Sea-level rise is an increase in sea level. Multiple complex factors may influence this change.
Sea-level has risen about 130 metres (400 ft) since the peak of the last ice age about 18,000 years ago. Most of the rise occurred before 6,000 years ago. From 3,000 years ago to the start of the 19th century sea level was almost constant, rising at 0.1 to 0.2 mm/yr. Since 1900 the level has risen at 1 to 2 mm/yr; since 1993 satellite altimetry from TOPEX/Poseidon indicates a rate of rise of 3.1 ± 0.7 mm yr–1. Church and White (2006) found a sea-level rise from January 1870 to December 2004 of 195 mm, a 20th century rate of sea-level rise of 1.7 ±0.3 mm per yr and a significant acceleration of sea-level rise of 0.013 ± 0.006 mm per year per yr. If this acceleration remains constant, then the 1990 to 2100 rise would range from 280 to 340 mm. Sea-level rise can be a product of global warming through two main processes: thermal expansion of sea water and widespread melting of land ice . Global warming is predicted to cause significant rises in sea level over the course of the twenty-first century.
