Antonio J. Carpio1, E. Laguna1.*, R. Pascual-Rico1,*, M. Martínez-Jauregui2, J. Guerrero-Casado3, J. Vicente1, R. C. Soriguer4, E. Delgado1, P. Acevedo1

Sea level rise has accelerated during recent decades, exceeding rates recorded during the previous two millennia1. Many coastal habitats and species around the globe are vanishing2. This situation is expected to worsen due to anthropogenically induced climate change. However, the magnitude and relevance of expected increase in sea level rise (SLR) for marine and terrestrial species reliant on coastal habitat for foraging, resting or breeding is unknown. We combined freely available digital elevation models for continental and remote island beaches across ocean basins with field data and sea level rise projections to explore the potential impact of SLR under various IPCC SLR scenarios on sea turtle nesting habitats at some of the largest rookeries worldwide. The study sites host five out of seven living species and all of them are categorized from vulnerable to critically endangered3 and essential due to sea turtles return to natal beaches to nest4. Our results confirm that the majority of sea turtle nesting habitat could vanish within the next few decades, leading to the depletion of many populations worldwide. Thus, even under moderate climate change scenarios, a large proportion of sea turtle nesting habitat will be flooded by 2050 and not survive to the end of the century. Overall, nesting populations with a low steep beaches slope and those species nesting at open beaches such as leatherback and loggerheads sea turtles might be the most affected under future SLR scenarios.