Around the world, cities are expanding. In North America, according to figures from the United Nations, 82% of the population live in urban areas, closely followed by Latin America. In Europe the figure is 74%. Compared to this, Africa is still fairly rural, less than half of its population (43%) live in cities.

But this is bound to change. While today's global average of city dwellers is 55%, the UN forecasts more than two-thirds of the world's population will live in urban areas by 2050. And Africa and Asia will drive this increase: Of the two and a half billion people that will be added to the world's urban population, 90% will be Africans and Asians.

A random gathering of 100 urban men and women today would include 13 Africans. In three decades, that figure is expected to have risen to 22.

Still, differences remain. Some countries, such as Niger, Burundi, Rwanda, and Malawi, remain largely rural, with only one in five inhabitants living in an urban area. Despite the lure of its megacities, Nigeria accounts for the continent's largest rural population (95 million), followed closely by Ethiopia (85 million).

Urban to beat rural in 2033

But the trend towards the city is unstoppable. Around 2033, the balance will shift: From that point on, Africa's urban population will exceed its rural population, rising to 60% by 2050.

Today, Southern Africa tops the chart of Africa's most urbanized regions. North and Central Africa are also highly urbanized and well past 50%, with West Africa quickly catching up. The West Africa region — which includes Nigeria and the bustle of the Lagos metropolis — holds the largest share of Africa's urban population and is set to keep that position. In Central Africa, the huge Democratic Republic of Congo stands out, which on its own will be home to an urban population of 126 million by 2050.

Uncontrolled construction and climate risks

The downside is that the rapid urban expansion is almost impossible to control and regulate. People living in Congo's megacity Kinshasa, in the Sahel cities of Niamey and N'Djamena, or in the Ivorian metropolis Abidjan can tell a tale of the devastation caused by recurring floods, sweeping away makeshift houses in floodplains.

According to the African Cities Research Consortium, a UK Foreign Office research program, about 60% of the urban population in sub-Saharan Africa live in informal settlements — areas that are increasingly vulnerable to the impacts of climate change. "They are more facing higher exposure to climate risks, while having a lower capacity to adapt," according to the online report.

Africa's megacities no doubt have an important role to play in channeling urbanization. And their numbers are increasing: Cairo, Kinshasa, and Lagos are the only cities on the continent with more than 10 million inhabitants today, but Luanda and Dar es Salaam will join them by 2030. By then, Congo's capital Kinshasa, currently roughly on a par with the Nigerian economic metropolis Lagos, will have almost reached Cairo's population — and by 2035 will be home to 25 million people.

And yet, the picture would not be complete without the smaller cities: More than 90% of Africa's cities have fewer than 100,000 inhabitants. One in three of the continent's urban dwellers — about 185 million in all — live there. It is at this lowest level that the urbanization is taking form, street after street penetrating rural areas and absorbing the surrounding rural communities.

Small and medium cities drivers of urbanization

The Africapolis online data platform also uses the measure of spatial proximity of cities to describe ongoing urbanization: If the average distance between metropolitan areas was 61 kilometers (38 miles) in 1950, it had already shrunk by 40 kilometers by 2015.

"Small agglomerations are the most important link between rural and urban areas," according to a study by Africapolis. These small towns would offer the rural population the opportunity to sell their produce at markets, to access health and public services, and go looking for jobs.

This article was adapted from French by Philipp Sandner.

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