One in 14 people worldwide lives in a “megacity”—a city with a population of over 10 million people.
Megacities present unique opportunities and challenges: They often have more public transit and access to services such as health care and education, but may struggle to manage waste, sanitation, and the consequences of sprawl.
Urbanization will be one of the most seismic shifts in population to occur over the coming decades. Urban residents first comprised a majority of the global population in 2007, and the UN estimates that by 2050, 68 percent of all people will live in urban areas.
The sustainability of urban centers depends on how cities evolve. Urban populations consume more food and energy than rural populations do, but their fertility rates are also lower, meaning that urbanization contributes to slowed population growth. With the number of megacities projected to grow from 33 in 2019 to 43 in 2030, they are poised to have an immense impact on population dynamics and resource trends worldwide.
A Tale of Three Megacities
PopEd’s high school curriculum, Earth Matters, includes a unit that considers the rise and ramifications of urbanization. The lesson plan “A Tale of Three Megacities” invites students to explore Lagos, Tokyo, and São Paulo—three cities with unique challenges and advantages in an increasingly urbanized world.
The lesson begins by asking students to consider two maps that show the world’s urban population by country for 1960 and 2016. Individually, and as a class, students analyze the trends they observe over more than 50 years of urban growth.
The concept of “megacities” is introduced with an online interactive map from The Economist, “Bright lights, big cities.” This resource is a visualization of the growth of cities from 1950 through 2014 and then projected out to 2030. After playing the visualization for students, the teacher identifies Lagos, Tokyo, and São Paulo on the map. Lagos, Nigeria, is the largest city in Africa and one of the most rapidly growing megacities. Tokyo, Japan, is the largest city in the world, though it’s projected to lose that status as Japan’s aging population continues to shrink. São Paulo, Brazil, is the largest city in the Western Hemisphere and home to nearly a tenth of Brazil’s population.
Students then divide into three groups, one for each city, and visit “City Stations” that the teacher has created from resources provided in the lesson plan.
The City Stations
The City Stations each contain seven different items for students to examine to learn more about their assigned city. Items include charts, videos, articles, and photos, all of which illuminate different realities about their respective megacities.
The following are excerpts of some of the City Station items, along with student assignments.
- A population pyramid for Nigeria enables students to make predictions about Nigeria’s future demographic dynamics and how they will impact Lagos.
- A news article reports the collapse of a floating school in the waterfront slum of Makoko and describes how the ingenuity of the school stood in opposition to city officials’ characterization of the slum as unlivable. Students consider why a floating school might uniquely meet the needs of Makoko and what its collapse means for the future of the settlement.
- A line graph shows the African countries with the highest GDPs and each one’s GDP growth from 2000 to 2013, along with a short explanation of the growth of Lagos’s economy. Students consider what sectors of the economy contributed to the growth of Lagos’s middle class.
- A bar graph compares transportation use in Tokyo to that of other cities such as Seoul and London. Students consider what makes Tokyo an outlier in public transit and how its low use of personal vehicles affects Tokyo’s carbon emissions.
- A video depicts how tiny private rooms in Internet cafés have become home for thousands of residents who can’t afford traditional accommodations in the city, even though many of them are employed full-time. Students contemplate the circumstances that might lead someone to live in this type of non-formal, temporary housing.
- An article describes the urban “heat island” effect in Japan’s cities. Students explain this phenomenon and analyze how this increase in temperature might be correlated with an increasing number of storms in the region.
- A map shows the percent of GDP that is produced by each of Brazil’s federative units. Students assess what GDP tells us about a country or state and describe what the map indicates about São Paulo’s economy.
- An article recounts how São Paulo banned outdoor advertising such as billboards, and how removing these ads revealed previously hidden favelas, illuminating structural inequality in the city. Students decide whether making poverty more visible does more good or harm.
- A photo displays two adjoining neighborhoods—an area of wealthy high rise apartments next to a sprawling, impoverished favela. Students consider how daily life likely differs between the two neighborhoods.
After students finish examining all of the items at their respective City Stations, they form new groups of three with one person representing each city. Together, they compare and contrast the megacities and discuss the positives and negatives of urbanization demonstrated by each one.