One-half of North American imperiled species live in subterranean habitats, which largely are associated with karst (a type of landscape underlain by limestone that has been eroded over time, producing caves, sinkholes, towers and other formations). Further, karst aquifers provide a unique opportunity to investigate the effects of climate change on groundwater at timescales of human interest because these aquifers exhibit large variability in hydrologic responses, such as springflow (i.e. groundwater discharge) and water-table level (i.e. level below which the ground is completely saturated with water), at short timescales. By linking a global climate, regional climate, and hydrologic model, researchers can obtain input for a tool to measure species vulnerability. Modifying the tool to explicitly incorporate hydrologic factors such as spring flow and water-table level brings us a step closer to a more realistic assessment of species vulnerability in karst settings.