7 Cities Embracing Urban Renaturation for a Greener Future

New York, Sydney, Madrid... Imagine a future where cities are lush with trees, the air is cleaner, and summers are less oppressive. Urban renaturation is redefining how we live in major metropolitan areas.

About the author

César Javier Palacios

Environmental journalist

César Javier Palacios is an environmental journalist, geographer, naturalist, and holds a doctorate in Art History. After an extensive career as editor-in-chief at Diario 16 Burgos and later at Claro, he contributed to El País and El País Semanal. He later relocated to Fuerteventura, working with Canarias7 and Agencia EFE.

His experience spans roles with the Doñana Biological Station (CSIC), SEO/BirdLife, Global Nature, the Fuerteventura Island Council, the national parks of Garajonay and Timanfaya, and the Biosphere Reserves of Lanzarote, La Gomera, and La Palma. He also served as Communications Director for the Félix Rodríguez de la Fuente Foundation and FSC Spain.

César is the host of El Señor de los Bosques (a nature and gastronomy program on Spain’s national TV channel La2). He writes a column for 20 Minutos, blogs at La Crónica Verde, and collaborates with RNE and Radio5. In the summer of 2024, he launched his own show, Músicas a Vuelapluma on Radio Clásica (a classical music station in Spain).

Meet the author

Urban renaturation is an unstoppable movement reshaping the landscapes of major cities, making them friendlier, more livable, and sustainable. Experts across disciplines—geographers, urban planners, biologists, ecologists, doctors, and psychologists—are championing the integration of nature into urban areas to create resilient spaces in the face of climate change and rapid urbanization.

What will you find in this article?

The positive impact of urban renaturation on the health of urban residents

With more than half of the world’s population residing in urban areas and projected to exceed 68% by 2050, UN-Habitat’s World Cities Report 2022 calls for “greening environments.” Similarly, the World Economic Forum’s Positive Cities for Nature initiative promotes this type of urban landscaping.

Scientific research has consistently shown that exposure to green spaces enhances emotional well-being. For example, the Barcelona Institute for Global Health (ISGlobal) highlights the health benefits of living near green spaces, which include promoting physical activity, reducing obesity, and mitigating sedentary lifestyle-related illnesses.

Some studies suggest that spending as little as twenty minutes a day in a park or forest reduces levels of the stress hormone cortisol. In addition, trees function as effective air-purifying filters, while providing shade that can reduce high temperatures by up to ten degrees, making them pleasant climatic havens during increasingly frequent heatwaves.

Following the recommendations of Agenda 2030 and the United Nations New Urban Agenda, many cities are leading important plans to reintegrate nature into urban environments. We analyze below those that are already a reality and are leading the way.

New York: From railroad to green lung

New York’s “elevated skyway” is one of the most emblematic examples of urban renaturation in North America. National Geographic has dubbed it the “Miracle over Manhattan.” This park, inaugurated in 2009, was created on a former railroad track abandoned for decades.

Today it is a wooded space of almost 2.5 kilometers that crosses several neighborhoods of the city, with gardens, art, and rest areas. The idea was not only to create a place for residents to relax, but also to encourage urban biodiversity by providing habitats for insects and birds.

The High Line has become a place of recreation for millions of people, who find a space to disconnect from the hustle and bustle of the city, breathe fresh air, and enjoy the greenery. At the same time, the presence of the park has increased property values and generated new businesses in an area that until recently was very degraded.

Sydney: Urban renaturation to fight the heat

In Sydney, Australia, the authorities are promoting an ambitious urban renaturation plan with the planting of thousands of trees to ensure that 40% of the metropolitan area is wooded by 2050. This new “urban forest” seeks to combat the extreme heatwaves that have affected the city in recent years, a phenomenon that is becoming increasingly frequent due to climate change.

Beyond the ecological impact, the project has placed special emphasis on community participation. Citizens are invited to collaborate in the planting and care of these trees, which generates a sense of belonging and responsibility towards the new green spaces. The benefits are already being felt in air quality and reduced temperatures in specific sunny areas of the city. The renovation of Darling Harbour or the Barangaroo harbor area are good examples of this transformation.

Madrid: The resurrected river

The renaturation project of the Manzanares River in Madrid, initiated in 2016, has transformed a stretch of more than 8 kilometers that crosses the city, recovering the river ecosystem and improving the environmental quality of the area. Prior to this intervention, the river was channeled and separated from its natural environment, with stagnant and poorly oxygenated waters due to the lack of currents.

It consisted of opening the floodgates of the dams that controlled the flow of the river, which allowed the recovery of the natural flow and the formation of small islands and native vegetation. This has promoted the return of numerous animal species such as waterfowl, fish, amphibians, and insects, increasing biodiversity and creating a natural recreational area for the people of Madrid.

Today, the renaturalized Manzanares is a green area accessible to citizens, who enjoy its banks to stroll, observe wildlife, and connect with nature without leaving the city. A successful example of how the recovery of natural spaces in urban environments not only benefits the environment, but also the health and well-being of people.

Singapore: Green corridors with supertrees

Known as “the city in a garden,” Singapore has made strides in urban renaturation by integrating greenery into most of its infrastructure, to the point of being the second highest-ranked city in Treepedia’s Green View Index, which measures tree cover in urban areas.

An iconic example is the Gardens by the Bay complex, an emblem of bioconstruction where nature is presented as the backbone of modern sustainable cities. This project not only offers a tourist attraction, but has created a social space with more than 100 hectares where all kinds of events, exhibitions, and workshops are frequent. Its famous artificial supertrees (supertrees) of up to 50 meters high are powered by solar panels that allow them to be illuminated, and when it rains, a system collects water to irrigate the ferns, orchids, and vines that adorn them.

Paris: Turning squares into climate shelters

Paris, known worldwide as the “city of light,” has also launched a major urban renaturation project that seeks to mitigate the effects of climate change, with a special focus on adapting to the city’s increasingly frequent and severe extreme heatwaves. Mayor Anne Hidalgo’s ambitious plan, launched in 2019, proposes to transform the French capital into a greener and more sustainable city, improving the quality of life of Parisians. Even the Seine will be a river where you can bathe.

One of the main objectives of this plan is to increase the number of trees and vegetation in strategic areas of the city. For example, by reforesting emblematic squares such as the Place de la Bastille and the Place de la République, which will be transformed from huge paved spaces into green lungs. These squares, which have traditionally been meeting and transit points in the heart of Paris, are being redesigned to include large green areas with trees, gardens, and diverse vegetation to absorb heat and provide shade.

This approach seeks not only to improve the aesthetics of the city, but also to turn these areas into “climatic refuges,” spaces where citizens can take shelter during heat waves. Vegetation helps reduce ambient temperatures by absorbing heat and releasing humidity, creating cooler microclimates. According to different studies, the temperature in green areas can be two to three degrees lower than in concrete areas, and in some cases, this difference can be as much as ten degrees during the most intense heat waves.

In addition to the reforestation of squares, Paris is also committed to creating a “green belt” on the outskirts of the city. This project envisages the planting of more than one hundred and seventy thousand trees by 2026 in several districts. The ultimate goal is that, by 2030, all Paris residents will live within a ten-minute walk of a green space.

Antibes: Forests that prevent flooding

Small towns are also benefiting from urban renaturation. One example is Antibes, on the French Côte d’Azur, with a population of 75,000. There, its mayor Jean Leonetti has just presented a completely innovative environmental project: the demolition of houses in a flood zone to create a 1.5-hectare urban forest to help combat flooding. In October 2015, severe flooding between Cannes and Nice caused twenty deaths and damages valued at more than six hundred million euros.

Located on the Reibaud islet, along the Laval valley, the “deconstruction” of this space located in the red flood zone is planned as a program of acquisitions and demolitions progresses. The city already owns 50% of the land and all property acquisitions are carried out on an amicable basis.

The objective is to permeabilize the land to reduce the risk of flooding. A green space will be created with more than 300 trees, bordered by a bike path that will be able to absorb the Laval’s overflows and bring freshness to the city. The first phase will be completed in 2025.

Medellin: Green corridors that promote biodiversity

Emerging in 2016 as a nature-based response to reduce air pollution and rising heat, it is one of the most important and pioneering urban renaturation proposals in Latin America. Medellín, Colombia’s second-largest city, now has some thirty green corridors, a system that connects roads, streets, and squares, vertical gardens, streams, parks, and hills, fostering biodiversity and creating new spaces for recreation and connection with nature.

In total, there are more than 36 kilometers of interconnected green areas that cross the most densely populated sectors. Urban renaturation has been carried out with hundreds of thousands of plants and trees of native species, adapted to the climate and soil of Medellín, which guarantees greater durability and less need for maintenance. These species, in addition, are more efficient in CO₂ capture and thermal regulation. They hardly consume any water, giving in exchange friendly spaces where birds sing and butterflies fly, inviting us to reconnect with the nature we need so much.

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