Original subtitles

(dramatic music)

During the last ice age, 16,000 years ago,

ice sheets like this covered much of

the northern hemisphere.

So much water was trapped in the ice,

that sea levels were almost 122 meters,

360 feet, lower than they are today.

(water gushing)

Today, we're facing the opposite problem.

The Greenland ice sheet, the last remnant of that ice age,

is melting at a rapid pace as the Arctic heats up.

(intense orchestral music)

Greenland's ice sheet lost 55 billion tons of water

over just five days in July and August of 2019,

enough to cover the state of Florida in almost

five inches of water.

(dramatic horn music)

(water-fall)

( equipment)

Scientists are packing equipment and getting dropped off

at research camps across the ice caps, to track the melt.

(power auger whirring)

30 years ago, this research site, S10 Camp,

was chosen because it was just above the equilibrium line.

That's where the snowfall and the snow melt are the same,

year in and year out, making the ice very stable.

From here, scientists can measure the long-term climate

and monitor the movement of the Greenland ice sheet.

It was originally put in as a kind of control

where nothing happens.

Nothing really should be happening.

Nothing should be happening here

but the ice sheet is melting,

and faster than models predicted for this century.

Airborne dust and soot from the industrial world

darken patches of ice, absorbing more of the sun's

radiation, and accelerating melting.

(water gushing)

It's an amazing theory out there that the water gets

to the base of the ice sheet, and kind of pressurizes and

hydraulically lifts the ice sheet up, up to a meter at any

one time when that water shunts down the hole.

So, it does have a really big impact.

And the rate of lowering of this

particular part of the ice sheet

is beyond what models predict really.

By the end of summer,

scientists estimate about 400 billion metric tons of ice

will have melted or capped off Greenland's giant ice sheet.

(dramatic chime music)

(plane whirring)

Scientists worldwide are studying sea rise and the ice loss

on this vast icecap.

Greenland is 14 times the size of England.

Most of it is covered by an ice sheet.

Its average is two kilometers thick.

But in just the last 10 years,

there's been a lot of change.

And in the center, almost four kilometers deep.

Six, five, four

three, two, one, drop.

Six feet away.

A jet propulsion lab program called

'Ocean Melting Greenland' is designed to improve

sea level rise estimates by mapping topography

of the sea floor,

and measuring salinity and temperature along

the continental shelf of Greenland.

It's really a breathtaking landscape.

When you look out the window,

you really get a sense of just how huge these glaciers are.

These gigantic rivers of ice that are

draining the ice out of Greenland into the ocean.

J.P.L's team lead, Josh Willis, drops high-tech

probes designed to measure the action of

warm, salty Atlantic water.

Then, resurface and transmit data to the plane.

All to determine how the ocean is contributing

to the melting ice walls.

(radio chatter)

Greenland's definitely melting

and this year has been incredibly warm.

As we've flown over the ice sheet this year

we've seen evidence of melt pools

not just in the coast but far inland.

Even at high very elevations so

it's been a really warm year and I think it could be

a record year of ice loss for Greenland.

(Eerie music)

Here's our scientific gear

we have the time lapse camera

so that we can actually see

when it's capping icebergs.

The real frontier today is understanding the ocean

glacier interactions.

And even though Greenland's a far away place

the changes here are felt around the world.

In 2005 we put cameras at the Jakobshavn glacier

and now we have camera's at more than 10 glaciers.

Every time you learn something new,

the actual speed measurements,

the Jakobshavn Glacier's moving really fast.

It's discharging 40 billion tons per year.

(plane flying overhead)

40 Billion tons of ice,

that's equivalent to over 90 Million 747's,

fully loaded, with fuel.

That whole ice shelf is going to go.

The time lapse camera is set to take

a single picture every 30 minutes.

It shows the movement of the glacier over

the entire summer.

The front of the glacier is rapidly disappearing.

One reason is the heavy flow of fresh melt water

down to the sea.

Another is warmer ocean currents

reaching the face of the glacier.

My concern is that if ocean temperatures

continue to rise and there's more of these

warm currents in contact with all of these

outlet glaciers to the ice sheet,

we're just going to see more and more ice

coming out at a faster rate,

leading to global sea level rise.

Where these glaciers extend out into the ocean

Warmer ocean temperatures are melting them

up to 100 times faster under the surface than above.

Temperature rise and melting in the interior

causes the ice sheet to lose more ice

then it gains each year.

In turn, the equilibrium line is retreating further inland

while the glaciers are sliding further

toward the coast and into the warming oceans.

The question is, How fast?

The ice sheets bending more than it's gaining

that's why it's important.

We want this ice sheet to be an Equilibrium, Sadly it's not.

(Ice crashing into water)

GPS sensor's can precisely track the melt

and the movement of the ice sheet.

GPS is telling us how fast the ice is

moving here pretty much on the button of 51 meters a year.

51 meters a year, that's how fast the glaciers

are moving and sliding into the oceans.

(Radio Chatter)

3 , 2 , 1 , drop.

Every time a ton of ice comes off of Greenland

sea level goes up a tiny little bit and it's coming

off Greenland at billions of tons per year.

(Somber piano music)

If this lot were to melt and flow straight into

the ocean I'd suspect the rest of humanity would

know about it pretty quick.

(forlorn piano music)

When we see surface melting over the whole ice sheet.

I think that's really going to indicate something.

That's going to tell a message

that's like the climate is really changing.

This ice is natures thermometer

and it just reacts to the environment that it's in.

I think that's going to be kind of a wake up call

for people to see that wow for the first time

we're melting in what used to be called the dry snow zone.

Whoa!

(ice crashing into the ocean)

Eventually if it all melts

the oceans will rise another 7 meters.

That's 24 feet around the world, threatening coastal cities.

(high energetic guitar music)

It would be disastrous for many cities around the world.

From New York to London.

Shanghai to Sydney.

Sea level rise will affect all of us.

(somber electronic music)

Worse, it's already destabilizing weather patterns

in all parts of the world.

Coasts and inland.

(water crashing into shore)

So arctic warming doesn't mean that the whole world

just gets warmer it actually means

because of the slow down of the jet stream

that we have more extremes in the weather

and it's destabilizing the climate.

(roaring thunder and rainfall)

In Greenland, surface melt,

the warmer ocean waters washing in front of the glaciers

and shrinking sea ice are all happening at a fantastic rate.

Satellite data shows that some of the glaciers have

retreated as much as 10 miles per year in the

last decade and doubled their rate of melt.

A further 2 to 3 degree rise in global temperature

this century might be just enough to tip

the great ice sheet into an irreversible melt down.

(somber orchestral music)