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New international study assesses 25 years of sea level rise 

Sea level rise, a primary indicator of global climate change with serious implications for coastal communities, is the focus of a recently published international study.

Through the World Climate Research Programme’s Grand Challenge on Regional Sea Level and Coastal Impacts, the major study assessed the various datasets used to estimate the contributing components of sea level rise since the start of high-accuracy satellite altimetry in 1993 – and included those produced by the Sea Level_cci project team. 

Determining the magnitude and rate sea level rise helps to better understand the different processes involved and the data are useful for validating climate models used for making projections.

According to the study, the altimetry-based global mean sea level rise averages 3.1 (± 0.3 mm) per year, with an acceleration of 0.1 mm/yr per year over the 25-year period. 

Drivers of Global Sea Level Rise

The researchers also examined the components driving sea level rise: ice melt from mountain glaciers and the polar ice sheets, the other being thermal expansion of the oceans – hot water is less dense than cool water, all of which are driven by increased greenhouse gas concentrations warming the atmosphere.

Ocean thermal expansion, glaciers, and the Greenland and Antarctica ice sheets were found to contribute 42 %, 21 %, 15 % and 8 % to the global mean sea level rise between 1993 to the present period. The agreement between the observed global mean sea level rate and the sum of these components – also known as “Sea Level Budget Closure” – has now reached 0.3 mm per year over the last 13 years, despite significant uncertainty remaining for the land water storage component. This essentially confirms that measurements of Sea Level rise are very accurate.


Publication reference: Global Sea Level Budget Group: Global sea-level budget 1993–present, Earth Syst. Sci. Data, 10, 1551-1590,, 201