Cities Stories

6 Ways Trees Benefit All of Us

From a city park to a vast forest, trees deliver for us when we help them thrive.

Several people sit on a grassy hill under the shade of large trees. The New York City skyline is in the distance.
New York park People enjoy the shade of trees in a park facing the skyline of New York City. © Diane Cook & Len Jenshel

Trees have been with us throughout our whole lives. They’re the background of a favorite memory and that welcome patch of green our eyes seek as we gaze out our windows—an activity we’re doing a lot these days.

While they are silent and stationary, trees hold tremendous powers, including the power to make all our lives better and healthier.

If a tree has power, a forest has even more. What superpowers do trees have?

A Valdivian Coastal Reserve park guard stands between two giant Alerce trees covered in moss and leaves.
Alerce Trees A park guard stands among the Alerce trees in Chile’s Valdivian Coastal Reserve. TNC manages the reserve, where some of the trees are up to 4,000 years old. Older trees store a lot more carbon dioxide than younger trees. © Nick Hall

#1: Trees eat the greenhouse gases that cause climate change—for breakfast.

More like breakfast, lunch and dinner. Trees’ food-making process, photosynthesis, involves absorbing carbon dioxide from the air and storing it in its wood. Trees and plants will store this carbon dioxide throughout their lives, helping slow the gas’s buildup in our atmosphere that has been rapidly warming our planet.

Smarter management of trees, plants and soil in the US alone could store the equivalent carbon of taking 57 million cars off the road! Trees are looking out for us so we have to look out for them. Older, larger trees store a lot more carbon than young trees, so it’s important that in addition to planting new trees, we conserve and protect the giants of our forests like these ancient trees in South Carolina.

People lounge in the shade  of trees on Billings Lawn of Fort Tryon Park. The Hudson River in New York is visible.
Sitting in the tree's shade People enjoy the afternoon at Fort Tryon Park along the Hudson River in Manhattan, New York. In addition to encouraging heart-healthy physical exercise, green space reduces stress levels. © Diane Cook and Len Jenshel

#2: Trees boost our mental health while raising our physical health.

A healthy tree can lead to a healthy you and me. A study by a TNC scientist shows that time in nature—like a walk among the trees in a city park—correlates with a drop in anxiety and depression.

The good news: it doesn’t take a lot of time in nature for these soothing powers to kick in. You may have felt the benefits from a short walk or hike in your neighborhood. We’re drawn to green spaces, and for good reason.

Access to nearby green space also contributes to better physical health by encouraging us to move around and exercise. Because we move around more when we have access to trees and parks, nature can help lower rates of obesity.

An aerial view of The Spaghetti Junction in Louisville, Kentucky, a mess of multiple highways converging.
Louisville, Kentucky The Spaghetti Junction in Louisville, Kentucky. Louisville is a transit hub, and the air quality is affected by exhaust from tens of thousands of planes, trucks and trains. © Randy Olsen/The Nature Conservancy
Workers dig holes in the dirt next to a highway wall separator to plant trees.
Green Heart Planting Workers dig holes for installation of large trees along a Louisville highway. The trees will form a wall to reduce air pollution before it enters the community. © Mike Wilkinson

#3: Trees clean the air so we can breathe more easily.

Leave it to leaves. Trees remove the kind of air pollution that is most dangerous to our lungs: particulate matter. This pollution arises from the burning of fossil fuels, and can reach dangerous concentrations in the largest cities as well as in neighborhoods near highways and factories.

Your Dollars at Work

TNC is in the middle of the first controlled experiment testing neighborhood tree planting for health benefits in the same way that a new pharmaceutical drug would be tested.

Tree’s leaves will filter this dangerous pollution, but only if they’re planted near the people who need them; most of the filtration occurs within 100 feet of a tree. More trees in cities, especially in lower-income neighborhoods close to highways and factories, can reduce ailments like asthma and heart disease that cause 5% of deaths worldwide.

Fallen trees on a forest floor, covered in moss and surrounded by dead leaves and bare tree trunks.
Habitat from Fallen Trees Woody debris on the forest floor, a characteristic of older growth forests, provides great habitat for all sorts of life. © Severn Smith
Red fox pup closeup, holding a leaf in its mouth.
Red fox pup Old-growth forests create habitat at the ground level, allowing many diverse species (like this red fox pup) to thrive. © Steve Meyer

#4: Trees give a home to the wildlife we love.

From our windows, many of us can see how much our feathered and furry neighbors enjoy their ‘high-rise apartments.’ Even a single tree can provide vital habitat for countless species.

An intact forest can do even more, creating a home for some of the most diverse and resilient webs of life on the planet. Old-growth forests, the forests that we need to protect most urgently, create habitat at the ground level, at the top of their tree canopies, and everywhere in between. All of these different types of habitat in a single area allow so many diverse species to thrive.

A shaded street in Park Slope, Brooklyn, New York City, lined with many tall trees.
Tree-lined street A tree's shade acts like natural air conditioning, keeping the area five to eight degrees cooler than surrounding areas. Shady streets like this one in Park Slope, Brooklyn make walking and biking more possible. © 2018 Diane Cook & Len Jenshel

#5: Trees cool down your life, and could even save it.

Trees give us all shade—and that’s a good thing! Temperatures are rising and heatwaves are getting longer due to climate change. Some places feel the heat more than others. Neighborhoods with lots of pavement absorb more heat and can be five to eight degrees hotter than surrounding areas. These areas also stay hotter later into the night, which is detrimental to our health.

Enter our branchy, leafy neighbors. A tree’s shade acts like a natural air conditioning and can even keep down the energy costs of our actual air conditioning systems, which are increasingly working overtime.

The rushing water of Elder Creek, with moss covered banks, as it flows into South Fork of Eel River in Angelo Reserve.
Elder Creek Elder Creek flows into South Fork of Eel River in Northern California's Angelo Coast Range Reserve. The roots of the trees in this forest also hold water, filtering it and releasing it back into waterways © Ian Shive

#6: Trees filter your water, making your drinking supply cleaner and more reliable.

Raise a glass to a tree near you! Actually, raise your glass to trees far from you, as your water has traveled on a long journey to your faucet. Trees store and filter more than half of the water supply in the United States.

Forests do this by removing pollutants and sediments from rainfall and then slowly releasing the water back into waterways and underground aquifers. Thanks to trees, this naturally cleaner water is easier and cheaper to treat before it ends up in your tap. The water supply is also steadier because all of the rainwater didn’t end up in a river right away; it seeped through these natural filters over time.

To fully use their powers, trees need our help.

While trees are resilient, they are not invincible—and they need our help. When you support The Nature Conservancy, you’re helping to plant more trees, protect old forests and restore forests that have been partially developed. So, together, we’re helping our planet and giving an important gift to our children and their children.