Sea level: A review of present-day and recent-past changes and variability

In this review article, we summarize observations of sea level variations, globally and regionally, during the 20th century and the last 2 decades. Over these periods, the global mean sea level rose at rates of 1.7 mm/yr and 3.2 mm/yr respectively, as a result of both increase of ocean thermal expansion and land ice loss. The regional sea level variations, however, have been dominated by the thermal expansion factor over the last decades even though other factors like ocean salinity or the solid Earth's response to the last deglaciation can have played a role. We also present examples of total local sea level variations that include the global mean rise, the regional variability and vertical crustal motions, focusing on the tropical Pacific islands. Finally we address the future evolution of the global mean sea level under on-going warming climate and the associated regional variability. Expected impacts of future sea level rise are briefly presented.