Antarctica’s brief ice-mass rebound (roughly 2021–2023) was driven by natural climate variability linked to multiyear warming in the tropical warm pool, not a sustained new trend or “new normal” from global warming.

A study published 19 August 2026 in Nature (with University of Washington co-author Eric Steig and collaborators from other institutions) examined the temporary slowdown in Antarctic Ice Sheet mass loss.

Between about July 2021 and April 2023, satellite gravity data (GRACE/GRACE-FO) showed the continent gained roughly 695 billion tonnes of mass—the largest such event in the satellite record since 2003—temporarily offsetting the long-term average loss of about 140 Gt per year.

Most of the gain (~68%) occurred in East Antarctica’s Queen Mary Land–Wilkes Land sector due to exceptional snowfall/precipitation. West Antarctica continued losing mass.

UW professor Eric Steig noted: “When something changes, it is very tempting, even to scientists, to think ‘Oh, there’s a new normal happening,’ but this analysis shows that’s not the case. This is most likely a short-lived phenomenon.”

The connection to human-caused global warming is described as tenuous; the pattern aligns with natural background variability in the tropical climate system.

Antarctica has been losing mass overall for decades, primarily through ocean-driven melting and ice discharge (especially in West Antarctica).

Annual snowfall has not kept pace with losses on longer timescales. The 2021–2023 event was a temporary interruption; researchers emphasize it does not indicate a reversal of the longer-term decline or a sustained, warming-driven increase in Antarctic precipitation.

The Antarctic Ice Sheet remains the largest source of uncertainty in long-term sea-level projections.

Understanding short-term variability versus forced trends is important for interpreting future observations.

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Multiyear tropical warm pool warming drives slowdown in Antarctic mass loss

Antarctic Ice Sheet (AIS) mass loss has been a major contributor to global sea-level rise for most of recent decades, driven mainly by West Antarctica. During 2021–2023, a sharp rise in surface mass balance over Queen Mary Land and Wilkes Land (East Antarctica) offset West Antarctic losses and slowed the overall rate of ice-mass loss.

Although this temporary slowdown is consistent with the expected long-term precipitation response to global warming (poleward-shifted storm tracks and Antarctic moistening), the study identifies a different primary mechanism:

• The mass gain was linked to a recurrent atmospheric teleconnection driven by unusually persistent sea-surface temperature (SST) anomalies in the tropical warm pool (western Pacific and eastern Indian Oceans) from 2021 to 2023.
• Tropical warm-pool warming excited a poleward-propagating Rossby-wave train.
• This produced a high-pressure anomaly over East Antarctica that enhanced precipitation over Queen Mary Land and Wilkes Land.
• Moisture was primarily sourced from the mid-latitude Indian Ocean.

Similar multiyear tropical warm-pool warmings recur about once per decade in observations and historical climate simulations. Their precipitation influence is distinct from the effects of global warming. Therefore, the recent AIS mass gain is probably temporary and does not yet reflect a sustained, global-warming-driven moistening of Antarctica.

Key quantitative findings

• Long-term AIS mass-loss rate (2003–2024, GRACE/GRACE-FO): 140.5 ± 2.0 Gt yr⁻¹.
• July 2021–April 2023: AIS gained roughly 695 Gt (largest 22-month gain in the satellite record), temporarily bringing the net 2021–2024 balance near zero.
• ~68% of the gain (~470 Gt) occurred in the Queen Mary Land–Wilkes Land (QW) sector of East Antarctica, driven by exceptional snowfall.
• Anthropogenic forced precipitation increase (from CESM1 large-ensemble simulations) accounted for only ~9% of the observed QW precipitation anomaly during the event.

West Antarctica continued to lose mass throughout the period.

East Antarctic mass balance is highly sensitive to precipitation variability controlled by large-scale atmospheric circulation. Previous explanations for the 2021–2023 event had invoked atmospheric rivers, the triple-dip La Niña, and other factors.

This study shows the dominant driver was the tropical warm-pool teleconnection, which is a form of natural climate variability rather than a new forced trend.

The Antarctic Ice Sheet remains the largest source of uncertainty in long-term sea-level projections.

Published:  Nature (2026)

DOI: 10.1038/s41586-026-10912-x

Provided: University of Washington

Authors: Yunhe Wang, 
Qinghua Ding, 
Thomas J. Ballinger, 
Yoshihiro Nakayama, 
Dániel Topál & 
Eric J. Steig 

Abstract

Antarctic mass loss has been a major contributor to global sea-level rise for most of the last few decades, mainly driven by West Antarctica¹. During 2021–2023, however, a sharp increase in surface mass balance over Queen Mary Land and Wilkes Land in East Antarctica offset West Antarctic loss and slowed the rate of total ice mass loss^2,3. Although this slowdown is consistent with the expected long-term precipitation response to global warming through poleward-shifted storm tracks and Antarctic moistening⁴, our results point to a different mechanism. Here we show that the recent ice mass gain was linked to a recurrent atmospheric teleconnection driven by sea surface temperature anomalies in the tropical warm pool, which experienced unusually persistent warming from 2021 to 2023 relative to the previous two decades. On the basis of observations and model experiments, we find that tropical warm pool warming excites a poleward-propagating Rossby-wave train that induces a high-pressure anomaly over East Antarctica, enhancing Queen Mary Land and Wilkes Land precipitation and driving the observed mass gain, with moisture primarily sourced from the mid-latitude Indian Ocean. Similar multiyear warming in the tropical warm pool recurs about once per decade in observations and historical simulations, and its influence on precipitation is distinct from the effects of global warming. Therefore, the recent Antarctic Ice Sheet mass gain is probably temporary and does not yet reflect a sustained, global-warming-driven moistening of Antarctica.