public benefits of green roofs:
Some of the benefits for the larger built environment are:
improved air quality:
-16 s.f. of uncut grass produces enough oxygen per year to supply one human with their yearly oxygen intake requirement, and 11 s.f. of grass roof can remove almost ½ pound of airborne particulates from the air every year.
moderation of the heat island effect:
-11 s.f. of foliage can evaporate ½ quart of water on a hot day, or 180 gallons a year.
stormwater retention:
-during the summer, green roofs retain 70-80% of precipitation; during winter, 25-40%.
other:
-creation of microclimates, habitat preservation, recreation, etc.
