Jars of dirt removed from a Cold War-era weapon and lost in a freezer for decades could hold vital new information about climate change and rising sea levels. A. study published Monday in the Proceedings of the National Academy of Scientists states that plant fossils found in a sample of dirt collected from a mile under the ice in the mid-1960s indicate that pre-existing climate -human world at one time warm enough to melt completely. Greenland ice sheet.
The dirt researchers studied a sample of sediment from the bottom of an ice core, which was recovered by drilling down into the ice sheet that covers most of Greenland. It is very difficult to reach all the way down to the bedrock when taking samples due to incredible pressure from the ice, explained Drew Christ, lead author of the study and a graduate of the University of Vermont. Sediment has only been deposited from the bottom of the glacier on a few occasions. “We have less of this [sediment] the moon rocks, ”said Christ.
This particular sample yielded a great deal of plant material, some of which was visible to the naked eye. “It’s like walking, and getting a handful of twigs and wood floor material in the soles of your shoes and pouring it out at the end of the day,” said Christ. “It’s like that, but it’s frozen for 1 million years.”
Christ and the team behind the study used isotope analyzes of various elements that helped the researchers extract the last time the samples were exposed to the sun and cosmic rays. The date showed that the plant material is about 1 million years old.
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Before analyzing this particular sample, Christ said, scientists had “situational” evidence that Greenland’s ice sheet had completely melted away. But the discovery of these fossils conclusively shows that Greenland was once ice-free to house a number of plants. And that’s bad news for us right now. Greenland’s ice sheet is a climate bomb, with some speculations suggesting the page could raise sea levels by 20 feet (6.1 meters). if it melted completely. While slate won’t melt completely tomorrow, the ice sheet is now up melted six times faster than it was in the 1980s. The changes driven by rising carbon dioxide will take centuries to shape as the weather changes to a new equilibrium. Knowledge of history is essential to understanding the future of ice.
“Greenland’s ice sheet has become extinct in a climate system that has not affected humans,” Christ explained. “Before humans added hundreds of parts per million of fossil fuels to the atmosphere, our climate was able to melt the ice sheet. In the future, as we continue to warm the planet at an uncontrollable rate, we could force Greenland’s ice sheet to pass a few thresholds and melt and sea levels rise. . ”
The dirt sample that Christ and his team used to reach these conclusions has its own remarkable backing, suggesting that it was almost lost by history. The sample was first obtained from the first ever ice field of Greenland in a 1966 trip to a military base called Camp Century. The real purpose of the trip was the so-called James Bond-esque secret mission Project ice pulse (yes, in fact) to try to hide nuclear missiles under the ice near the Soviet Union (we don’t make up for this). The scientific part of the trip, while legitimate, was largely created to cover this Cold War browser. The Iceworm Project eventually failed, but at least we got this exciting iceberg out of it. (On the downside, however, climate change is melting out of Century Camp, and could toxic waste dumping from materials and chemicals left over from the Cold War.)
Even though the dirt sample itself is remarkable, as the Camp Century effort was the first ever ice core ever discovered from Greenland, researchers were largely interested in what the ice itself could tell. for them, and less investment in the filth that came with the heart.
“I was taking inch branches out of this stuff. We could see with our bare eyes, like, this is definitely plant material, ”said Christ. “Looking at this as someone born long after this has gone down, it’s the way it was [the scientists] not thinking to look more carefully? I think they had a higher priority to study the ice and then the soil wasn’t explored. ”
In what Christ describes as a “strange trick of history,” the earth was a low priority for explorers and was lost when the journey home. The samples were transferred to the back of a military freezer at the University of Buffalo, then moved incognito with a handful of other material to another freezer at a research facility in Denmark in the 1990s. It was only in 2017, as JP Steffensen, one of Christ’s advisors and author of the paper, made an inventory helping that facility prepare its freezer for transition, that the samples could be retrieved and fully inspected.
And even though researchers in the 1960s may not have known what they found when they excavated ancient dirt, Christ is thankful that their work provided one of the most exciting moments of his scientific career.
“The day we found the fossils was one of those ‘eureka’ times. I never thought those days were happening to scientists, but it happened to me, ”he said, describing how he first saw specks of plant material because the his team cleans the sediment samples for analysis. “I was jumping around in the lab. It was so interesting. ”