Assessing the exposure of buildings to long-term sea level rise across the Global South

Future sea levels are expected to rise, resulting in the progressive inundation of coastal cities. Because the spatio-temporal progression of this inundation is complex, few estimates have been made of how sea level rise will impact specific features of the built environment beyond 2100. Here we provide a first-order assessment of the exposure of buildings to sea level rise from satellite observation in Africa, Southeast Asia, and South and Central America. We define an inundation metric as a function of Local Sea Level Rise (LSLR) and consider this metric across a wide range of possible multi-century LSLR Values. Of the 840 million buildings in the study region, we find ~3.0 million at risk of inundation with 0.5 m LSLR, increasing to ~45 million with 5 m LSLR, and ~136 million with 20 m LSLR. Our results highlight geographic variability in exposure and demonstrate the benefits that low-emissions pathways imply for preserving built environments.