Altimetric satellites are able to measure sea level and can observe how it has been changing with climate change since 1992. Not only can they tell us the global change but also the regional changes. Sea level changes are due to thermal expansion of water, melting of the polar ice caps and continental glaciers and water inputs from land. Tide gauges are able to tell us that sea level rose at a slower rate before the 1990s and then the global sea level trend increased after that. This is likely due to the increase of greenhouse gasses and climate change. The continued observation of sea level by altimetric satellites will be able to inform us what the future of sea level is. [Credit: CNES (Centre National d'Etudes Spatiales) and Mira Productions].