Without adaptation, risks to land and people in coastal C&S from pluvial and coastal flooding will very likely2 increase substantially by 2100 and likely beyond as a result of SLR, with significant impacts even under RCP2.6 . Across these studies, by 2100, 158-510 million people and USD 7,919-12,739 billion assets under RCP4.5, and 176-880 million people and USD 8,813- 14,178 billion assets under RCP8.5 will be within the 1-in-100-year floodplain . There is medium confidence that accelerated SLR will increase shoreline erosion globally, although biophysical feedbacks will allow many coastlines to maintain relatively stable morphology if room exists to accommodate mangroves in estuarine and deltaic coasts and beach movement along open coasts . Limiting emissions to RCP2.6  significantly reduces future SLR risks . For example, by 2100, the population at risk of permanent submergence increases by 26% under RCP2.6 compared with 53% under RCP8.5 .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report