4Ocean seeks to investigate the physiological, ecological, and adaptive responses of marine organisms to ocean warming and ocean acidification . 4Oceans combines: 1) field surveys and experiments in marine volcanic CO2 vents, which cause local acidification of seawater and are used as proxy to represent future acidification conditions; and sites in the NW Mediterranean with highly variable seasonal temperatures and extreme heat waves; 2) ecophysiological laboratory experiments; 3) functional, trait-based analysis of biodiversity; and 4) ocean-based actions to minimize impacts. To achieve these objectives 4Oceans created a multi-disciplinary consortium with skills in coastal oceanography and carbonate chemistry, marine ecology, statistical modelling, physiology, genomics, dissemination and communication. 4Oceans has received funding from the French National Research Agency (ANR) under the Make Our Planet Great Again (MOPGA) research program (Grant Agreement ANR-17-MPGA-0001).