An international research team has extracted the oldest continuous ice core ever recovered from Antarctica, a cylinder of frozen climate history stretching back approximately 1.2 million years. The Beyond EPICA project, coordinated by Carlo Barbante, drilled about 2.8 kilometers down at a site called Little Dome C to pull up a record that nearly doubles the previous benchmark. With NASA declaring 2024 the warmest year in its instrumental record and atmospheric carbon dioxide now more than 50% above pre‑industrial levels, the core offers scientists a direct way to measure how today’s warming compares to the deepest past the ice can reveal.
From 740,000 Years to 1.2 Million
Before this latest effort, the longest continuous Antarctic ice-core climate record came from the EPICA Dome C project, which established a timeline reaching back approximately 740,000 years. That record captured eight full glacial cycles and gave researchers a baseline for understanding how greenhouse gas concentrations and temperatures have moved in tandem over deep time. But it stopped short of a critical window: the period before about 800,000 years ago, when Earth’s ice-age cycles shifted from a roughly 41,000-year rhythm to the slower 100,000-year pattern seen in recent geological history. The cause of that shift remains one of paleoclimate science’s most debated questions, and researchers have long argued that only older ice could provide the missing evidence.
The Beyond EPICA team pushed past that barrier. The British Antarctic Survey confirmed that researchers analyzed approximately 190 meters from the bottom of the approximately 2,800‑meter core and described it as capturing at least 1.2 million years of climate and atmospheric composition data. Those deepest sections contain trapped air bubbles from a time when the planet’s orbital mechanics drove a fundamentally different glacial rhythm. The cores have since arrived at BAS Cambridge for detailed chemical analysis, a process that will take years to complete but has already begun yielding early results on greenhouse gas levels, dust loading, and temperature proxies from the oldest ice ever handled in a laboratory.
Modern Warming in Ancient Context
The value of a 1.2‑million‑year record becomes clearer when set against the speed of current climate change. NASA’s monitoring determined that 2024 was the warmest year in the agency’s record, which uses a 20th‑century baseline and shows an unmistakable upward trend over recent decades. That finding sits alongside data from NOAA showing that atmospheric CO₂ levels are now more than 50% higher than in 1800, as summarized in a climate.gov explainer that traces the rise from pre‑industrial values near 280 parts per million to current concentrations above 420. The ice core’s trapped gas bubbles will eventually allow scientists to plot those modern concentrations directly against greenhouse gas levels during past warm periods, including interglacials that preceded the current one by hundreds of thousands of years.
Most coverage of the core has framed it as a “time machine,” and the phrase captures something real: no other archive on Earth preserves both temperature and atmospheric gas composition in a continuous, datable sequence this long. As researchers at the University of North Carolina have noted, Antarctic ice cores function as a direct archive of ancient air, preserving the composition of the atmosphere itself rather than just indirect clues. But a point often lost in that framing is what the core cannot do on its own. Ice cores record atmospheric conditions at the drill site, not global averages, and the oldest ice is often thinned and distorted by flow. Translating those local signals into global temperature estimates requires careful calibration with other records, and the full chemical workup of the deepest sections is still underway, meaning the most precise reconstructions will emerge gradually over the next several years.
Parallel Drills and a Global Effort
Beyond EPICA is not the only deep-drilling campaign reshaping the climate record. Australia has launched its own long-term project at Little Dome C, where a national deep drill recently cut its first Antarctic core as part of a bid to obtain ice dating back more than a million years. That effort, led by the Australian Antarctic Division, is designed to complement European work by providing an independent core from the same broad region, improving confidence in age models and climate reconstructions. Multiple deep cores from nearby sites can reveal how representative any single column of ice is and help scientists distinguish local anomalies from continent‑wide or global signals.
Such projects draw on a wide network of institutions, from national polar programs to universities and specialized laboratories, and they depend on skilled technical staff who can operate heavy drilling equipment in some of the harshest conditions on Earth. Recruitment campaigns advertised through channels such as Antarctic jobs portals illustrate the range of expertise involved, from mechanics and engineers to field scientists and logistics coordinators. The human infrastructure behind the cores is as critical as the scientific instruments: each meter of ice must be drilled, logged, transported, and stored under tightly controlled conditions to preserve the fragile gases and chemical signals that make these records so valuable.
West Antarctic Sediment Fills a Different Gap
While Beyond EPICA captures atmospheric gases frozen in East Antarctic ice, a separate effort is targeting the rock and sediment beneath the West Antarctic Ice Sheet. The international SWAIS2C project, short for Sensitivity of the West Antarctic Ice Sheet to 2 degrees Celsius, drilled at a location called Crary and retrieved the deepest rock core yet recovered from beneath the Antarctic ice sheet. That sediment core provides evidence of past West Antarctic Ice Sheet retreat during warm periods, a record that speaks directly to how much sea level could rise if the ice sheet destabilizes under current warming. Researchers from the University of Exeter and Imperial College London contributed to the effort, which was reported in early 2026 and framed as a crucial test of whether modest temperature increases can trigger rapid ice loss.
The two projects answer different questions. Beyond EPICA tells scientists what the atmosphere looked like over 1.2 million years; SWAIS2C tells them what the ice sheet did in response to past warmth. Together, they could provide the clearest picture yet of how sensitive Antarctic ice is to rising temperatures. The sediment record reaches back an estimated 23 million years, far deeper in time than any ice core can survive, because ice eventually deforms and loses its layered structure under pressure. Sediment, by contrast, compresses but retains its chronological order, preserving traces of ancient shorelines, microfossils, and chemical signatures that reveal when marine waters invaded presently ice‑covered basins.
Limits, Uncertainties, and the Road Ahead
Even with these advances, major uncertainties remain. Assigning precise ages to the oldest ice is challenging, particularly where layers have been stretched and thinned near the bedrock, and scientists must cross‑check ice-core chronologies against independent records such as marine sediments and volcanic ash layers. Access to key technical literature can also be constrained; for example, some readers encounter login gateways when attempting to view original research articles, underscoring the importance of open summaries and institutional press releases in communicating findings beyond specialist circles. Reconciling different proxies (ice, sediment, and model simulations) will require sustained collaboration across disciplines and countries, as well as continued investment in both field campaigns and laboratory infrastructure.
Despite these caveats, the emerging picture is stark. The combination of a 1.2‑million‑year atmospheric record from East Antarctica and a multi‑million‑year sediment archive from West Antarctica offers an unprecedented test of how the climate system responds to changes in greenhouse gases and orbital forcing. As analyses proceed, scientists expect to learn whether past warm periods with CO₂ levels comparable to or lower than today produced ice‑sheet configurations compatible with current coastlines, or whether they were marked by substantially higher seas. Those answers will not change the physics that link emissions to warming, but they will sharpen estimates of how quickly ice sheets can respond, and how much time coastal communities have to adapt before thresholds are crossed that, like bubbles trapped deep in the ice, cannot easily be reversed.
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*This article was researched with the help of AI, with human editors creating the final content.
