as landmarks give neighborhoods a unique identity and encourage civic pride. [Note 17]


  • Modest increases of 10% canopy cover in the New York City Area were shown to reduce peak ozone levels by up to 4 parts per billion or by nearly 3% of the maximum and 37% of the amount by which the area exceeded its air quality standard. Similar results were found in Los Angeles and along the East Coast from Baltimore to Boston. [Note 18] See the Town of Cary's Air Quality Index for today.
  • Leafy tree canopies catch precipitation before it reaches the ground, allowing some of it to gently drip and the rest to evaporate. This lessens the force of storms and reduces runoff and erosion. Research indicates that a mature-tree crown intercepts about 2,000 gallons of rainfall per year, reducing runoff and providing cleaner water. [Note 19]
  • A healthy community forest of 100,000 trees will retain 200 million gallons of per year, thus reducing runoff and associated damage and drainage costs. [Note 20] — Cary receives over its approximately 60 square-mile area an average of 44 inches of precipitation each year, which works out to about 40 billion gallons. Flooding of part of the Town is frequent. If an additional million trees were planted in the Town, they would absorb and thus reduce stormwater runoff by 2 billion additional gallons, and remove 5% of the water which otherwise would flow unabated into the low-lying areas. —
  • Trees absorb carbon dioxide, break down that compound, remove and use the carbon to build their trunks and limbs and leaves, and release the oxygen back into the atmosphere. [Note 21]
  • Trees absorb odors and pollutant gases (nitrogen oxides, ammonia, sulfur dioxide and ozone) and filter particulates out of the air by trapping them on their leaves and bark. [Note 22]
  • Trees cool cities by up to 10°F, by shading our homes and streets, breaking up urban “heat islands,” and releasing water vapor into the air through their leaves. [Note 23]
  • Shade from trees slows water evaporation from thirsty lawns. As trees transpire, they increase atmospheric moisture. [Note 24]
  • On hillsides and stream slopes and, frankly, almost everywhere, trees slow runoff and hold soil in place while trapping fertilizer and other polluting runoffs. [Note 25]
  • Trees provide food and shelter for wildlife critical for human existence. [Note 26]


  • Trees help girls succeed. On average, the greener a girl’s view from home, the better she concentrates and the better her self-discipline, enabling her to make more thoughtful choices and do better in school. [Note 27]


  • Trees and forests in urban areas convey serenity and beauty along a number of sensory dimensions. [Note 28]


Note 1. Wolf, K. L. 1999. Nature and Commerce: Human Ecology in Business Districts. In: Kollins, C., ed. Building Cities of Green: Proceedings of the 9th National Urban Forest Conference. Washington, DC: American Forests.

Note 2. Scott, Klaus I.; Simpson, James R.; McPherson, E. Gregory. 1999. Effects of Tree Cover on Parking Lot Microclimate and Vehicle Emissions. Journal of Arboriculture 25(3).

Note 3. Wolf, Kathy L. 1998. Trees in Business Districts: Positive Effects on Consumer Behavior! Fact Sheet #5. Seattle: University of Washington, College of Forest Resources, Center for Urban Horticulture.

Note 4. Miller, Alban L.; Riley, J.; Schwaab, E.; Rabaglia, R.; Miller, K. 1995. Maryland’s Forests: A Health Report. Annapolis: Maryland Department of Natural Resources Forest Service.

Note 5. The National Arbor Day Foundation. 2004. The value of trees to a community. (January 12).

Note 6. Heisler, G.M. 1986. Energy Savings With Trees. Journal of Arboriculture 12.

Note 7. U.S. Department of Energy. 2003. Energy Savers, Tips on Saving Money and Energy at Home. Energy Efficiency and Renewable Energy Clearinghouse.

Note 8. McPherson, E.G. 2001. Sacramento's Parking Lot Shading Ordinance: Environmental and Economic Costs of Compliance. Landscape and Urban Planning 57.

Note 9. Consensus of real estate brokers.

Note 10. Kaplan, R.; Kaplan, S. 1989. The Experience of Nature: A Psychological Perspective. Cambridge, MA: Cambridge University Press.

Note 11. Taylor, A.F.; Kuo, F.; Sullivan, W. 2001. Coping with ADD: The Surprising Connection to Green Play Settings. Environment and Behavior 33(1).

Note 12. NC-DHHS State Center for Health Statistics.

Note 13. New Jersey Forest Service. [undated]. Benefits of trees. Fact sheet. Jackson, NJ: Forest Resource Education Center.

Note 14. Parsons, R.; Tassinary, L.G.; Ulrich, R.S.; Hebl, M.R.; Grossman-Alexander, M. 1998. The View From the Road: Implications for Stress Recovery and Immunization. Journal of Environmental Psychology 18(2).

Note 15. Kuo, F.; Sullivan, W. 2001. Environment and Crime in the Inner City: Does Vegetation Reduce Crime? Environment and Behavior 33(3).

Note 16. Wolf, Kathy L. 2000. The Calming Effect of Green: Roadside Landscape and Driver Stress. Factsheet #8. Seattle: University of Washington, Center for Urban Horticulture.

Note 17. Tree People (an independent group of concerned Los Angeles citizens) Fact Sheet, 2014; George McDowell, repeatedly.

Note 18. Luley, Christopher J.; Nowak, David J. 2004. Help Clear the Smog with Your Urban Forest: What You and Your Urban Forest Can Do About Ozone. Brochure. Davey Research Group and USDA Forest Service, Northeastern Research Station.

Note 19. USDA Forest Service. 2003. Benefits of Urban Trees. Urban and Community Forestry: Improving Our Quality of Life. Forestry Report R8-FR 71. [Atlanta, GA.] Southern Region.

Note 20. USDA Forest Service. 2003. Is All Your Rain Going Down the Drain? Look to Bioretainment—Trees are a Solution. Davis, CA: Pacific Southwest Research Station, Center for Urban Forest Research.

Note 21. Tree People (an independent group of concerned Los Angeles citizens) Fact Sheet, 2014.

Note 22. Tree People (an independent group of concerned Los Angeles citizens) Fact Sheet, 2014.

Note 23. Tree People (an independent group of concerned Los Angeles citizens) Fact Sheet, 2014.

Note 24. Tree People (an independent group of concerned Los Angeles citizens) Fact Sheet, 2014.

Note 25. Tree People (an independent group of concerned Los Angeles citizens) Fact Sheet, 2014.

Note 26. Tree People (an independent group of concerned Los Angeles citizens) Fact Sheet, 2014.

Note 27. Taylor, Andrea Faber; Kuo, Frances E.; Sullivan, William C. 2002. Views of Nature and Self-Discipline: Evidence from Inner City Chil dren. Journal of Environmental Psychology 22(1-2).

Note 28. Dwyer, J. F.; Schroeder, H. W.; Gobster, P. H. 1991. The Significance of Urban Trees and Forests: Toward a Deeper Understanding of Values. Journal of Arboriculture 17(10).

Note 29. Forests, Trees, and Human Health. Editors: Nilsson, K., Sangster, M., Gallis, C., Hartig, T., de Vries, S., Seeland, K., and Schipperijn, J.; Springer Publishing Company, 2013.


Objective #1

That the Town of Cary establish an office dedicated solely to addressing environmental issues. The office will consist of two parts. One part will be a Skunk Works, a group given a high degree of autonomy and charged with devising ways that the Town can move rapidly towards sustainability. The second will be an inspection unit charged with ensuring compliance with sustainability measures undertaken by the Town.

Objective #2

That the Town of Cary establish within its limits a combination botanical garden and arboretum.

Objective #3

That within the next decade, the Town of Cary properly plant one million additional trees within its borders and nurture them correctly.

Objective #4

That the Town of Cary adopt a long-lived and beautiful noble hardwood tree as its Official Tree.

Objective #5

That the Town of Cary re-start the now-defunct Wake County Champion and Notable Tree List, and that it be administered by volunteers using a donated program and server space.