Antarctica Gained 695 Billion Tons of Ice: Shocking Truth
🕐 9 min read | 🌍 Natural Wonders
🔒 Key Takeaways
- Between 2021 and 2023 the Antarctic Ice Sheet reversed two decades of measured decline, gaining mass at roughly 108 billion tonnes per year — a cumulative surplus widely reported as about 695 billion tons.
- The gain was driven almost entirely by anomalous snowfall delivered by atmospheric rivers into East Antarctica, not by glaciers regrowing or the Southern Ocean cooling.
- Four Wilkes Land outlet glaciers — Totten, Moscow University, Denman and Vanderford — switched from accelerating loss to partial recovery during the same three-year window.
- The surplus temporarily subtracted about 0.30 mm per year from global sea level rise, offsetting a small fraction of the roughly 7.4 mm Antarctica has added since 1992 (IMBIE, 1992–2020).
For three decades, gravity-sensing satellites watched Antarctica shed ice at an accelerating pace. Then, between 2021 and 2023, the sign flipped: Antarctica gained 695 billion tons of ice, and researchers re-ran the corrections twice before publishing. The explanation has nothing to do with cooling — and everything to do with a warmer, wetter atmosphere.
What the 695 Billion Ton Antarctic Ice Gain Actually Means
In 2025, a team led by researchers at Tongji University published an analysis in Science China Earth Sciences showing that the Antarctic Ice Sheet stopped losing mass and began gaining it between 2021 and 2023. The reversal was sharp: after shedding roughly 74 billion tonnes per year during 2002–2010 and accelerating to about 142 billion tonnes per year during 2011–2020, the continent flipped to a gain of approximately 108 billion tonnes per year. Stacked across the anomaly window, that surplus amounts to hundreds of billions of tonnes of additional ice — a cumulative figure widely reported as about 695 billion tons. To visualise it, roughly 757 cubic kilometres of ice spread over Bangladesh's 148,460 square kilometres would form a slab about five metres deep, appearing in under three years. Crucially, this is land ice — the frozen mass resting on bedrock that actually controls sea level — not the floating sea ice that fluctuates every winter. And critically, the gain is a surface accumulation anomaly, not evidence that Antarctica's fast-flowing marine glaciers reversed course.
How GRACE-FO Satellites Weigh an Entire Continent
You cannot put Antarctica on a scale, so scientists weigh it using gravity. The GRACE-FO mission — twin satellites flying about 220 kilometres apart in formation, launched by NASA and the German Research Centre for Geosciences (GFZ) in May 2018 — measures the minute tug of Earth's mass on each spacecraft. When the leading satellite passes over a heavier region it speeds up almost imperceptibly, and a microwave ranging system tracks the changing gap to within roughly a micrometre, a small fraction of the width of a human hair. Converting those distance wobbles into gravity anomalies reveals how many gigatonnes of water have entered or left a region each month. Researchers must then subtract glacial isostatic adjustment — the slow rebound of bedrock still rising since the last ice age, which in parts of West Antarctica exceeds a centimetre per year — because it can otherwise masquerade as ice gain. The 2021–2023 Antarctic surplus survived those corrections and was supported by regional climate model output and satellite altimetry, which is why glaciologists treated the reversal as a real signal rather than an instrument artefact.
🤔 Did You Know?
The 2021–2023 Antarctic snowfall surplus of roughly 695 billion tons weighs several times more than all the ice remaining in the European Alps, whose glaciers hold only around 100 cubic kilometres of ice.
The Surprising Reason: Atmospheric Rivers Dumped Record Snow
The cause was not cooling — it was moisture. Anomalous atmospheric circulation steered a series of atmospheric rivers, narrow filaments of concentrated water vapour, deep into the East Antarctic interior, where they unloaded extraordinary volumes of snow. Warmer air physically holds more water vapour: roughly seven percent more per degree Celsius of warming, a relationship set by the Clausius–Clapeyron equation. Over an interior plateau where annual mean temperatures at Dome C sit near −50°C, that extra moisture cannot fall as rain — it falls as snow and compacts into firn and then ice. Shifts in the Southern Annular Mode and persistent blocking highs helped lock this moisture-delivery pattern in place across multiple seasons. In March 2022, one such event pushed temperatures at Concordia Station to −11.5°C, roughly 38.5°C above the seasonal average and reported as the largest temperature anomaly ever recorded at a weather station anywhere on Earth. The irony is that the mechanism fattening Antarctica's interior is the same warming that is thinning its margins.
Why East Antarctica Gained While West Antarctica Kept Bleeding
Antarctica behaves as two ice sheets with opposite personalities. East Antarctica is a vast high plateau averaging above 2,000 metres in elevation, much of it grounded on bedrock above sea level, where air temperatures rarely approach melting and mass change is governed mainly by snowfall. West Antarctica, by contrast, is a marine ice sheet: large sectors rest on bedrock hundreds of metres to over a kilometre below sea level, exposing their undersides to Circumpolar Deep Water that arrives around 1°C above the local freezing point. The 2021–2023 surplus was concentrated overwhelmingly in East Antarctica — especially the Wilkes Land and Queen Mary Land sectors — where snowfall piled onto the plateau. Meanwhile the Amundsen Sea sector, home to Thwaites and Pine Island glaciers, kept discharging ice, with grounding lines that have retreated kilometres inland since the 1990s. In effect the continent gained weight where gravity keeps it safe and kept losing it where the ocean can reach. That geographic split is why a headline mass gain does not equal a healthy ice sheet.
The Four Glaciers That Suddenly Stopped Shrinking
The most striking detail in the 2025 analysis concerns four East Antarctic outlet glaciers: Totten, Moscow University, Denman and Vanderford. Between 2011 and 2020 these systems were in accelerated loss, thinning at rates that alarmed glaciologists because Totten alone drains a catchment holding roughly 3.5 metres of potential sea level rise. Denman is equally unnerving: it flows over the deepest known land point on Earth, a subglacial trough mapped by BedMachine Antarctica in 2019 at about 3,500 metres below sea level, a geometry that favours unstable retreat. During 2021–2023 all four shifted from significant mass loss to partial recovery as the snowfall surplus outpaced their ice discharge. Importantly, their ocean-driven basal melting did not stop — it was simply outweighed at the surface by new accumulation. If the precipitation anomaly fades, researchers expect the underlying thinning trend to reassert itself within a few years.
What This Means for Global Sea Level Rise
Every tonne of water locked into Antarctic snow is a tonne removed from the ocean, since about 362 gigatonnes of water equals one millimetre of global sea level. A gain of roughly 108 billion tonnes per year therefore translates to a reduction of about 0.30 millimetres per year in global mean sea level — a genuine, measurable brake. Set that against the backdrop: IMBIE's 2023 assessment estimates Antarctica lost around 2,670 billion tonnes of ice between 1992 and 2020, contributing roughly 7.4 millimetres of sea level rise. Global sea level is currently climbing at about 4.3 millimetres per year and accelerating, driven by thermal expansion, Greenland and mountain glaciers as well as Antarctica. So the Antarctic surplus shaved on the order of seven percent off the annual rate for a few years — a pause, not a reversal. Climate models have long projected exactly this outcome: increased Antarctic snowfall in a warming world partially masking dynamic ice loss for a time. The open question is how long that mask holds.
Why This Is Not Evidence That Climate Change Stopped
Within days of the study's publication, the 695 billion ton figure circulated online as proof that Antarctica is recovering. The record does not support that reading. The gain lasted roughly three years against a decline trend measured continuously since 2002, and it came from a precipitation anomaly that is itself a signature of a warmer, moisture-laden atmosphere. At almost exactly the same time, Antarctic sea ice — the floating fringe — collapsed to its lowest extent in the satellite record that began in 1979, reaching about 1.79 million square kilometres in February 2023. That loss removes the buffer that damps ocean swell before it reaches ice shelf fronts. Meanwhile, satellite radar interferometry continues to record grounding line retreat and ice shelf thinning across the Amundsen Sea sector. Short-lived surface mass gains and long-term structural decline are entirely compatible; the underlying physics predicts both at once.
What Scientists Are Watching Next
The central question is persistence: was 2021–2023 a transient swing in Southern Ocean atmospheric circulation, or the start of a longer precipitation regime shift? GRACE-FO continues monthly monitoring, and a follow-on gravity mission is being planned by NASA and GFZ to avoid a repeat of the roughly 11-month data gap between GRACE's end in October 2017 and GRACE-FO's launch in May 2018. ESA's CryoSat-2 radar altimeter and NASA's ICESat-2 laser altimeter, which fires 10,000 laser pulses per second, provide independent elevation measurements that help separate light, low-density snow from dense glacier ice. Field teams working on Totten and Denman deploy phase-sensitive radar (ApRES) to measure basal melt rates directly beneath the ice, sometimes exceeding tens of metres per year near grounding zones. Preliminary indications suggest the accumulation anomaly weakened after 2023, with mass loss resuming in several West Antarctic basins. If the surplus proves temporary, Antarctica's underlying trajectory — accelerating discharge from marine-based sectors — will simply re-emerge from behind the snow.
Final Thoughts
Antarctica's 695 billion ton ice gain is real, satellite-verified, and almost universally misread: it was produced by the very warming it appears to contradict, and it lasted about three years against a three-decade decline. Check the numbers yourself — NASA's GRACE-FO mass-balance data portal publishes monthly ice sheet totals, and the NSIDC Sea Ice Index tracks Antarctic sea ice extent daily. Then read our deep-dive on Denman Glacier, where the deepest known land point on Earth sits 3,500 metres below sea level and may decide how fast the coastlines change.
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Frequently Asked Questions
Is Antarctica gaining or losing ice in 2025?
Over the long term Antarctica is losing ice, having shed roughly 2,670 billion tonnes between 1992 and 2020 according to IMBIE. Satellite gravity data did show a temporary reversal from 2021 to 2023, when the ice sheet gained mass at about 108 billion tonnes per year because of exceptional snowfall over East Antarctica.
Does Antarctica gaining ice mean global warming has stopped?
No. The gain was caused by increased snowfall, which climate models predict in a warming world because warmer air holds roughly 7% more moisture per degree Celsius. During the same period Antarctic sea ice fell to its lowest extent in the satellite record and West Antarctic glaciers continued retreating.
How much did the Antarctic ice gain slow sea level rise?
The 2021–2023 surplus removed about 0.30 millimetres per year from global mean sea level rise. With global sea level rising at roughly 4.3 millimetres per year, that offset around seven percent of the annual rate, and only for a few years.
Which Antarctic glaciers gained ice between 2021 and 2023?
Four East Antarctic outlet glaciers — Totten, Moscow University, Denman and Vanderford in the Wilkes Land sector — shifted from accelerated loss to partial recovery. Their ocean-driven basal melting did not stop; it was simply outweighed by surface snow accumulation.
How do satellites measure how much ice Antarctica has lost?
The GRACE-FO twin satellites fly about 220 kilometres apart and detect tiny changes in their separation caused by variations in Earth's gravity, which reveal monthly mass changes in gigatonnes. Those results are cross-checked with radar and laser altimetry from CryoSat-2 and ICESat-2, and corrected for bedrock rebound left over from the last ice age.
📚 Further Reading & Research Sources
The following journals and institutions publish peer-reviewed research on the topics covered in this article:
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NASA Earth Observatory / GRACE-FO mission imagery
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