Global mean sea level
Global average sea level has risen about 245 mm since 1880 (2020), and the rate of rise is speeding up.
Source: Church & White (2011) and UHSLC, via Our World in Data. Data through 2020. Download the data (JSON).
About this indicator
Sea level rises for two main reasons: water expands as it warms, and land ice — glaciers and the Greenland and Antarctic ice sheets — melts and adds water to the ocean. Both are driven by a warming climate.
Long tide-gauge records extended by satellite altimetry since the 1990s show a steady rise, and the pace has roughly doubled in recent decades. This series is measured relative to a 1993–2008 reference.
Why it matters: Higher seas mean more coastal flooding, erosion and storm-surge damage for the hundreds of millions of people who live near coasts.