Ashraf Rateb , Bridget R. Scanlon

As global sea levels rise, questions persist about the robustness of trends and their dynamics. Here, we offer a fresh perspective by examining the dynamics of global and regional mean sea-level trends using a probabilistic framework applied to the altimetric record. We show that the global mean sea-level (GMSL) rise accelerated from 2.5 mm/yr (1993-2000) to 4.2 mm/yr (2014-2021) with an average plausibility (85%) over the entire 29-year record. El-Niño Southern Oscillation modulates GMSL, with ~9% increase (decrease) in magnitude during El-Niño (La-Niña) events. Furthermore, our analysis identifies six regions (e.g., Pacific, Atlantic, Indian, Tropics, Southern Oceans and North Sea) with high probability of upward stable trends that persisted beyond interannual and decadal natural variability of arbitrary 29-year window, —suggesting a substantial contribution from external factors (e.g., climate change). By treating sea level trends as random processes and employing non-parametric probabilistic methods (e.g., Gaussian process regression) we obtain reliable estimates that account for trends complex patterns and inherent uncertainties, ultimately enhancing attribution processes and facilitating effective communication of sea level trend changes.