Identifying key drivers of habitability loss reveals pathways for climate change adaptation in the Pacific

Pacific islands and atolls face heightened climate risk due to low elevations and limited resources. The question of (unin)habitability in these locations is often simplified to characteristics of hazard exposure, reinforcing assumptions of inevitable mass migration. Here we use a multi-dimensional conceptualisation of habitability, built from local knowledge, to simulate habitability trends in the Pacific Island nation of Kiribati over the coming century. We find that water insecurity will be a driving factor in habitability loss, intensifying under extreme climate scenarios, while population pressures will further constrain resources. We show that regional disparities will lead to high internal migration rates, with movement to national urban centres preferred over movement abroad. Our work answers calls for a holistic and locally grounded understanding of habitability. By identifying how drivers of habitability change over time, we offer insights for targeted and timely climate adaptation.