Regional dynamics drive differences in future heat stress and reveal where Hawaiian corals are most likely to persist.

The Hawaiian Islands cause significant disruption to North Pacific oceanic and atmospheric flows creating highly localized spatial variability of ocean conditions on coral reefs. This variability affects climate impacts on these corals but is unresolved in global climate models. Using a dynamically downscaled model to resolve future conditions at high temporal (daily) and spatial (4 km) resolution for the Hawaiian Islands, we investigate projected heat stress and the adaptation rate required for corals to withstand projected end of century warming for three different emission scenarios. In the region, the Island of Hawai'i is projected to experience the greatest heat stress by the end of the century; however, we find that coral adaptation is possible to allow Hawaiian coral to persist in the three emission scenarios. Robust projections of future conditions and required adaptation rates on a local scale are critical for successful management of these crucial ecosystems.