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 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.

• 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.

• Reduced heat buildup. Trees in a parking lot can reduce on-site heat buildup, decrease runoff and
enhance night time cool downs. Tests in a mall parking lot in Huntsville, Ala. showed a 31 degree
difference between shaded and unshaded areas.

• 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.

• 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.

• 2,500 square feet of turf absorbs carbon dioxide from the atmosphere and releases enough oxygen for a
family of four to breathe.

• Lower attic temperatures. Trees shading homes can reduce attic temperatures 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.

• 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 percent more efficiently. The trees also allow the
sun to warm the house in the winter.