An Epic Journey into Greenland’s Buried Past and Our Perilous Future
by Jon Gertner
In The Ice at the End of the World, Jon Gertner explains how Greenland has evolved from one of earth’s last frontiers to its largest scientific laboratory. The history of Greenland’s ice begins with the explorers who arrived here at the turn of the twentieth century—first on foot, then on skis, then on crude, motorized sleds—and embarked on grueling expeditions that took as long as a year and often ended in frostbitten tragedy. Their original goal was simple: to conquer Greenland’s seemingly infinite interior. Yet their efforts eventually gave way to scientists who built lonely encampments out on the ice and began drilling—one mile, two miles down. Their aim was to pull up ice cores that could reveal the deepest mysteries of earth’s past, going back hundreds of thousands of years.
Jon Gertner’s book was published last year, has won at least one best book of the year award, and there are numerous excellent reviews already written. As such, I have little to add that hasn’t already been said.
Instead, I’ll highlight some of the items I found interesting, and include a bit of information that geoscientist Dr. Richard Alley sent me when I asked him some questions on ice cores and climate change. Dr. Alley was in Greenland for the drilling of the cores which he aged. He’s featured in Gertner’s book, and has also written a book on the Greenland drilling projects called The Two-Mile Time Machine.
If you want a short typical review here it is: an excellent, engaging book that entwines historical and modern explorations of Greenland with historical and modern science questions and discoveries. You may not have heard of some of the historical characters before, but after this book you won’t forget them. E.g., 6’ 7” Peter Freuchen, who confronted Nazis and anti-semites by towering over them and yelling “I am a Jew…”, was arrested by order from Hitler himself and sentenced to death, but escaped. His grandson, Peter Ittinuar, was the first Inuk in Canada to be elected as an MP (that information is not in Gertner’s book, but I came across Ittinuar’s name while doing more background reading).
On a personal note, this book was my first audiobook. I can read a book in a fifth of the time of an audiobook even with the speed cranked up to 1.5-1.75x (my usual video watching speeds). When I walk, I prefer to have my ears engaged with my environment rather than my phone. However, I’m now doing hours of walking that normally would go to reading and working—work that no longer exists (thanks, COVID19)—so as a compromise I used one ear for the book and the other ear for my environment.
I was so engrossed in the first part of the book that I walked 15 km non-stop: I didn’t want to stop listening. Would explorer Fridtjof Nansen and his team would even make it across the ice floes to the Greenland shore itself? The description of them trapped on an ice floe that was drifting out to sea and disintegrating in the swells and “boiling water” had my own adrenalin running.
Nearly all the early explorer stories— Fridtjof Nansen, Knud Rasmussen, Peter Freuchen Robert Peary, Alfred Wegner—were similar. Will this team perish, who will die, who will lose limbs to frostbite, how will they survive with food supplies so low yet so much distance to travel? Just when one series of hurdles are overcome there are other hurdles that seem even more insurmountable.
The tales were so engaging I didn’t even think of cranking the speed. Three members of Alfred Wegner’s team (same Wegner who proposed continental drift) stayed all winter under the Greenland ice sheet with no possibility of anyone getting in or out. One of them had gangrenous toes so his team mates, with no medical supplies, removed seven toes with a sharp pen knife and bone cutters.
This team were also among the first to dig and analyze layers of ice. One member dug down by hand 52 feet in total, and claimed he could date the ice at the bottom of the shaft.
This intrigued scientists. How far back could you age it? What other information was locked in the ice itself?
Twenty years later other teams used drills to go deeper. In the 1940s a French team had drilled the earliest deep ice cores (500 feet). In the 1950s scientists piggybacked on huge US military projects and drilled to 1,350 ft (400 m). By the early 60s they’d gone down about a mile (~5200 feet), and mid-60s they hit bottom and drilled up 100 m of Greenland bedrock as well.
In early 60s physicists suggested there might be a way to measure and date carbon isotopes found in the trapped air bubbles in the ice. There was, and in 1969 Dansgaard and others published One Thousand Centuries of Climatic Record from Camp Century on the Greenland Ice Sheet (info not in book).
The cores indicated there were abrupt changes in temperature 10,000-15,000 years ago. Previously, scientists had assumed that past and future climate changes were dominated by smooth changes due to gradual forcings (forcings are things that force climate to alter, such as orbital variations and changes in CO2). Abrupt climate change was something new. Perhaps these rapid fluctuations were artifacts from how the ice flowed and folded as it moved across bedrock layers. More drilling was needed.
Teams proposed the Greenland Ice Sheet Project (GISP), and by 1982 they’d reached 6,683 ft. Again, there were the wild climate swings around 10,000-13,000 years ago. It was a 10 degree C (18 F) change in less than a human lifetime. Scientists—being conservative by training—still wanted more evidence that this was actual change and not ice artifacts.
In 1989, they began two drilling programs. A US-based program, Greenland Ice Sheet Project 2 (GISP2), and a Danish-based program Greenland Ice Core Project (GRIP). These would drill about 30 km apart. If both showed the wild climatic swings in the same time interval then scientists would be more confident it was a real climatic shift and not an artifact.
GISP2 did show a “wholesale, sudden switch in the climate system—at about 18 degrees F” around 11,700 years ago. Gertner writes about this finding, but moves on to the next chapter without talking about the Danish drilling project, GRIP, which had finished a year earlier.
Curious now (or as always) I read some journal articles on GRIP and GISP2, developed questions, read more, had more questions, more reading, more questions, and I started getting lost in the details. I decided to contact Dr. Richard Alley, whom I mentioned previously.
One of the reports he sent me explained some of the terminology used in paleoclimate work. That helped! Till then I was not aware there were multiple terms for the same event. E.g., the warm interglacial period about 130,000 yrs ago is called Marine Isotope Stage 5e (MIS 5e), the Eemian in Europe, and the Sangamonian in North America.
I had also asked Dr. Alley why GISP2 and GRIP used two different dating methodologies, as per a journal article I read. I thought that for consistency scientists would use the same methodologies. He answered,
Which is more believable:
1) two different groups, with different funding and different participants, and maybe a bit of competition, independently date and analyze the cores, and come up with essentially the same answers;
2) the groups get together, come up with one committee that must produce a dating scale, and that committee produces a dating scale.
Oops. How embarrassing. Number 1, obviously. When I taught, I often mentioned that the best science is based on independent evidence with different methodologies converging on the same answers. That’s “consilience” or “convergence of evidence”. That’s how scientific consensuses are reached in things like theory of gravity, theory of evolution, germ theory, cell theory, atomic theory, plate tectonic theory, etc. When there’s scientific consensus on an issue that’s because the answers and the theory have been corroborated independently from multiple lines of evidence, often from many different scientific fields from independent groups in countries around the world.
Dr. Alley also confirmed for me that both GISP2 and GRIP showed similar sudden climatic change within a few years. This evidence led to the new field of abrupt climate change (now nearly 40 years old) as scientists worked to understand why sudden changes would happen, and would they happen again in the future. If it does, we—and our agricultural system—would not be able to adapt quickly enough. This does not mean rapid climate change will happen. It’s not a prediction. There’s some evidence that the Earth system may be less responsive in the warm times than the cold times. That is, the sudden warm jumps of 5-10 degrees C may happen more easily when the earth temperature is near ice age temperatures rather than current warmer temperatures. But, as Gertner also points out, it does open up darker possibilities for us to keep in mind.
I was going to write about some particularly clever detective work that was in Dr. Alley’s material, such as using the levels of methane and nitrous oxide in trapped air bubbles to determine if the climate fluctuations were regional or more widespread—that would have been fun to explore as information from Antarctic ice cores ties in with some of that clever work; and the Antarctic cores also extend the paleorecord so five Milankovitch orbital cycles show up. Milankovitch used orbital mathematics to propose that the wobbles and alterations in Earth’s rotation and orbit would lead to climatic cycles over tens of thousands of years. When the Antarctic ice cores were analyzed those cycles showed up beautifully to confirm Milankovitch’s math.
And it would be fun to discuss Dr. Wallace (Wally) Broecker’s ocean conveyor system that moves water around the planet, and how impacts on that system from melting ice could result in abrupt changes in climate.
But I’m already pushing 2000 words before editing. For more reading about the ocean conveyor system see Dr. Broecker’s The Great Ocean Conveyor: Discovering the Trigger for Abrupt Climate Change. It’s an older book about Dr. Broecker’s original ideas on the links between abrupt climate change and the ocean conveyor system.
Dr. Alley’s book The Two-Mile Time Machine: Ice Cores, Abrupt Climate Change, and Our Future is still available in print and in e-book. If you have some science background check his 2007 article Wally Was Right: Predictive Ability of the North Atlantic “Conveyor Belt” Hypothesis for Abrupt Climate Change.
Special thanks to Dr. Richard Alley who took time out from preparing to give a Zoom commencement address to send me material and answer my questions.
Be sure to check his Johnny Cash Ring of Fire volcano lesson, his Geoman lesson (Billy Joel’s piano man tune). For more serious youtube, but quite informative, is his CO2 Control Knob talk given at one of the American Geophysical Union annual general meetings (the largest gathering, about 20,000+, of Earth Scientists in the world). Some year I hope to overcome my anti-social nature to attend to ask questions and meet the people I keep pestering by email or on Facebook.