Building Cities in Harmony With Nature Is Essential for a Thriving Planet

From as far back as the Town Mouse and the Country Mouse, the urban and natural worlds have been understood and presented as opposites. But a deeper understanding of how economies and ecosystems work reveals that this is not actually true. 

In fact, the well-being of cities and the well-being of the natural world are inextricably linked, as a report released earlier this year by the World Economic Forum shows. Nearly half of the gross domestic product (GDP) of the world’s cities is threatened by nature and biodiversity loss. However, if cities choose to invest in nature, they can also give themselves an economic boost. 

“In the conventional paradigm, urban development and environmental health are like oil and water,” said Akanksha Khatri, the World Economic Forum head of nature and biodiversity, in a press release. “This report shows that this does not have to be the case. Nature can be the backbone of urban development. By recognizing cities as living systems, we can support conditions for the health of people, planet and economy in urban areas.”

The City and the Country  

The report is the fruit of a collaboration between the World Economic Forum and the Alexander von Humboldt Institute, which is supported by the government of Colombia. The BiodiverCities by 2030 initiative seeks to empower businesses, city governments, and ordinary people to “create an urban development model in harmony with nature” by the end of the decade. 

Up until now, the growth of cities has largely come at the expense of the natural world. Cities have historically been built near valuable ecosystems that provide the cities with essential resources like soil and water at the expense of their own health, and this is projected to continue: 90% of cities in the world’s biodiversity hotspots are expected to expand into wet tropical forests. While cities only take up 1% of the Earth’s ice-free land, they require an area 36 times that size to feed their inhabitants. Further, they are responsible for more than 75% of global greenhouse gas emissions.

However, it’s not realistic to simply put an end to urban living. Currently, cities generate 80% of global GDP and are home to 56% of the world’s people. By 2030, an additional 1.1 billion people will be living in cities, and, by 2050, three out of every four people will be a metropolitan. 

Further, cities and their residents are threatened by their current relationship with the natural world. According to the IPBES Global Assessment Report, biodiversity supports human survival in 18 key ways.

“It supports key economic activities through air quality, water cycles, and flood regulation, and underpins the production of energy, food, and medicine,” report co-author and World Economic Form BiodiverCities by 2030 Initiative lead Marina Ruta tells Treehugger in an email. “Despite cities around the world occupying different ecosystems, these contributions are essential to support the economies and societies of all. As a consequence of biodiversity loss, critical economic activities depending on nature are at risk of disruption.” 

Because of this, nature loss threatens 44% of urban GDP as of 2019, or $31 trillion. This is due to the risk of disruption in sectors including supply chains and transportation, energy and utilities, retail and consumer goods, aviation and travel, and information technology. 

Cities will also not be spared the impacts of the climate crisis and other environmental changes. More than 70% of the world’s 576 largest cities, or 414 total, are at high or extreme risk from pollution, water supply problems, extreme heat, or other natural disasters.

Flooding is the number one hazard menacing more than 1,600 cities, and it is becoming more likely due to the loss of habitats like mangroves that act as a buffer between the human population and the rising sea. Droughts are the second biggest threat to cities, and one in four urban areas is already water-stressed. As matters now stand, cities threaten the natural world, but the natural world is poised to take them down with it.

BiodiverCities 

However, the report's authors argue for a new way of doing things in which cities instead bolster the natural world and, in doing so, both survive and thrive.

“‘Nature-positive’ investments—such as Nature-based Solutions for infrastructure or returning land to nature—could create more than 59 million jobs in cities worldwide and generate over $1.5 trillion in annual business value by 2030,” Ruta says. “The analysis finds that spending $583 billion on interventions that enhance nature and reduce urban impacts on biodiversity can secure significant economic benefits as cities become more resilient, liveable and competitive.” 

Nature-based solutions include protecting urban watersheds, conserving or restoring coastal wetlands, or incorporating nature into the built environment. For example, both San Francisco and Córdoba, Spain have passed bylaws mandating that any building with 400 square meters (approximately 4,306 square feet) or more of roof space grow a green roof.

Another case study is Freetown, Sierra Leone. In 2017, the city was inundated with three days of rain that generated a landslide that killed more than 1,000 people and left more than 3,000 homeless. The city responded by building earthworks and planting 21,000 native trees to stabilize the hillside. The city’s mayor also encouraged public participation in this transformative vision by starting a “Freetown the Treetown” campaign to double the city’s tree cover by the end of 2022. The campaign included a “Treetracker” app that records the campaign’s progress on a tree-by-tree basis.

Turning an urban area into a BiodiverCity requires three major shifts, according to the World Economic Forum:

1. Adopting a “systems approach” to Urban Government: This means making decisions that take the needs of the natural world and all impacted human populations into account instead of just doing what is cheapest to solve immediate problems.
2. Incorporating nature into urban planning: This means building cities with nature in mind, both by preserving existing habitats and incorporating greenery into urban design through things like tree corridors or green roofs. 
3. Making green cities attractive to investors: This means standardizing biodiversity data that can be used to guide investments and creating new markets so that investing in nature becomes less risky. 

Cities of the Future

The report’s emphasis on the role of cities as both causes of and solutions to the climate crisis was echoed by the International Panel on Climate Change Working Group III’s Sixth Assessment Report on the Mitigation of Climate Change, released in April.

In a press conference announcing the report, IPCC Working Group III Vice-Chair Diana Ürge-Vorsatz told reporters that cities could make a difference by improving urban planning, promoting sustainable production and consumption of consumer goods, electrifying the grid and encouraging carbon storage through nature-based solutions like green roofs, tree planting, and urban lakes.

“There is significant potential for emissions reductions,” she said.

Both reports come as cities are finding ways to recover from the coronavirus pandemic, which has led to some creative ideas such as Barcelona’s plan to convert 21 streets–totaling 20 miles–into pedestrian green spaces, as Reuters reported. 

“As cities think about building for the post-pandemic future, they have a priority to provide their citizens with a more equitable and prosperous quality of life by protecting their natural resources,” Mauricio Rodas, co-chair of the Global Commission on BiodiverCities by 2030 and former mayor of Quito, Ecuador, says in the World Economic Forum press release.