A vivid account of buried history and climate transformation in Greenland reveals both the power and the limits of scientific narrative.
Paul Bierman did not expect to make a career-defining discovery in a jar of frozen dirt. Standing in a walk-in freezer in Copenhagen in April 2019, chilled by the stale cold of preserved ice cores, he held a glass container filled with subglacial soil—scraped decades earlier from beneath Greenland’s ice sheet. He didn’t yet know that it contained remnants of ancient plants. But when those fragments emerged under the microscope—preserved leaves and twigs from a long-lost tundra—Bierman recognized the moment for what it was: not just scientific revelation, but planetary warning.
That realization anchors When the Ice Is Gone (W.W. Norton, 2024), Bierman’s vivid and often moving account of what Greenland’s frozen archive reveals about the past—and what it forewarns about our climate future. Both a memoir of discovery and an accessible introduction to paleoclimate science, the book excels when it stays close to the ground—drilling into snowpack, analyzing grains of sand, and extracting stories from layers of ancient ice. Its limitations lie in its tight geographic focus and its reluctance to engage fully with the policy and systems-level responses that the science demands.
Bierman is a geomorphologist at the University of Vermont whose decades-long research spans from the Namib Desert to the Appalachians. But it is Greenland, he writes, that holds a “special place in my heart.” That attachment—equal parts intellectual and emotional—animates this book. With a storyteller’s eye, he revisits the recovery of the Camp Century soil core, drilled in 1966 by U.S. Army engineers beneath a Cold War–era base and long thought lost. Inside that core: unambiguous evidence that parts of Greenland’s vast ice sheet had vanished before—during a previous warm period more than 400,000 years ago.
The discovery, published in 2021 in Proceedings of the National Academy of Sciences (Christ et al.), challenged decades of assumptions. Scientists had long believed that Greenland’s mile-thick ice sheet, while shrinking at the margins, had persisted through multiple interglacial intervals. But the preserved tundra, dated through cosmogenic nuclides—rare isotopes produced by cosmic ray interactions in rock and soil—revealed a different truth. During that earlier warm episode, large portions of the ice sheet had disappeared.
Bierman guides readers through this revelation with clarity, humility, and a dry sense of wonder. He compares the ice sheet to a “sagging mattress” pressing down Earth’s crust and describes buried glacial layers as a “scrapbook” of planetary memory. He’s at his best when explaining the physics of glaciers and the tools of his trade—from isotope analysis to ice-penetrating radar—with language that is both precise and approachable. He’s also honest about the paradoxes of climate research, noting that his own flight to Copenhagen emitted roughly 1,000 pounds of CO₂.
The book moves chronologically, weaving together Bierman’s career, the history of Arctic science, the engineering feat of the Camp Century drill, and the glaciological insights that followed. Readers meet a cast of persistent if underrecognized figures—from 1930s German scientists overwintering on the ice to Cold War military engineers who, working in tunnels beneath the surface, inadvertently collected some of the most important climate data of the 20th century. The author’s admiration for their effort is clear, as is his understanding that these scientific contributions often emerged from geopolitical and military projects whose consequences were poorly understood at the time.
Where Bierman’s narrative gains the most urgency is in his depiction of time: not political or historical time, but deeptime. The Greenland Ice Sheet, he shows, has come and gone. Seven million years ago, ice began to form. Two and a half million years ago, glaciation intensified. Roughly 400,000 years ago, under conditions no warmer than today’s, the ice retreated and was replaced by tundra. Now, in the span of just two centuries of fossil fuel combustion, carbon dioxide levels have exceeded anything seen in over 800,000 years—and the melt has resumed.
This point is not speculation. The 2019 IPCC Special Report on the Ocean and Cryosphere (SROCC) identified Greenland as one of the most active contributors to sea level rise. Recent estimates attribute more than one-third of global sea level rise to Greenland’s meltwater—a proportion expected to grow if current trends continue. Full deglaciation would raise ocean levels by over 20 feet. That’s enough to submerge lower Manhattan, the Florida Keys, parts of Shanghai, and the homes of hundreds of millions of people.
Bierman delivers this message without sensationalism. He lets the data—and the cores—speak. But the narrative’s tight focus on Greenland, while lending it thematic coherence, limits its explanatory reach. There is little discussion of the West Antarctic Ice Sheet, now believed by many glaciologists (Pattyn et al., 2023, Nature) to be crossing a point of irreversible decline. Nor does Bierman explore the loss of mountain glaciers in the Andes, the Himalayas, or East Africa, where the cryosphere functions not as a sea-level threat but as a vital freshwater reservoir.
The omission is not simply geographical. The ice sheets are not isolated systems. They are connected to ocean currents, to atmospheric circulation, to ecosystems, and to political and economic realities. Bierman’s book would have benefitted from drawing these connections more explicitly. Readers come away with a rich understanding of the physics of glaciation, but only a sketch of how those changes might reshape geopolitics, migration, or global food security.
The same is true of climate policy. Bierman condemns the consequences of industrial-era emissions, but says little about the architecture of climate mitigation or adaptation. There is no mention of emissions pathways, energy transitions, or carbon pricing. Readers are not introduced to the scenarios modeled by the IPCC, which show that limiting warming to 1.5°C could dramatically reduce Greenland’s contribution to sea-level rise. Nor is there discussion of the justice dimensions of polar research—the fact that those most at risk from sea level rise contributed least to its causes.
To be fair, When the Ice Is Gone is a scientist’s memoir, not a manifesto. But other authors—Elizabeth Kolbert in Field Notes from a Catastrophe, or Katharine Hayhoe in Saving Us—have shown that scientific literacy and civic urgency need not be separate endeavors. Bierman stays largely within the bounds of scientific observation, and while his restraint lends credibility, it also leaves the reader with a sense of unease. The facts are there. The stakes are clear. The next steps are not.
And yet, Bierman’s reverence for the planet’s memory is undeniably powerful. He writes with tenderness about the tools that let scientists read time in ice and soil. He respects the patience of the data. When he holds a clump of glacial till, he sees not just sediment but story—of heat and cold, of collapse and rebirth. That quiet reverence infuses the book’s most memorable passages.
Still, reverence is not a substitute for synthesis. And in our moment, readers need both. They need to know not only what has happened and why it matters, but what can still be done.
For all its silences, When the Ice Is Gone remains a vital contribution to climate literature. It teaches without lecturing. It informs without overwhelming. And it leaves the reader with something rare: a sense of awe not at nature’s resilience, but at its memory—and its warning.
Paul Bierman is a professor of geology at the University of Vermont, where he directs the UVM Cosmogenic Nuclide Laboratory. His research includes Arctic fieldwork, Earth surface processes, and the application of isotopic dating to understand geomorphic change.
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