According to data released by the United Nations (UN, 2017), the global population has reached 7.6 billion, with more than half (54%) living in urban areas. In Brazil, according to data from the Brazilian Institute of Geography and Statistics (IBGE, 2010), 84.4% of the population lives in cities.
Within this scenario, by 2016 there were 31 megacities with populations exceeding 10 million inhabitants, located in the so-called "Global South"—a region comprised solely of developing countries. It is worth noting that the population explosion in these megacities was driven by migratory processes, in which thousands of people were drawn to cities in search of job opportunities and social mobility. Furthermore, a portion of this population can be described as displaced; they often migrate not by choice, but in search of better living conditions, fleeing natural disasters, armed conflicts, and other factors.
In large cities, nearly 1 billion people live in informal settlements[1], which make up significant portions of the residential fabric of urban areas. According to the thematic document prepared for Habitat III, held in Quito in 2016, this type of fabric is characterized by: housing lacking secure tenure, located in squatter settlements or informal rentals; neighborhoods that are generally cut off from basic sanitation services, safe drinking water, public spaces, and green areas; and exclusionary practices that have contributed to historical conditions of economic inequality and segregation. Consequently, under any of these conditions, residents are constantly vulnerable to disease, violence, evictions, and gentrification, as shown in the image below.
