Mapping the World’s Urban Population in 2050

Mapping the World’s Urban Population from 1500 – 2050

In 133 BC, Rome was the first city to hit a population of one million people.
While that number might seem small now, the truth is that modern megacities are just a blip in the long timeline of human history.
Today’s interactive data visualization from Our World in Data maps out how many people have lived in urban areas over time, as well as the powerful economic pull of cities after the Industrial Revolution.

Shifting Human Geography

The stages of urbanization can be roughly broken into two parts.
1500s – 1900s
Most people lived an agrarian life until the first Industrial Revolution. The urban population quadrupled over this lengthy timeframe, from 4.1% to 16.4%.
Urbanization accompanied the moves away from agricultural employment, but it was still a slow burn until the 20th century.
1900s – Present
The expansion of the global economy and population saw urbanization skyrocket along with it. The urban public leaped from 16% to 55% today, a trend which comes from both births within urban areas and rising human migration out of rural areas.
This turning point between the centuries becomes pretty clear when we look at the population shifts relative to each other:

What Defines An Urban Area?

While this widely cited data comes from the United Nations, many researchers suggest that the actual numbers are much more dramatic.
Why is there a discrepancy? It turns out that the definition of an urban population varies widely around the world. The UN figures are based on nationally-defined urban shares – but the thresholds and metrics used to calculate these are not uniform. Here are just a few examples:

Country	Definition
Argentina	Localities with 2,000 inhabitants or more.
Australia	Significant Urban Centres representing concentrations of urban development with 10,000 inhabitants or more.
Belgium	Communes with 5,000 inhabitants or more.
Canada	Areas with 1,000 inhabitants or more and at least 400 inhabitants per square kilometre.
Iceland	Localities with 200 inhabitants or more.
Japan	Cities defined as shi (A municipality that is 50,000 inhabitants or more); 60 per cent or more of the population engaged in urban type of business.
Netherlands	In the present publication, municipalities with 20,000 inhabitants or more.
Singapore	Entire population.
United States of America	Territory that meets minimum population density requirements and with 2,500 inhabitants or more.

Cities That Never Sleep

In 1950, two-thirds of the global population lived in rural areas, but this distribution will be reversed in a matter of decades. Almost 70% of the world will live in urban areas by 2050.
In total, 2.5 billion people could be added to global urban areas by 2050, and a whopping 90% of this increase will take place in Asia and Africa.
By the time the dust has settled, large portions of the urban population will be concentrated in megacities, which are areas defined as having 10 million or more inhabitants. These are projected to be the top 10 megacities by the middle of the 21st century:

City	Country	2010 Population (millions)	2050 Population (millions)
Mumbai	India	20.1	42.4
Delhi	India	17	36.2
Dhaka	Bangladesh	14.8	35.2
Kinshasa	DR Congo	9	35
Kolkata	India	15.6	33
Lagos	Nigeria	10.6	32.6
Tokyo	Japan	36.1	32.6
Karachi	Pakistan	13	31.7
New York	U.S.	19.4	24.8
Mexico City	Mexico	20.1	24.3