Trees are good.
Trees provide a cooling benefit during extreme heat waves, particularly when shade is cast over concrete or asphalt. Planting more trees in areas that need it could save hundreds of lives, says McDonald, who is based in Basel, Switzerland.
At the most ambitious level, planting 1.2 billion trees across the country could prevent about 460 additional heat-related deaths and about 81,000 additional doctor visits annually, the team projects. But even a five percent increase in preexisting canopy cover could make a substantial difference in cities such as Philadelphia or New York City, McDonald says. Both cities currently have millions of trees. “The places that are most suffering from tree inequality are also the best opportunities for new [trees].”