Assessing the vulnerability 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 vulnerability of buildings to sea level rise from satellite observation in Africa, Southeast Asia, and South and Central America. We circumvent factors such as local subsidence and ice sheet dynamics by defining an inundation metric as a function of Local Sea Level Rise (LSLR), rather than time. Of the 840 million buildings in the study region, we find ~ 3.0 million at risk of inundation with 0.5m LSLR, ~ 45 million with 5m LSLR, and ~ 136 million with 20m LSLR. Our results highlight geographic variability in vulnerability and demonstrate the benefits that low-emissions pathways imply for preserving built environments.