NASA says that seas have risen since 1992 by 3 inches, with some locations rising more than 9 inches, and anticipates an unavoidable rise of several feet in the future.
Caused by four main factors, of which two are global (ice melting and warming waters that expand) and two are local (a slowing Gulf Stream and sinking land), the amount and speed of sea level rise varies by location.
The consequences are staggering, creating more dangerous and powerful hurricanes and storm surges, and resulting in more intense and frequent flooding and devastation to coastal communities. In the United States, almost 40 percent of the population live in relatively high-population-density coastal areas, where sea level plays a role in flooding, shoreline erosion, and hazards from storms. You might be surprised to learn of the creation of ghost forests.
Georgetown University has created an Adaptation Tool kit but, as sea level rise expert John Englander points out, retreat may become a necessity. Flood iQ has a fascinating site where you can search your flood risk by address.
You might also want to watch a 4-part PBS series Sinking Cities which takes a look into how four cities (Miami, London, Tokyo, & New York) — all at particular risk — are adapting.