It is -38° in here.
I have never been anywhere this cold.
I've had to insulate my camera so the batteries keep working,
and keep my microphone close to my body so the wiring doesn't freeze and fall apart.
This is the United States National Ice Core Laboratory,
in Denver, Colorado,
and I figured it was best to interview the scientists that work here
outside this giant freezer.
We have about 20,000 metres of ice represented here
and that's from probably, anywhere from 60-80 different boreholes around the world.
The deepest one we have is about 30,600 metres through the ice sheet of Antarctica.
In our lab, the oldest ice that we have is about 420,000 years old
and that's from the Vostok Ice Core, drilled in east Antarctica, back in the mid-90s.
When a new core comes in,
we piece it up and ship it out to the principal investigators.
All of this is meteoric ice,
which means ice that's fallen from the sky.
They don't want any of the tundra or sea ice,
because it would contaminate the meteoric ice that we have.
One of the principal investigators who was running an analysis
can check his system from home,
and he asked if somebody was eating potato chips in the break room
because he started seeing a higher amount of sodium in his samples.
And they, said, well... yeah(!)
That's how sensitive this is.
If the mains fail, we have a natural-gas-fuelled generator out in back,
it automatically switches power to the freezer building.
We're 100% backed up. On everything.
Each one of these tubes contains a sample of ice from the Arctic or Antarctic.
And the deeper underground the core was taken from, the older it is:
all that fallen snow crushed down over perhaps hundreds of thousands of years,
along with anything else that happened to be dragged along from the atmosphere.
Pretty much anything that's in the atmosphere
whether it's the atmospheric gases, or dust, or anything like that,
eventually lands on the ice sheets of Antarctica and Greenland
and will get buried and trapped within the snow.
And as that compresses into ice, it preserves that information
so we can actually use these ice cores
to recreate what our atmospheric chemistry was like
dating back to about 850,000 years ago.
We can also determine what global temperatures were and how they changed over time
by studying the stable isotopes of oxygen within the water molecules.
Essentially, they're looking at the ratio between ¹⁶O and ¹⁸O.
And by using a lot of modern-day studies,
they can figure out what the temperature was
in the area where that snow fell.
There's a wide varieties of ways that we can date these ice cores
with Greenland cores, often times we can actual see visible layers
that change from summer to winter, based on the dust concentration
so, sort of like tree rings, count those seasons going backwards
and get a date that way.
And then occasionally we'll run across things like volcanic ash layers
and if there's enough material within an ash layer
we can use radiometric dating to get a very specific age on that volcanic layer.
The margin of error in terms of our ages
are usually within, you know, ±10 years or so.
So it's pretty accurate, especially when we're looking at ice
that's a few hundred thousand years old.
By understanding the natural variations of climate change
we can better predict what's going to happen moving forward
now that humanity has made a pretty significant impact
on what's going on with our planet
in terms of the amount of greenhouse gases that we've put into the atmosphere
over the last century.
We can better understand the past
and using that knowledge of the past
we can better model what's going to happen moving forward into the future.
Thank you to all the team here
at the US National Ice Core Laboratory.
Pull down the description for more about them and about their work
and I think my eyelids are sticking together?
(You can't see it, but you do have frost all on your eyelashes.)