42
Figure 2.1-1). In the 21st century, urban growth will be concentrated mainly in Africa and Asia (Figure 2.1-3). According to United Nations forecasts, the level of urbanization will rise to 56 % in Africa and to 64 % in Asia by 2050. The urbanization level in Europe, Latin America and North America is likely to rise only mod-erately. In 2050, 73 % of the global urban population are expected to be living in Asia and Africa (UN DESA, 2015); today the figure is approx. 65 % (Figure 2.1-4).
Large differences emerge when urbanization levels are studied in relation to a country’s level of develop-ment: in industrialized countries the urbanization level is likely to increase from 78 % in 2015 to around 85 % in 2050; in developing countries and emerging econo-mies, by contrast, an increase from 49 % to 63 % can be expected. Because of the higher population fig-ures in Asia and Africa, this will involve a significantly higher absolute increase in the urban population (Fig-ure 2.1-2). In India, for example, the level of urbaniza-tion only rose from 28 % to 31 % between 2000 and 2010, but that meant an absolute increase of 85 mil-lion inhabitants (UN DESA, 2015). About 90 % of total world-population growth is expected to be in Africa and Asia in the period 2014–2050. This corresponds to approx. 2.2 billion people (UN DESA Population Divi-sion, 2015) who will be needing housing, work and sup-plies of basic goods and services. This will pose major challenges for many countries in the coming decades, particularly in the context of informal urbanization
processes (Box 2.1-1). Seven countries are expected to account for about half of urban growth (1.24 billion people): India (404 million), China (292 million), Nige-ria (212 million), Indonesia, USA, Pakistan and the DR Congo (over 50 million each; UN DESA, 2014).
The shifts within the system of cities will continue in the coming years with a growing number of cities and mega-cities (Section 2.2.1). Until 1950, there were only two mega-cities with more than ten million inhab-itants: New York and Tokyo. Up until today, the num-ber of mega-cities has risen to 28 (Figure 2.1-5); by 2030 there are likely to be 41 mega-cities, which will then accommodate 14 % of the urban population (730 million inhabitants). In 2030, about 434 million inhab-itants (9 % of the world’s urban population) will live in 63 cities in the ‘emerging mega-cities’ size category of 5-10 million inhabitants. The number of urban resi-dents living in cities with 1-5 million inhabitants (called
‘medium-sized cities’ by the UN) is expected to increase most in absolute figures from 128 million to 1.13 bil-lion inhabitants in the period 1950–2030. The rela-tive share of the population in cities with between 0.5 and 1 million inhabitants in 1950 only came to 8.8 % and is expected to rise to 10.1 %, by 2030, which cor-responds in absolute terms to slightly more than half a billion people worldwide. Cities with fewer than 300,000 inhabitants are home to the largest share of the global urban population. Although their relative share of 60 % in 1950 will decrease to 38 % by 2030, Figure 2.1-1
City dwellers as a percentage of the population by countries; global distribution of cities with more than 500,000 inhabitants (2014).
Source: UN DESA Population Division, 2014 Percentage urban
80 or over 60 to 80 40 to 60 20 to 40 Less than 20
Urban agglomerations
Megacities of 10 million or more Large cities of 5 to 10 million Medium-sized cities of 1 to 5 million Cities of 500,000 to 1 million
43 approx. 1.9 billion people will be living in these cities in
2030 (UN DESA, 2015; UN DESA Population Division, 2014). While mega-cities and million-strong cities will thus experience most growth in relative terms, cities with fewer than half a million inhabitants will continue to be the most significant category in absolute popula-tion figures. The global distribupopula-tion of different types of cities has important implications for the functioning of national and international city systems and is there-fore much more than just a marginal statistic. The con-figuration of the national city systems is relevant, e. g., for local concentration overload, national decentraliza-tion and the centre-periphery divide, as well as for the global urban future (Section 2.2.1).
Urban shrinkage as a development trend
The opposite process to the global growth of cities and the urban population is that of urban shrinkage, which is neither a new nor a geographically limited phenome-non (Hollander et al., 2009; Martinez-Fernandez et al., 2012). Currently, large-scale shrinkage processes are to be found particularly in the USA (in the Rust Belt, e. g.
Detroit), Europe (e. g. Ruhr area, Manchester, Liver-pool) and Japan (Sorensen, 2006; Wiechmann, 2008), in the old industrial regions of China, and in the periph-eral regions (i. e. predominantly rural areas) of many developing countries and emerging economies. For the decade from 2014 to 2024, the United Nations predicts a fall in population for 3 % of cities (>300,000 inhabit-ants) worldwide (UN DESA Population Division, 2014).
A decline in the absolute urban population is expected
in 19 countries up to 2050, including Japan, Russia, Germany and Cuba (UN DESA, 2015). In Germany, e. g., 23 % of municipalities (with at least 5,000 inhabitants) recorded a decline in the population between 1990 and 2010; in the case of small and medium-sized cities, as many as 41 % are shrinking (BBSR, 2015); in France this is happening in 18 % of the municipalities, in Hun-gary in as many as 51 % (Wiechmann, 2015).
Whereas the urban shrinkage of the 1980s and 1990s in Europe was due to sub- and exurbanization processes – i. e. migration from inner cities to the sub-urbs, or residential relocations from densely populated areas to neighbouring rural regions – urban growth and shrinkage can be observed today as parallel processes in some regions (Turok and Mykhnenko, 2007). These Figure 2.1-2
Growth of the urban population (2002–2015): map of the world. The size of territories of the countries on the world map (a cartogram) is distorted. The country depictions are not based on land area, but on the number of additional city dwellers who moved to cities in the respective countries between 2002 and 2015.
Source: © www.worldmapper.org
Figure 2.1-3
Urbanization, a megatrend. Jakarta, Indonesia.
Source: Frauke Kraas/WBGU
44
are complex processes sometimes rooted in local pro-duction cycles with economic, demographic, spatial and social causes. In the former Eastern Bloc states, demographic effects (emigration and falling birth rates) were mainly responsible for urban shrinkage.
In many old industrial cities and regions, de-industri-alization processes are the primary cause of shrinkage processes. Especially cities with an import-competing economic structure that did not simultaneously initiate the switch to a service- and knowledge-based indus-try, are among the losers of structural change and the globalization of economic interdependency. These cit-ies not only lost jobs as a result of the more favourable production conditions abroad; their relative economic importance also declined as a result of the success of the export-oriented cities. Today they are
character-ized by high unemployment and emigration (Ezcurra and Rodriguez-Pose, 2013; Daut et al., 2014). A fur-ther consequence is a high level of housing vacancies.
Since buildings are durable goods, the excess supply of residential and commercial properties as a result of emi-gration manifests itself in the erosion of local real-es-tate prices. Despite far-reaching political interventions, such as subsidies and investment grants, it was almost impossible to stop the exodus from these structurally weak regions.
For a long time, in the context of a policy led by premises of growth, shrinkage processes were a phe-nomenon that was ‘not envisaged’ in urban and regional planning (Wiechmann, 2009). More recently, however, urban shrinkage processes have increasingly been addressed in urban planning, especially in
Ger-Figure 2.1-4
Urban population (columns) and level of urbanization (lines) by region (1950–2050).
Source: WBGU based on data from the UN DESA Population Division, 2014
0 1,000 2,000 3,000 4,000 5,000 6,000 7,000
1950 1970 1990 2010 2300 2050 0
20 40 60 80 100
Year
Urbanization level [%]
Urban population [millions]
Africa
Latin America and CaribbeanAsia
Europe North America Oceania
(0.7 billion/30% urban)1950 1990
(2.3 billion/43% urban) 2030
(5.1 billion/56% urban)
60%
3%4%
17%
9%
7%
50%
7%
7%
20%
7% 9%
38%
15%
9%
22%
6% 10%
>10 million 5–10 million 1– 5 million
0.5–1 million 0.3–0.5 million
<0.3 million
Figure 2.1-5
Global urban population distribution (absolute and relative) by city-size class (1950, 1990 and 2030)..
Source: WBGU, based on UN DESA Population Division, 2014
45 many (BBSR, 2015). In addition to developing new
economic locational strategies and concepts for the planned dismantling and conversion of abandoned residential areas, and the re-vegetation of formerly built-up areas, this requires a paradigm shift away from growth-oriented planning (Wiechmann and Pallagst, 2012). In view of generally declining tax revenues in shrinking cities, this conversion can pose great chal-lenges for cities, but it also offers chances for sustain-able development.
2.1.2
Drivers of urbanization
The growth of cities worldwide is driven by different dynamics, which are influenced by the natural location, the availability of resources, demographic structures, local or national economies, political systems and infra-structures. In addition to quantitative growth of cities in terms of area and population (accompanied by urban redevelopment or densification, e. g. through high-rise development), the term urbanization also means the diffusion of urbanity, i. e. urban qualities, economic activities and characteristics as a social phenomenon Box 2.1-1
Development of informal settlements worldwide:
status quo and forecasts
Informal settlements come into existence as a result of the rapid processes of urbanization, like those currently taking place especially in the cities of the emerging economies and developing countries (Davis, 2006: 31). These processes have been intensifying since the 1940s in South America, since the 1960s in South Asia, and since the 1970s in Sub-Saharan Africa (Bähr and Mertins, 2000; UN-Habitat, 2003). Impor-tant reasons for this were, and still are, the lack of afforda-ble, adequate housing created by both the public and private housing markets, poor governance, ineffective urban planning and low levels of investment in urban infrastructure. In addi-tion, informal urbanization processes are reinforced by rapid population growth and migration, especially by people with a low socio-economic status (UN-Habitat, 2014b; Section 7.3).
There are considerable deficits as regards the data basis, due to differences in the definition of informality (Box 2.1-2), the diversity of informal settlements, and related delimita-tion difficulties, as well as the lack of data available on the number of residents of informal settlements and their living
conditions in many countries (UN-Habitat, 2015d). Although there are no estimates on informal settlements, nearly a third of all city dwellers in emerging economies and developing countries lived in slums in 2014 (UN, 2015d). The number of slum dwellers as a relative percentage of the urban population actually declined between 2000 and 2014 from 39 % to 30 %;
in East, South-east and South Asia by more than 12 percent-age points (Figures 2.1-6, 2.1-7). The highest percentpercent-age remains 55 % in Sub-Saharan Africa. Overall, the living con-ditions of 320 million people were improved between 2000 and 2014 because they received access to either an improved water supply, better sanitation facilities, adequate housing or less dense living conditions (UN, 2015d: 60). However, the absolute number of slum dwellers rose worldwide to a total of 850 million people in 2012 (UN DESA, 2015).
In view of the continuing high level of urbanization dynamics especially in African and Asian cities, a severe lack of adequate, affordable housing will continue there in the near future if there is no massive effort to counteract this problem (Section 7.3). Otherwise, the number of residents of informal settlements could grow by a further 1–2 billion peo-ple by 2050 (UN DESA, 2013), with considerable impacts on the urban transformation towards sustainability.
Figure 2.1-7
Informal settlements of temporary migrants near the Yamuna river, Delhi, India.
Source: Frauke Kraas/WBGU Figure 2.1-6
Approx. 850 million people currently live in inadequate housing conditions; informal settlement in Seelampur, Delhi, India.
Source: Frauke Kraas/WBGU
46
(Heineberg, 2014: 31, 414 f.; Figure 2.1-8). Attempts to explain urbanization relate primarily to demographic, economic or societal processes, all of which are closely interwoven.
2.1.2.1
Demographic factors
Urbanization is initially a demographic process. The (relative and absolute) growth of the urban population is based on natural growth or immigration, as well as changes in administrative borders through the incor-poration of surrounding villages, etc. The importance of these processes varies over time and according to region (Jürgens and Bähr, 2009: 43).
In the industrialized countries, after the first major urbanization and city-founding phases in Antiquity and the Middle Ages, there was a further urbaniza-tion phase with a strong growth in the urban popula-tion between 1750 and 1950. It was triggered by the first demographic transition, as well as national and international migratory movements from the country to the cities, caused by industrialization and structural change in agriculture. In Duisburg, for example, approx.
60 % of the population in 1907 had relocated there, 13 % of these from abroad (Stewig, 1983). According to estimates, 50-55 million Europeans emigrated
over-seas between 1820 and 1920 (net migration, i. e. taking return migration into account), approx. 60 % of them to the USA (Bähr, 2010); many of these people settled in cities in search of work.
The pace of city growth in the developing countries and emerging economies, which, especially in Asia and Africa, did not begin until the second half of the 20th century in the course of decolonization, is currently much faster than in the industrialized countries (Sec-tion2.1.1). The main factor here is the surplus of births over deaths because of the young age structure (Heine-berg, 2014). Approx. 60 % of urbanization in develop-ing countries and emergdevelop-ing economies is due to natural growth, and almost all the remaining growth to migra-tion (country-to-city and city-to-city); only a small percentage is a result of the reclassification of admin-istrative units (UN DESA, 2015: 24). However, the per-centages vary regionally. While approx. two-thirds of the urban population increase in Sub-Saharan Africa is due to natural growth (Tacoli et al., 2015), the cor-responding figure in many Asian countries has fallen below 50 % since the 1990s (UN DESA, 2015: 24).
However, international comparisons are made difficult by incorporations of surrounding villages, etc., differ-ent definitions of the city, and a lack of data on migra-tion at the city level (Tacoli et al., 2015). In addimigra-tion, Box 2.1-2
On the (changed) understanding of informality
The concept of informality has developed since the 1970s in the discourses on economic development in the developing countries (Hart, 1973; Schamp, 1989; Escher, 1999). The term was taken up and spread by the International Labour Organization in its studies on development economics. The concept of informality referred exclusively to non-registered economic activities by poor sections of the population, e. g.
street traders, non-registered employees in the transport and repairs sector, or waste collectors in the cities of the emerging economies and developing countries. These areas were seen in contrast to formal, state-registered business activities.
This narrow view of separate sectors was gradually extend-ed to a study of two overlapping economic cycles (Santos, 1979). Prosperous informal sectors have only been taken into account in the more recent literature (Werna, 2001; Roy, 2009).
In the meantime, the interconnectivity of the formal and informal economies is hardly called into question, because a dichotomization of formality versus informality obstructs one's view of the many complex interactions between the actors involved. It therefore does not seem appropriate to classify the various transitions, mixed forms and entan-glements of socio-economic, political or cultural activities, arrangements and procedures as formal or informal.
Bearing this in mind, civil-society networks and private
investors have increasingly been included in the discourse on informal settlements alongside state organizations (Mitlin and Satterthwaite, 2004). In addition, the rigid contrasting of for-mality and inforfor-mality has been watered down. The various theoretical-conceptual developments that are merging the two dimensions are similar in this context. Terms used in the meantime include "informality-formality continuum" (Roy, 2005: 148), "degrees of complementary and supplementa-ry informalities" (Altrock, 2012: 176 f.) or "co-production by formal and informal actors" (Mitlin, 2008: 14). AlSayyad (2004) has even declared informality to be a new urban life form – based on Louis Wirth's article 'Urbanism as a way of life' published in 1939. Because of the remaining vagueness, other authors now question the benefits of the informality concept altogether, and refer to an analysis of 'negotiations of power, legitimacy and resources' for urban development that is independent of the concept (Herrle and Fokdal, 2011). This approach in particular points to the possibility or necessity of legitimizing urbanization processes outside the formal legal system (Herrle and Fokdal, 2011: 11 f.).
The term informality usually describes the grey zone of legal and illegal action (Section 2.5.2.2) and, in principle, cov-ers both non-conforming, legitimate processes and illegal, criminal processes. Although the transitions are fluid, they can basically be distinguished by whether the non-conform-ing processes aim to promote the common good or, for exam-ple, secure the chances of survival, or whether individuals or groups exploit the precarious situation of poorer population groups to get rich (Wehrmann, 2001).
47 migratory movements are difficult to quantify because
they can be multi-local and/or temporary (e. g. sea-sonal). In Thailand, e. g., it is estimated that one third of all internal migrants migrate temporarily to Bangkok every year during the dry season (Tacoli, 2011).
The distance and duration of migration are closely connected with the causes of migration (Kraas and Bork, 2012). These can include voluntary migration into cities (e. g. in search of better job opportunities, education or healthcare), officially initiated and con-trolled labour migration, seasonal labour migration, and forced migration caused by crises and conflicts.
In recent years, civil wars and conflicts in the Middle East and Africa (particularly Syria, Afghanistan, Iraq, Nigeria and Eritrea) and economic crises in the west-ern Balkan states (especially Albania, Kosovo and Ser-bia) have triggered large waves of refugees to Lebanon, Jordan, Pakistan, Turkey and Europe. The number of asylum applications in Germany, for example, rose from 127,000 in 2013 to about 500,000 in 2015; there was a total of over a million registered refugees (BMI, 2016).
Providing refugees with housing is a big challenge for cities and municipalities.
In addition to national and international migration, the ageing of the population associated with the demo-graphic transition is a key challenge. While over-60-year-olds currently make up 12 % of the population worldwide, in Europe the figure has already reached 24 % (UN DESA Population Division, 2015). In the USA, this ageing process is still greatly mitigated by immigration. By 2050 – with the exception of Africa – it is anticipated that at least a quarter of the popu-lation in all regions of the world will be over 60 years old (UN DESA Population Division, 2015). Especially in regions with high emigration, it is the older people who remain behind. In these regions, shrinkage and ageing are closely related processes that make a
transforma-tion process more difficult due to a lack of financial resources (Sorensen, 2006: 237). The rising average age of the urban population poses new challenges for many cities in the fields of housing, the residential environ-ment, transport and social services.
2.1.2.2
Economic factors
One important attraction of cities for migrants is the larger and broader range of job opportunities. For example, industrialization was an important driver of urbanization in industrialized countries from the 19th century onwards (Section 2.2.2). Globalization and the revolution in transport and communications have led to a reorganization of global economies with ever-increas-ing links between markets and a growever-increas-ing global divi-sion of labour (Hall and Pfeiffer, 2000).
Cities with an export-oriented sector mix bene-fit from the increasing integration in the world mar-ket, since the additional demand from foreign markets strengthens the local economy and creates new jobs.
Local economic activities that primarily manufacture goods for local and regional markets also benefit as a result of the more vigorous local consumption (Moretti, 2010) and from links along the value chain (Dauth et al., 2014).
Cities with an ample supply of building land and an unbureaucratic planning system or few regulatory restrictions respond to population pressure by build-ing new houses and apartments. When there are supply constraints, the population pressure leads primarily to higher real-estate prices (Glaeser et al., 2005). In cities with a high proportion of poverty groups and a lack of affordable housing, it is primarily informal settlements that grow when housing is in short supply (Section
Cities with an ample supply of building land and an unbureaucratic planning system or few regulatory restrictions respond to population pressure by build-ing new houses and apartments. When there are supply constraints, the population pressure leads primarily to higher real-estate prices (Glaeser et al., 2005). In cities with a high proportion of poverty groups and a lack of affordable housing, it is primarily informal settlements that grow when housing is in short supply (Section