When it rains pollutants like oil, gasoline, road salt, and litter are washed off streets and sidewalks into our local waterways. Trees, grasses, and shrubs help to absorb and slow this runoff, protecting drinking water, aquatic life, and overall ecosystem health.

Trees act like natural mini reservoirs that help manage this stormwater by:

• Catching rain on their leaves, branches, and bark
• Absorbing and filtering rainwater through their roots
• Reducing soil erosion by softening the impact of falling raindrops

Trees also help us save energy and lower utility bills by affecting how buildings heat and cool. They do this by:

• Providing shade to reduce heat absorbed by buildings
• Releasing moisture into the air, which cools the surrounding environment
• Acting as windbreaks that reduce heat loss during colder months

Placement matters:

• In summer, planting trees on the east and west sides of buildings helps keep interiors cooler.
• In winter, allowing sunlight to hit the south-facing side can warm buildings naturally—unless shaded by dense evergreens, which could actually increase heating costs.

Air pollution is a serious health issue. It can lead to asthma, coughing, headaches, heart disease - even cancer. Over 150 million people live in areas with unsafe air quality.

Urban forests - clusters of trees in cities - help clean the air by:

• Absorbing harmful gases like ozone, carbon monoxide, and sulfur dioxide
• Trapping fine particles like smoke and dust
• Producing the oxygen we breathe
• Cooling the air, which helps reduce ozone levels
• Cutting down on energy use, which means less pollution from power plants

Note: Some tree species, like willows and sweetgums, release natural gases that can contribute to ozone formation. So while trees are incredibly helpful, choosing the right types is important too.

The average car emits nearly 5,000 kilograms of carbon dioxide (CO₂) per year—just from regular driving. Trees help fight this pollution in two key ways:

• They absorb and store CO₂ in their trunks, roots, branches, and leaves. Even when used as wood products, trees continue to hold carbon rather than releasing it into the air.
• By shading and insulating buildings, trees reduce the need for heating and cooling, which lowers CO₂ emissions from power plants.

Each benefit that trees provide - stormwater management, energy savings, cleaner air, and carbon storage - can be translated into a dollar value. These values are then added together to estimate how much one tree can save us over time.

If you want to learn more about how these values are calculated, check out www.itreetools.org.