Investigating the effects of urban heat island on human well-being across Africa

Urban heat islands (UHI) are an increasingly important consequence of urbanization, with potential implications for human well-being. Yet, understanding of the UHI–well-being nexus remains geographically and conceptually fragmented, particularly in Africa, where empirical evidence remains limited. This thesis investigates the relationship between UHI and human well-being by combining a global assessment of the scientific literature with a continent-wide empirical analysis of African cities. A systematic review and bibliometric analysis of 4,857 publications retrieved from Scopus and Web of Science revealed rapid growth in research on UHI and human well-being, but strong geographical concentration in China and the United States and persistent underrepresentation of the Global South. The literature has increasingly shifted from urban surface characteristics and thermal comfort toward human health, heat vulnerability, well-being, and nature-based solutions, highlighting the need for context-specific evidence from underrepresented regions. To address this gap, UHI patterns and their relationships with vegetation, environmental performance, and human well-being were assessed across 999 African cities. Using nighttime land surface temperature and 2-km surrounding areas, UHI was detected in 82% of cities, with urban temperatures averaging 0.99°C higher than surrounding areas. However, UHI was not uniformly associated with reduced human well-being. Instead, its relationships with life satisfaction and human development varied according to environmental performance and vegetation characteristics, demonstrating important context dependence. Overall, this thesis shows that the implications of urban heat cannot be understood from temperature alone. Integrating UHI with vegetation, environmental conditions, and dimensions of human well-being provides a more comprehensive understanding of urban heat vulnerability and highlights the need for context-specific approaches to urban adaptation across African cities.