Critical Analysis of World Cities: Sustainable Development and Urban Challenges

Walk through any major Indian city today and you’ll see two stories playing out at once. Gleaming offices and metro lines sit a few kilometres from settlements where basic services are still catching up. This isn’t unique to India. Cities everywhere are wrestling with the same question: how do you keep growing without breaking the systems that feed and house everyone? Understanding this tension is at the heart of critically analysing how the world’s biggest cities are planned, and what happens when planning falls behind population.

Cities as engines of progress 🔗

Cities have always been where human innovation concentrates. They house universities, research labs, financial markets, and the dense social networks that turn ideas into industries. This is why urban centres punch so far above their weight economically. Globally, the largest 600 cities hold roughly a fifth of the world’s population but generate around 60 percent of global GDP, a concentration of output that UN-Habitat’s flagship urbanisation research has tracked for years. In India, the pattern is even sharper. Cities occupy barely 3 percent of the country’s land area yet contribute close to 60 percent of national GDP, a ratio highlighted in NITI Aayog’s report on urban planning reform.

But that same concentration of people and activity is exactly what makes cities fragile. When millions of people depend on a limited land area for water, food, housing, and jobs, small planning failures compound quickly into large ones. The future of any mega city, whether it’s Mumbai, Jakarta, or São Paulo, depends on whether its growth is managed or simply absorbed.

Why rural-urban migration is straining food security 🔗

The twenty-first century has seen an unprecedented shift of people from villages to cities, especially across the developing world. In many countries, this movement isn’t gradual. It happens fast enough to outpace the infrastructure meant to support it. As people leave agricultural work behind and move to cities, two things happen simultaneously: the rural workforce producing food shrinks, and the urban population that needs to buy that food grows.

A shrinking margin between production and demand 🔗

Since the mid-1980s, many regions have seen a steady decline in surplus land available per person, and with it, a decline in per capita food production. The Green Revolution’s biotechnology gains through the 1960s pushed yields up dramatically, but by the 1980s those gains had largely plateaued, even as populations kept climbing. This mismatch is a structural problem, not a temporary one.

The scale of what’s at stake is significant. A recent UN report from the High Level Panel of Experts on Food Security and Nutrition found that over 75 percent of the world’s food-insecure population now lives in urban and peri-urban areas, relying entirely on markets rather than growing their own food, according to research summarised by Cornell’s Department of Global Development. That’s a fundamental shift from decades past, when food insecurity was framed mostly as a rural problem.

Closer home, the pressure shows up differently but just as clearly. Roughly 180 million rural residents live adjacent to India’s 70 largest cities, a number expected to keep rising as smaller towns absorb population overflow, per data compiled through the International Organization for Migration’s review of Indian urban migration. As this periphery grows, so does the demand it places on land, water, and food systems that weren’t designed to expand this quickly.

When farmland disappears: lessons from China 🔗

Nowhere illustrates the arable land problem more starkly than China. Rapid industrial growth, sprawling urban expansion, and decades of overcultivation have steadily eaten into the country’s farmland. According to World Bank figures cited by the ChinaPower Project at CSIS, China’s total arable land shrank by more than 12 million hectares between 2009 and 2021 alone. By 2022, the country had 31 percent less arable land than the United States, despite having roughly four times the population to feed.

Urban land grows faster than urban population 🔗

What makes this especially worth studying is a pattern researchers have found across hundreds of Chinese cities: the rate at which land gets converted into urban use routinely outpaces the rate at which the urban population actually grows. In other words, cities are consuming farmland faster than they’re adding residents, a mismatch that leaves large stretches of converted land underused while agricultural capacity keeps shrinking. This is precisely the kind of unplanned expansion that critical analyses of world cities warn against: growth without a corresponding increase in efficiency or benefit.

China isn’t an isolated case. Globally, urban expansion is projected to reduce arable land by roughly 2 to 2.4 percent by 2030, with the resulting crop losses concentrated most heavily in Asia and Africa, the regions already facing the steepest urbanisation curves. The lesson generalises well beyond one country: when cities expand outward without a plan for what happens to the farmland they replace, food systems absorb the cost quietly, until shortages make the cost impossible to ignore.

Planning the world’s biggest cities for the long run 🔗

Sustainable planning isn’t optional for cities like New York, Los Angeles, London, Paris, Jakarta, Bangkok, Mexico City, and São Paulo. It’s a survival requirement. These cities differ enormously in geography and governance, but they share a common challenge: balancing continued economic growth against finite land, water, and energy.

Consumption concentrated in dense areas 🔗

Globally, cities account for 60 to 80 percent of total energy consumption and generate as much as 70 percent of human-caused greenhouse gas emissions, largely from fossil fuel use in energy supply and transport, as detailed in UN-Habitat’s World Cities Report. That concentration is also an opportunity. Because so much consumption is packed into relatively small urban footprints, targeted interventions in transport, building design, and energy grids can move the needle on climate outcomes faster than diffuse rural interventions ever could.

Unplanned growth has real costs 🔗

When urbanisation happens without coordinated planning, the outcomes are predictable: rising inequality, expanding informal settlements, and worsening climate vulnerability. This is exactly why UN-Habitat’s more recent World Cities Report frames the coming decades bluntly, projecting the global urban population will grow by another 2.2 billion people by 2050, and warning that this growth has to be managed deliberately rather than left to unfold on its own.

Connecting cities to their suburbs to ease the pressure 🔗

One of the more practical tools for reducing migration pressure on core cities is investment in transportation networks connecting cities to their suburbs and satellite towns. Reliable road, bus, and rail links between a metropolis and its periphery give people a genuine alternative to migrating all the way into the urban core just to access jobs, healthcare, or education.

This matters because unmanaged outward sprawl, driven heavily by automobile dependence and weak regional planning, is already a defining feature of large cities worldwide, a trend the United Nations tracks under its sustainable development goal on inclusive urbanisation, using the ratio of land consumption to population growth as a formal indicator. Where cities have built strong suburban transit links, that ratio tends to stay more balanced. Where they haven’t, cities sprawl outward far faster than their populations actually grow, consuming farmland and open space in the process.

India has started experimenting with this approach through initiatives that treat peri-urban and small-town development as an extension of city planning rather than an afterthought. State-level efforts, such as Odisha’s Rural-Urban Transition Policy, aim to bring urban-grade infrastructure to peripheral areas before migration pressure forces the issue, an approach recommended more broadly in NITI Aayog’s 2021 review of India’s urban planning capacity. The logic is straightforward: if opportunity exists closer to home, fewer people need to migrate into an already strained core city.

What the future holds for mega cities 🔗

The trajectory of mega cities over the next few decades is tied directly to two variables: how fast populations keep growing, and how well planning systems adapt to that growth. Neither variable is fixed. Population growth can be shaped by economic opportunity outside urban cores, and planning systems can be strengthened through policy, investment, and better governance.

What’s clear is that the old model, treating urban growth as something to manage after it happens, is no longer adequate. Sustainable mega-city development has to fold in ecological limits, social equity, and economic viability from the start, not retrofit them once problems appear. India’s own urban population is projected to reach roughly 600 million by 2031, close to 40 percent of the country’s total population, a scale of transition that leaves very little room for reactive planning.

The cities that manage this transition well will likely be the ones that treat food security, land use, and transportation as a single interconnected system rather than separate departments solving separate problems. The ones that don’t will keep discovering, the hard way, that growth without planning eventually runs into its own limits.

What do you think? Do you think Indian cities are moving fast enough on peri-urban transit and planning to keep pace with migration, or is the gap widening? And should food security be treated as a core part of urban planning policy, rather than a separate agricultural issue?

References

1. https://unhabitat.org/un-habitat-launches-the-world-cities-report-2016
2. https://www.niti.gov.in/sites/default/files/2021-09/UrbanPlanningCapacity-in-India-16092021.pdf
3. https://cals.cornell.edu/news/2024/07/17-billion-people-urban-and-peri-urban-areas-face-food-insecurity
4. https://www.iom.int/resources/urban-migration-trends-challenges-and-opportunities-india
5. https://chinapower.csis.org/china-food-security/
6. https://wuf.unhabitat.org/news/world-cities-report-launched-warning-we-must-get-cities-right
7. https://unhabitat.org/11-3-sustainable-urbanization