Evolution of Global Sea‐level Rise Projections and Their Uncertainty

Authors

• Andra J. Garner, Rowan University Glassboro
• Amy Appollina, Department of Environmental Science Rowan University Glassboro NJ USA
• Jessica Slotter, Portland State University
• Gregory G. Garner, Independent Researcher, Glassboro NJ
• Aimée B. A. Slangen, Royal Netherlands Institute for Sea Research Yerseke The Netherlands
• Robert E. Kopp, Rutgers University - Newark
• Benjamin P. Horton, University of Hong Kong

Publication Title

Earth's Future

Document Type

Article

Publication Date

8-27-2026

Subjects

Sea‐levels -- projections

Rights

Copyright (c) 2026 The Authors

This work is licensed under a Creative Commons Attribution 4.0 International License.

Abstract

For more than 40 years, scientists have projected future sea‐level change. Documenting how sea‐level projections have evolved is vital for tracking progress, uncertainties, and future research needs. Here, we update and analyze a database of global‐mean sea level (GMSL) projections dating from 1982 to 2025, identifying five key findings. First, GMSL projection generation has been concentrated in a small number of developed countries, with 95% of projections produced in the United States, United Kingdom, European Union, or Australia. Second, while GMSL projections for 2050 and 2100 have been published regularly since the early 1980s, only 30 of 103 studies have produced projections extending beyond 2100; all but one of these 30 studies postdates 2010. Third, among studies providing multiple estimates, the range of highest GMSL projections for 2100 has broadened since 2007, reaching 0.6–2.0 m across publications since the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6). Fourth, GMSL projections from the IPCC have historically been conservative compared to projections from individual studies. Prior to AR6, ∼66% of 2100 projections at the upper end of uncertainty intervals from individual studies exceeded the corresponding upper projections from IPCC reports. However, the inclusion of “low‐confidence” GMSL projections in AR6 to assess higher amounts of GMSL change of poorly known likelihood reduces this problem: the 83rd percentile of these low‐confidence projections is exceeded by < 25% of upper estimates from individual studies. Finally, analyses suggest that the arrival time of key GMSL milestones are often similar for projections spanning multiple eras and using various methodologies.

Locate the Document

https://doi.org/10.1029/2025EF007836

DOI

10.1029/2025EF007836

Persistent Identifier

https://archives.pdx.edu/ds/psu/45095

Citation Details

Garner, A. J., Appollina, A., Slotter, J., Garner, G. G., Slangen, A. B. A., Kopp, R. E., & Horton, B. P. (2026). Evolution of Global Sea‐Level Rise Projections and Their Uncertainty. Earth’s Future, 14(8). Portico. https://doi.org/10.1029/2025ef007836