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

This research focuses on improving our understanding of relative sea-level (RSL) change from the Industrial Period (post-1800 CE) to the present. Accurate reconstructions of RSL are critical for contextualising modern sea-level trends and refining future projections. However, many existing sea-level datasets have sea level index point (which tell us where sea level was in space and time) ages derived from age modelling which use outdated calibration methods and or now obsolete age modelling methods, which limit their comparability and integration with instrumental records.To address these issues, we developed the Post-1800 CE Sea Level Database (P-1800SLD) – a globally consistent and quality-controlled compilation of 932 sea-level index points (SLIPs) from 41 sites. The majority of SLIPs are derived from microfossil-based reconstructions. All SLIP ages have been recalibrated using the latest radiocarbon calibration curves (IntCal20/SHCal20) and modelled within a Bayesian framework to improve chronological accuracy and reduce uncertainty. The inclusion of detailed metadata ensures transparency and supports future updates or alternative modelling approaches.This research provides a robust foundation for integrating geological and instrumental records of sea-level change, offering valuable insights for climate science, coastal management, and sea-level rise projections.