Antarctic ice grew for first time in 20 years — but warming is still to blame

Antarctic ice grew by 695 billion tons over nearly two years starting in 2021, reversing a decline that had persisted for more than two decades, according to new research.

The gain might appear to signal a slowdown in global warming, but the findings point in the opposite direction. Warming had not eased — rather, years of unusually warm seas near the equator had driven heavier snowfall over Antarctica.

The findings were published in volume 656 of the international journal Nature by Wang Yunhe of the Institute of Oceanology at the Chinese Academy of Sciences and Ding Qinghua of the University of California, Santa Barbara.

Warmer seas brought more snow to Antarctica

According to the research team, Antarctic ice shrank by an average of 140.5 billion tons per year between 2003 and 2024, driven mainly by warm ocean water seeping beneath glaciers in West Antarctica and melting them from below.

From mid-2021, however, the trend reversed. Of the 695 billion tons gained, 470.3 billion tons — about 68 percent of the total increase — accumulated in the Queen Mary Land and Wilkes Land regions of East Antarctica.

The team found that snowfall during the period exceeded normal levels by 351.2 billion tons, and ice-core records drilled from nearby glaciers confirmed that similarly heavy snowfall had occurred during comparable periods in the past.

In short, the Antarctic ice sheet grew simply because it snowed more than usual.

The seas around Indonesia and the Philippines rank among the warmest on Earth. Even a small rise in sea surface temperatures there can generate powerful updrafts that reshape atmospheric circulation across the hemisphere.

The research team said those waters ran about 0.5 degrees Celsius above normal from 2021 to 2023. Small as that sounds, in the ocean a half-degree shift carries enough energy to set the entire atmosphere in motion.

The updrafts triggered by that 0.5-degree anomaly created waves in the upper atmosphere that propagated southward, building a zone of higher-than-normal air pressure over East Antarctica.

The elevated pressure rerouted wind patterns, pushing moist air from the Indian Ocean toward the Antarctic interior. The team said atmospheric conditions remained similarly configured throughout the period of heavy snowfall.

To trace the moisture's origin, the team divided Earth's surface into 54 zones and tracked where evaporated water from each zone ultimately fell. Even under normal conditions, three zones in the southern Indian Ocean account for 49 percent of East Antarctica's precipitation; during the period of increased snowfall, 45 percent of the additional moisture came from the Indian Ocean.

The team concluded that the total amount of water evaporating from the Indian Ocean had not increased — rather, the high-pressure wind corridor had redirected a greater share of that moisture toward Antarctica.

A temporary phenomenon that occurs roughly once a decade

The research team defined an event as one in which cumulative sea surface temperatures in the region exceeded the norm by 4 degrees Celsius or more over 36 consecutive months, then compared recent conditions against historical records.

Climate simulations based on 1,800 years of data showed such events occurring about 10.6 times per century, a frequency consistent with results from 20th-century observational data. That makes it a recurring pattern — one that arrives roughly once a decade.

The team therefore concluded that the recent Antarctic ice gain resulted from a temporary surge in precipitation driven by unusually warm equatorial seas, not from any lasting change in the pace of warming.

However, the team acknowledged it could not explain why the waters near Indonesia had remained warm for multiple years running. It said La Niña, Indian Ocean temperature patterns and long-term Pacific variability each showed a moderate association with the phenomenon, but none could be identified as a definitive cause.

Reference paper

DOI: 10.1038/s41586-026-10912-x

Wang, Y., Ding, Q., Li, X. et al. Multiyear tropical warm pool warming drives slowdown in Antarctic mass loss. Nature 656, 897-904 (2026).

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