In June 2022, a gold miner in Yukon, Canada made a remarkable discovery. While working on the traditional lands of the Tr’ondëk Hwëch'in First Nation, he discovered the unusually well-preserved frozen remains of a large woolly calf that died 30,000 years ago.
But this is not the only discovery of its kind, as the Arctic holds many buried secrets... About 15 percent of the Northern Hemisphere is made up of permafrost—that is, land that does not thaw seasonally, but rather Instead, at least it stays frozen.
Two years—and, usually, much longer.
The oldest permafrost yet discovered is located in the Yukon and has been frozen for 740,000 years. Permafrost also varies in thickness from only 1 meter in some areas to more than a kilometer in others.
And permafrost is exceptionally good at preserving biological remains. If any ice crystals are near the remains buried in the permafrost, they help remove moisture.
And microorganisms that would otherwise rapidly decompose plant and animal tissues operate at a slower metabolic rate in these subfreezing temperatures.
The result is that instead of relying on fossilized skeletons to look like an ancient animal, permafrost can sometimes offer scientists a literal freeze frame. In 2016, another gold miner came face-to-face with a 7-week-old gray wolf cub that had been preserved in permafrost for 57,000 years.
Researchers found she was feeding on salmon, and they believe she died soon after, possibly when her house collapsed. In 2020, reindeer herders encountered remains that undoubtedly belonged to a bear. But they were found to be 39,500 years old.
They belonged to a cave bear.
Its species became extinct about 24,000 years ago. Earlier, scientists had once seen skeletal remains of a bear in the cave.
Even the incomplete remains of animals found in permafrost have yielded incredible results. In 2021, researchers identified a new species of mammoth by reconstructing DNA sequences from 1.6-million-year-old mammoth teeth—making it the oldest sequenced DNA on record.
And extraordinary discoveries extend beyond the animal kingdom: In 2012, scientists successfully regenerated a flowering tundra plant from seeds they found locked in 32,000-year-old squirrel burrows.
However, most of the prehistoric remains we've discovered so far in the permafrost are at risk, as the permafrost is rapidly melting. Climate change is warming the Arctic 3 to 4 times faster than the rest of the world.
And the increased frequency of extreme weather events, such as lightning and wildfires, is burning vegetation and soil that would otherwise help keep permafrost cool. When permafrost melts, it has relevant and far-reaching effects.
The ground can break in on itself and collapse,
and the landscape can experience flooding and erosion, causing previously stable trees to bend and form so-called "drunk forests". It can also trigger large-scale landslides and threaten critical infrastructure.
By the year 2050, 3.6 million people could be at risk from melting permafrost. This includes many Indigenous and First Nations peoples who have inhabited the Arctic region since ancient times.
Right now, they are grappling with difficult decisions about how to protect their communities and traditional ways of life in the face of climate change. The effects of the melt will extend beyond the Arctic. This is because permafrost stores an estimated 1.6 trillion tons of carbon.
That's more than doubling the amount in Earth's atmosphere by 2022—and more than what humans have released from burning fossil fuels.
Permafrost is one of the world's largest carbon reservoirs because of all the organic matter it contains—some intact, but most of it in the form of partially decomposed soils and sediments.
As it begins to melt, microorganisms decompose organic material more efficiently, releasing gases such as carbon dioxide and methane. This triggers a feedback loop: as more gases are released, the climate warms, causing more permafrost to melt and releasing more greenhouse gases.
To preserve snapshots of what the planet was like thousands of years ago—when mammoths and cave bears roamed its territory—and to support the diversity of life on Earth for thousands of years to come, keeping the Arctic cool. Required.
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