Unprecedented Heat Wave Recorded in Antarctica During Southern Winter

In July 2024, temperatures across Dronning Maud Land in East Antarctica exceeded the climatological mean by more than 9°C for 17 consecutive days — the most intense winter heatwave recorded in the 46-year satellite era [1]. At localized points, the anomaly reached 28°C above normal and persisted for over two weeks [2]. Translated to a Northern Hemisphere equivalent, that would be like London experiencing mid-30°C temperatures in January.

This was not a one-off. In March 2022, Concordia Station on the East Antarctic plateau hit −9.4°C — roughly 38.7°C above the seasonal baseline — the largest temperature anomaly recorded at any location on the planet [3]. In September 2025, stratospheric temperatures above the South Pole climbed 35°C above normal, from roughly −55°C to −20°C, as the polar vortex weakened again [4].

Three events in four years, each record-setting by different measures. Together, they form a pattern that is forcing scientists, policymakers, and the 900 million people living in low-elevation coastal zones [5] to reckon with what Antarctic instability actually means.

Source: Nature / AMS / WMO

Data as of Apr 28, 2026CSV

The Anatomy of a Polar Heatwave

The 2024 winter event has now been formally analyzed in a peer-reviewed study published in npj Climate and Atmospheric Science [1]. The researchers traced the chain of causation through several linked atmospheric disturbances.

First, the Antarctic polar vortex — a belt of strong upper-atmosphere winds that ordinarily contains cold air over the continent — weakened and became distorted. Stratospheric temperatures rose by more than 15°C in early July, with a second surge in early August [2]. This vortex disruption allowed a persistent high-pressure ridge to establish itself over East Antarctica, which in turn opened a corridor for an atmospheric river: a long, narrow plume of warm, moisture-laden air that pushed from lower latitudes into the continental interior [2].

Clouds associated with the system then acted as a thermal blanket, trapping heat near the surface and preventing radiative cooling [2]. Antarctic sea ice, already near record lows, and the unusually warm Southern Ocean compounded the effect by sustaining heat flux into the continent [1].

The March 2022 event followed a similar script. An intense atmospheric river, fed by convection and tropical cyclone activity over the Indian Ocean, advected subtropical heat and moisture across the ice sheet [3]. An increase in jet stream waviness linked low and high latitudes, channeling energy poleward [3]. That event was so intense it caused widespread surface melt along coastal areas, exacerbated record-low sea ice extent, and is thought to have triggered the final collapse of the Conger Ice Shelf [3].

The September 2025 stratospheric warming episode — a phenomenon so rare in the Southern Hemisphere that only a handful have been recorded — further weakened the polar vortex and drew scientific concern about whether a pattern of recurring disruptions was emerging [4][6].

How Rare Are These Events — and Could They Happen Without Human Influence?

Antarctica's longest continuous meteorological record comes from Orcadas Station on the South Orkney Islands, operational since 1903 [7]. Continent-wide analysis of extreme near-surface air temperatures, using data from 17 stations through 2019, provides baseline context for how anomalous recent events are [7].

Computer simulations comparing current climate conditions with a counterfactual world absent human greenhouse gas emissions show that anthropogenic climate change made the 2024 winter heatwave both stronger and more likely [1][2]. Under pre-industrial conditions, such an event would have been "exceptionally rare" [2]. Attribution modeling of the March 2022 event found that climate change made it approximately 2°C warmer than it would otherwise have been, with projections indicating that end-of-century heatwaves could be an additional 5–6°C warmer still [8].

Under high-emission scenarios, events of this magnitude could become up to 20 times more frequent by the end of the century [2]. That projection transforms what is currently a once-in-many-decades occurrence into something approaching a once-per-decade or even more frequent event.

The Natural Variability Argument

Not all scientists frame these events as straightforward signals of anthropogenic forcing. The Southern Annular Mode (SAM) — the dominant mode of atmospheric variability in the Southern Hemisphere — controls much of Antarctic surface temperature variation [9]. ENSO (El Niño-Southern Oscillation) variability interacts with SAM in complex, phase-dependent ways: SAM-related pressure anomalies shift depending on whether El Niño or La Niña conditions prevail [9].

Research published in Frontiers in Earth Science has documented rapid warming over East Antarctica since the 1940s driven by increasing SAM-ENSO coupling [9]. The internal origin of west-east asymmetry in Antarctic climate change has been attributed to a robust high-latitude mode of multidecadal natural variability, arising primarily from high-latitude dynamics combined with topographical effects and winter amplification [10].

However, the mainstream scientific assessment — reflected in the npj Climate and Atmospheric Science study — holds that while natural variability modes like SAM, ENSO, and interdecadal Pacific oscillations set the stage, anthropogenic warming amplifies the resulting extremes beyond what natural cycles alone would produce [1]. The "unprecedented" framing is supported by the satellite-era record: no comparable winter event appears in the 46-year observational dataset [1].

Ice Shelves Under Pressure

The immediate physical question is what happens to Antarctic ice when winter air temperatures routinely exceed historical norms. The answer depends on which shelf you are asking about.

Thwaites Glacier, the 120-kilometer-wide "Doomsday Glacier" in West Antarctica, loses roughly 50 billion tons of ice annually — approximately 4% of total global sea level rise [11]. That rate has doubled over the past 30 years [11]. The International Thwaites Glacier Collaboration has concluded that the Thwaites Ice Shelf is likely to break up and drift away within the coming decade, which would accelerate the glacier's retreat into the ocean [12]. By itself, Thwaites holds enough ice to raise global sea levels by 65 centimeters; because it buttresses other ice sheets, its destabilization could unlock over 3 meters of total rise [11].

A 2023 study in Nature Climate Change found that increased West Antarctic ice shelf melting over the 21st century is now unavoidable regardless of emissions pathway [13]. The Ross and Filchner-Ronne ice shelves — the two largest in Antarctica — face a different but equally consequential risk: modeling indicates potential for a cold-to-warm ocean regime shift within their sub-shelf cavities [14]. Once that transition occurs, grounding line retreat in some locations becomes irreversible, and ice loss accelerates substantially [14].

The Ronne Ice Shelf presents a counterintuitive nuance. Some research suggests that moderate warming could actually reduce basal melt rates by decreasing the formation of High Salinity Shelf Water (HSSW) that drives melting beneath the shelf [15]. This is not a reassuring finding — it means the relationship between surface warming and ice shelf stability is nonlinear and harder to predict than simple temperature-rise models suggest.

Sea Level Projections: What the Numbers Mean for Coastlines

The range of projected sea level rise by 2100 spans from 0.3 meters under the most optimistic emissions pathway (SSP1-2.6) to potentially 2 meters if high emissions combine with rapid ice sheet collapse [16]. The IPCC's central range is 43 to 84 centimeters, but its reports explicitly state that a 2-meter rise "cannot be ruled out" [16].

Source: IPCC AR6 / Nature Climate Change

Data as of Apr 28, 2026CSV

After 2100, the trajectory steepens. A study in The Cryosphere examined the long-term sea-level commitment from Antarctica and warned that ice loss becomes rapid and irreversible beyond 2100 under high-emission scenarios [17]. Preliminary modeling of Thwaites alone suggests up to 6 centimeters of sea level contribution by 2100, but under worst-case conditions, Thwaites and the ice sheets it buttresses could contribute over 4 meters by 2300 [11].

The human exposure is staggering. Nearly 900 million people live in low-elevation coastal zones [5]. By 2100, that figure could reach 1.2 billion under high economic growth scenarios [5]. Miami, Guangzhou, and New York top the list of cities by value of assets exposed to coastal flooding — between $2 and $3.5 trillion [18]. Across Asia and the Pacific, annual economic damages from sea level rise are projected to reach $144–198 billion by 2050, a 4- to 6-fold increase over current levels [19].

The distribution of risk is grossly unequal. Bangladesh, China, India, Indonesia, Japan, Pakistan, the Philippines, Thailand, and Vietnam together account for 70% of the global population exposed to 21st-century sea level rise [19]. Sea level rise in Bangladesh alone is projected to displace 0.9 to 2.1 million people by 2050 [19]. Small island developing states in the Pacific face existential threats at far lower thresholds of rise.

Treaty Obligations and Policy Responses

The Antarctic Treaty System, signed in 1959 by 12 nations and now encompassing 54 parties, governs Antarctica primarily as a zone for peaceful scientific research [20]. Its Protocol on Environmental Protection (the Madrid Protocol) designates Antarctica as a natural reserve devoted to peace and science but does not directly regulate global emissions or compel adaptation responses to ice loss.

The bridge between Antarctic science and climate policy runs through the Paris Agreement. Under its framework, signatories submit Nationally Determined Contributions (NDCs) — emissions reduction targets updated on a five-year cycle [21]. Antarctic Treaty Parties have been encouraged to communicate to governments the urgency of meeting their NDCs to preserve Antarctic and Southern Ocean environments [20].

However, no government has formally updated its NDC specifically in response to post-2022 Antarctic data. The updated NDC cycle, with targets set for 2035, has been a point of diplomatic pressure: the United States has encouraged countries to set ambitious 2035 NDCs aligned with limiting warming to 1.5°C [21]. A key Nature study found that warming of 3°C would trigger rapid Antarctic ice loss contributing approximately 0.5 centimeters per year of sea level rise by 2100 [22] — a threshold that current aggregate NDCs do not prevent.

The Monitoring Gap

The infrastructure tracking Antarctic change is stretched thin and unevenly funded. The U.S. National Science Foundation's Office of Polar Programs, which supports both Arctic and Antarctic research, commands a budget exceeding half a billion dollars [23]. But the money does not flow equally.

Antarctic infrastructure faces a substantial maintenance backlog. McMurdo Station — the continent's largest research base — has deteriorated to the point where it cannot accommodate new large field teams until later this decade [24]. The NSF's Antarctic Infrastructure Recapitalization (AIR) program received $60 million in its FY2023 budget request, but the scope of needed modernization far exceeds that figure [24]. Funding for the IceCube Neutrino Observatory was proposed to be cut nearly in half, from $7.94 million to $4 million, and the NSF planned to terminate the lease of the research vessel Nathaniel B. Palmer in FY2026 [23].

Arctic monitoring faces its own pressures. A 2025 NOAA assessment found that risks to funding and staffing, alongside aging infrastructure, threaten the Arctic Observing Network's ability to maintain long-term trend analyses [25]. Arctic fieldwork costs 4 to 10 times more than equivalent work at lower latitudes [25]. The Polar Geospatial Center warned that its high-resolution data products "may be the last of its kind…for the foreseeable future" due to NSF funding not being renewed [23].

The imbalance matters because attribution confidence depends on observational density. Antarctica has far fewer weather stations per square kilometer than the Arctic, and both lag behind temperate-zone monitoring networks. Who decides how this funding is allocated? In the United States, it is ultimately Congress, via NSF appropriations, with input from the National Science Board and agency program officers. Internationally, Antarctic research funding follows national science budgets, with no binding coordination mechanism to ensure comprehensive coverage of the continent.

A Research Boom in the Shadow of Uncertainty

The scientific community has responded to these events with a surge of research. Since 2011, over 26,800 academic papers have been published on Antarctic ice sheets and sea level, with a peak of 2,841 papers in 2023 [26]. As of early 2026, 792 papers have already been published this year.

Source: OpenAlex

Data as of Jan 1, 2026CSV

That volume reflects both the urgency of the question and the difficulty of answering it. Current climate models struggle to reproduce the full magnitude of observed Antarctic temperature extremes, which means projections carry wide uncertainty bands. The gap between what models predict and what the ice sheet actually does — particularly regarding marine ice sheet instability and cliff collapse mechanisms — remains one of the most consequential unknowns in climate science.

What Comes Next

The three Antarctic heat events of 2022–2025 share a common architecture: polar vortex disruption, anomalous poleward heat transport, and surface amplification under conditions that pre-industrial climate dynamics would have made vanishingly unlikely. Whether they represent the opening of a new regime or a cluster of extreme outliers will depend on the next decade of observations — observations that current funding trajectories may not adequately support.

The stakes are not abstract. Each fraction of a degree of warming translates, through ice sheet physics, into centimeters of committed sea level rise that will reshape coastlines over centuries. The question is not whether Antarctica's ice will respond to a warming planet, but how fast, how much, and whether the roughly 900 million people living on vulnerable coasts will have the time and resources to adapt.