May 22, 2017

Reassessment of 20th century global mean sea level rise

Sönke Dangendorf, Marta Marcos, Guy Wöppelmann, Clinton P. Conrad, Thomas Frederikse, Riccardo Riva
Proceedings of the National Academy of Sciences
  • States that estimates of global mean sea level (GMSL) before the advent of satellite altimetry vary widely, mainly because of the uneven coverage and limited temporal sampling of tide gauge records, which track local sea level rather than the global mean
  • Introduces an approach that combines recent advances in solid Earth and geoid corrections for individual tide gauges with improved knowledge about their geographical representation of ocean internal variability
  • Yields smaller trends before 1990 than previously reported, leading to a larger overall acceleration
  • Identifies three major explanations for differences with previous estimates
  • Reconciles observational GMSL estimates with the sum of individually modeled contributions from the Coupled Model Intercomparison Project 5 database for the entire 20th century
  • Results increase confidence in process-based projections presented in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change