Empirical projection of global sea level in 2050 driven by Antarctic and Greenland ice mass variations

Abstract

Global mean sea level rise, driven by ice mass loss in Antarctic and Greenland Ice Sheets (AIS and GrIS), is a significant consequence of global warming. Although various ice sheet models have attempted to predict the ice mass balance and subsequent sea level changes, non-trivial disagreements between models exist. In this study, we employ an empirical approach to estimate the future (2050) ice mass changes for both ice sheets, assuming their historical patterns of ice dynamics would persist in the coming decades. To achieve this, we estimate decadal-scale ice discharge variations by subtracting the surface mass balance (SMB) from the observed ice mass changes and extrapolate linear trend and acceleration components of ice discharges up to 2050. We also consider future SMB data from CMIP6 models to estimate net ice mass balance. Our estimates suggest that from 2021 to 2050, the global sea level rise due to AIS and GrIS ranges between 6-19 mm and 15-31 mm, respectively. Additionally, we investigate regional sea level variability resulting from geoid changes induced by ice mass changes in both regions, highlighting that heterogeneous sea level changes may cause more pronounced sea level rises in lower latitude regions, where major cities are located.