Name: Ice Age mummies frozen in time - Brendan Rogers and Jessica Howard
Uploaded: 2023-02-26T13:55:50.000Z
Duration: 5 min 58 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

In June 2022, a gold miner  in the Canadian Yukon

副詞形分詞節

While working on the traditional lands  of the Tr'ondëk Hwëch'in First Nation,

he uncovered the exceptionally well-preserved frozen remains

of a woolly mammoth calf  that died 30,000 years ago.

because the Arctic holds  many buried secrets...

About 15% of the Northern Hemisphere contains permafrost—

that is, ground that doesn't  thaw seasonally,

but has instead stayed frozen  for at least two years—

The oldest permafrost yet discovered is located in the Yukon

from just 1 meter in some areas  to over a kilometer in others.

And permafrost is exceptionally good at preserving biological remains.

If any ice crystals are close  to remains buried in permafrost,

And microorganisms that would otherwise quickly decompose

plant and animal tissues  operate at slower metabolic rates

The outcome is that, instead of having  to rely on fossilized skeletons

to extrapolate what an ancient animal might have looked like,

permafrost can sometimes offer scientists literal freeze-frames of times long gone.

In 2016, another gold miner  came face-to-face

that had been preserved in permafrost for 57,000 years.

Researchers learned that she'd been feasting on salmon,

possibly when the den  she was nestled in collapsed.

In 2020, reindeer herders  encountered remains

But it turned out that they were as much as 39,500 years old.

Its species went extinct about 24,000 years ago.

Before this, scientists had only ever seen cave bear skeletal remains.

Even incomplete animal remains  found in permafrost

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 finds go beyond the animal kingdom:

in 2012, scientists successfully  regenerated a flowering tundra plant

from seeds they found encased  in 32,000-year-old squirrel burrows.

However, all the prehistoric remains  we have yet to discover in permafrost

are at risk, along with much more, because permafrost is thawing rapidly.

Climate change is warming the Arctic  at 3 to 4 times the rate

And an increased frequency in extreme weather events,

is burning the plants and soil that  otherwise help to keep permafrost cool.

When permafrost thaws, it has  concerning and far-reaching effects.

The ground can fracture  and collapse in on itself,

and the landscape can experience flooding and erosion,

making previously stable trees tilt and form so-called “drunken forests.”

It can also trigger massive landslides and threaten critical infrastructure.

By the year 2050, permafrost thaw may endanger 3.6 million people.

This includes many Indigenous and First Nations people

who have lived across the Arctic region since time immemorial.

Right now, they're dealing  with difficult decisions

about how to protect their communities  and traditional ways of life

The effects of thawing will also extend far beyond the Arctic.

This is because permafrost stores  an estimated 1.6 trillion tons of carbon.

That's over double the amount  in Earth's atmosphere as of 2022—

and more than humans have ever released by burning fossil fuels.

Permafrost is one of the world's largest carbon reservoirs

because of all the organic material  it contains—

but much of it in the form of partially  decomposed soils and sediments.

microorganisms decompose  organic material more efficiently,

and release gases  like carbon dioxide and methane.

as more gases are released, the climate warms,

causing more permafrost to thaw  and release even more greenhouse gases.

To preserve snapshots of what the planet was like thousands of years ago—

when mammoths and cave bears  trod its terrain—

and to support the diversity of life  on Earth thousands of years to come,