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Population & Cities: fun facts and quiz
The essentials in 7 ideas, with fun facts, an illustrated story and a quiz to see how much you know.
The essentials
World Population
About 8 billion people live on Earth. It took all of human history to reach 1 billion, around 1804, and just over 200 years more to reach 8 billion in 2022.
Key fact
The UN expects the population to peak in the 2080s.
Urbanisation
Urbanisation is the growing share of people living in towns and cities. Since 2007, more people have lived in cities than in the countryside.
Key fact
By 2050, about two in three people may live in cities.
Megacities
A megacity has over 10 million people. Tokyo’s metro area, with about 37 million, has long been ranked the largest, alongside giants like Jakarta, Delhi and Shanghai.
Key fact
There are more than 30 megacities today.
Population Density
Population density is people per square kilometre. Monaco packs in about 19,000; Mongolia has about 2.
Key fact
Density is an average; it doesn’t show where people cluster.
Ageing Populations
In many countries, people are living longer and having fewer children, so the average age is rising. Japan has one of the oldest populations.
Key fact
Global life expectancy is about 73 years.
Migration
People move for work, study, family or safety. About 280 million people, roughly 1 in 30, live outside the country they were born in.
Key fact
Most migrants move for work.
Planning Cities
Cities plan transport, housing and green space to stay pleasant to live in. Some, like Copenhagen, are famous for having more bikes than cars.
Key fact
Good public transport cuts traffic and pollution.
Fun facts
Roughly 7% of all the people who have ever lived are alive today.
Ancient Rome was probably the first city to reach about a million people, some 2,000 years ago.
Greater Tokyo’s railways carry tens of millions of passenger trips every day.
Bangladesh is the most densely populated large country, with over 1,000 people per square kilometre.
In Japan, sales of adult nappies have overtaken sales of baby nappies.
The United States is home to more international migrants than any other country, around 50 million.
Brasília was planned from scratch in the shape of an aeroplane, or a bird, seen from above.
Story: First in Line
First in Line
1 January 1892. Ellis Island, New York’s new immigration station, opens its doors. First in line is Annie Moore, a 17-year-old from Cork, Ireland.
She has crossed the Atlantic with her two younger brothers to join their parents. Officials give her a $10 gold coin to mark the day.
Around 12 million people passed through Ellis Island before it closed in 1954. Millions of Americans today descend from them.
True or false?
Tap your answer to see if you got it, and why.
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Question 1 of 10
The world passed 8 billion people in 2022.
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True. According to the United Nations.
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Question 2 of 10
Urbanisation means a growing share of people living in cities.
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True. Cities grow faster than the countryside.
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Question 3 of 10
A megacity has more than 10 million people.
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True. That’s the usual definition.
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Question 4 of 10
Two places with the same population can have different densities.
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True. It depends on their area.
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Question 5 of 10
Japan has one of the world’s oldest populations.
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True. Nearly a third of its people are over 65.
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Question 6 of 10
About 1 in 30 people live outside the country they were born in.
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True. About 280 million people.
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Question 7 of 10
Good public transport can reduce traffic.
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True. Fewer people need to drive.
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Question 8 of 10
The world’s population has shrunk since 1900.
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False. It has grown about fivefold.
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Question 9 of 10
Urbanisation means a country’s population must shrink.
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False. It’s about where people live, not how many there are.
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Question 10 of 10
There are only two megacities in the world.
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False. There are more than 30.
Keep going in the app
KnowSoda learns what you know and brings back what you’re about to forget. Population & Cities has 6 more ideas at the Advanced and Expert levels.
Sources
- UN DESA — World Population Prospects 2024 and World Urbanization Prospects
- IOM — World Migration Report 2024
- World Bank — Population density and life expectancy data
- City of Copenhagen — Cycling statistics
- UN DESA — World Population Prospects
- The National Archives (UK) — Domesday Book
- U.S. Census Bureau — City population data
