Data Exploration: Urbanization
Urbanization Data Introduction By Max RoserAdapted by Mike Papritz and Bennett SherryMost humans live in cities today. Yet for most of our history, this was not the case. The shift to cities is a long story, but it’s one that accelerated quite recently.
2Urbanization Data IntroductionBy Max RoserIntroductionHuman population began its slow pace of growth many thousands of years ago. As agriculture developed, human populations grew denser—more of us lived closer to each other in less space. Humans started settling in permanent farming villages. Eventually, population density increased even further in some places, leading to the development of a new type of human community: the city.For most of the last 6,000 years, the number of cities and the number of humans living in cities has increased steadily. Over our very long history, a greater and greater percentage of the human population moved to cities, a trend we call urbanization. But still, for most of human history, the majority of people did not live in cities. Before 1600 CE, less than 5 percent of people lived in cities. By 1800, this share reached 7 percent, and by 1900, it had increased to 16 percent. In the past century, this trend has only accelerated. Today, over half of the 7 billion humans on Earth live in cities.What is a city?There’s no agreement on what defines a city. Different people define a city in different ways. And for many scholars, what constituted a city in 200 BCE was smaller than the minimum size of a city in 2000 CE. Chart 1 shows the size of urban areas in several different countries and regions since 10,000 BCE. Of course, for most of that time, no one lived in cities. But starting around 3700 BCE, the first cities developed. Zooming in to a smaller scale of time in Chart 2, you can see just how recently urbanization took off.Chart 1:Urban area over the long-term: https://ourworldindata.org/grapher/urban-area-long-term By Our World in Data, CC BY 4.0.
3Urbanization Data IntroductionBy Max RoserChart 2:Urbanization over the past 500 years https://ourworldindata.org/grapher/urbanization-last-500-years By Our World in Data, CC BY 4.0.These charts make it look like cities cover the entire world. But if we look closer at the data, we see that’s not true. Cities have always depended on the labor of people outside of cities—farmers and herders. About 71 percent of the Earth’s land is habitable (suitable for human life). Today, we use about half of that for agriculture. Chart 3 shows how humans have used land over the last two millennia (note that ha is an abbreviation for hectare; one hectare is about two and a half acres). Our “built environment”—cities, towns, roads, and other infrastructure—has increased substantially in the past century, but it still only accounts for 1 percent of the Earth’s habitable land. Despite the relatively small percentage of Earth’s surface covered by cities, if you compare the rise in agricultural land use in the last 200 years to urbanization, you can see that cities have an impact that stretches beyond their ZIP codes.
4Urbanization Data IntroductionBy Max RoserChart 3:Land use over the long-term: https://ourworldindata.org/grapher/land-use-over-the-long-term By Our World in Data, CC BY 4.0.Urban consequencesWhat are the consequences of living in more densely populated areas? Are there things people living in cities, even cities small by today’s standards, must do to live so close to so many others? For example, do people create new jobs to manage larger populations of strangers? What problems might emerge living in closer proximity to others? What might be the benefits? Are there activities—such as farming—that city dwellers are unlikely to do and must then depend on others from outside the city doing? Some historians argue that when earlier humans transitioned from hunter-gatherer lifestyles to farming, the lives of many became more difficult. But what about cities? Ancient cities were often dirty places that put people at risk of disease. Why did so many people choose to live in crowded, complicated cities?One answer might be that cities provide new opportunities and wealth. Chart 4 shows the relationship between gross domestic product (GDP)—a measurement of a nation’s economic production—and the percentage of people who live in cities in that country. Over the past 500 years, there has been a strong correlation between the percentage of people in a country living in cities and how wealthy that country is. It appears that populations urbanize as they get richer, or, perhaps, they get richer as they urbanize.
5Urbanization Data IntroductionBy Max RoserThe causes and effects of urbanization are complex, and our data for humanity’s long history is incomplete. However, we know that living in cities has historically had lots of advantages. Some advantages include high levels of concentrated economic activity, access to trade, the availability of more human labor, shared infrastructure like walls and granaries, and a division of labor that means not everyone has to farm. For the last 6,000 years, more and more people have built and moved to cities to try and have access to these advantages.Chart 4:Urban population vs. GDP: https://ourworldindata.org/grapher/urbanization-vs-gdp?time=1500..latestBy Our World in Data, CC BY 4.0.Do you think global urban population always grew? What might be the causes of historical changes in urban population? Why did early cities develop where they did? How did urbanization change human societies? How did it change our planet? What parts of the world and what types of people have benefited most from urbanization?
6Urbanization Data IntroductionBy Max RoserMax RoserMax is the founder and director of Our World in Data. He began the project in 2011 and for several years was the sole author, until receiving funding for the formation of a team. Max’s research focuses on poverty, global health, and the distribution of incomes. He is also Programme Director of the Oxford Martin Programme on Global Development at the University of Oxford, and Co-executive Director of Global Change Data Lab, the non-profit organization that publishes and maintains the website and the data tools that make OWID’s work possible.Image creditsCover: An aerial view of Causeway Bay in Hong Kong, China, on 10 April 2010. Hong Kong is one of the most crowded and expensive city in the world. ©In Pictures Ltd./Corbis via Getty Images) https://www.gettyimages.com/detail/news-photo/an-aerial-view-of-causeway-bay-in-hong-kong-china-on-10-news-photo/535491454