5 Sustainable urbanization and human security
Introduction
For the first time in history, the majority of the world population now lives in cities. By 2050, two in every three persons will live in urban areas, and virtually all population growth during this period, around 3 billion people, will be absorbed by cities, primarily in developing countries (UN, 2008). Considering the impending consequences of global warming, such as accelerating sea level rise and more extreme weather patterns, we might see an even stronger urbanization trend. Adverse climate is a potential additional contributor to rural-urban migration everywhere, and in particular in poorer countries where livelihoods, economies and political structures may be inept at local adaptation (e.g. Barnett and Agder, 2007; Tacoli, 2009; Raleigh and Jordan, 2010). Various forms of environmental change can also directly limit adaptive capacities and wellbeing of urban dwellers.
City growth and migration to urban areas are both drivers and byproducts of economic development. Yet, a growth that is too strong can be a challenge. Rapid urbanization puts significant demands on a society’s ability to provide public services like adequate housing, electricity, water supply, health care, education, and jobs. Widespread shanty towns around major cities in the developing world epitomize the challenges of accommodating a fast expanding population. According to a recent survey, many governments of developing countries now explicitly discourage urbanization; 78 percent of African and 71 percent of Asian countries have implemented policies to reduce migrant flows to large cities (UN, 2008: 12).
Rural-to-urban migration is often seen as a consequence of high and increasing population pressure in the countryside, with associated scarcities of renewable resources like cropland, forests, and freshwater (Homer-Dixon, 1999; Barrios et al., 2006). Various forms of environmental degradation, including desertification, prolonged droughts, and soil salinization, are other factors that might deteriorate agricultural livelihoods and push people to the cities. On the other hand, rapid urbanization may cause many of the same environmental problems that plague densely populated and poorly managed countryside: water scarcity and contamination, land shortage, and insufficient sanitation (Brennan, 1999). And while opportunities for employment are usually better in urban areas, the labor market will struggle to absorb fast-growing populations. Higher income inequalities and differences in privileges among city dwellers is another likely source of urban frustration and despair. While urbanization in itself does not necessarily constitute a threat to peace and stability, urban pressures within the context of economic stagnation and poor governance could increase the risks of violence and political turmoil (Gizewski and Homer-Dixon, 1995).
A commonly voiced goal in the arena of international sustainable development is to provide the coming generations with a secure future, formally expressed and popularized in the World Commission on Environment and Development (WCED, 1987). So far, however, there has been little consideration of what responses will be needed in urban areas affected by environmental change and rapid population growth. Indeed, the debate on social consequences of climate change is disproportionately focusing on rural communities and concerns. In an effort to fill this gap, this chapter focuses on the ways through which aspects of human security can be developed into a central framework for organizing the debate over the sustainability of metropolitan areas.
The rest of the chapter proceeds as follows. It first describes recent and likely future trends in urban population growth with a particular focus on developing countries. It then discusses whether and how environmental change in conjunction with rapid population growth may affect urban security. Findings from emerging research on determinants of urban social disorder suggest that rapid urbanization may be less of a security threat than often assumed. The chapter then briefly discusses what responses are needed at the city-level to cope with the joint challenges of growing populations and climate change, and concludes and identifies some priorities for a future research agenda on sustainable cities.
Trends and projections in global urban population
The world’s population crossed the 7 billion mark in 2011 and the number is rising by about 75 million per year. Current projections indicate that there will be about 9.3 billion people on earth by 2050. However, in absolute terms the growth rate of the global population peaked in the late 1980s (at about 88 million per year) and the relative growth rate (currently at 1.1 percent per year) has halved since it peaked in the early 1960s (US Census Bureau, 2010). The “population explosion” originally set the stage for numerous Malthusian doomsday claims (e.g. Ehrlich, 1968) and continues to dominate the environmental security discourse today (e.g. Redding, 2007; see Urdal, 2005 for a review). Yet, there is another less acknowledged major demographic trend that could have very significant security implications: urbanization. According to UN statistics, the global share of the urban population increased more than fourfold during the twentieth century, and while population growth rates are gradually stagnating, urbanization continues at high speed. In coming decades, the largest urban population changes are expected to occur in developing countries in Asia and Africa, particularly in coastal areas (Goldstone, 2010; Hunt and Watkiss, 2011).
Urban population growth is the joint product of three phenomena: natural increase, rural-to-urban migration, and reclassification of rural land (Cohen, 2006; UNFPA, 2007). Although the relative weights of these contributing factors vary significantly between different urban areas, the most important source of urban population growth in developing countries is natural population increase – i.e. a high birth-to-death ratio (UNFPA, 2007: 5, 13). As fertility rates are expected to drop with social and economic development (Mason, 1997), rural-to-urban migration may become the most powerful driver of urbanization in the future. Urbanization is tightly linked to development; some of the most rapidly urbanizing countries over the last fifty years, such as Botswana and the United Arab Emirates, have experienced exceptionally high economic growth rates. Indeed, no country in the industrial age has managed sustained economic growth without urbanization. As the economies in the developing world are expanding, so are the urban populations. While people may flee a countryside dominated by personal insecurity, poverty, and environmental degradation, urban centers tend to offer a higher level of services such as health care and education. Greater urbanization could mean a more efficient use of energy, and the combined demographic trends of global population ageing and urbanization have been suggested to lead to lower global emissions (O’Neill et al., 2010).
With global warming and accompanying challenges, such as sea level rise, more extreme weather, and general deterioration of agricultural productivity in parts of the world, the global rate of migration and urbanization might increase even further (McGranahan et al., 2007). Picking up on this possibility, a report by Christian Aid (2007: 1) warns of a “human tide” and considers migration “the most urgent threat facing poor people in developing countries.” Other studies are much more cautious in their wording (e.g. Bardsley and Hugo, 2010; Raleigh and Jordan, 2010). The multi-causal nature of human migration implies that any attempt to quantify the extent of future “environment-induced” urbanization will be fraught with uncertainty. Regardless of the importance of environmental push factors relative to economic and other motives, however, the crucial reality remains: nearly all population growth within the next few decades will be absorbed by cities.
Population pressure and political violence
Proper management of urban growth and changing population structures is key to preserving human security. Rapid population growth can seriously constrain local governments’ ability to provide basic services, including employment, housing, electricity, water, and enforcement of law and order and development of social capital, thus greatly affecting the quality of life of the citizens. According to Goldstone (2002), it is exactly when overurbanization combines with underdevelopment – where the job market and the economy cannot keep up with urban population growth – that violence and instability may arise. Similarly, the mixing of ethnicities and shifting demographic composition of urban centers are cited as central destabilizing factors in urban environments. Climate-induced urbanization and temporary rural-to-urban distress migration are likely to add to these challenges (Raleigh and Jordan, 2010). People fleeing the disaster-struck – or environmentally unsustainable – countryside may have limited resources and social networks to rely on if the social safety-net offered is inadequate (Gizewski and Homer-Dixon, 1995; Sygna, 2005). Although the nature and consequences of such population dynamics are poorly understood, recent research indicates that environmental conditions are more closely associated with local than long-distance mobility that often takes the form of (temporary) rural-to-urban migration. The environment is very rarely the most important reason for migration (UNDP, 2009), and where environmental conditions matter, migration is more often conducted as a proactive diversification strategy to cope with anticipated long-term declines in livelihood than a result of immediate stress from a natural disaster (Bardsley and Hugo, 2010; Massey et al., 2010; Tacoli, 2011).
Environmental change is relevant to population-security dynamics beyond merely acting as a push factor for migration. For example, concentration of people and economic activities in cities increase exposure of lives and assets to extreme weather and, in the longer run, to sea level rise. According to the Fourth Assessment Report of the UN’s Intergovernmental Panel on Climate Change (IPCC), a 40 cm rise in sea level will result in flooding of more than 100 million people every year under business as usual scenarios (Nicholls et al., 2007). The potential for societal instability would appear significant as the scale of urban poverty in low-income countries is growing rapidly (Tacoli, 2011).
The broad literature on social movements and collective action offers a number of insights into how increasing urban population pressure might transform into political violence, and the notion of population pressure is central in the environmental security literature (Homer-Dixon and Blitt, 1998; Homer-Dixon, 1999). Possible theoretical approaches range from almost deterministic assumptions about ethnic hatreds and associated security dilemmas (e.g. Horowitz, 1985; Posen, 1993; Kaufmann, 1996) via modernization-based arguments of radicalization of aggrieved, unemployed youths (e.g. Huntington, 1996; Goldstone, 2002) to classic theories of structural inequalities and relative deprivation (e.g. Gurr, 1970). Common to all of these contributions is their attention to the distribution of opportunities and privileges among the urban population.
Often framed in a rural context, rapid population growth may lead to a reduced per-capita access to subsistence resources, such as water, pasture, and food, as resource reproduction is unable to keep up with the growing demand. High population pressure may also lead to a decline in the overall supply of some resources, for example, due to pollution, deforestation, overgrazing, and unrestrained fishing. Further, resource scarcity may spark or escalate inter-group competition (Østby et al., 2011). Under unfavorable economic and political conditions, such competition may take the form of violent conflict. Poor countries are argued to be particularly susceptible to violent resource conflicts as they have limited capacity to adapt to changing environments and often lack institutional arrangements for peaceful conflict resolution (e.g. Smith and Vivekananda, 2007).
While some individuals and communities manage to adapt or enlarge their access to diminishing resources, others will exit and settle in more promising environments, including in urban areas. In this way, urbanization may act as a safety valve, relieving the countryside of the impending population pressure. On the other hand, large-scale migration to the cities might merely translate the problem of overpopulation into an urban setting. There is no shortage of studies that see rapid urbanization as a potentially destabilizing force (e.g. Homer-Dixon and Blitt, 1998; Homer-Dixon, 1999; Kahl, 2006). Potential risk factors include economic marginalization of migrants, poor integration and adjustment to city life, political radicalization, and greater opportunities for collective action (Gizewski and Homer-Dixon, 1995).
The empirical evidence for a connection between urbanization, environmental change, and violent conflict so far is weak and inconclusive. In an analysis of urban ethnic violence in Kenya in the 1990s, Kahl (2006: 132) finds that rapid rural-to-urban migration pushed the urban infrastructure and social services beyond their limits, and that this was the prime cause of the conflict. Huntington (1996: 113), providing a more sweeping account of the urbanization-violence nexus, argues that the newly uprooted masses of rural-to-urban migrants throughout the Islamic World in the 1970s and 1980s were attracted to radical Islamic movements as these provided slum dwellers with social services and offered a “dignified identity.” In contrast, quantitative cross-national studies find little evidence that high urban growth rates or poor environmental conditions increase the baseline risk of violent conflict. If anything, urban population growth appears to be associated with less conflict (see e.g. Collier and Hoeffler, 2004; Urdal, 2005). However, one should bear in mind that these literatures often consider different forms of conflict and vary in their assessment of the environmental context so that seemingly opposing findings need not be contradictive.
Urban social disorder: trends and new findings
According to the Urban Social Disorder dataset from the Peace Research Institute Oslo (PRIO), there has been a slight increase in the average number of urban disorder events over the last fifty years (Urdal and Hoelscher, 2012). This weak trend is evident for lethal as well as non-lethal events, albeit with considerable inter-annual variation (Figure 5.1). Although increasing populations may have contributed to the weak upward trend, better news coverage and more systematic reporting in recent times are probably also important explanatory factors. The rate of the contemporaneous population growth in these cities is many times higher, however, implying a considerable drop in per-capita rate of disorder events throughout this period.
So far, statistical analysis of the urban social disorder data has revealed little evidence of a systematic connection between increasing urban populations and increasing risk or frequency of social disorder (Urdal and Hoelscher, 2012; Buhaug and Urdal, 2013). If anything, it seems that population growth is negatively associated with unrest. Notably, the most rapidly expanding cities in Asia and Sub-Saharan Africa generally have very few disorder events. This trend does not in principle dismiss the possibility that higher pressure on urban environments and public services increase social unrest. It could be that the demography-security relationship is strictly non-linear whereby a certain critical mass is required for mobilization and population growth beyond this threshold matters relatively less. Of course, we cannot exclude the possibility of a different threshold effect, whereby cities are able to absorb the burgeoning population only up to a given point (which may not yet have been reached in most cases), after which environmental degradation, underperforming public goods delivery, and inadequate labor market lead to societal disintegration and widespread political violence. Current studies also do not attempt to assess the counterfactual – what are the most likely security scenarios under different urbanization patterns? Moreover, data scarcity limits contemporary empirical analysis to using population figures as proxies for a host of related city-specific conditions (unemployment, poverty, quality of housing and infrastructure, social inequalities, etc.) that by no means are perfectly correlated with high/increasing urban population pressure. Direct measures of city-level environmental conditions and infrastructure are largely absent.
Given that rapid urban population growth appears unrelated to the frequency and severity of social disorder, it is in no way substantiated that future adverse environmental change – to the extent it may amplify the strong rural-urban population movement in developing countries – will be a major driver of political violence in cities. Rather, we believe urban political violence will continue to emerge in response to general societal features and events, such as economic shocks, low secondary educational attainment, absence of democratic institutions, and ongoing intrastate conflict (Urdal and Hoelscher, 2012; Buhaug and Urdal, 2013).
Responses to address urban vulnerability
Government initiatives to discourage rural-to-urban migration, such as evicting squatters and denying them services, have generally failed to halt urbanization (UNFPA, 2007). Instead, such policies could hinder improvements in urban planning and sustainability. Rather than introducing negative sanctions that fail to address the root causes of high urban pressures, governments should pursue broader developmental policies that will increase the economic contribution of urban populations, such as facilitating education and regular employment, basic health care, and safe water and sewage. These policies will, over the long term, also reduce urban natural population growth by lowering fertility.
Even if high urban population growth may not increase the level of social conflict directly, physical concentration of people and economic activities make cities particularly vulnerable to environmental change (Hallegatte and Corfee-Morlot, 2011). The most important effects of climate change on urban centers relate to sea level rise on coastal cities; extreme events on built infrastructure; as well as effects on health; energy use, and water availability (Hunt and Watkiss, 2011). Urban centers in low-elevation coastal zones in the developing world are of particular concern as they tend to be very densely populated and expanding rapidly (McGranahan et al., 2007). In terms of asset exposure, however, major coastal cities in the developed world, such as the USA, the Netherlands, and Japan dominate the list.
The cost of rebuilding infrastructure and buildings, as well as less tangible social and cultural ties to the land, means that relocation of exposed coastal cities is unlikely. Instead, risk-reducing adaptation strategies need to be developed. Required initiatives may include strengthening of barrages, flood embankments and natural barriers, improved early warning systems and plans for evacuation, climate-sensitive building regulations and land use planning, and risk-sharing through insurance and reinsurance (Hanson et al., 2011). A crucial adaptation challenge for local actors is to understand the nature of future climate change risks in their region and to identify the main causes of urban vulnerability. To date such adaptation has been scarce. A few cities in high-income countries appear to be at the forefront of adaptation planning and implementation, such as Chicago, London, Miami, New York, Paris, and Toronto (Hallegatte and Corfee-Morlot, 2011).
A better understanding of societal vulnerabilities to climate change impacts can assist local authorities to communicate with local, other sub-national, and national decision-makers in order to mobilize political will, assess adaptation options and design cost-effective and timely responses. This is a complex challenge since many cities are likely to be hit by shifting climate patterns as well as potentially increased intensity and frequency of extreme events, such as flooding and droughts. However, in many cases measures may be of “no regret,” i.e. they would yield benefits if implemented today, even in the absence of climate change. This is especially true in developing countries, in which basic urban infrastructure is often absent, leaving room for actions that both increase immediate well-being and reduce vulnerability to future climate change (Hallegatte and Corfee-Morlot, 2011).
Global urbanization will continue at high speed in the foreseeable future and urban growth will be especially strong in the developing world. The total urban population in the world is expected to nearly double over the next 40 years. While urban populations in principle are more easily reached by government policies and population concentration often implies economies of scale, rapid urban growth in combination with direct impacts of environmental change and poor urban management may produce considerable strains on the capacity to provide services like housing, water, sewage, power, transportation, health care, and education. Clustering of people and assets may also increase vulnerability to extreme weather events and sea level rise. A key challenge is maintaining high economic growth to accommodate the burgeoning urban youth into the labor market without forsaking the environment. At present, strategic planning of sustainable cities of tomorrow is largely absent, and climate adaptation of urban centers is still primarily a feature of developed states.
Thus far, there is little evidence to suggest that rapid urbanization is a significant contributing factor to political violence in cities. Less is known about whether and how local environmental conditions and degradation affect urban security. In fact, comparative research on determinants of urban social unrest is still in its infancy so it is not hard to find areas of improvement for future research. We conclude that there are three major challenges for existing quantitative scholarship.
First, most previous quantitative research is limited to investigating direct relationships or simple interaction effects, thereby enforcing rather crude causal assumptions. The general ignorance of conditional effects – such as underlying social cleavages, quality of governance, and the environmental context – has been a ready criticism of quantitative analyses among case-oriented researchers (e.g. Homer-Dixon, 1999). Future studies should specify the conditions under which urbanization and high urban population growth is more likely to cause human insecurity.
Second, quantitative cross-national research has been hampered by poor and overly coarse data, and empirical analyses are often conducted at a too high level of aggregation. Whereas the theoretical arguments typically concern local-level relationships between increasing population pressure and local violence, statistical models typically apply a country-level approach where national urbanization statistics are regressed on country-level conflict data. Better city-specific data on socio-economic, demographic, and environmental conditions may be obtained through more extensive use of comprehensive surveys, such as the Demographic and Health Surveys (DHS) program. A major priority for future research should be to re-examine drivers of urban violence using indicators measured precisely at the city level.
Third, previous quantitative research on urban population growth and violence is almost exclusively limited to studying conventional armed conflicts (e.g. Collier and Hoeffler, 2004; Urdal, 2005). In contrast, there is an increasing awareness that urban violence, often constitutes a mixture of criminal and political motives, and where the violence may take the form of homicides, organized crime, sexual violence, and terrorist acts (e.g. Jütersonke et al., 2007). The new Urban Social Disorder data presented above (Urdal and Hoelscher, 2012) go some way toward this goal but further systematic data collection is needed. Future research on urban insecurity should expand the scope of conflict and look at wider patterns of political and social unrest below conventional armed conflict.
Finally, adapting cities in the south, and indeed in the north, to climate change may contribute to a more sustainable development of urban centers. In the south, developing urban infrastructure like housing, water and sanitation, transportation and education is likely to have long-term positive impacts that could even eventually contribute to curb social disorder and violence. Overall, the adaptive policies most likely to succeed are those that respond to existing local needs, contribute to other development goals, and can be locally driven (McGranahan et al., 2007). Vulnerable urban settlements in low-income countries clearly deserve international support in measures to adapt to environmental change. Likewise, the shift in focus from discouraging to sustainably governing urban population growth is not the sole responsibility of developing country governments. International organizations and developed country donor agencies are crucial in supporting broad strategies for urban development.
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