Africa’s cities are growing rapidly, and that growth is not necessarily a problem. Urbanisation can connect people to jobs, services, markets and economic opportunities. But as populations increase and built-up areas expand, cities can also become more exposed to flooding, extreme heat, water stress and other environmental risks. The important question, therefore, is not whether African cities should grow, but whether they are growing in ways that increase or reduce vulnerability.
Climate vulnerability is not simply a consequence of living in a city. Risk emerges from the interaction between a hazard, the people and assets exposed to it, and the conditions that make them more susceptible to harm. How a city grows therefore matters: where homes and businesses are built, how land is used, whether infrastructure keeps pace with development, and whether natural systems such as wetlands and green spaces are preserved can all influence the level of risk a city carries.
Urban growth can change the way risk is distributed
Flooding provides a clear example. Heavy rainfall is a hazard, but rainfall alone does not explain why one neighbourhood experiences severe disruption while another does not. Development in flood-prone areas, inadequate drainage, blocked waterways, impermeable surfaces and infrastructure that has not kept pace with urban expansion can all increase exposure and vulnerability. Rapid and unplanned urbanisation is increasingly recognised as a factor that can compound flood risk in growing cities, particularly when infrastructure and urban management lag behind expansion.
The same principle applies to heat. Recent World Bank analysis found elevated urban heat in Lagos, Ibadan, Benin City and Port Harcourt, with areas experiencing higher surface temperatures often corresponding with a lack of water bodies and green spaces. Urban expansion and the replacement of natural landscapes with built surfaces can further intensify these effects.
This means vulnerability is rarely distributed evenly across a city. Two communities can experience the same rainfall or temperature conditions but face very different consequences because their infrastructure, location, environmental conditions and access to services are different.
Infrastructure is part of the equation
Many African cities are already dealing with significant infrastructure deficits. Roads, drainage systems, water supply, waste management and housing often have to support populations growing faster than existing systems were designed to accommodate. Climate pressures add another layer to this challenge.
The issue is therefore not simply about building more infrastructure. It is about understanding where infrastructure is needed, what conditions it needs to withstand and how development decisions may create or reduce future risk. A drainage system that does not account for changing rainfall patterns may provide inadequate protection. Development in environmentally sensitive areas can create vulnerabilities that become far more expensive to address later.
Urban planning and disaster risk management consequently need to work together. Resilience depends not only on physical infrastructure but also on land-use planning, risk assessment, governance, early warning systems and the capacity to maintain and manage infrastructure over time.
Africa still has an opportunity to build differently
There is an important reason not to frame this only as a story of growing vulnerability: much of Africa’s urban transformation is still ahead.
The 2026 State of African Cities Report projects that Africa’s urban population could reach 1.4 billion by 2050 and notes that more than half of the continent’s future urban infrastructure has yet to be built. This presents a significant challenge, but also an opportunity. Decisions made now about land, infrastructure, services and urban planning can influence whether future growth locks cities into existing vulnerabilities or creates more resilient urban systems.
This matters because urban development can be difficult and expensive to reverse. Once settlements expand into flood-prone areas, natural drainage is lost or critical infrastructure is built without adequate consideration of environmental conditions, correcting the problem can require substantial investment. Understanding risk before development takes place can therefore be more effective than trying to retrofit resilience afterwards.
Better decisions require better information
This is where data becomes critical.
A city cannot effectively manage risks it cannot see. Decision-makers need to understand not only where a city is today, but how it is changing. Population data can show where pressure on services is increasing. Geographic and satellite data can reveal changes in land use, vegetation and built-up areas. Infrastructure data can highlight where systems are under strain, while climate and hazard data can help identify areas where environmental risks are increasing.
The real value comes from connecting these different forms of information. A flood map, for example, tells only part of the story. Understanding which communities and critical infrastructure fall within that area, how the land has changed and what infrastructure exists there provides a much more useful picture of vulnerability.
This is why cities need more than data collection. Data must be organised, connected, analysed and translated into information that can support decisions. Otherwise, valuable information can remain fragmented across institutions and systems, making it difficult to understand the bigger picture.
Growth should not have to mean greater vulnerability
African cities will continue to grow, and that growth is essential to the continent’s economic and social future. The challenge is ensuring that urban development keeps pace with the risks that accompany it.
That means asking better questions: Where is development happening? Which communities and assets are exposed to environmental hazards? What is changing in the natural and built environment? Which infrastructure systems are under pressure? And what does the available data tell us about how these risks could evolve?
The goal is not simply to build bigger cities, but to build cities that can grow while remaining liveable, resilient and responsive to changing conditions. Better data cannot achieve that on its own, but it can help governments and organisations understand what is changing, identify where risks are emerging and make more informed decisions about what to do next.
For African cities, the opportunity is clear: growth does not have to mean greater vulnerability. But making growth more resilient will require us to understand the places we are building, the risks they face and the data that can help us plan better.
