On the periphery of Lagos, Nigeria, lies Makoko, a burgeoning slum community perched on a lagoon. Residents live in makeshift homes on stilts made of collected wood and tarp, and get around primarily by canoe.  Once a small fishing village, Makoko now draws migrants from neighboring countries, who flock to Nigeria for low-paying, unskilled jobs.

In many ways, Makoko serves as a microcosm of urbanization in Sub-Saharan Africa, which has the world’s fastest pace of urban population growth:

  • 6 of the 10 countries with the highest urbanization rates in the world in 2013 are in Sub-Saharan Africa.
  • Nigeria itself has the 9th largest urban population in the world, surpassing 80 million in 2013. It also ranks as the country with the most urban dwellers in all of Africa.
  • The world’s total urban population reached an estimated 3.8 billion in 2013, and is projected to swell to nearly 6.3 billion in 2050.
  • Since 2008, a majority of the world’s population reside in urban areas.

This post takes a closer look at the data on urbanization in World Development Indicators. But a word of caution is necessary first: the definition of urban areas varies from country to country and may not be consistent among different data sources within a country. The urban/rural estimates rely on data produced by national sources, which reflect the definitions and criteria established by national authorities. Due to variations of each country’s overall population size, national statistical offices are in the best position to establish the most appropriate criteria to characterize urban areas in their respective countries (United Nations Population Division).

Urban population growth key to attaining middle income status
According to the World Bank publication Urbanization and Growth, no country has ever attained middle-income status without urban population growth.  But urban growth is not always painless for policymakers and the general public.

Well, what’s happened in Nigeria? The country moved from low to lower-middle income status in 2008; and earlier this year, Nigeria’s GDP estimates were improved and revised upward, revealing that it is Africa’s biggest economy and the 23rd largest in the world  at $522 billion in 2013. At the same time, Nigeria is confronting growing problems of pollution, traffic congestion, and poverty in its urban communities in Lagos. And Nigeria is not alone in these issues.

Real adverse environmental affects of urbanization

When we think of cities, we often picture crowded streets, constant traffic, heavy pollution, and strained resources.  This isn’t an inaccurate assessment—urban growth is often correlated with all of these things and urbanization can have adverse environmental effects,  concentrating pollution and harming health. Data show us that as the urban population grows, so does energy useCO2 emissions, and motor vehicle ownership.  It’s no wonder, then, that crowded areas like Makoko can be a logistical obstacle for governments. In 2012, parts of Makoko were knocked down for being “an environmental nuisance, security risk and an impediment to the economic and gainful utilization of the waterfront.”

It’s not all bad news, though.

Upside to urbanization: better access to water and sanitation
Urban living is also linked to higher school completion rates and improved water and sanitation facilities.  In Sub-Saharan Africa, about 80% ofthe urban population has access to an improved water source, compared with 53% of the rural population. And access to improved sanitation facilities in urban areas is almost twice that in rural areas. View the gaps between urban and rural access to water and sanitation in Sub-Saharan Africa in the charts below.

Urban population growth in other regions

While Sub-Saharan Africa outpaces all other regions in urban population growth, the actual proportion of urban population is the highest in Latin America and the Caribbean.  79% of the people in this region reside in urban areas, a rate that is followed by both the Europe and Central Asia, as well as the Middle East and North Africa regions at 60%.

The aquatic community of Makoko is just one example of how cities expand to accommodate population growth.  More data on population can be found in the World Development Indicators database as well as the Population Estimates and Projections database.

Indicators used in this post:
GDP (current US$) NY.GDP.MKTP.CD
Urban population growth (annual %) SP.URB.GROW
Urban population (% of total) SP.URB.TOTL.IN.ZS
Energy use (kt of oil equivalent) EG.USE.COMM.KT.OE
CO2 emissions (metric tons per capita) EN.ATM.CO2E.PC
Motor vehicles (per 1,000 people) IS.VEH.NVEH.P3

Published in collaboration World Bank

Author: Leila Rafei works with the Client Services and Communications (CSC) team of Development Data Group.

Image: Kenyan workers prepare clothes for export at the Alltex export processing zone. REUTERS/Thomas Mukoya