| Popis: |
Local sea-level changes deviate from the global mean and unforced variability often masks sea-level changes driven by greenhouse forcing. Both cause difficulties when local observations are compared to projections. We present two analyses of local sea level aiming at improving understanding local causes of sea-level rise and variability. First, we analyse local sea-level budgets at 557 tide-gauge locations from 1993-2019. On average, the sum of contributing processes explains 49% of the observed inter-annual variance. Sterodynamic processes explain most of the variability. The average observed trend is 2.6 mm yr-1 with contributors summing up to 2.7 mm yr-1. Secondly, we extrapolate the current trajectory of sea-level rise and estimate how unforced variability can mask or exaggerate future long-term sea-level changes. Unforced variability can cause sea-level changes up to multiple decimeters on 30-year time scales, and the differences between projections and the trajectory are thus generally not significant. |
