Leclercq et al. (2026) Abrupt trend change in global mean sea level and its components in the early 2010s

Identification

• Journal: Communications Earth & Environment
• Year: 2026
• Date: 2026-01-12
• Authors: Lancelot Leclercq, Julius Oelsmann, Anny Cazenave, Marcello Passaro, S. Jevrejeva, Sarah Connors, Jean-François Legeais, Florence Birol, Rodrigo Abarca-del-Río
• DOI: 10.1038/s43247-025-03149-5

Research Groups

• Université de Toulouse, LEGOS (CNES/CNRS/IRD/UT3), Toulouse, France
• Tulane University, School of Science & Engineering, New Orleans (LA), USA
• Deutsches Geodätisches Forschungsinstitut der Technischen Universität München, Munich, Germany
• National Oceanography Center, Liverpool, UK
• European Space Agency, Climate Office, Harwell, UK
• CLS, Rue Hermes, Ramonville St Agne, France
• University of Concepcion, Department of Geophysics, Concepcion, Chile

Short Summary

This study identifies an abrupt trend change in global mean sea level (GMSL) and its thermal and mass components in the early 2010s, revealing an increased rate of GMSL rise from 2.9 mm/yr (1993-2011) to 4.1 mm/yr (2012-2024), likely driven by internal climate variability.

Objective

• To analyze global mean sea level (GMSL) and its components (ocean thermal expansion, ocean mass change, terrestrial water storage, and land ice) using satellite altimetry and other observational data to detect and precisely determine the timing of an abrupt trend change in the early 2010s.

Study Configuration

• Spatial Scale: Global, Pacific Ocean, continental regions (excluding Greenland and Antarctica), Greenland and Antarctic ice sheets, global glaciers.
• Temporal Scale:
  • GMSL: January 1993 to December 2024 (satellite altimetry era)
  • Thermosteric sea level: 2004-2020 (Argo era)
  • Ocean mass (barystatic): January 1993 to May 2022 (extended GRACE/GRACE Follow-On era)
  • Ocean Heat Content (OHC): January 1993 to May 2022
  • Ice sheet mass balance: 1992 to 2020
  • Global glacier mass balance: 1992-1993 to 2021-2022 (hydrological years)
  • Terrestrial Water Storage (TWS): April 2002 to December 2024 (GRACE/GRACE Follow-On era)

Methodology and Data

• Models used:
  • Bayesian Estimator of Abrupt Change, Seasonal and Trend (BEAST)
  • DiscoTimeS (Bayesian method for detecting seasonal signals, discontinuities, and trend changes)
  • Linear Regression (accounting for autocorrelation)
  • Akaike Information Criterion (AIC) and Bayesian Information Criteria (BIC) for model comparison
• Data sources:
  • Satellite altimetry: DT2024 reprocessing of TOPEX/Poseidon and Jason missions (Copernicus Climate Change Service), DT2021 (AVISO).
  • Ocean temperature: Ensemble mean from five datasets (Scripps Institution of Oceanography (SIO), International Pacific Research Center (IPRC), JAMSTEC, EN4 version 2.2, ISAS) based on Argo float observations.
  • Ocean mass (barystatic): AVISO Ocean Heat Content – Earth Energy Imbalance (OHC-EEI) extended dataset v5, based on GRACE/GRACE Follow-On and ESA’s SLBC_CCI.
  • Ocean Heat Content (OHC): AVISO OHC-EEI extended dataset v5.
  • Ice sheet mass balance: IMBIE project data for Antarctic and Greenland ice sheets.
  • Global glacier mass balance: Glacier Mass Change Gridded Data from the Fluctuations of Glaciers Database (WGMS).
  • Terrestrial Water Storage (TWS): GRACE/GRACE-FO dataset from GFZ (RL06 Level-3).
  • Historical mean sea level reconstruction (for robustness check).

Main Results

• The global mean sea level (GMSL) rise rate increased abruptly from 2.9 ± 0.22 mm/yr over 1993-2011 to 4.1 ± 0.25 mm/yr over 2012-2024.
• Abrupt trend changes were detected in the early 2010s (between 2010 and 2012) in GMSL, thermosteric sea level, ocean mass (barystatic), and total ocean heat content.
• The terrestrial water storage (TWS) component also showed a trend change in late 2011.
• Statistical model comparison (AIC, BIC, RMSE) confirmed that a piecewise linear trend model with a breakpoint around 31 December 2011 is a better fit for GMSL evolution than a single linear trend or a quadratic acceleration model.
• The abrupt trend change in the mass component is primarily attributed to terrestrial water storage (liquid water bodies) and, to a lesser extent, ice sheet melting.
• The observed regime shift in sea level and its components is likely driven by internal climate variability (e.g., Pacific Decadal Oscillation, North Atlantic Oscillation), although an additional contribution from increased radiative forcing due to reduced aerosol emissions cannot be entirely excluded.

Contributions

• Provides robust evidence for an abrupt trend change (regime shift) in global mean sea level and its components in the early 2010s, offering an alternative interpretation to the widely accepted steady acceleration over the altimetry era.
• Simultaneously analyzes multiple sea level budget components using two independent Bayesian change-point detection methods (BEAST and DiscoTimeS) to enhance confidence in the findings.
• Links the observed sea level shift to a broader, quasi-global phenomenon of abrupt trend changes reported in numerous other climate parameters around the same period.
• Discusses the potential drivers of this shift, favoring internal climate variability while acknowledging a possible role for increased anthropogenic radiative forcing.
• Confirms the robustness of the abrupt trend change using a longer historical sea level reconstruction based on tide gauge records.

Funding

• ESA Climate Change Initiative Sea Level project (grant number 4000126561/19/I-NB).

Citation

@article{Leclercq2026Abrupt,
  author = {Leclercq, Lancelot and Oelsmann, Julius and Cazenave, Anny and Passaro, Marcello and Jevrejeva, S. and Connors, Sarah and Legeais, Jean-François and Birol, Florence and Abarca-del-Río, Rodrigo},
  title = {Abrupt trend change in global mean sea level and its components in the early 2010s},
  journal = {Communications Earth & Environment},
  year = {2026},
  doi = {10.1038/s43247-025-03149-5},
  url = {https://doi.org/10.1038/s43247-025-03149-5}
}