Global hotspots of unprecedented tropical cyclone risk and suitable adaptation responses

Submitted manuscript presenting a global, high-resolution assessment of unprecedented tropical cyclone (TC) risk under climate change. “Unprecedented” TCs are defined as events occurring in historically unaffected areas or exceeding local adaptive capacity. Plausible future TC hazards from three synthetic TC models (STORM, CHAZ-CRH and CHAZ-SD) are combined with population exposure and multi-scale adaptive capacity to classify 27,474 coastal regions into TC region types, with two critical categories: transitional-increase regions, where major TCs emerge, and neo-climatic regions, where TCs may occur for the first time. Under SSP5-8.5, by 2050, 28–73% of the exposed population lives in regions with more frequent major TCs, and up to 2.6% in candidate neo-climatic regions identified only by STORM. Risk hotspots appear where increasing hazard meets low adaptive capacity, notably in Yemen and Haiti. Region types and their uncertainty are linked to tailored disaster risk reduction measures, from low-regret actions to potentially irreversible interventions. This work is part of the TRANSCLIMA project (Detection and Global Risk Assessment of Coastal Transitional Climate and Neo-Climate Regions in a Warming World), funded by the European Union’s Horizon Europe research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 101111262 (HORIZON-MSCA-2022-PF-01). Computations were run on MareNostrum 5 (Barcelona Supercomputing Center; RES project IM-2025-1-0025).