What is Green Space?
Green Space is a plot of undeveloped land separating or surrounding areas of intensive residential or industrial use that is maintained for recreational enjoyment. It is an area within an urban environment which is dedicated to nature. One of the most familiar forms of green space is a recreational park, such as New York City's famous Central Park, although green space can also take the form of urban wetlands or urban forest canopy. Many societies have historically valued parks, and in the later half of the 20th century, many additional benefits to green space were discovered by researchers.
How Can Green Space Be Used?
Green space provides a place to recreate. Many green spaces have hiking trails, picnic lawns, and other areas which are geared to community use. People often enjoy wandering around in parks, attending events held in parks such as concerts, and experiencing the natural environment. Many cities around the world have famous parks and green spaces along with botanical gardens; some of them have been enjoyed for centuries.
In addition to being nice to look at and enjoyable to play in, green space also has a number of other benefits. Researchers on urban temperatures and air quality have discovered that the more green space a city has, the healthier it is. Large swaths of green space can act as "air scrubbers," with plants pulling pollution out of the air and emitting oxygen as a byproduct. Green space can also help to regulate the temperature in a city, preventing radical fluctuations which can make urban life unpleasant.
Green space also provides a natural habitat for animals, and in some cases, thriving wildlife communities have arisen in areas set aside for green space. Green space helps to preserve the natural environment and the diversity of regional species, from butterflies to birds, which is an obvious benefit.
Green space also helps with water conservation. Urban forest canopies reduce the rate of evaporation, keeping water in a city, and urban wetlands help reduce flooding and manage storm water runoff. The environmental benefits of green space do not generally conflict with human uses, making the choice to prioritize green space in city planning much easier.
A growing number of cities have recognized the need for green infrastructure in the form of parks, greenbelts around new development, and living walls and roofs. Many city plans include a statement about a desire to maintain or expand urban green space to make life healthier and more pleasant for residents. A new study found that inner-city youth living in neighborhoods with more green space had an obesity rate about 13% lower than children living amid more concrete and fewer trees.
Human Benefits of Green Spaces
Adapted from the lecture The Healing Garden: Social Research by Dr. Susan Barton, PLSC100: Plants and Human Culture. November 18, 2008.
Interaction with gardens and natural spaces offers a variety of mental, physical and social benefits for humans, ranging from stress reduction, quicker healing, and mitigation of Attention Deficit Disorder in children to decreasing crime and air pollution. Sustainable sites consider human energy and creativity as a renewable resource, recognizing the potential for healthy living and employment conditions. City planners, governments, and ordinary citizens are only just beginning to appreciate the tangible benefits of green spaces and take advantage of opportunities for improving quality of life in urbanized areas.
Stress and violence reduction. Parks, garden spaces, street trees, and landscaped traffic islands provide more than a pretty panorama, effectively reducing the stress of our daily lives by invoking a feeling of tranquility. Studies have shown that stressed individuals feel better after exposure to natural scenes. Accordingly, green spaces also reduce instances of aggression and violence.
Enhanced health. Studies throughout the world have proven the power of green spaces to improve human health. Cities with high numbers of parks battle obesity and diabetes. Recent studies in the Netherlands and Japan show that people with easy access to green space boasted better health and lower mortality rates. Even relatively passive contact with nature such as viewing it from a window lowers blood pressure and anxiety levels.
More rapid healing. Texas A&M's Roger Ulrich examined exactly how window views from a hospital room effected recovery time in surgical patients. He matched patients with similar demographics and surgical procedures but different window views; one facing a brown brick wall of an adjacent building, and the other looking at a small stand of deciduous trees. Those looking at the trees had fewer negative nurses evaluations and post-surgical complications, used weaker painkillers, and remained in the hospital a shorter time by 8.5% compared to patients looking at a building wall.
Improved environmental conditions. City greenery cleans and cools the air for improved quality of life. A study in Chicago determined that the city's trees filtered 234 tons of particulate pollution and cleansed the air of 98 tons of nitrogen dioxide, 93 tons of sulfur dioxide, and 17 tons of carbon monoxide. Vegetated areas also provide relief from the heat island effect caused by the heat-trapping quality of asphalt, concrete, and building materials. Air under a tree's canopy can be as much as 5° - 10° F cooler compared to full sun, with the underlying pavement up to 36° F cooler.
Crime reduction. Most people assume that increased vegetation translates to an increase of crime by offering hiding places for criminals and their criminal acts. Open mowed areas are generally considered safest, while densely vegetated areas are the most feared. Contrary to these common beliefs, maintained green spaces actually reduce crime. A study of 98 vegetated and un-vegetated apartment buildings in Chicago showed that vegetated spaces cut crime by half, in addition to inspiring pride for surroundings that translated into less litter and less graffiti. Besides mitigating psychological precursors to violence by reducing stress and anxiety, green spaces increase a neighborhood's collective surveillance. Vegetated landscapes invite more people to use them, ensuring more eyes on the watch to prevent crime in outdoor spaces.
Increased workplace productivity. In the business environment, green spaces improve productivity and morale among workers. Studies show that desk workers with a view of nature either out a window, in a picture frame, or around them in the form of indoor plants feel more relaxed overall, and those with no visibility of plants suffer the most stress and anxiety.
Safer driving. Vegetated roadsides may also serve a social benefit by reducing fatigue, anger, aggression, fear and stress of automobile drivers. A study using videotapes to simulate differing levels of vegetation along roadside suggests that parkway design and roadside vegetation reduces frustration among drivers.
Positive effects on children. A national movement called No Child Left Inside popularized by Richard Louv in his book, Last Child in the Woods, speaks to the countless benefits natural spaces have on child development. One national study of 450 children with Attention-Deficit/Hyperactivity Disorder determined that exposure to natural environments alleviated symptoms of the condition. Another study shows that views of trees from the home improves self-discipline among inner city girls, including enhanced concentration, inhibition of impulsive behavior, and delay of gratification. After creative play in verdant settings, children overall demonstrate increased ability to concentrate, complete tasks, and follow directions.