What can the Global South teach us about sustainable cities?

Cities across the Global South have long been overshadowed by their richer, more industrialized counterparts.

From segregated bike lanes to the 15-minute city, urbanist trends are still largely set by cities in Europe, North America and the more affluent parts of Asia.

But that’s slowly changing. Now, cities elsewhere are breaking free and claiming their place in the foreground.

One city that exemplifies this shift is Freetown, the capital of Sierra Leone in West Africa.

Following over 150 years of British colonial rule, the city was inadequately equipped to manage the demands of rapid growth following independence. 

Its troubles were exacerbated by the rapid expansion of informal settlements that lacked clean water, electricity and sanitation, as well as widespread poverty – not to mention the devastating civil war between 1991 and 2002 and the Ebola outbreak of 2014.

Despite these challenges, Freetown has taken impressive steps to become a more sustainable city.

Last year, it made headlines for its mayor’s transformative initiatives, including groundbreaking efforts in sewage treatment, the planting of nearly a million trees, and the appointment of Africa’s first-ever urban heat officer.

These achievements challenge the common narrative that innovation and inspiration flow in one direction: from rich countries to poorer ones.

So, what can cities worldwide learn from the latest urban innovations in the Global South?

Here are some success stories from Freetown and other cities across Africa, Asia and Latin America to inspire the future of sustainable urbanism.

Good leadership drives change

Cities in the Global South often face deep-rooted systemic challenges that hinder economic and social progress.

One such obstacle is interference from national politics, says Kenneth Lynch, a professor at the University of Gloucestershire.

“A large city like Freetown, in a state like Sierra Leone, can become dominant. It can be what we might call a primate city – that means it becomes nationally very important politically.”

What happens in Freetown, according to Lynch, affects all of Sierra Leone – drawing the attention of national politicians, who all too often prioritize their own interests at the city’s expense.

This means cities, especially those in the Global South, need strong leadership to drive meaningful change of their own accord and stave off interference from above.

Since 2018, Freetown has been led by mayor Yvonne Aki-Sawyerr, who has proven one of Africa’s most inspiring and ambitious urban leaders.

Her flagship initiative, Freetown the Treetown, aims to plant 1 million trees to bring back the city’s lost forests, which had been devastated by rapid urbanization.

This bold reforestation initiative has already far exceeded its original goal, with 1.9 million trees planted as of May 2024. It has now set an ambitious new target of planting 5 million trees by 2028.

“The rate of growth of the population of our city, the lack of planning, and challenges around the way building permitting is done at a centralized level have meant that in spite of five years of hard work, we still see that there’s more that we can do,” says Aki-Sawyerr.

Aki-Sawyerr received the 2024 German Africa Prize for her achievements in transforming Freetown. She also featured in Time Magazine’s 2021 TIME100 Next and 2023 TIME100 Climate lists for her environmental advocacy.

Plan around nature – not against it

The challenge of transforming regions in the Global South into sustainable urban cities largely stems from colonial-era urban planning.

African urban planning approaches were heavily influenced by European colonial ideologies, which were primarily designed to serve the interests of the colonizers at the expense of native people.

This included spatial segregation that separated natural spaces from human settlements, purportedly for sanitary purposes.

“It is kind of a colonialist dream or fantasy that you can design the environment out,” says Lynch.

Rural-to-urban migration often forces individuals into high-risk areas or informal settlements, where they are exposed to multiple environmental hazards, including floods, landslides, wildfires and heatwaves.

“What you’re creating is this kind of dream – that in a city, you’re going to be exempt and immune from environmental hazards. But actually, you may be creating the conditions for those hazards to be worse. In that situation, we need to be aware of those risks and plan for more resilient societies.”

Lynch argues that urban planners should aim to mitigate the impacts of these disasters rather than “controlling nature” – instead seeking to integrate the natural environment into cities.

One such example is sponge cities – a groundbreaking approach that uses natural elements such as wetlands, parks, and permeable surfaces to capture and manage rainwater efficiently.

Invented in China by landscape architect Kongjian Yu, the sponge city concept primarily aims to mitigate flooding by ‘soaking up’ excess water using vegetation and porous earth.

Key to the success of these ‘sponges’ is tailoring them to natural factors such as topography, rainfall patterns and native plant species, while also addressing specific community needs.

Sponge cities have since spread outside of China and been implemented across the globe, including in Berlin, Jakarta and Auckland.

Meanwhile, the success of the ambitious Freetown the Treetown project has turned it into a highly replicable model that other cities can follow.

Give the people a say

One of the keys to tackling urban environmental challenges is to expand community participation. This can build long-lasting change by ensuring that solutions align with the needs of local people. 

Lynch says policymakers must actively listen to their constituents and take swift action when issues are brought to their attention.

“If we are more aware of what causes the problems in our area, we can ask with more evidence for things to be done about it,” he explains.

In 2021, Freetown appointed Africa’s first chief heat officer, Eugenia Kargbo, to tackle the impacts of rising temperatures as part of its broader Transform Freetown initiative.

Kargbo’s work goes beyond addressing the immediate challenges of rising temperatures and places particular focus on low-income women.

“Women are one of the most disadvantaged groups exposed to extreme heat,” she says.

The dedication of Freetown’s women leaders shows how policymakers can drive positive change in cities – especially when they put communities and their people at the heart of this transformation.

In some cities, residents even have a direct say on how their taxes are spent.

This is known as participatory budgeting, which gives local people a say in how their local government spends its budget, allowing them to share their ideas and priorities to improve their community.

First implemented in Porto Alegre in southern Brazil in the late 1980s, participatory budgeting has proven effective in mobilizing communities, especially low-income groups, to drive transformative urban change.

The process has since been adopted in cities around the world, including Warsaw, Chicago and Espoo and Lahti in Finland.

These cities are challenging the culture of top-down governance and highlighting the importance of listening to – and learning from – those directly affected by urban policies.

“That’s what can give us transformed and resilient and healthy cities – not necessarily always looking for the big top-down solutions,” says Lynch.

“And certainly not listening to populist politicians who simply stand and criticize and stamp their feet – particularly those who already have a lot of wealth and don’t really understand what it is to be poor, to face the challenges that people face in informal settlements around the world.”

One size doesn’t fit all

While the world’s cities may face many of the same challenges, each city’s circumstances are unique, and solutions must always be tailored to the local context.

Still, Lynch argues that there are plenty of lessons that cities can learn from each other.

In the Kenyan capital, Nairobi, he recalls an inspiring proposal to connect informal settlements to the city using cable cars – a solution popularized by Medellín, Colombia. Aki-Sawyerr is considering a similar system for Freetown.

Another groundbreaking transport innovation is bus rapid transit (BRT) – essentially a metro system operated with buses, with dedicated bus lanes and stations to drastically increase capacity and reliability compared with regular buses.

This innovation, which emerged in Curitiba, Brazil, in 1974, has inspired similar mass transit systems worldwide, including TransMilenio in Bogotá and TransJakarta in the Indonesian capital, which has grown into the world’s largest BRT system.

“Everyone has to be listening,” says Lynch. “You often hear people say ‘don’t just stand there – do something.’ I say, ‘don’t just do something – stand there,’ because we have to stop and reflect.”

Reflecting on his study in Sierra Leone, Lynch feels deeply inspired by the people of Freetown. He senses an “incredible resilience and sense of hope and an unwillingness to go back to the problems they experienced during the civil war.”

“They’re really very keen not to go back.”