Seventy years of sea level variations along the Zhejiang Coast of East China Sea with future projections

Sea level rise (SLR) critically impacts coastal safety. Analyzing 70 years of data from 10 stations along the Zhejiang coast, we find that in 2020, sea levels stood 40.3 cm above the national datum, with higher levels in estuaries than eastern islands. While the 70-year average rise rate is moderate at 0.25 cm/yr, it has accelerated significantly in the last two decades.Future projections excluding acceleration estimate rises of 7–18 cm by 2050 and 17–39 cm by 2100; however, if acceleration persists, nonlinear extrapolation suggests increases of 16–29 cm by 2050 and 54–88 cm by 2100, matching high-emission climate scenarios simulated by the coupled global climate models. Northern and estuarine regions exhibit higher SLR rates driven primarily by vertical land movement (VLM). Additionally, significant interdecadal fluctuations, linked to 10–20 year periodic signals and strongly correlated with the Pacific Decadal Oscillation (PDO), show a sign reversal around 2003.