Antarctica’s Ice Sheet Stages a Remarkable Comeback – Watts Up With That?

A groundbreaking study published in Science China Earth Sciences has unveiled a stunning reversal in the fortunes of the Antarctic Ice Sheet (AIS), which gained mass at an unprecedented rate between 2021 and 2023. This marks the first significant ice growth in decades, challenging the prevailing narrative of relentless ice loss and highlighting the complex interplay of natural variability and climate dynamics. Using data from NASA’s GRACE and GRACE-FO satellite gravimetry missions, the findings offer a nuanced perspective on Antarctica’s role in global sea level changes and raise critical questions about the drivers of ice sheet behavior.

The study, led by Dr. Wei Wang and Prof. Yunzhong Shen at Tongji University, reports that the AIS gained mass at a rate of 107.79 ± 74.90 Gt/yr from 2021 to 2023, a dramatic shift from prior decades of decline. As the article states, “From 2002 to 2010, the AIS has experienced a mass loss with a change rate of -73.79 ± 56.27 Gt/yr, which nearly doubled to -142.06 ± 56.12 Gt/yr for the period 2011-2020.” This earlier mass loss, driven primarily by intensified depletion in West Antarctica and parts of East Antarctica’s Wilkes Land-Queen Mary Land (WL-QML) region, contributed significantly to global sea level rise—0.20 ± 0.16 mm/yr from 2002-2010 and 0.39 ± 0.15 mm/yr from 2011-2020. In contrast, the recent ice growth has had a “negative contribution, offsetting global mean sea level rise at a rate of -0.30 ± 0.21 mm/yr” from 2021-2023, effectively slowing the rise of global sea levels.

The turnaround is particularly pronounced in East Antarctica, where four critical glacier basins—Totten, Moscow, Denman, and Vincennes Bay—reversed their mass loss trends. The article notes, “The four key glacier basins in WL-QML region… exhibited mass loss intensification with a rate of 47.64 ± 8.14 Gt/yr during 2011-2020, compared to 2002-2010, with the loss area expanding inland.” Yet, between 2021 and 2023, these basins showed significant mass gains, attributed to “anomalous precipitation accumulation.” This surge in snowfall appears to have counteracted the factors previously driving ice loss, namely surface mass reduction (72.53%) and increased ice discharge (27.47%).

The implications of this rebound are far-reaching. The article warns that “the complete disintegration of these four glaciers could potentially trigger a global mean sea level rise exceeding 7 meters,” emphasizing their pivotal role in global climate stability. The recent mass gains suggest a degree of resilience in East Antarctica, which had been considered relatively stable compared to the rapidly depleting West Antarctica and Antarctic Peninsula. These regional differences underscore the need for a more granular understanding of Antarctica’s ice dynamics, as the AIS does not behave uniformly across its vast expanse.

What triggered this abrupt shift? The study points to anomalous precipitation as the primary driver, suggesting that natural variability plays a significant role in short-term ice sheet changes. Some researchers have speculated that episodic events, such as volcanic activity or ocean circulation shifts, could contribute to these fluctuations. For instance, the 2021 Hunga Tonga volcanic eruption, which injected sulfur dioxide into the stratosphere, may have temporarily cooled the Southern Hemisphere, potentially enhancing snowfall in Antarctica. Such natural phenomena challenge the assumption that slow, CO2-driven warming is the sole driver of ice trends, highlighting the limitations of climate models that often overpredict warming and ice loss.

However, the optimistic data comes with caveats. West Antarctica continues to lose mass, and the risk of marine ice sheet instability remains a concern according to the authors. Rapid ice loss could still occur if underlying glaciers destabilize, potentially overwhelming the gains from increased snowfall. The study’s authors stress the need for continued monitoring, noting that “their pronounced ablation patterns already constitute a critical climate warning signal, warranting greater scientific attention to their stability.” —yawn.

This development underscores the complexity of Antarctica’s ice system and the pitfalls of oversimplified climate narratives. The interplay of precipitation, potential volcanic influences, and regional variability suggests that short-term fluctuations can significantly alter long-term trends. The unexpected AIS rebound challenges policymakers and researchers to integrate this new data into their understanding of climate dynamics, moving beyond one-size-fits-all assumptions about ice loss and sea level rise.

Reference: Wang et al., “Spatiotemporal mass change rate analysis from 2002 to 2023 over the Antarctic Ice Sheet,” Science China Earth Sciences, 2025. DOI: 10.1007/s11430-024-1517-1