21st century, ocean warming in the range 0.8ºC-3.8℃ is projected near the surface , 0.8°C-3.0℃ at intermediate depth and 0.15℃-0.18℃ in deeper waters . The duration and intensity of marine heat waves have increased   and both parameters are projected to continue increasing in the future . Under Representative Concentration Pathway  8.5, at least one long-lasting marine heat wave is projected for every year by 2100, up to 3 months longer and about four times more intense than present-day events . Salinity is projected to increase, with anomalies from +0.48 to +0.89 psu by the end of the century  .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report