Abstract: Revealing the cause of global mean sea level (GMSL) rise helps to advance the knowledge of current climate change, and make adaptive planning. Space geodesy technique along with Argo float greatly improves the investigation of the cause of sea level rise on global and regional scales. These observations serve as important supplements to model output that usually fail to capture long-term trend, in addition to providing independent verifications, they also help to understand the drivers of sea level change on long-term and interannual scales. This paper reviews the achievements and progresses in the cause of sea level change, with a particular focus on discussing the contributions of mass variations over global land area. Observations suggests that, over recent two decades, 65% GMSL rise is caused by ocean mass increase due to mass loss in polar ice sheet and mountain glacier, and land hydrology. The remaining GMSL rise is induced by ocean thermal expansion. Given that global warming is expected to continue, both ice mass loss and ocean thermal expansion are associated with acceleration, which results in accelerated GMSL rise. These results have important implications for understanding climate change and projecting future GMSL rise. Except for presenting the major achievements, we also highlight some challenges that confront the study of the cause of GMSL rise, for example:①Observations are not able to close the sea level budget at local scales. ②The discrepancy of GMSL budget increases significantly after 2016.

Key words: sea level rise, satellite altimetry, satellite gravity, thermal expansion