Protecting densely populated coastal areas, such as river deltas or megacities, from sea-level rise with dikes and seawalls will likely limit land loss and migration of people away from the coasts. But these protections are overlooked in most migration estimates. A new study predicts coastal protection could limit migration to 17 to 72 million people during the 21st century-less than half of some previous estimates. The study, published in Earth’s Future, AGU’s journal for interdisciplinary research on the past, present and future of our planet and its inhabitants, is the first to look at the effects of coastal protection on migration rates on a global scale. The analysis takes into account a wide range of climate change and economic scenarios.