ENVIRONMENTAL BENEFITS OF GREEN SPACES

How Green Spaces Benefit the Environment

[Download Environmental Fact Sheet PDF]

Urban advantages. More green space within a city's boundaries can improve the urban environment. Among the green space advantages listed in Ecoplanit Madison: Green Space Goal (UW-Madison Department of Urban and Regional Planning) are: helping to regulate air quality and climate, reducing energy consumption by countering the warming effects of paved surfaces, recharging groundwater supplies, and protecting lakes and streams from polluted runoff.¹

Water quality protection. Proper landscaping reduces nitrate leaching from the soil into the water supply and reduces surface water runoff, keeping phosphorus and other pollutants out of our waterways and preventing septic system overload.²
The runoff water and sediment that occurs from impervious surfaces in urban areas carries many pollutants, including metals such as Pb, Cd, Cu, and Zn; hydrocarbon compounds as from oil, grease and fuels; and household and industrial hazardous wastes such as waste oils, paint thinners, organic preservations, and solvents. Turfgrass areas can be designed for the catchrnent and filtration of these polluted runoff waters.⁹

Reduced heat buildup. Through the cooling process of transpiration, turfgrasses dissipate high levels of radiant heat in urban areas.  Trees in a parking lot can reduce on-site heat buildup, decrease runoff and enhance nighttime cool-downs. Tests in a mall parking lot in Huntsville, Ala. showed a 31-degree difference between shaded and unshaded areas.³

Noise and Glare Reduction. Studies have shown that turfgrass surfaces absorb harsh sounds significantly better than hard surfaces such as pavement, gravel, or bare ground ⁸. These benefits are maximized by an integrated landscape of turfgrasses, trees, and shrubs.

Reduced soil erosion. A dense cover of plants and mulch holds soil in place, keeping sediment out of lakes, streams, storm drains, and roads and reducing flooding, mudslides and dust storms.³

Improved air quality. Trees, shrubs and turf remove smoke, dust and other pollutants from the air. One tree can remove 26 pounds of carbon dioxide from the atmosphere annually, equaling 11,000 miles of car emissions. One study showed that one acre of trees has the ability to remove 13 tons of particles and gases annually.⁴

Lower summer air temperatures. Trees shading homes can reduce attic temperatures by as much as 40 degrees. According to the EPA, urban forests reduce urban air temperatures significantly by shading heat sinks such as buildings and concrete and returning humidity to the air through evaporative cooling.⁵

Natural resource conservation. By using trees to modify temperatures, the amount of fossil fuels used for cooling and heating is reduced. Properly placed deciduous trees reduce house temperatures in the summer, allowing air conditioning units to run 2% to 4% more efficiently but allowing the sun to warm the house in the winter.⁶

Green roofs cool urban hot spots. Led by cities such as Chicago and Toronto, as well as a number of universities, evidence is mounting that green roofs (i.e. roofs totally or partially covered with vegetation) can play an important role in saving energy, reducing the urban heat island effect, and adding more green space to a built environment.⁷

See below for more resources on how green spaces benefit the environment:

Ecoplanit Madison: Green Space Goal UW-Madison's Department of Urban and Regional Planning
http://urpl.wisc.edu/ecoplan/index.php?page=goal_1

How Interior Plants Help Lower a Room’s Temperature, Saving Air Conditioning Costs
[Download PDF]

Benefits of Landscapes: Aspen Environmental Companies
http://www.aspenenviro.com/benefits.html

The Value of Public Space
[Download PDF]

Looking for Lawns: A study about the impact lawns have on the environment, conducted by NASA's Ames Research Center in California
http://earthobservatory.nasa.gov/Study/Lawn/

Proclamation of Environmental Guiding Principles
[Download Word Doc]

Bibliography: Environmental Fact Sheet

1 UW-Madison Department of Urban and Regional Planning: Ecoplanit Madison: Green Space Goal
http://urpl.wisc.edu/ecoplan/index.php?page=goal

2 Virginia Cooperative Extension: The Value of Landscaping
http://www.ext.vt.edu/pubs/envirohort/426-721/426-721.html#TOC

3 Wolf, K.L., Ph.D., University of Washington
http://www.cfr.washington.edu/research.envmind/transportation.html; Wolf, K. L. 2004, Trees, Parking and Green Law: Strategies for Sustainability. Stone Mountain, GA: Georgia Forestry Commission, Urban and Community Forestry
http://www.cfr.washington.edu/research.envmind/
Roadside/Trees_Parking.pdf

4,5,6 Virginia Cooperative Extension: The Value of Landscaping, op. cit

7 http://www.greenroofs.com/aboutus.htm

8 Robinette, G.O. 1972. Plants, people, and environmental quality. U.S. Dep. Interior, National Park Service, and Am. Soc.

9 Schuyler, T. 1987. Controlling urban runoff: A practical manual for planning and designing urban BMPs. Metropolitan Washington Council of Governments, Washington, DC.