At least once in the last million years Greenland was actually green! When the thick ice caps melted, vast landscapes of the North Polar region turned from white to green. A new study paints this picture of Greenland’s past history, which could very well be the region’s future due to climate change.
The change back then – uncovered through an incredible collection of Cold War-era samples – is attributed to the period of extreme warming. The warming, which has occurred in Earth’s recent geological history, eventually swept away all of the ice cover, causing vegetation to sprout from the land below.
“Our study shows that Greenland is much more susceptible to natural global warming than we thought – and we already know that humanity’s uncontrollable warming of the planet far exceeds the natural rate,” says geologist Andrew Christ, who led the research.
Cold War messenger in a cookie tin
In 1966, a team from Camp Century, a Cold War military base, dug into the ice cap and extracted samples from a depth of 1.4 km to examine the sediments. Although the real mission – named Project IceWorm – was to bury around 600 nuclear missiles, the camp was projected as a polar science station mission. However, the mission was not successful, but the team collected ice core samples from thousands of feet deep that could shed light on Earth’s ancient history.
But there was a twist! The central tube sample collected – packaged in a cookie tin – was lost, having traveled from one military freezer to another for decades. The sample was rediscovered in 2017 and landed in the hands of scientists at the University of Vermont in 2019, after a hiatus of nearly 53 years! Unknown until then, the sample turned out to be the first fossil plant of its kind extracted from the bottom of Greenland.
Study samples half a century old
When the international team of scientists studied the sediment under a microscope, they came across evidence of something very peculiar in nature. To their surprise, the scientists found remains of twigs and leaves instead of just sand and rock. The results show that Greenland was once home to mosses, lichens, spruces and firs, that too within the last million years!
The team conducted a rare aluminum and beryllium isotope study to understand how long the vegetation had been there and it turns out the plants grew in the ground without ice for a long time. “Ice caps usually pulverize and destroy everything in their path, but what we have discovered are delicate, perfectly preserved plant structures. They are fossils, but they look like they died yesterday. It’s a capsule time of what lived in Greenland that we wouldn’t find anywhere else,” says Christ.
Additionally, examination of radiocarbon and luminescence dating helped find the exact time, indicating that the melting took place within the last million years. Throughout Earth’s history, climatic conditions have varied greatly, from ice ages to warmer interglacial periods. And Greenland’s sensitive environment seems to have reacted drastically to these changes.
How was Greenland?
Among academics, there have been ongoing debates about what exactly Greenland’s ecosystem was like before the last interglacial warm period, which ended around 120,000 years ago. According to the official statement from the University of Vermont, this research is crucial evidence of ancient plant material that once thrived in northwest Greenland. Their findings highlight that Greenland was ice-free for the past million years due to the Earth’s warming.
Today, 80% of Greenland’s landmass is covered in ice caps, but it could face similar greening trends again due to increased warming. Understanding the pattern of past melting can help scientists predict what the future holds for the white continent. It is estimated that melting Greenland ice can cause sea levels to rise twenty feet, which would flood nearly every coastal city on the globe.
“It’s not a twenty-generation problem. It’s an urgent problem for the next 50 years,” says Paul Bierman, a geoscientist at the University of Vermont, who led the study with Andrew Christ.
The new research will be published in the journal Proceedings of the National Academy of Sciences on March 30 and can be viewed here.