analyze the United Nations Urbanization Report with a focus on Jakarta, Indonesia, the world's most populous city. we look at Jakarta's population concentration of 42 million people, Dhaka's explosive growth, and Seoul's depopulation crisis to predict where the world's cities will rank in 2050.
which is the world's most populous city? Jakarta, Dhaka, and Seoul compete for the future
what do we think is the world's largest city? it's easy to assume that New York, London, or Tokyo, Japan, have long held the title, but according to the latest World Urbanization Prospects 2025 report from the United Nations Department of Economic and Social Affairs (DESA), the world's most populous cityas of this year is Jakarta, Indonesia, the vibrant heart of Southeast Asia.
more than just a shift in the world's city rankings, this result is emblematic of the extreme urbanization challenges Asia faces in the 21st century: the polar opposites of "explosive growth" and "population cliff. jakarta's population of42 million people, which pushed Tokyo to the top spot, is due to the United Nations' new criteria for measuring the size of cities. this report analyzes the shifts in the criteria used to rank the world's most populous cities, the contrast between the cities behind them, and predicts the urban landscape of the future.
the criteria for ranking cities has changed: what does 'urban livable population' mean?
the UN's new methodology for evaluating cities looks beyond administrative boundaries
whenever the United Nations' Urbanization Report is released, many people are surprised by the changes in the rankings, especially when the world's most populous cityswitches from Tokyo to Jakarta, thanks to the UN's new methodology for measuring population: the concept of urban agglomeration.
this is the population of a densely populated, contiguous territory that is not confined to the administrative boundaries of the City Proper, but is grouped into a single urban functional area. the intention is to reflect the actual economic and social sphere of influence of the city, including the extensive suburbs outside the core city. it's an effective way to capture the realistic scale of cities like Jakarta, where population has exploded outside the central city to form a sprawling mega-region. Measured by this metric, the population of Jakarta's functional areain Indonesia has already surpassed that of Tokyo since around 2010, and was officially confirmed as the world's most populous city in the World Urbanization Prospects 2025 report.
breaking down the top 10 most populous cities in the world by 2025
according to the latest report from the United Nations, the world's metropolitan population rankingsfor 2025 are dominated by Asia.
Population ranking of the world's metropolitan living areas in 2025 according to UN DESA (Top 3 and Seoul)
ranking city (Country) estimated Living Area Population in 2025 projected 2050 1st jakarta (Indonesia) approximately 42 million people stagnant growth and capital relocation issues 2nd place dhaka (Bangladesh) approx. 40 million people projected to be #1 in 2050 (about 52.1 million) 3rd tokyo (Japan) approximately 33 million people projected population decline and declining ranking 10th place seoul (South Korea) approximately 22.5 million people population decline and likely to drop out of the top 10in 2025, the top spot is occupied by Jakarta(approximately 42 million people), followed by Dhaka, Bangladesh (approximately 40 million), and Tokyo, Japan (approximately 33 million). nine of these cities, excluding Cairo, Egypt, are located in Asia, showing that the current drivers of population explosion and urbanization are concentrated in Asia's emerging economies. seoul, the capital of South Korea, is ranked 10th with approximately 22.5 million people.
polarized futures: growth explosion cities vs. population cliff cities
urbanization in the 21st century is not a monolithic picture: Jakarta and Dhaka are battling overcrowding and teetering on the brink of environmental collapse, while Seoul and Tokyo are facingthe opposite crisis of population decline and are slipping down the global metropolitan populationrankings.
jakarta, the sinking number one city: the environmental dilemma of 42 million people
the explosive growth of Jakarta, currently the world's most populous city,stems from Indonesia's demographics. indonesia is the world's fourth most populous country, with a population of 280 million, and more than half of that population is concentrated on the island of Java. many of these people have flocked to the job-rich capital city of Jakarta, creating a population concentration of around 42 million people.
but this overcrowding has come at the cost of a devastating environmental disaster: Jakarta is one of the fastest sinking cities in the world due to rapid urbanization and excessive groundwater extraction. some parts of the city, especially the northern part, are sinking by 25 centimeters per year, and experts warn that by 2050, large parts of the city could be submerged below sea level.
as a result, the Indonesian government has embarked on a nearly $35 billion project to build a new capital city, Nusantara, to address this environmental crisis and decentralize economic power that is overly concentrated on the island of Java. this is an example of "urbanization gone wrong," where overcrowding destroys the urban environment, leading to a structural response that eventually leads to the government abandoning the city itself.
dhaka, world number one in 2050: an unplanned megacity created by 'climate refugees'
dhaka, Bangladesh, currently ranked second in the world's cities, is one of the most dramatic examples of future urbanization. the United Nations Urbanization Reportpredicts that Dhaka's urban populationwill reach around 52.1 million by 2050, overtaking Jakarta to become the world's number one city.
dhaka's growth is being driven by "migration for survival. as Bangladesh's rural areas are being devastated by climate change-induced sea level rise, soil salinization, and riverbank erosion, Dhaka is acting as a 'last resort' for them. the rate of migrant influx far exceeds the city's natural population growth rate.
the problem is that this explosive population growth is not accompanied by economic development or industrialization. dhaka is the epitome of "urbanization without industrialization," where the population expands without the financial capacity to provide infrastructure and public services. as a result, Dhaka suffers from traffic paralysis, some of the world's worst air pollution, and chronic drinking water and sanitation problems, all of which severely hinder the city's viability. the deteriorating quality of infrastructure creates a vicious cycle that reduces productivity and slows economic growth.
seoul and Tokyo, why are they falling down the rankings?
while Jakarta and Dhaka struggle with overcrowding, Tokyo and Seoul, two megacities in developed Asia, face the opposite problem. the United Nations Urbanization Reportpredicts that Tokyo's declining populationwill likely push it to seventh place in the world's citiesby 2050, while Seoul, inSouth Korea, will drop out of the top 10.
this drop in the world's metropolitan population rankings is a direct reflection of the severe declining birthrate and aging problem that both countries share. japan already has an aging rate of 29.9%, the highest among the G7 countries, and South Korea is also facing a population cliff crisis. the future of Tokyo and Seoul is not one of overpopulation, but rather one of "underpopulation," resulting in declining urban vitality and shrinking economic structures - a stark contrast that demonstrates that Asia's megacities are facing two completely opposite types of challenges.
the 2050 megacity outlook and the challenges of new urbanization
defining megacities and future growth drivers
the definition of a megacityis a large city with a population of 10 million or more. according to the 2025 World Urbanization Prospects, the number of megacities worldwide will more than quadruple from eight in 1975 to 33 in 2025, with more than half of them located in Asia.
the 2050 Megacities Outlooksuggests that Africa and South Asia will be the new centers of urbanization. cities such as Addis Ababa, Ethiopia; Dar es Salaam, Tanzania; Kuala Lumpur, Malaysia; and Hyderabad, India are predicted to be among the new megacities of 10 million or more people.
the warning of 'urbanization without industrialization'
the growth of emerging megacitieshighlights the importance of economic growth, environmental sustainability, and comprehensive infrastructure to keep pace with population growth. In some regions, particularly in sub-Saharan Africa and India, population density has increased dramatically without accompanying economic growth or industrialization. this leaves city governments unable to provide infrastructure and public services, leaving the majority of urban residents in a state of severe "multidimensional poverty. future urban policies need to move beyond accommodating population and focus on ensuring the 'quality of growth' through industrialization.
FAQ: Myths and truths about the World Population City Rankings
Q. what exactly is the 'urbanized population'?
A. It is a criterion used by the United Nations Urbanization Report, and is the population calculated by lumping together actual densely populated and contiguous areas rather than administrative boundaries. it is a concept that includes the densely populated areas of Seoul and the metropolitan areas in Korea, reflecting the broader area that cities actually affect.
Q. jakarta is number one, why do you want to move the capital?
A. The main reason is environmental concerns. as the world's most populous city, Jakarta faces a serious crisis of sinking cities due to rapid urbanization and excessive groundwater use. the government is building a new capital, Nusantara, to avoid this environmental disaster and to decentralize the economic power concentrated on the island of Java.
Q. how severe is the population decline in Seoul and Tokyo?
A. Both cities are directly affected by the nation's ultra-low birthrate and aging population trends. according to the 2050 World Urbanization Prospects, Tokyo's population decline and Seoul's fall in the population rankings are not just a matter of ranking, but a demographic shift that will pose a serious challenge to the economic vitality of the cities and the maintenance of their social systems.
Q. if Dhaka is ranked number one in 2050, what challenges are expected?
A. The growth of Dhaka's urban populationis largely dependent on 'subsistence migration', including the influx of climate refugees, which means that population growth is much faster than economic growth. this can cripple essential urban infrastructure such as water, sanitation, and transportation, and lead to problems typical of 'urbanization without industrialization' that exacerbate urban poverty.
conclusion: The conditions for a sustainable city
jakarta, which holds the title ofthe world's most populous city, and Dhaka, which is expected to take the top spot in 2050, are battling population explosion and environmental threats. meanwhile, Seoul and Tokyo, long synonymous with urban growth, are facing the opposite crisis of population decline and are slipping down the global cityrankings.
this stark contrast presents a complex portrait of the 21st century civilization we face. sustainable cities won't just be bigger, they'll be places where economic growth keeps pace with population growth, environmental sustainability, and inclusive infrastructure ensures that all residents can enjoy an enriched life.
the transformation ofthe world's most populous cityis a warning of the twin challenges of extreme urbanization in 21st century Asia: overcrowding and the population cliff.
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