Carbon sequestration, air quality, and climate change
- A tree can absorb as much as 48 pounds of carbon dioxide per year, and can sequester one ton of carbon dioxide by the time it reaches 40 years old. 
- One large tree can provide a supply of oxygen for two people. 
- According to the USDA Forest Service, “Trees properly placed around buildings can reduce air conditioning needs by 30 percent and save 20-50 percent in energy used for heating.” 
- The net cooling effect of a young, healthy tree is equivalent to ten room-size air conditioners operating 20 hours a day. 
- In one day, one large tree can lift up to 100 gallons of water out of the ground and discharge it into the air. 
- For every five percent of tree cover added to a community, stormwater runoff is reduced by approximately two percent. 
Recreation and Wildlife
- Healthy trees provide wildlife habitat and contribute to the social and economic well-being of landowners and community residents. 
EPA Urban Heat Island Effects
- Reduced energy use: Trees and vegetation that directly shade buildings decrease demand for air conditioning.
- Improved air quality and lower greenhouse gas emissions: By reducing energy demand, trees and vegetation decrease the production of associated air pollution and greenhouse gas emissions. They also remove air pollutants and store and sequester carbon dioxide.
- Enhanced storm water management and water quality: Vegetation reduces runoff and improves water quality by absorbing and filtering rainwater.
- Reduced pavement maintenance: Tree shade can slow deterioration of street pavement, decreasing the amount of maintenance needed.
- Improved quality of life: Trees and vegetation provide aesthetic value, habitat for many species, and can reduce noise
A reasonable estimate of the lifetime of trees is 100-150 years. Based on information from the USDA Forest Service , the lifetime of trees varies by region and species, but generally ranges from 50 years to 300 years of age. An average lifetime of trees planted in forests for long-term restoration purposes might be 100-150 years. Here are a few examples by region
- In the Southeast, conifers may live 100-150 years, while hardwoods may live 150-200 years.
- In the northeast and lake states, some conifers (e.g. white pine and red pine) may live 100-150 years, while Jack pine lives 80-100 years; mixed hardwoods (e.g. maples and oaks) might live beyond 150 years, while aspen and birch might only live 50-70 years.
- In the Pacific Northwest, conifers may live 200-300 years and longer.