CoralWarm will generate for the first time projections of temperate and subtropical coral survival by integrating sublethal temperature increase effects on metabolic and skeletal processes in Mediterranean and Red Sea key species. CoralWarm unique approach is from the nano- to the macro-scale, correlating molecular events to environmental processes. This will show new pathways to future investigations on cellular mechanisms linking environmental factors to final phenotype, potentially improving prediction powers and paleoclimatological interpretation. Biological and chemical expertise will merge, producing new interdisciplinary approaches for ecophysiology and biomineralization. Field transplantations will be combined with controlled experiments under IPCC scenarios. Corals will be grown in aquaria, exposing the Mediterranean species native to cooler waters to higher temperatures, and the Red Sea ones to gradually increasing above ambient warming seawater. Virtually all state-of-the-art methods will be used, by uniquely combining the investigators expertise. Expected results include responses of algal symbionts photosynthesis, host, symbiont and holobiont respiration, biomineralization rates and patterns, including colony architecture, and reproduction to temperature and pH gradients and combinations. Integration of molecular aspects of potential replacement of symbiont clades, changes in skeletal crystallography, with biochemical and physiological aspects of temperature response, will lead to a novel mechanistic model predicting changes in coral ecology and survival prospect. High-temperature tolerant clades and species will be revealed, allowing future bioremediation actions and establishment of coral refuges, saving corals and coral reefs for future generations.