Asian Megacities Shape Their Own Future Through Regional Lessons, Climate Planning and Technology

Tokyo and Jakarta Show Why Local Context Matters

Jakarta, now the world's largest functional urban area, faces a challenge that once shaped postwar Tokyo: how to build major infrastructure without losing the neighborhood life that makes a city work. Across Asia, that tension is pushing planners to look more closely at nearby cities for lessons instead of relying on development models imported from Europe or North America.

Benjamin Bansal, an economic historian of postwar Tokyo and a consultant for the United Nations Department of Economic and Social Affairs, describes the connection between the two capitals:

Jakarta, now the world's largest functional urban area, faces a version of the same tension between incremental neighborhood life and large-scale infrastructure that once defined Tokyo.

Seven of the world's 10 largest cities are in Asia, including Tokyo, Delhi, Shanghai and Dhaka. Their populations and densities create planning demands on a scale that many Western cities have not experienced. The entire northeastern corridor of the United States, combining Boston, New York and Washington, contains approximately 60 million to 70 million people, roughly comparable to China's Greater Bay Area.

Asian cities also have different cultural traditions, economic structures and environmental conditions. A planning approach built around suburban houses, for example, addresses a different pattern of daily life from one built around dense neighborhoods and buildings with many floors.

Scholars call the growing exchange of ideas within the region "intra-Asian urbanism." Examples include India's adaptation of China's Special Economic Zone model and Dalian's use of Japanese urban greening practices. The central task is to understand why a policy worked in one place and change it to suit another.

What Tokyo and Jakarta Can Learn From Each Other

Tokyo rebuilt after World War II and then managed explosive growth during Japan's economic miracle. Its transformation combined taller buildings, efficient public transportation and the continued presence of neighborhood shops and services. The city often developed incrementally, allowing districts to change gradually while keeping social networks intact.

Tokyo's approach helped preserve lively streets even as skyscrapers changed its skyline. Instead of completely demolishing and rebuilding districts, gradual redevelopment allowed infrastructure improvements and everyday neighborhood commerce to coexist.

Jakarta faces a similar balance at an even greater scale, alongside the demands of a tropical coastal environment. Flooding, traffic congestion and informal settlements are central challenges. Its approaches to water management and transportation offer lessons for other Asian cities growing quickly under comparable pressures.

Tokyo's experience provides principles that Jakarta can adapt, particularly the combination of strong transport networks and neighborhood continuity. Jakarta, in turn, offers experience in handling the environmental pressures of a large tropical metropolis. Learning can move in both directions, with each city contributing knowledge shaped by its own geography and history.

India's SEZ Experience Shows How Policies Change

India's adoption of ideas from China's Special Economic Zones shows how a policy changes when it crosses a border. SEZs are designated areas where governments use special rules to attract investment and business activity. In Asia, they became part of a deliberate strategy to connect economies to global supply chains, expand the labor force and increase incomes and savings.

India's Commerce Minister Murasoli Maran visited Shenzhen in 2000 and described the experience as:

an eye-opener

India subsequently introduced new rules for private zones modeled on the Chinese approach. A government report described the 2005 SEZ Act and its intended purpose in these terms:

a growth catalyst, on the model of the SEZs in China

help India replicate the Chinese success story of rapid industrialization.

India's land ownership arrangements, labor regulations and social and cultural conditions produced different results. China's zones were largely developed by the state and strategically placed in underdeveloped areas. India's zones were predominantly developed privately and often located in regions that were already developed.

Researchers examining this process describe the limits of direct replication:

Models cannot be straightforwardly replicated, and we call for more attention to the outcomes of attempted replication, in particular the urban development implications of selective, complex, multi-level adaptation of a Chinese 'model' and its interaction with local Indian contexts.

Scholars use the term "policy mobilities" for this movement and transformation of ideas. Traditional policy transfer describes decision makers selecting and applying practices they consider successful. Policy mobilities pays closer attention to geography, social conditions and the relationships among the people and institutions making policy.

India's experience makes the practical lesson concrete: the actors developing a zone, the land available and the rules governing workers all shape its outcome. Adapting a model requires understanding those parts and how they interact locally.

• After World War II, Tokyo rebuilt and later managed rapid growth during Japan's economic miracle.
• In 2000, Murasoli Maran visited Shenzhen, helping inspire India's new approach to private economic zones.
• In 2005, India's SEZ Act formalized an approach intended to draw lessons from China's industrialization.

Beijing, Seoul and Tokyo Grow Outward and Upward

Research tracking Beijing, Seoul and Tokyo from the late 1980s to the mid-2010s found that all three expanded both horizontally and vertically. Horizontal expansion means buildings spread across more land. Vertical expansion means more space is created through taller buildings.

Seoul almost doubled its area of mid-rise or taller buildings between 2002 and 2015. Beijing combined fast vertical growth with extensive horizontal expansion during 2001 to 2014. Tokyo, a more mature megacity, grew in a more balanced way, with limited outward expansion shaped by geographical constraints and established development patterns.

The three cities generally spread outward first, then added height in areas that were already developed. Their different stages of development, geography and planning policies helped determine how that pattern unfolded.

East Asian urban residents are more likely to live in mid-rise or taller buildings close to city centers. North American urban residents generally tend to live in houses for individual families in suburban areas. Those different building patterns affect transport needs, energy use and environmental impact.

For other Asian cities, the comparison offers a way to think about managing density: concentrate development in selected areas while preserving others, with the balance determined by local conditions.

Karachi's Expansion Brings Flood Risks Into Focus

Karachi illustrates the environmental pressures facing megacities in coastal areas crossed by rivers. Research found that its urban area increased from 13.4% to 23.7% of the total area between 1990 and 2020. That is an increase of 10.3 percentage points, accompanied by reductions in vegetation, water bodies and wetlands.

The same study found that erosion along the riverbank reduced the Malir River's area from 17.19 square kilometers to 5.07 square kilometers by 2020. It identified that change as a key factor contributing to flooding during the monsoon season.

Flood projections indicate that urbanized areas would be the most affected, with 66.65% potentially inundated by 2035. The figures connect changes in land use and river conditions with the exposure of built areas to future flooding.

Karachi's experience shows why urban expansion and environmental planning need to be considered together. More land covered by buildings can coincide with less vegetation, fewer wetlands and changes to waterways, making the management of water a central part of managing growth.

Heat and Aging Put More Residents at Risk

Record temperatures swept through South and Southeast Asia in 2024, affecting cities from Dhaka and Delhi to Phnom Penh and Manila. The heat strained infrastructure and healthcare systems, adding pressure to cities already managing rapid growth.

The urban heat island effect makes cities hotter than surrounding rural areas. Dense development can retain heat, worsening exposure for residents, particularly older people and people with low incomes living in crowded informal settlements.

Nearly half of all global deaths associated with heat between 2000 and 2019 occurred in Asia and the Pacific. A study of Jakarta projects that deaths associated with heat among older residents in August could rise to 12 to 15 times the level of the 2010s by the 2050s. Population aging and higher temperatures drive that projection.

Asia's demographic changes add urgency to climate planning. By 2050, the region's older population is expected to nearly double to 1.3 billion. Falling birth rates and slower migration from rural areas are also leading some cities to begin shrinking, requiring planners to adjust infrastructure and services for aging residents.

Jakarta's projected increase in deaths brings those trends together. Climate adaptation must address rising temperatures alongside changes in who lives in the city and which residents need the most support.

Nusantara and China's Clusters Test Different Approaches

Indonesia's new capital, Ibu Kota Nusantara (IKN), is an experiment in building a city from the ground up around sustainability and resilience to climate change. It is promoted as a city integrated with tropical ecosystems, with 67.75% of its land designated for protected areas, including forests and city parks.

Research nevertheless projects an urban heat island effect in Nusantara. By the middle of the 21st century, temperatures early in the night are projected to increase by up to 0.78 degrees Celsius from urbanization alone, 1.9 degrees Celsius from global warming and 2.54 degrees Celsius when both effects combine.

The Nusantara findings place green design and climate adaptation in the same planning task. A large share of protected land can be part of a city's design while urban development and global warming still raise temperatures.

China is pursuing another approach: organizing existing megacities into clusters, with a large central hub surrounded by smaller cities. Plans for regions such as the Pearl River Delta around Guangdong and Shenzhen envision urban units approaching, and potentially exceeding, 100 million people.

The cluster model allows each city to remain an individual participant while contributing different strengths to an integrated region. Smaller cities act as spokes around at least one very large hub, creating room for greater diversity across the urban area.

Advocates of the cluster approach express its sustainability ambition this way:

We think of clusters as the most sustainable form of urbanization... in all ways.

Nusantara and China's clusters represent different responses to the same broad demand: organize urban growth around local needs rather than reproduce a single imported pattern. One starts with a new capital; the other reorganizes connections among existing cities.

Why Cities Matter to Economic and Geopolitical Power

Asian megacities are also centers of geopolitical competition. Their industries, transport connections and economic roles help determine how countries participate in global supply chains and build international influence.

The Chicago Council on Global Affairs connects urban development directly with that competition:

there is no understanding geopolitical competition in the 21st century without an understanding of urbanization and cities.

Within each megacity, wealth, access to services and the organization of urban space create different layers of local politics. Different parts of a city serve different roles in domestic and international economic connections, including the production and movement of goods.

SEZs helped shape this growth as Asian urban populations expanded rapidly during the 20th century. Shenzhen, declared China's first SEZ just over 40 years ago, grew from a fishing village into a global technology hub. Its development illustrates how investment policy and city building can connect a country more closely to international production networks.

The discussion of cities and economic power describes the connection between industrial policy, supply chains and international influence in these terms:

The origin of any system story of imperial rise is industrial policy. In many ways, this harkens back to the European colonial era and the way cities connect to global supply chains and anchor a country's growing economic weight and gravity in the world. In other words, geopolitical power begins with building a supply chain empire, and that begins with building cities.

Industrial policy means government decisions intended to shape the development of industries. In this account, city infrastructure and production networks form part of the foundation of a country's growing economic weight.

Beijing and Shenzhen Use Data to Guide Urban Decisions

Beijing researchers have developed an artificial intelligence framework for urban inventory and reduction planning. In simple terms, the work examines existing building space, identifies reductions and considers how vacated sites could be used.

The researchers used the U-Net deep learning model and frequently captured remote sensing images to analyze changes in building space between 2018 and 2019. Deep learning helps computers identify patterns in images. The results showed a substantial decrease in building area, mainly affecting environmentally important areas such as agricultural land and urban green spaces.

Random forest regression methods, which combine multiple decision tree models to estimate outcomes, were then used with data on vacated building spaces. Researchers developed and simulated layouts for restoring cultivation and greenery in areas outside planned construction zones, and for housing, industry and public service facilities within planned construction areas.

Shenzhen researchers approached a different problem: measuring urban vitality, or how actively places support daily activity. They combined large datasets derived from social media with models of access to local destinations.

The study used open access application programming interfaces from Dianping, Amap and Baidu Maps. These interfaces allow software to obtain platform data. Researchers combined them with the two-step floating catchment area method to examine access and spatial interactions between Points of Interest (POIs), such as shops and services, and residential zones.

Beijing's building analysis and Shenzhen's accessibility work combine technology with practical planning decisions. They draw on the region's digital infrastructure and data systems to address spatial constraints and neighborhood activity in ways that Western cities are only beginning to explore.

Housing and Services Determine How Density Works

The United Nations Economic and Social Commission for Asia and the Pacific (ESCAP) warns that unchecked urban growth could deepen inequality, overwhelm public services and fuel social and environmental tensions without urgent, inclusive reforms.

Soaring housing costs and stagnant wages are pushing millions into expanding slums vulnerable to climate shocks. Informal settlements are often the first places affected by climate disasters and the last to receive sanitation or emergency relief.

ESCAP describes the economic risk of treating housing primarily as an investment:

When housing becomes a commodity, rather than a place to live, it creates systemic risks for urban economies and by extension national and even global economies,

Shenzhen's research on urban vitality offers another view of density. Communities with high vitality had diverse amenities clustered closely together, including restaurants, shopping centers and hotels. They also had higher population densities and more efficient land use.

The findings suggest that density can support urban livability when residents have adequate amenities and services. The practical issue is how homes, destinations and public resources are arranged, rather than simply how many people occupy an area.

The research also supports polycentric development, which means organizing a city around several centers rather than a single core. Establishing secondary commercial centers and areas that combine different uses outside the core can redistribute resources and urban functions, reduce excessive concentration in central districts and promote fairer development.

Across these cities, adapting ideas means connecting major infrastructure with neighborhood needs, economic growth with access to services, and new development with environmental conditions. The lesson linking Tokyo, Jakarta, India's SEZs and Shenzhen's neighborhoods is that a city's local circumstances shape how any model works.

The Essentials

• Seven of the world's 10 largest cities are in Asia, including Tokyo, Delhi, Shanghai and Dhaka.
• Tokyo and Jakarta share the challenge of balancing major infrastructure with neighborhood life.
• India's adaptation of China's SEZ model produced different outcomes because of local land arrangements, labor rules and development patterns.
• Beijing, Seoul and Tokyo expanded outward and upward at different rates, shaped by geography, policy and development stage.
• Karachi's urban share rose from 13.4% to 23.7% between 1990 and 2020, alongside losses of vegetation, water bodies and wetlands.
• Jakarta's August deaths associated with heat among older residents are projected to rise to 12 to 15 times the level of the 2010s by the 2050s.
• Nusantara's protected land plan and China's urban clusters represent different approaches to organizing growth.
• Beijing and Shenzhen researchers are using artificial intelligence, imagery and platform data to study building space and urban activity.
• Housing affordability, access to services and an aging population remain central planning challenges.
• Several urban centers and well distributed amenities can help spread resources beyond a city's core.