David Nowak, a senior US Forest Service and author of a study that documents the loss of tree cover, lists 10 benefits trees provide to society:

  • Heat reduction: Trees provide shade for homes, office buildings, parks and roadways, cooling surface temperatures. They also take in and evaporate water, cooling the air around them. “Just walk in the shade of a tree on a hot day. You can’t get that from grass,” Nowak said. To get the full temperature benefit, tree canopy cover should exceed 40% of the area to be cooled, according to a recent study in the Proceedings of the National Academy of Sciences. “A single city block would need to be nearly half-covered by a leafy green network of branches and leaves,” the authors wrote.
  • Air pollution reduction: Trees absorb carbon and remove pollutants from the atmosphere.
  • Energy emissions reduction: Trees reduce energy costs by $4 billion a year, according to Nowak’s study. “The shading of those trees on buildings reduce your air conditioning costs. Take those trees away; now your buildings are heating up, you’re running your air conditioning more, and you’re burning more fuel from the power plants, so the pollution and emissions go up.”

Want to help beat the heat? Grow more, help save trees

  • Water quality improvement: Trees act as water filters, taking in dirty surface water and absorbing nitrogen and phosphorus into the soil.
  • Flooding reduction: Trees reduce flooding by absorbing water and reducing runoff into streams.
  • Noise reduction: Trees can deflect sound, one reason you’ll see them lining highways, along fences and between roads and neighborhoods. They can also add sound through birds chirping and wind blowing through leaves, noises that have shown psychological benefits.
  • Protection from UV radiation: Trees absorb 96% of ultraviolet radiation, Nowak says.
  • Improved aesthetics: Ask any real estate agent, architect or city planner: Trees and leaf cover improve the looks and value of any property.

Improved human health: Many studies have found connections between exposure to nature and better mental and physical health. Some hospitals have added tree views and plantings for patients as a result of these studies. Doctors are even prescribing walks in nature for children and families due to evidence that nature exposure lowers blood pressure and stress hormones. And studies have associated living near green areas with lower death rates.

  • Wildlife habitat: Birds rely on trees for shelter, food and nesting. Worldwide, forests provide for a huge diversity of animal life.