Abstract
Climate change and human activities threaten water resources in the Canary Islands, where increasing temperatures and decreasing precipitation intensify water stress. In order to develop strategies to protect water resources, it is necessary to know how water availability will evolve in this region. The Fundación para la Investigación del Clima (FICLIMA) methodology offers high-resolution projections (100 m × 100 m), which allow us to understand how climate change alters the long-term dynamics of the water balance in islands with complex orography and microclimates. The results reveal a decrease in the water balance due to increased evapotranspiration and stable or reduced precipitation. Severe decreases in the water balance are expected by the end of the century, reaching reductions of 50-75% on El Hierro or total depletion on Gran Canaria. Sustainable water management and the implementation of adaptive policies will be essential to guaranteeing water security in the future.