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In his new book, When the Ice is Gone: What a Greenland Ice Core Reveals About Earth’s Tumultuous History and Perilous Future, Paul Bierman, geoscientist and Professor in the Rubenstein School of Environment and Natural Resources at �պ����� (�պ�����), drills into the complex history of the Greenland Ice Sheet.

In 2019, Bierman gained access to long-lost frozen soil samples collected from the world’s first deep ice core. Upon examining the rare material in his lab at �պ�����, he and his team made an astonishing discovery: Perfectly preserved leaves, twigs, and moss. These findings revealed that Greenland’s ice sheet had melted naturally about 400,000 years ago. Bierman’s book recounts this pivotal moment in his career, the fascinating environmental and geopolitical history of Greenland, and the mysterious journey of 30 kilograms of invaluable frozen soil and ice.

Elizabeth Kolbert, author of The Sixth Extinction, says "When the Ice is Gone tells the story of the scientists who pieced together the history of the Greenland Ice Sheet and, as a result, can now peer into its future. Paul Bierman, is himself one of these scientists, and he brings to his subject a deep affection and a wealth of experience. The result is at once fascinating, sobering, and eye-opening."

Bierman’s book holds stories of interconnectivity and lessons on the importance of transcending political echo chambers. Through it all, Bierman remains an optimist and invites readers to consider how they might learn from the past to change the course of our future.

is now available wherever books are sold.

Can you talk about the timeline of the book and how it came to be?

The book resulted from that detailed our initial discovery of bits of plants and insects in the frozen soil samples from the bottom of the first deep Greenland ice core. An ice core that was collected from Camp Century, a U.S. military and scientific research base established inside the ice sheet during the Cold War. That first paper was published in 2021 and shortly after it was released, I got a call from the senior editor at WW Norton saying, “this is really cool, would you write a popular book about it?”

My first reaction was “I only know how to write textbooks.” But I have loved and have taught public science communication for 30 years. So, with a little more conversation and encouragement I agreed. I owe a lot to my editors, Amy and Huneeya, because they really taught me how to write a trade book throughout this process.

The book travels through time, and it seems to travel across disciplines as well, is that correct?

Yes, time, space, and disciplines. It travels through deep time actually. One of the chapters is about Greenland itself. So, I went back billions of years to detail the rocks of Greenland, which hold what may be the first evidence of life on earth. From rocks I then move to the glaciers that formed on the island, the ice sheet that covers the island and then to the peopling of the island. I cover both the native Greenlanders and the western colonization of Greenland. I delve into the remarkable feat of building Camp Century, the Army’s city under the ice, and the exploitative relationship between the U.S. military base and native Greenlanders.

I tried to write this book in a way that would not just be of interest to geoscientists or climate scientists, but to anyone who wants to understand a remote island in the Arctic. It’s not your average climate change book. It is for anyone who is interested in the Cold War, or who is curious about the amazing science that was taking place in the 1950s and 60s.

What did you learn about the scientists from that era?

They were visionary in their thinking. In the 1950s they were thinking about changing climate and the potential of ice cores. At the time, they hoped to be able to decipher up to 10,000 years of change recorded in the ice. I don't think any of them imagined that we would find millions of years of change archived in the material that they collected.

Almost every one of the original scientists is now dead. But I was able to get to know them to some degree through my research. Henri Bader, one of the lead scientists on the project, was particularly impressive. He seemed to avoid the press, so it was hard to learn about his life; there are very few articles. I know that he had no children. His wife was a generous supporter of the arts. He supported Black scientists at a time when racism was rampant. He supported LGBTQ+ people. I wish I knew him, for a white man in his discipline in the 1950s and 60s, he was incredibly progressive.

I also came across some interesting connections. Like the scientist Gerry Wasserburg – he was instrumental in dating moon rocks in the 1960s, but before that he was really interested in ice. Well it turns out he was my PhD advisor’s PhD advisor. And Chester Langway, who was a major figure in the deep ice drilling program on Greenland, once gave a lecture in Perkins Hall at �պ�����. His name showed up in the Burlington Free Press during my research. Those were a few spine-tingling moments.

You yourself have prioritized diversity in your lab. What have you found that brings to the research?

Oh, it's huge. And not just in my lab, but in the way we collaborate with others. Recently we’ve been working with folks from the Columbia Climate School and with the Danes in Copenhagen at the Niels Bohr Institute. I think the cross-cultural piece is important. There has long been a friendly rivalry between the Danes and the Americans in polar research, and they are the reason we have the samples at all. Maintaining and building relationships across borders is essential.

Diversity of thought is also crucial. One graduate student working with me, Halley Mastro, has a background in botany and environmental studies, and so I look at this core as a geoscientist with a lot of training in environmental history, and she looks at the core from a botanical point of view. Together we do way better than we either could alone.

The scientists who sought to drill into the ice sheet did not live to see your discovery and what you found thanks to their work. How do you think about the role that scientists play to facilitate future discoveries?

I’m certainly standing on the shoulders of the people who came before me. These men, and at least one woman, in the 1950s did something that everybody thought was impossible. They built Camp Century, a base for 200 people inside the ice sheet. They drilled the first ice core in the world to penetrate an ice sheet and managed to sample the soil at the very bottom. That didn’t happen again until 1993.

They attacked a problem that should have been impossible to solve. And I think the analogy for me in this is that we have a wicked problem right now with climate change. But we also have really smart people. So, I take it as a challenge. If we put our heads together, we can solve problems that may seem impossible. And what we do now will lead to younger, brighter minds making discoveries we can’t begin to imagine.

You’ve said that you are an optimist, which may surprise people given the title of your book and the dire prospect of a future when the Greenland ice sheet melts again. What keeps you hopeful?  

I refuse to be hopeless and throw up my arms in defeat. When the Ice is Gone details a tumultuous history of a warming earth, which caused the ice to vanish from Greenland 400,000 years ago. It is no doubt a warning of a perilous future.

But it is also an opportunity. The ice does not have to be gone. We can save the ice, but that is going to require substantial change to our entire energy system. Change that gets excess carbon dioxide out of the atmosphere. It’s a big challenge but look at what humans have done. They put people on the moon. They drilled through over a mile of ice more than half a century ago. That past ingenuity keeps me hopeful.

Paul Bierman’s research and the work of his team at the �պ����� Cosmo Lab has been featured in the , , , , and more. �պ����� undergraduate student , is creating , the trailer and first episode are now available. And �պ����� graduate student, Halley Mastro and Bierman recently together about fossils beneath yet another Greenland ice core. illustrate our work in Greenland and in our lab on campus.