There are dramatic regional differences in the pace and scale of urbanisation. Some of the cities predicted to be among the largest in the world in 2025 were no more than villages and small towns in 1950. Then, Shenzhen had 3,148 inhabitants, Kinshasa 0.2 million, Jakarta 1.4 million, Chicago five million and London 8.4 million. In 2010, these five metropolitan areas all have roughly nine million inhabitants. By 2025, it is predicted that Chicago will reach ten, Jakarta and Shenzhen 11, and Kinshasa 15 million. London’s population, on the other hand, is predicted to be no larger than it was 75 years before. The map above charts the size and growth of a selection of world cities with more than a million people from 1950 (white circle) to 1990 (light green circle) and indicates the projected growth to 2025 (dark green circle) based on UN predictions.
While growth in many European and North American cities reached its peak by 1950, the rest of the world saw its cities grow most significantly in the next four decades. Tokyo grew by more than half a million inhabitants each year between 1950 and 1990, Mexico City and São Paulo by more than 300,000 each per year, Mumbai by around 240,000 per year and Manila and Cairo by approximately 160,000 per year. The only exceptions in this period were cities in China and Sub-Saharan Africa, which experienced only modest growth. But from the 1990s onwards, while cities continued to grow rapidly in South and South-east Asia (622,000 new inhabitants per year in Delhi between 1990 and 2010), cities in China started their growth spurt. The South Guangdong metropolitan area (which includes Shenzhen, Guangzhou and Dongguan) saw its 5.5 million inhabitants in 1990 increase six-fold to reach almost 32 million in just 20 years. In the next 15 years, it is predicted that the most rapid urban growth will take place in Sub-Saharan Africa where cities like Ouagadougou, Dar es Salaam and Kampala will double their population, and Lagos and Kinshasa will have to accommodate more than five and six million new inhabitants respectively. These predicted trends can be seen in the annual population growth rates for the 2010 to 2025 period highlighted for a selection of cities on the map.
The two charts above show the broader urbanisation and health contexts within which these differential patterns of metropolitan population growth across the surface of the globe are occurring. The first displays the evolution of urbanisation levels for world regions, highlighting that the world’s population is still divided; with one half living in highly urbanised nations and the other in nations in which most live in rural areas. The second chart shows the speed with which emerging economies in Latin American and Eastern Asia have caught up with North America and Europe in terms of life expectancy: Eastern Asia has gained close to 25 years of life in the space of 50 years. It also reveals how hard life expectancy in Africa has been hit by the HIV/AIDS epidemic, which derailed it from its growth path in the 1990s, causing it to trail close to ten years behind South Central and West Asian countries.