Sea level is rising by about 30-40 cm per century, in part due to global warming. Due both to rising water levels and beach erosion (sometimes called shoreline retreat), coastlines are moving inland at a rate of about 30-100 cm per year (Pilkey and Cooper, 2004). Because of high and growing populations in coastal areas, increased attention is needed on understanding reasons for shoreline retreat, the potential societal consequences, and political action required to prevent economic and social disruption.
Reference
Pilkey, O.H. and J.A.G. Cooper, 2004: Society and sea-level rise. Science, 303, 1781-1782.