Natural selection could determine whether Acropora corals persist under expected climate change

Marine heatwaves are intensifying under climate change, exposing populations of reef-building corals to mass mortality and intense selective pressure. It remains unknown whether adaptation can keep pace with warming and maintain reef functioning. We have developed an eco-evolutionary metapopulation model for Acropora , an ecologically important yet highly threatened coral taxon. We find that although corals have some adaptation capacity, they will suffer severe heatwave-induced declines over the coming decades. For a future where emissions lead to ~3°C of global warming, natural selection could allow populations to persist, albeit in severely depleted states with elevated extinction risk and potential loss of ecosystem functioning. Yet, for thermally sensitive coral populations to thrive post-2050 demands rapid reductions of greenhouse gas emissions that limit global warming to 2°C.