Identifying coral refugia from observationally weighted climate model ensembles

Abstract:

Reef-building corals face a variety of mounting anthropogenic stressors originating both at the global scale (increasing sea surface temperatures (SSTs), rising sea levels, and ocean acidification) and the local scale (such as destructive fishing, overfishing, sedimentation, invasive species, nutrient over-enrichment, and chemical pollutants). We provide estimates of the dates of coral reef departure for the world’s reef systems, based on CMIP6 SST projections under various emissions scenarios. We first assess the skill of each model using historical model runs and the observational record, and then downscale the observationally weighted mean using 4-km-resolution satellite SST observations and a local approximate Gaussian process model. Finally, we use in situ coral reef health data to translate the weighted, downscaled SST projections to bleaching and mortality projections, with the goal of informing reef conservation management at local scales.