Lately, I came across a data set on OurWorldinData.org that was mapping the projected urbanization increases between now and 2050. It made me uncomfortable when comparing where most urban planners and designers work and where most of the growth will take place. According to that data, Niger will urbanize by another 248 %, Tanzania by 147 % and India by 54% within the next 25 years. Almost all countries are in the band between 30 degrees North and 20 degrees South – the very zone that is the hottest and the one with the most extreme weather conditions. The profession has not responded to that yet – at least not at the scale and the level of thinking that is needed to avoid a catastrophe in the making.
Imagine – a dense urban settlement that appeared overnight. People just move to the city and settle in places that seem available. They build houses from what they could find or could buy with their limited means. Nothing has been prepared for the arrival of these new city dwellers. There is no infrastructure and no system that devises land. Everything is patched together informally and without any bigger picture in mind.
Imagine – a seemingly endless carpet of houses emerges with wide streets, large plots and parking garages for several cars. In plans and models, this city appears completely green with tens of thousands of trees and parks. Buildings are made from elaborate materials, well maintained and occupied by people that not only own the houses, but also the big cars in front of them. What seems to have gone missing is the abundance of green that has been replaced by tarmac.
Two scenes that are not untypical for the 50 degrees wide band around the globe’s equator. Two completely different economic conditions, but both portray cities that are not ready for the future: Cities that are not ready for extreme heat and freak weather.
What’s missing is a paradigm shift. We cannot respond to unprecedented urban growth with outdated models of planning. We can’t expect cities to simply “absorb” more people and somehow remain liveable. What’s at stake is not just comfort—it’s survival.
What Must Be Done?
Design for Thermal Equity: Cities in hot zones need to be designed with heat-resilience as a core principle, not an afterthought. It starts with the urban form: compact, shaded, mixed-use neighbourhoods with walkable streets are far more thermally comfortable than sprawling, low-density developments with wide, sun-baked roads. Green roofs, tree canopies, water bodies — these aren’t luxuries, they are infrastructure for survival. Maximizing shade, airflow, and evaporative cooling and passive design techniques — thick walls, high ceilings, courtyards, verandas — have existed for centuries in hot climates. These vernacular models need to be rediscovered, adapted, and scaled.
Invest in Informality: Informal settlements are not temporary — they are the backbone of urban growth in much of the Global South. Instead of trying to replace them with master-planned neighbourhoods, we need strategies that upgrade and support informal communities from within. They include micro-infrastructure investments (shade structures, water points, drainage), flexible zoning that legitimizes mixed-use and self-built housing and access to materials and tools that promote climate-resilient building techniques.
Informal does not mean inferior. With support, these communities can become models of low-carbon, low-cost resilience. But we can do more: where we expect informal settlements to emerge, we can pre-emptively provide key infrastructure that is hard to integrate after. A network of paths and roads, a drainage system that avoids flooding and land slides and a sewerage system that helps keeping infectious diseases in check could be developed and rolled out at little cost – certainly compared to retroactively integrating this type of infrastructure – if possible at all.
Decolonize Urban Models: Much of contemporary architecture and planning is still steeped in Euro-American ideals. Glass towers, air-conditioned malls, eight-lane highways — these are exported templates that ignore local climate, culture, and resource limits. In the context of Dar es Salaam or Niamey, they are not just inappropriate; they are dangerous. Instead, we need to design from the ground up — learning from local practices, involving communities in decision-making, and shifting value systems to prioritize livability over formality, and resilience over aesthetics.
Plan for Uncertainty: The urban future is not just hot — it’s uncertain. Extreme heat waves, sudden downpours, floods, droughts, and even climate migration will test the adaptability of cities. This requires flexible planning systems that can evolve over time. Rather than locking cities into rigid masterplans, we need to think in terms of frameworks and tools that allow for incremental, participatory development. Small-scale interventions — like decentralized cooling stations, mobile clinics, green corridors, and floodable parks — can be scaled quickly and adapt over time.
Rethink Metrics of Success: A “green” city isn’t one with lush renders and tree-planting targets. A successful city is one where people can breathe, move, work, and live — even in 45°C heat. Planners and designers must embrace new indicators: heat stress reduction, walkability under shade, water access, microclimate health, and social cohesion.
The climate crisis is not a future scenario. It is already shaping the way cities are lived, built, and imagined. The urbanizing equator — this narrow band of rapid growth and rising temperatures — will be the hotbed of urbanization. The question is: will we continue exporting models that do not suit? Or will we start designing cities that are fundamentally built for heat? The future of the city is hot — but it doesn’t have to be hostile. It can be humane, adaptive, and alive.
Cover map generated with the use of ChatGPT
