The Rate of U.S. Coastal Sea-Level Rise Doubled in the Past Century

A recent report released by the Department of Energy concludes that U.S. tide-gauge data in aggregate provide no evidence for relative sea-level (RSL) acceleration above the historical mean trend. However, that conclusion rests largely on cursory analysis of a small number of tide-gauge records that are known to be unrepresentative of large-scale RSL behavior. Here I analyze all long active tide-gauge RSL data records on the contiguous U.S. (CONUS) coast to make a comprehensive estimate of spatially averaged RSL changes over the CONUS (CONUS RSL) during the past 125 years. I find that long-term rates of CONUS RSL rise doubled in the past century, from about 2.0 mm yr$^{-1}$ in 1900 to roughly 4.2 mm yr$^{-1}$ in 2024, and that recent rates are higher than the longterm historical mean rate since 1900, which is approximately 3.1 mm yr$^{-1}$. That is, CONUS tide gauges give obvious evidence of RSL acceleration, which is likely related to ongoing climate change.