A global chronologically standardised database of high-resolution proxy sea-level reconstructions since 1800 CE

Understanding relative sea-level (RSL) change since the early industrial period to the present is essential to contextualise modern trends and improve future projections. However, existing databases of Common Era RSL reconstructions contain ages derived from outdated radiocarbon calibration curves, limiting inter-comparability and integration with instrumental records. We present the Post-1800 CE Sea Level Database (P-1800SLD), a global, chronologically consistent compilation of high-resolution RSL reconstructions spanning 1800–2025 CE. The database provides a centralised dataset of 14C, 210Pb and chronostratigraphic marker data compiled from previously disparate sources. It contains 932 modelled or directly dated sea-level index points (SLIPs) from 41 sites (95% are modelled SLIPs derived from microfossil-based reconstructions) adhering to quality-based criteria. SLIP ages have been recalibrated using IntCal20 or SHCal20 and modelled using a Bayesian framework. Most updated SLIP ages agree with those originally published. Validation against tide-gauge records shows strong agreement for water levels (average r2 = 0.82; average RMSE = 0.10 m). Detailed meta-data are included in the database to support future updates and alternative modelling approaches.