For seagrasses, recent projections for climate-change impacts vary by species and region. Warming is projected to increase the habitat available to Zostera marina on the east coast of the USA by 2100 but contract its southern range edge by 150-650 km under RCP2.6 and RCP8.5, respectively . Other species, such as Posidonia oceanica in the Mediterranean, might lose as much as 75% of their habitat by 2050 under RCP8.5 and become functionally extinct  by 2100 . Observed impacts of MHWs  indicate that increasing intensity and frequency of MHWs  will have escalating impacts on seagrass ecosystems . Habitat suitability can also be reduced by moderate RSLR, due to its impact on light attenuation  .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report