As noted in SROCC, given the diversity of coastal wetlands as well as the dependence of their future vulnerability to climate change on adaptation pathways , projections of future impacts based on shoreline elevation estimated from satellite data and CMIP5 projections  vary greatly. Although all approaches have individual strengths and weaknesses , paleorecords provide some clarity because they yield estimates of wetland responses to changes in climate in the absence of other anthropogenic drivers and are therefore inherently conservative. On the basis of paleorecords , we assess that mangroves and salt marshes are likely at high risk from future SLR, even under SSP1-1.9, with impacts manifesting in the mid- term . Under SSP5-8.5, wetlands are very likely at high risk from SLR, with larger impacts manifesting before 2040 . By 2100, these ecosystems are at high risk of impacts under all scenarios except SSP1-1.9 , with impacts most severe along coastlines with gently sloping shorelines, limited sediment inputs, small tidal ranges and limited space for inland migration  .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report