The slow erasure of Greenland’s vast ice sheet—an archive of planetary and human history made of air bubbles and frozen water molecules—is a devastating loss of potential knowledge, says an expert in such memory traces. 

Less than 60 years after the world learned that the Earth’s geologic history, as well as some of the more impactful (for better and worse) evolutions in human existence, could be “read” in ice cores drilled deep into frozen places like Greenland, these libraries of ice are imperilled by global warming, writes University of Edinburgh literature professor David Farrier in a recent op-ed for the Washington Post. 

Recalling the revelation that ice could be a storehouse of memory, Farrier describes how American scientists, excavating an ice core nearly a mile long near a secret nuclear base on Greenland, “were puzzled by the discovery of light and dark bands in the ice.”

With the help of Danish geophysicist Willi Dansgaard, an expert in dating ice cores using oxygen isotopes, the scientists learned that the core they had extracted “was stratified with 100,000 years of snowfall, arranged in seasonal layers that could be read like lines on a calendar.”

With everything from pollen to ancient plants to volcanic dust to wildfire ash to the chemical detritus of industrial processes hiding within the Greenland ice, there is much to read.

Citing research by Andrew Christ, a geologist at the University of Vermont who determined that Greenland’s soil (and the plants it once supported) “was last exposed to the air less than one million years ago,” Farrier adds that ancient ice “not only tells us about the world as it once was, but also foreshadows the world to come if our efforts to mitigate climate change fail.”

According to other reports by the Post, writes Farrier, such a failure could see Greenland losing “35,900 billion metric tonnes of ice by 2100,” an impact that would “significantly contribute to the three feet of sea level rise predicted to occur by the end of the century, which would [in turn] disrupt ocean currents and make storms and hurricanes more destructive.”

And should Greenland’s ice melt away, such an ebbing will take with it “a profoundly human tale.” Among the events that can be read in the world’s striated ice formations are the Black Death (as the attendant economic collapse reduced lead smelting and, therefore, lead particle emissions) and the decimation of Indigenous civilizations upon the arrival of disease-carrying Europeans in what is now North America, Farrier notes. (Antarctic ice cores “record a decline in atmospheric carbon in the 100 years after 1492, as the Indigenous population collapsed and agricultural land briefly reverted to forest.”)

Further events logged in the ice libraries of the world: “a sudden surge in synthesized nitrogen dates the invention of the Haber-Bosch fertilizer process in 1914”, while “radionuclides inscribe the nuclear weapons tests in the 1950s.”

There are happier footnotes, too, notes Farrier. “The shift from chlorofluorocarbons to hydrofluorocarbons at the end of the 1980s marks a change in environmental consciousness.” And the endings to other stories are yet to be written. “Even the pandemic will be recorded, as global carbon emissions fell by 7% in 2020.”

The ice core also captures “the massive acceleration in anthropogenic carbon since the 1990s.”