Johnny Appleseed was ahead of his time. Not because he fed so many people by planting apple trees (really, he got them drunk instead, as his real goal was encouraging the production of cider), but because he created so much shade to enjoy on hot days. More than two centuries later, American cities are wishing they had better followed Appleseed’s lead, as rising temperatures and a lack of tree cover combine to make urban life increasingly stifling.
Two new studies show how simply planting more trees can provide huge temperature benefits, not to mention how the additional plant life would boost biodiversity and improve mental health for urbanites. The first finds that tree cover can cancel half of the heat island effect, in which the urban jungle gets much hotter than the surrounding countryside. The second compares neighborhoods in 65 American cities, finding that canopy-deprived areas suffer up to 40 percent more excess heat than heavily greened spots.
Places like New York and Atlanta and Los Angeles, then, don’t just have to foster and maintain their “gray” infr... Read more
