Ocean warming will continue over the 21st century , with the rate of global ocean warming starting to be scenario- dependent from about the mid-21st century . At the ocean surface, it is virtually certain that SST will continue to increase throughout the 21st century, with increasing hazards to many marine ecosystems . The future global mean SST increase projected by CMIP6 models for the period 1995-2014 to 2081-2100 is 0.86°C  under SSP1-2.6, 1.51°℃  under SSP2-4.5, 2.19°℃  under SSP3-7.0 and 2.89°℃  under SSP5- 8.5 . Stronger surface warming occurs in parts of the tropics, in the North Pacific, and in the Arctic Ocean, where SST increases by >4℃ in 2080-2099 under SSP5- 8.5 . The CMIP6 climate models also project ocean warming at the seafloor, with the magnitude of projected changes being less than that of surface waters but having larger uncertainties . The projected end-of-the-century warming in CMIP6 as reported here is greater than assessed with Coupled Model Intercomparison Project 5  models in AR5 and in SROCC for similar radiative forcing scenarios , because of greater climate sensitivity in the CMIP6 model ensemble than in CMIP5 .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report