The discovery

The IMBIE team asked how much mass Greenland and Antarctica lost over the longest satellite era yet assembled, how that loss changed by decade and how much came from surface mass balance versus ice flowing faster into the ocean.

The research question and why it matters

The IMBIE team asked how much mass Greenland and Antarctica lost over the longest satellite era yet assembled, how that loss changed by decade and how much came from surface mass balance versus ice flowing faster into the ocean.

Earlier IMBIE assessments reconciled satellite estimates beginning mainly in 1992 and established that both ice sheets were losing mass at accelerating rates. This update extends the consensus record into the 1970s using early Landsat and other archives, adds participating surveys and follows the record through 2023, allowing researchers to compare conditions before and after the sharp increases of the 1990s and 2000s.

What researchers found

Between 1979 and 2023, the two ice sheets lost an estimated 11,309 ± 565 billion tonnes of ice and added 31.4 millimeters to global mean sea level. Antarctica contributed 13.3 millimeters and Greenland about 18.1 millimeters. Glacier-dynamic imbalance accounted for 84% of the combined loss. Greenland's average loss rate increased from about 60 billion tonnes a year in the 1980s to 264 billion in the 2010s; Antarctica's rose from about 48 to 202 billion tonnes a year over the same decades.

Results at a glance

Key results from the tested systems

11,309 ± 565 Gt

combined ice loss

Estimated for Greenland and Antarctica from 1979 through 2023.

31.4 mm

sea-level contribution

Cumulative global mean equivalent from the two ice sheets.

84%

dynamic loss

Share attributed to glacier discharge exceeding ice replacement.

45

independent estimates

The synthesis drew on 42 surveys and 27 satellite missions.

How the research worked

Researchers compared and combined estimates derived from changes in ice-sheet elevation, gravitational attraction and the difference between snowfall input and ice discharge. They reconciled overlapping records from 27 satellite missions, quantified uncertainty and produced annual mass-balance series reaching back to 1972 for Greenland and 1979 for Antarctica. Regional climate models were then used to separate surface gains and losses from glacier-dynamic imbalance.

Subjects or systemLaboratory
Research designInternational satellite-observation synthesis combining altimetry, gravimetry and input–output estimates with regional climate models
Evidence base45 independent ice-sheet mass-balance estimates assembled from 42 satellite surveys across 27 missions; Greenland observations begin in 1972 and Antarctic observations in 1979, with both records continuing through 2023

How to interpret this design

This design can measure patterns and associations in the observed population. It cannot, by itself, prove that the exposure caused the outcome because unmeasured differences, reverse causation and selection effects may contribute.

The evidence comes from a controlled physical or chemical system. That control helps establish what happened under the tested conditions, while scale-up, durability, manufacturing and real-world performance remain separate questions.

What strengthens or limits the finding?

The assessment combines three independent satellite-measurement families, many research teams and a half-century record, reports uncertainty and releases an openly accessible consensus dataset. Early observations are sparser, methods share some correlated errors and the split between surface and dynamic loss depends on regional climate models.

The central measurement is direct and rigorous for the narrow claim being made. That does not mean every broader implication is settled.

Funding and disclosure context

The launch record does not yet reproduce a complete funding statement; readers should consult the paper's declaration. The recorded conflict information is: The authors declare no competing interests. Funding or a disclosed relationship does not by itself invalidate a result, but it is relevant when judging design choices, analysis and the need for independent replication.

What it means

The long record provides a stronger observational baseline for testing ice-sheet models and estimating the contribution of polar ice to sea-level change. It shows that ocean-driven acceleration of outlet glaciers has dominated the cumulative loss, even though extreme surface melting remains important in Greenland. The temporary slowdown during 2020–2023 reflects snowfall and milder summers, not recovery of the ice sheets.

Beyond the abstract

Deeper analysis

Three measurement families strengthen the record

Elevation measurements track changes in ice volume, gravimetry senses changing mass and input–output accounting compares snowfall with discharge. Agreement after different corrections makes the combined trajectory more persuasive than any one technique alone.

Dynamic loss points toward the ocean

When warmer ocean water thins floating ice shelves or glacier fronts, grounded ice can flow seaward faster. The 84% partition therefore helps identify the main physical route of cumulative loss, although the exact split still depends on modeled snowfall and melt.

A few centimeters matter globally

Global mean sea level is an average; tides, currents, land motion and gravitational effects redistribute the local change. Even so, adding 31.4 millimeters raises the baseline from which storm surges and high tides reach coastal infrastructure.

Short pauses do not erase cumulative change

Several snowy Antarctic years and milder Greenland summers reduced net loss after 2020. A four-year fluctuation can be real while remaining too short to outweigh the multi-decade rise in discharge and cumulative sea-level contribution.

Keep the claim in proportion

What it does NOT prove

  • It does not forecast one exact amount of sea-level rise for 2100 or 2150.
  • It does not show that every glacier, basin or year changed at the same rate.
  • It does not mean surface melting is unimportant; the 84% figure describes the combined cumulative balance in this record.
  • It does not establish that the 2020–2023 slowdown will continue or that long-term loss has reversed.
  • It does not include every source of global sea-level change, such as mountain glaciers, ocean thermal expansion or land-water storage.

Important limitations

  • Satellite coverage is much thinner in the 1970s and 1980s than in recent decades, producing larger early-period uncertainty.
  • Altimetry, gravimetry and input–output techniques observe different physical quantities and require method-specific corrections.
  • Some estimates share missions, climate models or correction data, so they are not fully statistically independent.
  • Partitioning mass loss into surface and dynamic components relies on regional climate-model estimates rather than direct observation of every process.
  • The continental totals conceal large regional differences, including snowfall gains in East Antarctica and persistent discharge increases in West Antarctica.
  • A historical mass-balance dataset can constrain projections but cannot resolve uncertain future emissions, ocean forcing or ice-sheet instability on its own.

How this fits with previous research

Earlier IMBIE assessments reconciled satellite estimates beginning mainly in 1992 and established that both ice sheets were losing mass at accelerating rates. This update extends the consensus record into the 1970s using early Landsat and other archives, adds participating surveys and follows the record through 2023, allowing researchers to compare conditions before and after the sharp increases of the 1990s and 2000s.

Questions still unanswered

  • How much of the recent snowfall-driven slowdown will persist beyond 2023?
  • Which outlet glaciers are closest to sustained dynamical change that cannot readily reverse?
  • How can early satellite records and uncertainty correlations be improved further?
  • Will new missions narrow the gap between observed mass loss and model projections?
  • How quickly will ocean warming alter discharge from the most vulnerable Antarctic basins?
Government verification and context

Relevant U.S. government resources

These resources serve different purposes. A registry can verify what researchers planned, a repository can locate government-funded work, and an agency page can supply authoritative background. None automatically proves that this paper's conclusion is correct.

Government repositoryU.S. Geological Survey

USGS Publications Warehouse

The authoritative catalog of USGS scientific publications, used to check related government research and long-term observational context.

Authoritative contextNational Oceanic and Atmospheric Administration

NOAA research and data

Federal observations and research on climate, oceans, atmosphere and ecosystems provide context for environmental claims. They do not automatically validate a separate model or paper.

Reuse note: Facts and discoveries are summarized here in original language. We link to government material instead of copying it wholesale, and we do not reuse agency logos, photographs, charts or third-party material unless the specific reuse rights are verified.

Sources and provenance

Greenland and Antarctica lost 11.3 trillion tonnes of ice from 1979 to 2023

This review was developed from the source record below and, when separately available, the primary paper or government report. The summary and analysis on this page are original editorial writing.

Source organization
Northumbria University
Source type
University
Authors
Inès Otosaka, Andrew Shepherd, Charles Amory, Martin Horwath, Erik Ivins, Michalea D. King, Sophie M. J. Nowicki, Anthony J. Payne, Eric Rignot, Louise Sandberg Sørensen, Nicole-Jeanne Schlegel, Karen M. Simon, Benjamin E. Smith, Tyler C. Sutterley, Michiel R. van den Broeke, Isabella Velicogna and the IMBIE Team
Journal / report
Scientific Data
Publication date
September 16, 2026
DOI
10.1038/s41597-026-08088-0
PMID
Not available
Institution
Northumbria University, University of Washington Applied Physics Laboratory and the international Ice Sheet Mass Balance Inter-comparison Exercise collaboration
Funding
European Space Agency and NASA support for the IMBIE assessment; additional project- and author-level funding was not available in the institutional records reviewed for this page
Conflicts
The authors declare no competing interests
Open access
Yes
Reuse approach
Study design and results summarized independently from Northumbria University's institutional report, its research-portal record and the open peer-reviewed paper; no source wording, satellite imagery, figures, maps or tables reproduced.
Open source organization page ↗Open primary paper or report ↗Inspect the Northumbria University research recordRead the open Scientific Data paperReview NASA's ice-sheet and sea-level overview

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