- The Stauning Alps, at the very edge
of the Greenland ice sheet,
are home to countless glaciers.
It's at the front line of a global catastrophe.
50 years ago, much of this valley was covered by a glacier,
but it's receding rapidly.
It's amazing to think that the ground that we're standing
on right now hasn't been exposed to the open world
since the last ice age.
We've come here to see how the Arctic is changing firsthand.
This year, Greenland has experienced two
of the most extreme temperature spikes on record.
In the Arctic, the rock gets subjected to extreme pressures.
- [Woman] Fresh avalanche.
- Water penetrates into the rock,
it freezes, it expands, the rock cracks and falls apart.
But none of us thought it was going to be quite that bad.
Ice is the glue that holds mountains together.
For the rapid increase in extreme warming events
over the last two decades, mean that these mountains
are becoming much more unstable.
Right now, this is less like climbing,
and more like
tiptoeing along a wire.
Trying not to dislodge anything.
That's not easy because everything is ready to go.
Watch out!
Rocks!
Heads, heads, heads!
- You okay, Steve?
- [Steve] Yup.
- It was painful, and dangerous.
- [Woman] Nearly at the top.
- This is a glimpse into the future for the Arctic.
It's the place that's changing fastest of anywhere
on Earth.
And it's all different over the last few years
in ways that you can see.
The very glacier that we're on is doomed,
is seeping away year by year,
and will be gone in a matter of years.
Eastern Greenland may seem far away,
but what's happening here will impact us all.
Because the Arctic is warming twice as fast
as the rest of the planet.
- You come somewhere like this, and you see how bad it is,
and you witness it firsthand and then you go back home,
and you think, "What can I do? What little things can I do
"that make that difference?"
- People need to make little changes on a big scale.
Everyone needs to be making changes,
and governments need to be throwing their weight behind it
on a large scale.
What I can do is insignificant,
but if a couple of billion people can affect
the same changes that I do,
then all of the sudden, you're making a difference.
If the Arctic continues warming at the current rate,
and the Greenland ice sheet should melt,
the worldwide effect would be catastrophic.
Just a small rise in sea level would sink New York,
Hong Kong, Bangkok, and many other major coastal cities.