A rising sea level combined with more storms, washes away vulnerable beaches. With the sand gone, the coast is more vulnerable to waves going further inland, threatening fresh water wells with salinisation, leading to land erosion, and making the areas less attractive for tourism. When a beach starts to deteriorate, the process can be amazingly quick.
It is very likely that the 20th century warming has contributed significantly to the observed rise in global average sea level and the increase in ocean heat content. Warming drives sea level rise through thermal expansion of seawater and widespread loss of land ice. Based on tide gauge records, after correcting for land movements, the average annual rise was between 1 and 2 mm during the 20th century.