Loss of coral reef growth capacity to track future increases in sea level

Sea-level rise (SLR) is predicted to elevate water depths above coral reefs and to increase coastal wave exposure asecological degradation limits vertical reef growth, but projections lack data on interactions between local rates of reefgrowth and sea level rise. Here we calculate the vertical growth potential of more than 200 tropical western Atlanticand Indian Ocean reefs, and compare these against recent and projected rates of SLR under different RepresentativeConcentration Pathway (RCP) scenarios. Although many reefs retain accretion rates close to recent SLR trends, few willhave the capacity to track SLR projections under RCP4.5 scenarios without sustained ecological recovery, and underRCP8.5 scenarios most reefs are predicted to experience mean water depth increases of more than 0.5 m by 2100. Coralcover strongly predicts reef capacity to track SLR, but threshold cover levels that will be necessary to prevent submergenceare well above those observed on most reefs. Urgent action is thus needed to mitigate climate, sea-level and futureecological changes in order to limit the magnitude of future reef submergence.