A phenomena that affects coastal areas, the increasing levels of sea water observed in the past few years causes edges of these coastal areas to lose land as it is encroached by rising water levels. During the 20th century, sea level rose about 15-20 centimeters (roughly 1.5 to 2.0 mm/year), with the rate at the end of the century greater than over the early part of the century. Scientists believe that sea level rise is one of the many effects of climate change.