In 1966, US military scientists drilled ice about 1.5 kilometers deep in northwest Granlandia and pulled out fragments of soil from the bottom, according to phys.org. The find lay forgotten in the freezer for several decades before it was accidentally discovered in 2017.
Two years later, scientists from the University of Vermont examined the soil with a microscope and saw, to their surprise, not sand and stones, but branches and leaves. This led them to believe that in the recent geological past, Greenland was not covered with a one and a half kilometer layer of ice, but, possibly, taiga forests.
Subsequent studies of these fossil plants and sediments, in which scientists from Columbia and Copenhagen Universities participated, revealed that for the last million years or several hundred thousand years, Greenland has indeed been partially or completely free of ice. “What we found were perfectly preserved plant structures,” the authors report. “These are fossils, but they look like they died yesterday. It is a time capsule that has preserved what once lived in Greenland".
This discovery suggests that there have been times in history when the Greenland ice completely melted. These warm periods in the history of the Earth are similar to the one towards which we are moving now, irreversibly changing the climate. The fact that Greenland is more sensitive to these changes than previously thought means that if warming, it could melt quickly - this would raise the oceans by 6 meters and threaten all coastal cities on Earth. According to the authors of the study, this problem may become relevant within the next 50 years.
The new study is published in the journal Proceedings of the National Academy of Sciences.