Air Quality

Trees are an efficient and cost-effective way for a community to improve its air quality and reduce pollution.  A mature tree absorbs between 120-240 pounds per year of small particles and gases, like carbon-dioxide, which are released into the air by automobiles and industrial facilities.  In addition, a single tree produces nearly three-quarters of the oxygen required for one person; and a canopy of trees in an urban environment can slash smog levels up to six percent.  American Forests reports that just 25,000 acres of forest can offset the equivalent emissions of 10 billion automobile miles.

Water Quality

Trees help anchor soil and reduce storm water runoff, saving the high costs of drainage ditches, storm sewers, and other "engineered solutions" to storm water management.  A street lined with 32-foot tall trees can reduce runoff by almost 327 gallons, allowing cities to install smaller and less expensive water management systems.  Reducing runoff also decreases topsoil erosion and the amount of silt and other pollutants washed into streams, rivers, and lakes.

Lower Heating and Cooling Costs

Trees have demonstrated the ability to reduce heating and cooling costs and counteract the "heat island" effect in urban environments.  Urban areas with little vegetation can experience temperatures of up to seven degrees higher than those with tree cover.  This translates into significantly higher energy costs to cool buildings.  Properly planted trees can cut heating and cooling costs by as much as 12 percent and reduce overall power demand.

Reduced Noise Pollution

Noise pollution is an often overlooked problem.  Excessive or unwanted sound has negative physical and psychological effects.  Noise can come from many sources, especially roads and highways.  Trees can play an important role in deadening unwanted noise.  Sound waves are absorbed by a tree's leaves, branches, and twigs.  Studies suggest that belts of trees 100 feet wide and 45 feet long can cut highway noise in half.