With the world’s population reaching eight billion on November 15, 2022, various predictions have been made about when the number of people on Earth will peak. Studies vary, with some suggesting that world population will peak at 8.8 billion people by the middle of this century before beginning to decline. Other projections, such as those made by the United Nations, estimate that the world population could reach more than 10 billion by 2080.
In any case, the significant increase in population has led to significant congestion in several of the world’s largest cities, raising serious concerns about pollution and overcrowding.
To put this list in some perspective, the population of Greater London, UK is around nine billion, and New York, USA, is approximately 8.5 billion.
Here are the ten most populous cities on Earth and what it’s like to live in them.
10. Osaka, Japan – 19.2 million people
Keihanshin Metropolitan Area, which includes Japan’s third largest city Osaka, is home to about 19.2 million people. Historically important as a center of commerce and industry, the city is still a financial center, home to many large Japanese companies.
Osaka is known for its food culture and modern architecture, making it popular with tourists. And thanks to a half-decent public transport system that would be unheard of in the UK, the city’s underground manages to carry over 900 million people a year.
But not all news is good. As with any modern metropolis, traffic is a huge problem thanks to overcrowded roads, and decent housing is hard to come by… even if you have tons of money.
9. Beijing, China – 19.4 million people
China’s second largest city is one of the oldest cities in the world and home to most of the country’s largest enterprises. This has led to massive population growth over the past 50 years and an increase in wealth among many of its residents. In fact, Beijing has the most billionaires in the world.
But not all news is good. Thanks to a combination of industrial pollution, frequent sandstorms and car emissions, many Beijing residents are often told to stay indoors to avoid potential health hazards.
Car use has increased significantly over the past ten years, despite an impressive subway system and various bicycle projects.
And with a population density of 4,600 people per kilometer, Beijingers probably find it hard to find a moment to themselves.
8. Mumbai, India – 20.1 million people
Mumbai is built on seven islands and is a historic city full of culture and art. It is also home to the Indian film industry (Bollywood), known worldwide for its dynamic films and musical numbers.
Most importantly, it is the commercial and financial capital of India. Most of India’s largest companies are based in Mumbai, which has led to a huge influx of people from rural areas wanting to live there.
This naturally creates some headaches, with the main problems being poor sanitation and low quality housing. Mumbai also has some of the busiest roads in the world, mainly due to its lack of high-capacity infrastructure and a public transport system that cannot cope with demand.
7. Dhaka, Bangladesh – 20.2 million people
Bangladesh’s capital is growing at a rapid pace, fueled in part by a booming publishing industry. This has resulted in huge high-rise apartments and offices springing up all over this sprawling metropolis.
This historic city is the center of Bengali culture, hosting countless art festivals and religious events throughout the year. It is also home to the Government of Bangladesh as well as historical buildings such as the Nimtali Palace and Lalbagh Fort.
However, due to its position in the Ganges Delta, Dhaka is somewhat prone to flooding during the monsoon and cyclone seasons.
6. Cairo, Egypt – 20.4 million people
In addition to its historically significant architecture, Cairo is probably best known as home to one of the ancient wonders of the world; the ancient Egyptian complex of pyramids at Giza. It is also home to 11 percent of Egypt’s population.
There are plans to build two monorail systems to serve the city, which will help alleviate the significant traffic problems the city is currently experiencing.
The frequent dust storms and desert climate may sound like a deterrent, but that doesn’t stop people from wanting to visit…
5. Mexico City, Mexico – 21.6 million people
Mexico City sits high on the plateau known as the Valley of Mexico, 2,240m above sea level, and is the oldest capital in the Americas.
The growth of this metropolis is remarkable. In 1900, its population was barely 500,000. But due to the large number of people from rural areas coming to the city to look for work, this rose to nine million in the 1970s. Due to the lack of housing, this influx led to a large number of people creating illegal slums around the city.
Mexico City is now a business center as well as a popular tourist attraction full of museums and places to eat. Amazingly, if Mexico City were an independent country, it would be the fifth largest economy in South America.
More images from BBC Science Focus:
4. Sao Paulo, Brazil – 21.8 million people
It’s a bit of a cliché, but São Paulo is a city of huge contrast. A place where extreme poverty meets great wealth, with the financial district’s tallest skyscrapers towering over the city’s slums, known as favelas.
Water supply problems are a problem in São Paulo, as there are few natural sources of drinking water in the city. The haphazard nature of the layout of the city and its buildings doesn’t help.
However, crime is down and air quality has steadily improved in recent years, making it a more pleasant place to live for all of its 22 million residents.
3. Shanghai, China – 26.3 million people
Many years ago, Shanghai was a small fishing village. But thanks to its location by the southern estuary of the Yangtze River, it has since become the largest city in China and one of the largest in the world.
It is also home to the Nanjing Road shopping district, a mix of modern malls and traditional Chinese shops and eateries. Its 5.5km of streets rank alongside London’s Oxford Street and Paris’ Champs-Élysées as some of the busiest shopping districts in the world, with one million people shopping there every day.
2. Delhi, India – 29.3 million people
The National Capital Territory of Delhi (NCT) encompasses the city of New Delhi (the nation’s capital) as well as several other regional states.
The city itself has been around for over 2,000 years, which brings its own set of problems. The infrastructure is outdated, although there have been many road construction projects recently that have helped ease traffic.
Pollution from roads and industry is also a big problem in Delhi, as is the standard of housing. It is estimated that 50 percent of the population lives in substandard housing.
1. Tokyo, Japan – 37.4 million people
The towering metropolis of Tokyo covers only 13,452 km2, which means there are an average of 2,642 people for every kilometer in the entire Tokyo area. This high density obviously creates problems for residents in terms of living space and travel.
As might be expected, the housing shortage is widespread. Therefore, the small apartments measuring only 9m2 are becoming increasingly popular with younger residents as they try to be close to the city center for work.
Getting around the city is also very problematic. Roads are often completely congested in and around the city. Public transport is also often crowded and expensive, although it is almost always on schedule.