Two mature trees provide enough oxygen for a family of four. One acre of trees removes 2.6 tons of CO 2 per year. Forest planting is one of the most cost-effective ways of reducing CO 2 . By cooling the air and ground around them, the shade from trees helps cool the Earth's temperature.
Trees are good noise barriers, making a city and neighborhood quieter.
Trees help prevent city flooding by catching raindrops and offsetting runoff caused by buildings and parking lots. Hospital patients heal faster, require shorter stays and less painkillers if room windows face trees. A tree-line buffer between fields and streams helps remove farming pollutants before they reach the water. Trees are the longest living and largest living organisms on Earth. In deserts, leaves absorb moisture from the dew and frost of the cool nights and release it to cool the air during the warm days.