We’ve all heard it — we need oxygen from trees to survive. It’s the primary campaign from tree lovers around the world in our quest to save the forests. However, although oxygen is important for survival, it is not the only air quality improvement maneuver for which trees should be praised.
A lesser known, yet equally interesting, feature of trees is how they cool air through evapotranspiration. As trees transpire, they release water into the atmosphere through their leaves. As the water changes state from liquid to vapor, the surrounding air is cooled, similar to how we sweat. This effect is especially beneficial in urban areas where heat is trapped by concrete and asphalt surfaces and can make summer days unbearably hot. Especially in recent years, where global temperatures have spiked, trees can offset increased temperatures on a local scale.