Improved closure of the global mean sea level budget from observational advances since 1960

Balancing the global mean sea level (GMSL) budget is essential for understanding sea level changes. Large uncertainty after 1960 is reduced by accounting for recent observational advances. Budget closure occurs within 0.18 millimeters per year for all periods analyzed (1960–2023, 1993–2023, and 2005–2023). Trends for these three periods are 2.06, 3.41, and 3.94 millimeters per year, revealing an increase in the rate. The annual residual between observed GMSL and the sum of contributions is only between −13 and 10 millimeters since 1960 and ±5 millimeters after 2005. Further, the GMSL acceleration budget is now closed. The principal drivers for the GMSL trend (acceleration) since 1960 are 43% (41%) from thermosteric ocean expansion, 27% (9%) from glacier melting, 15% (16%) from Greenland, 12% (13%) from Antarctic, and 3% (21%) from land water storage. Results highlight the importance of data processing and bias correction techniques in tracking GMSL and its contributions.