This blog originally appeared on the Worldwatch Institute's blog and is reposted with permission.

Cities are the world’s future. Today, more than half of the global population—3.7 billion people—are urban dwellers and that number is expected to double by 2050. There is no question cities are growing; the only debate is over how they will grow. Will we invest in the physical and social infrastructure necessary for livable, equitable, and sustainable cities? Follow the Worldwatch Institute as we prepare for the May 10, 2016 release of State of the World: Can a City Be Sustainable? 

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As increasing numbers of people squeeze into cities, where can urban communities grow green spaces?

The world’s expanding cities are in a delicate balancing act. If they do not embrace strategic, high-density development, urban areas will increasingly encroach on surrounding farmland and natural spaces. This, in turn, creates the need for additional energy and transit infrastructure and widens their climate impacts. But if cities develop without green or open spaces, urban residents risk suffering from health problems, deteriorating social cohesion, and the loss of economic opportunities as the appeal of urban life fades.

Luckily, landscape architects and urban planners are finding innovative solutions to pack more green spaces within city boundaries, without pushing out existing living and working spaces. Below are five examples of stunning parks that incorporate green spaces into the fabric of urban life.

Blight to Beauty

The Atlanta BeltLine, Atlanta, Georgia, United States

Photo Courtesy of Worldwatch Institute
Rendering of the Atlanta BeltLine (Ryan Gravel).

 

Photo Courtesy of Worldwatch Institute
The splashpad at Historic Fourth Ward Park. Left photo: Christopher T. Martin. Right photo: Atlanta BeltLine, Inc

The Atlanta BeltLine is a prime example of “upcycling” underutilized urban space. Initially a hypothetical thesis project by a student at Georgia Tech in 1999, the project has become one of the largest urban redevelopment programs in the United States. It boasts a planned 520 hectares (1,300 acres) of new parkland—that’s more than the 340 hectares (840 acres) of New York City’s Central Park. Add the 400 hectares (1,000 acres) of remediated brown fields and 5,600 units of affordable housing, and the scale of the project becomes clear. The BeltLine rings the center of Atlanta using an existing 35-kilometer (22-mile) rail corridor that fell into disuse when the city grew beyond its initial boundaries. Today, the rail line links 45 neighborhoods, providing both transportation corridors and public space complete with an arboretum and spaces for fitness, play, art, and special events.

The Lowline, New York City, United States

Photo Courtesy of Worldwatch Institute
Rendering of the Lowline.

Photo Courtesy of Worldwatch Institute
The Lowline Lab before installation (Brandt Graves). The existing Lowline Lab.

Like its New York City cousin the High Line, the Lowline takes advantage of neglected transit routes to add a vertical dimension to public green spaces. Although it is still in its concept phase, the Lowline proposes an innovative design in an abandoned trolley terminal. What makes this project so intriguing is its use of passive solar technology to illuminate the space and provide light to plants and people below street level. A solar reflector dish guides sunlight from above to an underground dome that scatters the light.

Prioritizing People Over Cars

Madrid Río, Madrid, Spain

Photo Courtesy of Worldwatch Institute
Rendering of Madrid Río (CityLife).

Photo Courtesy of Worldwatch Institute
Madrid Río in 2004 and 2011, before and after burying the highways.

After a massive highway was built on both sides of the Manzanares River in Madrid in the 1970s, nearby neighborhoods declined and most Madrileños avoided the region entirely. In 2003, however, Mayor Alberto Ruíz-Gallardón implemented his vision to bury the highways and move traffic through tunnels instead (not without great political pushback). Ultimately, however, the river banks were freed for pedestrians and more than nine kilometers (six miles) of the Madrid Río Park were designed with playgrounds, ball fields, bike paths, and a wading pool known fondly as “the beach.”

Cheonggyecheo, Seoul, South Korea

Photo Courtesy of Worldwatch Institute
Cheonggyecheo Stream Park (Kimmo Räisänen).

Photo Courtesy of Worldwatch Institute
Cheonggyecheo Stream before and after highway removal (Intermediate Landscapes).

Peeling back the 5 kilometers (three miles) of elevated highway that covered the once-polluted Cheonggyecheon Stream has turned a congested area in Seoul into a green haven for picnickers and pedestrians. While the park is far from perfect in its environmental design (water is pumped through 11 kilometers, or seven miles, of pipes from the Han River to feed the stream), some wildlife has returned, pollution has decreased, property values have gone up, and some 90,000 people visit daily. Combined with expanded bus service, higher parking fees, and restrictions on cars, nearby congestion has gone down and reduced small-particle air pollution along the corridor. The area also experiences lower local temperatures compared to those of nearby areas, a boon as climate change extremes are likely to increase in frequency.

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