Urbanization

• 1. Introduction

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  Urbanization is the slow tilt of humanity toward its cities, and in 2007 that tilt crossed a line never crossed before. According to the UN, that year marked the first time in human history that more than 50% of the world population was living in cities. A century earlier, at the turn of the 20th century, just 15% of the world's population lived in cities. The curve bending between those two numbers describes a shift in how people live, work, and recreate. Urbanization is not only the movement of bodies from countryside to city. It is the shift in the proportion of a national population classified as urban, and the way societies and culture adapt to that change. The numbers ahead grow vast. By 2050, forecasts put about 64% of the developing world and 86% of the developed world in cities. The UN projects nearly all global population growth from 2017 to 2030 will happen in cities, roughly 1.1 billion new urbanites in ten years. What pulls people in, what it costs them, and what it does to the air, the water, and the mind are the questions this documentary follows. The first question is older than any city skyline. How did villages of common bloodlines become a planet of strangers?

• 2. From Villages To Strangers

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  The accumulation of hunter-gatherers into villages many thousands of years ago was the first major change in settlement patterns. Village culture rested on common bloodlines, intimate relationships, and communal behaviour. Urban culture replaced that with distant bloodlines, unfamiliar relations, and competitive behaviour. The trade was familiarity for proximity to strangers. From the earliest cities in the Indus Valley Civilization, Mesopotamia and Egypt until the 18th century, a stubborn balance held. The vast majority of people worked subsistence agriculture in a rural context. Small town centres existed only for trade at markets and small-scale manufactures. Because agriculture stayed primitive and relatively stagnant, the ratio of rural to urban population sat at a fixed equilibrium. A first detectable rise in the global urban share can be traced to the 1st millennium BCE. That equilibrium finally broke in the late 18th century. The British Agricultural Revolution and the Industrial Revolution severed the old ratio. Across the 19th century, urban population grew at a pace without precedent, fed by migration from the countryside and by a tremendous demographic expansion. In England and Wales, the share living in cities with more than 20,000 people leapt from 17% in 1801 to 54% in 1891. Under a broader definition, the urbanized population of England and Wales reached 72% in 1891, while France stood at 37%, Prussia at 41%, and the United States at 28%. Yale University published urbanization data spanning 3700 BC to 2000 AD, mapping the rise and spread of cities across the whole period.

• 3. What Pulls People In

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  Money, services, wealth and opportunities are centralized in cities, and many rural inhabitants arrive to seek their fortune and alter their social position. Businesses cluster in urban areas because they provide jobs and exchange capital. Whether through trade or tourism, foreign money flows into a country through ports and banking systems commonly located in cities. The lure is access: to the labour market, to better education, housing and safety, and to shorter commutes. Conditions like density, proximity, diversity, and marketplace competition are treated as benefits of the urban environment. Cities also offer specialist services absent in rural areas, which demand workers and so multiply job opportunities. Elderly people may be forced to move to cities where doctors and hospitals can meet their health needs. Rural flight pushes as much as cities pull. Farm life has always been exposed to unpredictable environmental conditions, and in drought, flood or pestilence survival can become extremely problematic. In a New York Times article on migration away from farming in Thailand, the work was described as hot and exhausting, with the observation that everyone says the farmer works the hardest but gets the least amount of money. In response, the Agriculture Department of Thailand has tried to promote farming as honorable and secure. Urbanization opens doors closed to women in rural areas, drawing them into paid employment and education, a shift that may cause fertility to decline. Yet women can remain disadvantaged by an unequal labour market and an inability to secure assets independently of male relatives.

• 4. The Cost Of Density

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  Eric Hobsbawm, in The age of revolution: 1789-1848, called urban development of that era a gigantic process of class segregation, pushing the new labouring poor into great morasses of misery outside the centres of government and business. He noted the near-universal European division of large cities into a good west end and a poor east end. The cause was probably the south-west wind, which carried coal smoke and pollutants down so the western edges of towns stayed cleaner than the eastern ones. As cities develop, costs skyrocket, and the working class is pushed out of the market, officials and local employees among them. Similar dynamics now affect less developed countries, where rapid city growth makes inequality worse. Conflict over land rights, driven by the effects of globalization, has cost less politically powerful groups such as farmers their land. In China, where land acquisition measures are forceful, urbanization has reached 54%, far above India's 36%, where peasants form militant groups like the Naxalites to oppose such efforts. Obligatory and unplanned migration often produces the rapid growth of slums. Many rural-urban unskilled migrants, drawn by economic opportunity, cannot find a job or afford housing and end up in slums. The Overseas Development Institute has proposed labour-intensive policies to make use of less skilled workers. Walkable communities show a 38% higher average GDP per capita than less walkable urban metros, a figure attributed to Leinberger and Lynch.

• 5. Reshaping The Land

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  Between 1992 and 2015, urban areas more than doubled, growing from 33 million hectares to 71 million hectares. That expansion consumed 24 million hectares of some of the most fertile croplands, 3.3 million hectares of forestlands and 4.6 million hectares of shrubland. The footprint is measured not only in spread but in heat. An urban heat island forms when industrial areas absorb and retain heat. In rural areas, much of the sun's energy evaporates water from plants and soil. Cities hold less vegetation and exposed soil, so buildings and asphalt absorb the energy and surface temperatures climb. Vehicles, factories, and heating and cooling units release still more heat. A Qatar University study found land-surface temperatures in Doha rose annually by 0.65 degrees Celsius from 2002 to 2013 and 2023. Urban runoff is another signature of the city. Rain on rooftops, roads, parking lots and sidewalks flows to storm drains instead of percolating into groundwater. That contaminated stormwater is typically untreated and reaches nearby streams, rivers or coastal bays. Eutrophication follows, a process that causes low oxygen levels and algal blooms that may harm aquatic life. The ocean absorbs a quarter of the CO2 produced by humans, which lessens greenhouse effects but makes the water more acidic. A drop in pH prevents the proper formation of calcium carbonate that molluscs and coral need for shells and skeletons. In April 2026, satellite data showed Earth's night-time brightness has increased significantly due to artificial lighting tied to urbanization.

• 6. The Body In The City

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  Rapid urbanization has raised mortality from non-communicable diseases linked to lifestyle, including cancer and heart disease. Urban health levels are on average better than rural ones. Yet residents of poor urban areas such as slums and informal settlements suffer disproportionately from disease, injury, premature death, and the combination of ill-health and poverty that entrenches disadvantage over time. Many of the urban poor cannot pay for health services and turn to less qualified, unregulated providers. Diet shifts with the move to the city. Rural populations have tended toward plant-based diets rich in grains, fruits and vegetables and low in fat. Migrants often shift toward processed foods higher in meat, sugars, refined grains and fats, with less time for home cooking and more disposable income for ready-to-eat meals. In Thailand, that transition from a carbohydrate-based diet to one higher in fat and sugar drove a rise in obesity. Food deserts compound the problem. Nearly 23.5 million people in the United States lack access to supermarkets within one mile of their home, an absence linked to higher rates of obesity. In the United States, food deserts are most commonly found in low-income and predominantly African American neighbourhoods. Body mass index and cholesterol levels rise sharply with national income and the degree of urbanization. Asthma tracks the same path. Exposure to nitrogen dioxide, carbon monoxide, and particulate matter under 2.5 micrometres can cause DNA methylation of CpG sites in immune cells, raising children's risk of developing asthma.

• 7. Mind, Crime, And Culture

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  A 2004 study of 4.4 million Swedish residents bears on how urban living shapes mental health. At the level of the social group, urbanization is thought to contribute to social disintegration and disorganization, producing disparities that leave individuals feeling insecure. Perceived insecurity can stem from the physical environment, such as personal safety, or from the social environment, such as a loss of positive self-concepts after negative events. Increased stress is the common psychological cost, tied to that insecurity and to reduced social support, increased violence, and overcrowding. Crime and urbanization have historically gone hand in hand. Higher population density sits beside greater availability of goods, and committing crimes in urbanized areas is more feasible. Modern media has raised awareness of the income gap between rich and poor, breeding feelings of deprivation that can lead to crime. Per capita income, income inequality, and overall population size all factor in, with inter-city commuting contributing to theft and burglary independent of population size. Crime tends to cluster in city centres, falling off with distance from the centre. Culture bends too. US cities tend to have looser, more permissive social norms than rural areas, and a study in Japan found rural people more likely to weigh how their choices affect others. The pattern is not clean. When researchers tested social norms across China, people in urban areas reported tighter norms. Youth moving from rural China to Beijing and Shanghai showed no consistent change in thought style. Their region's rice-farming or wheat-farming history predicted their thinking better, suggesting cultural histories live on in modern cities.

• 8. Cities By Design

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  Los Angeles is the best-known example of a networked, poly-centric urbanization, a pattern variously called edge city by Garreau in 1991, network city by Batten in 1995, or postmodern city by Dear in 2000. When the residential area shifts outward, it is called suburbanization, and some argue it has formed new points of concentration outside the downtown in both developed and developing countries such as India. In the United States, this outward process reversed as of 2011, with re-urbanization driven by chronically high transport costs. Counter urbanization runs the other way, with cities losing population to rural areas, particularly among richer families, helped by improved communications and driven by fear of crime and poor urban environments. This has fed the phenomenon of shrinking cities in parts of the industrialized world. Urbanization can be planned or organic. Planned urbanization, such as the garden city movement, rests on an advance plan made for military, aesthetic, economic or urban design reasons. UN agencies prefer urban infrastructure installed before urbanization occurs. New urbanism and smart growth push walkability, mixed-use development, high-density design, land conservation, social equity, and economic diversity. Greater Seoul shows how far concentration can go, home to 50% of South Korea's entire national population. Greater Manila, with 20 million people and over 20% of its national population, qualifies as a primate city, though Quezon City at 2.7 million and Manila at 1.6 million remain ordinary cities within it. Developing urban resilience and sustainability is the heart of Sustainable Development Goal 11, named Sustainable cities and communities, the framework that will shape whichever way the next billion urbanites settle.