Near-term future sea-level projections supported by extrapolation of
tide-gauge observations
Abstract
Global, regional and local sea-level projections rely on complex
process-based models of the climate-ocean-cryosphere system. While
extrapolation of observational data has been examined on global and
regional scales, this approach has not yet been used for the additional
complexities of local coastal sea-level projections. Here, we evaluate
the sea level trend and acceleration for a global network of tide-gauge
observations over 1970-2023, which are then extrapolated to provide
local projections up to 2050 and compared with the process-based
projections from the IPCC Sixth Assessment Report (AR6). For 2050
relative to 2020, the observation-based projections agree with AR6
process-based projections within the 90% uncertainty range at the
majority (99%) of 237 tide gauges. Thus, the observation-based
projections provide complementary perspectives of near-term local
sea-level changes, and this agreement provides increased confidence in
the current understanding and projections of sea-level changes over
coming decades.