World Urbanization
Aerial view of Sao Paulo at night
Credit: SNEHIT / Shutterstock
Summary
More than half the world’s population now lives in cities whose growth, both in numbers and surface area, is aggravating the problems of housing, traffic, pollution, energy consumption and social inequality. International organizations, NGOs and civil societies are calling for public policy changes in order to effect a transition to cities with low carbon emissions—cities that are more compact, more resource-efficient, and socially fair.
More than half the world’s population now lives in cities (55% in 2015 as against 30% in 1950 and probably 68% in 2050). This global urbanization means that cities are becoming ever denser, more sprawling and interconnected, the focus of both the innovations and pathologies of contemporary societies. Megacities are on the increase: 513 urban areas now have over a million inhabitants compared with only 16 in 1900 and none in the early nineteenth century. Five of these have more than 20 million inhabitants (Tokyo, Delhi, Shanghai, Mexico City, Sao Paolo).
Networks of cities
The great urban areas of the world form the architecture of the globalization process: they are both its decision-making centers and the hubs of physical networks. A dual process combines an ever-increasing dispersal of production activities thanks to the development of mobility, both physical (transport) and non-physical (telecommunications), with an over-concentration of innovation in cities (economies of scale and especially density of interaction).
Top 150 urban areas by population and GDP, 2014-2015
Comment: A comparison of two maps showing the 150 largest urban areas in the world reveals very strong distortions between population and wealth. On the one hand, some urban agglomerations of between 10 and 20 million inhabitants have a high GDP (New York, Los Angeles, London, Paris), and on the other there are very many, especially in Asia, which have an extremely large population and low or very low GDP. We should remember that the total GDP of an urban area sometimes conceals very considerable gaps in wealth between social groups and/or neighborhoods.
Ideas about cities are neither stable nor shared, and statistical sources use different definitions. During the 1960s, the megalopolis of the east coast of the United States was described as a conurbation concentrating capital, authority, and power (Jean Gottmann). By the late 1980s, there were three megalopolises in the world: the east coast of the United States, Tokyo-Osaka-Kobe in Japan and the European backbone stretching from London to Milan (Roger Brunet). In the late 1990s, the concept of world megalopolitan archipelago appeared (Olivier Dollfus), to describe all the great cities where command and innovation activities were concentrated. A city’s hierarchical position in the global urban system can be defined by its degree of connectivity of all types (informational, intellectual, banking and transport networks), but this analysis of hierarchy has now given way to the study of a vast complex network (Jacques Lévy).
Territorialization of inequality
Urban population growth and the continuing rural exodus toward cities explain the speed of urbanization and create a demand for housing, infrastructures and services which many cities are unable to fulfill.
Top 15 urban areas, 2030
Comment: According to UN forecasts, by 2030 all 15 of the largest urban areas in the world will have close to or more than 20 million inhabitants, 7 will have between 20 and 25, 4 will have around 30 and 2 will have more than 35 (Delhi and Tokyo). However, these figures have resulted from a variety of changes over the past 80 years: very rapid in the case of Asian and African cities, but slower in New York and Japan. Urban areas in the poorest countries are growing fastest.
This pressure is stronger in the cities of the South, where the exodus of the poorest permanently sustains shantytowns (or slums), made up of precarious dwellings on the edge of or even inside cities, in areas that are unbuildable, unfit for habitation, and dangerous.
Shanty towns and other types of informal habitat, 2014
Comment: The map showing the population living in shanty towns and other informal dwellings is particularly mixed. As part of the urban population (the colored areas), the level is over 40% in most African countries, and exceeds 90% in South Sudan, the Central African Republic, and Sudan. In terms of numbers (proportional circles), the highly populated emerging countries (China, India, Brazil) show a large number of people living in shanty towns, whereas their proportion of the urban population is lower than in Africa.
With no rights of ownership, the very poor who live there have no access to drinking water or sanitation. According to the 2015 UN-Habitat statistics, at least 881 million pe live in overcrowded, informally-built housing where they are subject to socio-spatial exclusion. While between 2000 and 2014, the share of the urban population in Southern countries who live in shantytowns declined (from 39% to 30%), the numbers in absolute terms continue to grow, reflecting very diverse situations according to place and time. In some cases, city officials, having first attempted to make these sites invisible (surrounding them with high walls), and then to raze them to the ground (they simply spring up elsewhere), have finally laid on a minimum level of services, and sometimes legalized them or provided materials for upgrading the buildings. In other cases, the inhabitants are left to their own devices, more or less separated into communities supported by NGOs, and subject to the violence of the informal economy or organized crime. Despite being cut off geographically and socially, these shantytowns are not completely removed from the official city since they provide it with domestic labor, odd jobs, and street trade, at the cost of commuting over very long distances.
In contrast to this residential segregation suffered by default are forms of territorialization chosen by the rich. They may involve the gentrification of former down-at-heel working-class districts in the town center, whose inhabitants have been driven out, or the creation of exclusive residential quarters sheltering gated communities. First developed in the United States from the 1970s onward on the peripheries of towns, they are now very common in emerging countries and in the South, contributing to the extension of the urban sprawl.
Reinventing the city?
This dual growth of cities, in terms of both people and space occupied, has led to an increase in daily commutes, pollution (accounting for three-quarters of global greenhouse gases), and consumption of raw materials and energy in amounts that can no longer be sustained.
Extension of urban sprawl in selected cities, 1975-2015
Comment: The extension of urban sprawl in the seven examples selected reveals very different relationships between the most densely populated urbanized area (vertical city) and its horizontal extensions (geographical) which commonly encroach on rural space (houses or shanty towns). Some structures are polynuclear, connected by densely populated axes (Pakistan, Vietnam), while others, especially the Hong Kong/Shenzhen/Guangzhou/Macao urban area, have very high densities within a perimeter of over 150 kilometers in diameter.
Since the late 1970s, successive international conferences have encouraged changes in public policies: these involve a transition toward low carbon emissions and more compact cities which manage resources carefully and are socially fair (1976 Vancouver Declaration, 1992 Rio Conference and Agenda 21, 1996 Istanbul Summit, and Habitat III in Quito). City networks (the 80 cities of the C40 Cities Climate Leadership Group), smart cities, eco-neighborhoods, slow cities or experiments with urban agriculture are all signs of a growing awareness, and changes are being proposed in the areas of transport, waste management, energy, water, and construction, but these often leave aside questions of equality and social inclusion.
- globalization > Globalization
- The term globalization refers to a set of multidimensional processes (economic, cultural, political, financial, social, etc.) that are reconfiguring the global arena. These processes do not exclusively involve a generalized scale shift toward the global because they do not necessarily converge, do not impact all individuals, and do not impact everyone in the same way. Contemporary globalization means more than just an increase in trade and exchanges, an internationalization of economies and an upsurge in connectivity: it is radically transforming the spatial organization of economic, political, social and cultural relationships.
- megalopolis > Megalopolis
- Concepts relating to urban environments are neither stable nor standardized between different disciplines and countries, which offer varying statistical definitions. Metropolization describes the trend for populations, activities and value to be concentrated in large-scale urban areas (key issues: economies of scale, accessibility vs sprawl, congestion, pollution, socio-spatial fragmentation, etc.). The major global conurbations constitute the architecture of globalization processes (hubs of decision-making and of physical networks). We are witnessing a dual dynamic in which production activities are dispersed (driven by increasing physical and information mobility), while innovation is over-concentrated in urban areas. The rapid growth of the global urban population and the densification of interrelations between urban areas suggest abandoning hierarchical analysis altogether and instead speaking of a global urban network.
- network > Network
- Classical geography tended to place too much importance on surface areas, territories, countries and soil, but network analysis has now become central to its approach. Networks are defined as spaces in which distance is discontinuous and consists of nodes linked by lines. Some are physical (networks for the transportation of people, goods and energy, IT cables and information super highways), others not. When they are partly virtual (such as the internet), they also involve individuals and organizations. Philosophers (Gilles Deleuze and Félix Guattari), sociologists (Manuel Castells), political scientists (James Rosenau), and economists use this concept to analyze the interconnected functioning of individuals.
- communities > Community
- According to the German sociologist Ferdinand Tönnies (1855-1936), community (Gemeinschaft) is the opposite of society (Gesellschaft) and denotes any form of social organization in which individuals are linked by natural or spontaneous solidarity, and driven by common goals. According to current usage, it applies to any social grouping that appears to be united, whatever its mode of integration (international community, European or Andean Community, or adherents of a religion). The ambiguous term of international community describes an ill-defined set of political actors (states, international organizations, NGOs, individuals, etc.) based on the idea of that humanity is united by common objectives and values or an allegiance to central political institutions, which is far from being the case.
- NGOs > Nongovernmental Organization
- Use of this expression became more widespread following its inclusion in Article 71 of the United Nations Charter. NGOs do not have an international legal status and the acronym is used in different contexts to refer to very different kinds of actors. It generally designates associations formed by individuals over the long term in relation to not-for-profit goals, often linked to values and beliefs (ideological, humanist, ecological, religious, etc.) rather than financial interests. Active on a wide range of issues at both the local and global levels, NGOs now number tens of thousands, but vary greatly in the scale of their budgets, staff and development.
- informal economy > Informal economy
- The concept of the informal sector (International Labor Office, 1970s) initially designated specific types of employment then widened to describe a phenomenon affecting all economies. Between 50 and 75% of the labor force in developing countries works in the informal economy (excluding agriculture) in businesses that are unregistered and unincorporated, producing goods or services for sale or barter (International Labor Organization). Insecure, poorly paid and lacking social protection, informal workers belong to the most vulnerable groups (poor women, children, rural or international migrants). The people employing them evade legislation, taxes and inspections to some degree. Home-based labor, unreported subcontracting and second jobs connect the formal and informal sectors. The illegal nature of the informal economy prevents any measurement of its contribution to national GDP.