Abstract

More than half of the world’s population now lives in cities. Today, urbanisation is dominated by Asian cities, with 19 of the world’s 33 megacities located in Asia. By 2050, urban areas are projected to host 37 megacities, including Addis Ababa and Dar es Salaam, shifting the geography of rapid urbanisation to Africa (United Nations, 2025). Many of these cities in the global South are marked by informality (Banks et al., 2020; Chen et al., 2026; Satterthwaite et al., 2020), which is understood as economic activities, housing and social practices that exist outside legal frameworks and state planning, both crucial to a city’s functioning. A significant proportion of the global South’s urban population is within these informal systems, typically population dense, lacking infrastructure and characterised by poor living, environmental and health conditions.