Sustaining cities

Marginal Column


  • German Federal Agency for Civic Education, *Dossier Megastädte
  • UN-HABITAT, United Nations settlements program,
  • National Academy of Engineering, Megacities and the Developing World,
  • UrbanTec, Smart technologies for better cities,

Megacities like Lagos, Mumbai and Mexico City generate numerous problems but also exercise an enormous attraction.


The experts are not entirely in agreement, but it certainly happened sometime in 2007 or 2008: for one fraction of a second, exactly half the world’s population lived in rural areas and the other half in cities. Since this notable moment, the trend has been moving inexorably in just one direction; the future of humanity is in the cities. The United Nations settlements program UN-Habitat estimates that up to 70 percent of the world’s population will be living in cities by 2030 – a trend that is being reflected in the terminology. The largest representatives of the class “city” are bursting their bounds and becoming “megacities”, “metropolises” are morphing into “megalopolises”.

Quantitatively, the UN defines a megacity as a conurbation comprising over ten million inhabitants. There were only two megacities, New York and Tokyo, in 1950. By 2000, this number had already grown to over 20. Today, depending on the source, up to 40 urban areas qualify as megacities – and climbing. With over 35 million inhabitants, the Tokyo metropolitan region is the largest of the megacities. The list of the “smaller” urban giants, with populations of around ten million, is becoming steadily longer, particularly in Asia. The number of million-plus cities is also mushrooming. The United Nations forecasts around 300 cities of over one million residents by 2015. However, experts agree that the sources cited in association with urbanization cannot always be verified. Also, many figures become obsolete before they can even be documented.

Enormous attractiveness in spite of massive problems

Megacities are contradictions made of stone, steel and plastic tarps. On the one hand, the internal structure of most mega- agglomerations is pushed to its limits. The often uncontrolled growth gives rise to economic, ecological and social problems; many megacities are struggling with chaos, poverty and environmental decline. On the other hand, the giant cities attract large segments of the population. In South Korea, for example, around half of the entire population already lives in a single city (Seoul).

And in spite of all their problems, the cities are still most able to build a functioning infrastructure for large numbers of people – not only as a living environment, but as an economic setting, as well. For example, with around 13 million inhabitants, Dhaka, the capital of Bangladesh, is home to only around nine percent of the total population but generates over 60 percent of the gross domestic product of the entire country. A report of the German Federal Agency for Civic Education (Bundeszentrale für politische Bildung bpb) goes a step further and concludes that it is the megacities that are contributing to solving, or at least alleviating, the main problems of humanity: “What would the environment look like if population pressure were not dampened by concentration? Even China cannot provide its rural population with essential services like schools, doctors and hospitals in spite of its enormous economic growth.”

Creative energy ensures survival

What is the source of the obvious strength and survival capability of large cities? As far back as 1996, UN-Habitat noted that the basis of the cities is self-organization. Urbanization expert Dr. Rüdiger Korff * from the University of Passau also believes that the survival of cities does not depend primarily on government oversight and planning but on the inhabitants’ creative energy: “A dynamic, livable city cannot be created either by planning or through the free-market economy, but only by the city’s inhabitants themselves.”

Additionally, a functioning basic infrastructure plays a decisive role for the future of the cities and their inhabitants. Problems of utilities supply, waste management and traffic demand new solutions. Energy efficiency, climate protection, transportation infrastructure, waste recycling and water supply are the pillars on which modern cities can continue to grow. According to the OECD, this demands investments of over 30 trillion euros by 2030. That represents a huge opportunity for the global economy – and for the 70 percent of humanity that will be living in the cities by then.