Human-induced climate change has caused various catastrophic alterations in the natural order of the planet. However, these alterations have enabled the human race to study various natural processes that have taken place over millions of years, such as the discovery of the million-years-old fossilized plants that were perfectly preserved 1.4 kilometers (0.9 miles) beneath the Greenland Ice Sheet.
In 1966, the US Army scientists drilled down through nearly a mile of ice in northwestern Greenland and exposed a fifteen-foot-long tube of dirt from under the ice. This frozen deposit was collected and was forgotten in a freezer until it was accidentally rediscovered in 2017.
In 2019, Andrew Christ, a scientist from the University of Vermont studied the sediments under the microscope to find that instead of rock and sand, they contained twigs and leaves. Published in the journal Proceedings of the National Academy of Sciences, the finding suggested that the ice had already disappeared in the recent geologic past and most probably a vegetated landscape stood where a mile-deep ice sheet as big as Alaska stands today.
Image: Ginny Catania/NAT Geo
For the past year, Christ and an international team of scientists – led by Paul Bierman at UVM, Joerg Schaefer at Columbia University, and Dorthe Dahl-Jensen at the University of Copenhagen – have examined these one-of-a-kind fossil plants and remains from Greenland. Their results reveal that Greenland must have been ice-free within the last million years.
Andrew Christ said,
Ice sheets typically pulverize and destroy everything in their path. But what we discovered was delicate plant structures – perfectly preserved. They’re fossils, but they look like they died yesterday. It’s a time capsule of what used to live on Greenland that we wouldn’t be able to find anywhere else.
While many surprising discoveries beneath ice sheets and glaciers have been made in mountain ranges, gigantic meteor craters, and even bacteria thriving in freezing environs expected too cold for life. Now, researchers have found plant fossils in an ice core drilled from almost a mile under the Greenland Ice Sheet.
Scientists Discovered Fossilized Plants beneath Greenland Ice Sheet | Image: University of Vermont
To determine the time period of the matter in the ice core, scientists studied the proportions of isotopes of aluminum and beryllium. Luminescence studies display when sediment was last uncovered to light. Radiocarbon dating of wood in the samples points out their age. And oxygen isotopes in the ice disclosed that the original precipitation fell at much lower elevations than the current ice sheet.
All these analyses revealed that Greenland was entirely, or at least largely, free of ice at some point in the last million years – leading to the growth of vegetation which was later covered under ice again. Moreover, there is a concerning implication to the discovery that suggests the Greenland Ice Sheet is more susceptible to climate change than expected. If this ice sheet melts, it would raise sea levels by 7.2 meters (24 feet) alone. Worryingly, the ice sheet has lost 3.8 trillion tons of ice since 1992.
The rapid glacier melts and the changing climate has been threatening the very existence of the planet. Unless these phenomena are halted, life on earth will be wiped out.