Trees create a much more livable environment. Fox, Tom. 1990. The Neighborhood Open Space Coalition, New York, New York. When Cambridge tax assessors judge streets from 'excellent' to 'poor', street trees rank as their number-one priority in a rating a street 'excellent'. Brabrec, Elizabeth. 1992.
Trees Make Sense.
Trees are an important part of the local and national fight against air pollution and against the progress of global warming. By removing carbon dioxide and other pollutants from the air and releasing oxygen back into the air, trees improve air quality. Air pollution levels are measured by the amount of particulate matter in the air, high levels of which are irritating to the respiratory system. Trees aid in removing particulate matter from the air by trapping particles on the exposed surfaces of twigs and leaves. The study found that air pollution along freeways is approximately three times higher than that acceptable to man.