Anthropogenic climate change will likely outpace coral range expansion

Past coral range expansions suggest that high-latitude environments may serve as refugia, potentially buffering coral biodiversity loss due to climate change. We explore this possibility for corals globally, using a dynamic metacommunity model incorporating temperature, photosynthetically available radiation, pH, and four distinct, interacting coral assemblages. This model reasonably reproduces the observed distribution and recent decline of corals across the Indo-Pacific and Caribbean. Our simulations suggest that there is a mismatch between the timescales of coral reef decline and range expansion under future predicted climate change. Whereas the most severe declines in coral cover will likely occur within 40 to 80 years, large-scale coral reef expansion requires centuries. The absence of large-scale coral refugia in the face of rapid anthropogenic climate change emphasizes the urgent need to reduce greenhouse gas emissions and mitigate nonthermal stressors for corals, both in the tropics and in higher latitudes.