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This white wilderness,
this emptiness, is the North Pole.
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I'm standing in the middle
of a frozen ocean.
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Beneath my feet and for
over 500 miles in every direction,
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00:00:44,090 --> 00:00:46,930
there are several metres of ice.
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00:00:48,170 --> 00:00:51,209
But something significant is
likely to happen here,
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00:00:51,210 --> 00:00:53,170
at the North Pole, soon.
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00:00:54,650 --> 00:00:58,289
Chances are that some time,
within the next few decades,
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perhaps even as soon as 2020,
there will be open water here
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00:01:04,610 --> 00:01:08,290
for the first time
in human recorded history.
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00:01:10,570 --> 00:01:14,649
The Arctic
and Antarctic are changing.
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00:01:14,650 --> 00:01:18,769
Enormous masses of ice that have been
frozen for thousands of years
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00:01:18,770 --> 00:01:20,890
are breaking apart and melting away.
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00:01:34,450 --> 00:01:38,929
Ice scientists are going to
extremes to find out exactly
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00:01:38,930 --> 00:01:40,329
what's going on.
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00:01:40,330 --> 00:01:42,810
For them, these are exciting times.
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00:01:44,410 --> 00:01:46,850
But the transformation that's being
seen here will be felt
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00:01:46,851 --> 00:01:49,530
far beyond the polar wilderness.
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In this programme,
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I'll be trying to understand what
these changes mean, not just to the
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wildlife and people that live around
the Poles, but for the whole planet.
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00:02:18,610 --> 00:02:22,730
I'm starting my journey in the
Arctic, the far north of our planet.
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00:02:26,890 --> 00:02:30,209
It's still very cold
outside by most people's standards,
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00:02:30,210 --> 00:02:33,409
but the Arctic has been warming fast,
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00:02:33,410 --> 00:02:36,209
twice as fast as the rest
of our planet.
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My first mission is to find out
what effect
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that's having on the animals.
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Although first, we have to find them.
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It's April in Svalbard.
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00:02:48,090 --> 00:02:51,449
We are 1,000 miles
north of the Arctic Circle,
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in search of the region's
top predator.
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We need to travel away from the land
and out over the frozen sea.
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There's some tracks
right beneath us.
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Over there.
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I'm with a Norwegian team,
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which is giving the polar bears of
Svalbard their yearly health check.
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She's under us now.
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I'll come round for a clean shot.
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The team works together to
give an anaesthetic injection
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00:03:52,290 --> 00:03:54,930
from a dart gun without hurting
the bear.
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It takes tremendous skill.
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00:04:02,770 --> 00:04:04,370
Ah, you've got it.
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I'll just back off
until she's asleep.
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Nobody likes to see a magnificent
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animal like a polar bear lolling
about unconscious on the ice,
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but it's only by darting them
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in this way and keeping check on them
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00:04:33,890 --> 00:04:36,449
year after year,
that we can be sure we know
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what is happening to them and the
population of polar bears as a whole.
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00:04:42,210 --> 00:04:45,569
Over the last 30 years,
many teams have been seeing
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the condition of their local bears
deteriorate.
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00:04:49,370 --> 00:04:51,090
Although not every bear is suffering.
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How much? 96, there.
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00:05:04,290 --> 00:05:09,249
And 102 here, so that's 197, yeah.
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Is that good?
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It's not too bad,
it's a bit above average.
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00:05:15,130 --> 00:05:17,929
So she's a bear in a good condition
for Svalbard.
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00:05:17,930 --> 00:05:24,369
The trouble is that if this was
underweight, she would be in trouble.
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00:05:24,370 --> 00:05:29,169
Not only from her own point of view,
but from the point of her cubs,
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because an underweight female
gives birth to underweight cubs
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00:05:32,930 --> 00:05:36,649
and underweight cubs have a great
problem of surviving
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their difficult first year
in these circumstances.
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It can be minus 40 degrees Centigrade
when polar bear cubs emerge
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at the start of the Arctic spring,
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from their dens where they were born.
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00:06:03,650 --> 00:06:06,410
This mother hasn't
eaten for half a year.
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00:06:08,490 --> 00:06:12,769
She and her cubs need to fatten up
fast over the next few months and
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00:06:12,770 --> 00:06:17,130
their chances of survival depend on
what's happening beneath their feet.
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00:06:21,170 --> 00:06:24,329
These polar bears aren't walking
on land.
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They're roaming across the frozen
surface of the sea.
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00:06:31,530 --> 00:06:33,890
And the bear's food lives
under the ice.
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00:06:47,450 --> 00:06:51,610
Ringed seals are hunted
by polar bears.
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00:06:52,770 --> 00:06:58,809
In fact, in some parts,
polar bears eat almost nothing else.
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00:06:58,810 --> 00:07:03,930
So, it's very understandable that
this mother ringed seal...
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00:07:05,330 --> 00:07:09,290
who's looking at me now,
should be a little apprehensive.
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00:07:13,010 --> 00:07:16,730
That pup of hers is only about
three or four days old...
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00:07:19,090 --> 00:07:24,410
and the pup won't be able to swim
for another two or three days.
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00:07:26,450 --> 00:07:30,529
Seals have good reason to be
nervous around their holes.
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00:07:30,530 --> 00:07:33,609
They need the holes to breathe
when the sea is frozen,
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00:07:33,610 --> 00:07:35,890
but this makes them easy to find.
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Polar bears can sniff out seal holes,
even if they're covered in snow.
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00:07:49,850 --> 00:07:52,210
Spring is the best hunting season.
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This mother's found a food store
under the snow
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that was probably made
by an Arctic fox.
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00:08:02,530 --> 00:08:04,489
It's a time of plenty now,
85
00:08:04,490 --> 00:08:07,449
but the bear family need to make
the best of it
86
00:08:07,450 --> 00:08:10,770
because the good times are about
to come to an end.
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00:08:16,130 --> 00:08:17,569
As the weather warms,
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the ice beneath the bears' feet
starts to break up and then melt.
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00:08:22,130 --> 00:08:26,890
And as the ice dwindles, so do the
bears' chances of a successful hunt.
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Most of the ice is lost over these
shallow coastal waters,
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where most of the seals live.
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It's now summer and these bears
have a choice ... take their chances
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on the shrinking ice floes,
or make for the safety of the land.
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It's a case of sink or swim.
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00:09:05,650 --> 00:09:07,969
Bears have always gone
hungry in the summer,
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00:09:07,970 --> 00:09:10,529
but the length of time
when there's enough ice for them
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to go hunting is getting shorter and
shorter, across much of the Arctic.
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This is hitting cubs
particularly hard,
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because they can't survive for as
long without feeding as their mother.
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00:09:27,970 --> 00:09:31,850
Cubs that were born
underweight are at the greatest risk.
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00:09:41,450 --> 00:09:45,369
This mother and her cubs may well
not get another meal
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until the sea freezes again
in winter.
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00:09:48,290 --> 00:09:53,049
There's not much to eat on land and
the fact is that the longer the cubs
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00:09:53,050 --> 00:09:57,570
have to wait until the ice returns,
the more likely they are to die.
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00:10:00,850 --> 00:10:04,849
Longer summers with no ice
are probably the main reason why
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00:10:04,850 --> 00:10:07,770
many polar bear populations
are dropping.
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00:10:22,450 --> 00:10:26,529
To help monitor bears into the
future, this female is being fitted
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with a radio collar to track
her movements.
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00:10:33,570 --> 00:10:36,769
It's an extraordinary sensation to be
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so close to such a powerful animal.
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With luck, carrying that collar,
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she will have more years to go yet...
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and be telling us a great deal
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about herself and the rest
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of the race of polar bears, as they
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face this very uncertain future.
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00:11:04,090 --> 00:11:07,209
The future of the ice cover on
the sea isn't just
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an issue for the animals.
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00:11:08,730 --> 00:11:11,049
It's a big concern for the people
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00:11:11,050 --> 00:11:12,649
who live in the Arctic
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00:11:12,650 --> 00:11:15,010
and travel across the ice every day.
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00:11:23,570 --> 00:11:28,049
David Iqaqrialu is an Inuit
from the village of Clyde River
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00:11:28,050 --> 00:11:29,650
in the Canadian Far North.
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00:11:35,650 --> 00:11:40,209
There are very few roads up here,
so David and his community,
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00:11:40,210 --> 00:11:44,210
like most Inuit people, have always
travelled across the frozen sea.
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00:11:46,130 --> 00:11:50,769
Dog sleds are the safest way to
get around because the dogs feel
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00:11:50,770 --> 00:11:53,530
thin ice underfoot and won't lead
travellers into trouble.
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00:11:57,290 --> 00:11:59,730
Old-timers, like David,
know the ice is as well as we know
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00:11:59,731 --> 00:12:02,490
the streets in our local
neighbourhood.
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00:12:06,210 --> 00:12:07,409
Every spring,
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00:12:07,410 --> 00:12:11,330
cracks have always formed in
the same places at the same time.
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It's going to be big very soon.
After two weeks maybe...
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it will be more open.
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00:12:22,210 --> 00:12:26,169
But now, cracks are appearing
where they never did before.
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00:12:26,170 --> 00:12:30,530
So, David and his friend,
Laimikie, have taken on a new job.
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00:12:32,210 --> 00:12:35,569
They are using special GPS units
to record the position
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of new cracks or weak ice.
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00:12:40,370 --> 00:12:42,129
These findings will be used
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00:12:42,130 --> 00:12:44,129
by locals for their own safety,
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00:12:44,130 --> 00:12:46,450
but they're also being studied
by ice scientists,
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00:12:46,451 --> 00:12:51,569
who want to predict how the ice
will change in years to come.
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THEY SPEAK THEIR NATIVE LANGUAGE
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00:12:58,370 --> 00:13:02,849
The Inuit are keen to know what
the future holds too
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00:13:02,850 --> 00:13:05,689
because they've seen
with their own eyes the changes
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00:13:05,690 --> 00:13:08,250
that the scientists have seen
from space.
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00:13:10,050 --> 00:13:12,969
This satellite photo from 1980
shows the Arctic Ocean
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at the end of the summer,
when ice cover is at its minimum.
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Since then, there's been a 30%
drop in the area covered by ice.
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00:13:25,170 --> 00:13:30,009
But these images can't tell us about
changes to the most important factor,
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the thickness of the ice.
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00:13:36,250 --> 00:13:38,609
Measuring thickness
across the whole ocean
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was beyond scientists for many years,
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until help came
from an unexpected source.
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The Arctic Ocean is of huge military
importance, as it's the shortest
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route between North America
and Russia.
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00:14:14,450 --> 00:14:18,929
Since the late 1950s, British,
US and Russian submarines
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00:14:18,930 --> 00:14:22,170
have been patrolling
the Arctic Ocean.
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00:14:23,810 --> 00:14:28,209
But as well as looking out for
enemy activity,
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they've also been measuring
the thickness of the ice,
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critical when looking for
a place to surface.
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00:14:37,210 --> 00:14:40,329
When scientists got permission to
look at the submarine crew's records,
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00:14:40,330 --> 00:14:44,569
they discovered that the ice
has been thinning fast.
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00:14:44,570 --> 00:14:47,810
In fact, it's nearly
halved in thickness since 1980.
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00:14:52,250 --> 00:14:54,289
Across most of the Arctic Ocean,
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there are now just
a couple of metres of ice.
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00:15:01,610 --> 00:15:06,009
It's so thin that it could melt away
almost entirely in the summertime,
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and that includes
the ice at the North Pole.
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If current trends continue,
then there will be
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open ocean here by summer's end,
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some time within
the next few decades.
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00:15:20,690 --> 00:15:23,889
So, the days of the Arctic Ocean
being covered
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00:15:23,890 --> 00:15:26,969
by a continuous sheet of ice
seem to have passed.
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00:15:26,970 --> 00:15:30,409
Whether or not that's a good or
bad thing, of course,
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depends on your point of view.
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00:15:35,810 --> 00:15:38,529
Nobody has had a better view of the
changes to the Arctic Ocean
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than the people of Barrow,
the most northerly town in Alaska.
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00:15:43,370 --> 00:15:47,089
The people here have always
survived by hunting on the frozen sea
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and they celebrate this
at a festival every year.
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00:15:51,890 --> 00:15:55,729
The blanket toss was once the best
way to spot distant animals to hunt,
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00:15:55,730 --> 00:16:00,169
as lifelong resident
Lewis Brower explains.
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00:16:00,170 --> 00:16:03,329
When we throw ourselves up into the
blanket, you know,
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00:16:03,330 --> 00:16:07,169
you get that much more of an 'Ahh'
of seeing further and further out,
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00:16:07,170 --> 00:16:09,849
so sometimes, you'll jump 15-20 feet
in the air,
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00:16:09,850 --> 00:16:13,130
and hopefully, you're being caught
right back into the blanket.
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00:16:15,130 --> 00:16:17,250
I'm OK!
THEY LAUGH
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00:16:18,930 --> 00:16:21,609
But the old way of life
is under threat.
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00:16:21,610 --> 00:16:26,449
When Lewis was young, the sea stayed
frozen to the horizon until July,
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00:16:26,450 --> 00:16:29,449
and some ice remained
off-shore all summer.
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00:16:29,450 --> 00:16:31,489
But now, it's breaking up in June
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00:16:31,490 --> 00:16:35,769
and melting away completely
for two or three months.
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00:16:35,770 --> 00:16:39,569
I used to go out on the ice all
the time at this time of the year,
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00:16:39,570 --> 00:16:44,650
but we can't do that any more,
cos there's no more ice.
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00:16:46,090 --> 00:16:50,489
Lewis can also see that the
loss of sea ice is affecting
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00:16:50,490 --> 00:16:52,570
the animals he hunts for a living.
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00:16:54,050 --> 00:16:57,769
Since 2007, something very strange
has been happening
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00:16:57,770 --> 00:17:00,850
on this stretch of coastline,
close to Barrow.
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00:17:04,570 --> 00:17:09,129
Mother walruses, confused by the lack
of ice, are crowding onto the land
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00:17:09,130 --> 00:17:10,290
with their pups.
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00:17:11,930 --> 00:17:14,329
This very tight crowding isn't normal
200
00:17:14,330 --> 00:17:17,730
and it's caused many youngsters
to be crushed to death.
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00:17:20,330 --> 00:17:23,449
Many Arctic animals are threatened
by the changing conditions
202
00:17:23,450 --> 00:17:28,009
and that's also bad news
for the traditional hunters.
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00:17:28,010 --> 00:17:31,930
But the ice loss could be good news
for some people.
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00:17:35,970 --> 00:17:38,649
There are trillions of dollars' worth
of oil
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00:17:38,650 --> 00:17:40,649
and gas under the Arctic Ocean.
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00:17:40,650 --> 00:17:42,689
But the only way to get to them,
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00:17:42,690 --> 00:17:46,969
until now, has been by building
expensive artificial islands,
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00:17:46,970 --> 00:17:48,169
like this.
209
00:17:48,170 --> 00:17:49,929
But if the sea ice goes,
210
00:17:49,930 --> 00:17:53,089
it will be much easier to
drill for the huge riches below.
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00:17:53,090 --> 00:17:57,449
So, the countries that surround
the Arctic are scrambling
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00:17:57,450 --> 00:17:58,850
to stake their claims.
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00:18:10,210 --> 00:18:15,689
This daring attempt by the Russians
to claim the disputed seabed
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00:18:15,690 --> 00:18:19,009
at the North Pole in 2007 caused fury
among the competing countries
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00:18:19,010 --> 00:18:22,650
and it's unlikely to be
the last such dispute.
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00:18:30,181 --> 00:18:32,780
The Arctic has never been
so important
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00:18:32,781 --> 00:18:35,381
and not just because of
its resources.
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00:18:38,381 --> 00:18:39,740
The North-West passage,
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00:18:39,741 --> 00:18:43,780
a legendary sea route around the
north of Canada and Alaska, cleared
220
00:18:43,781 --> 00:18:49,020
of ice in the summer of 2007 for the
first time since records began.
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00:18:49,021 --> 00:18:51,900
This promises a much faster
222
00:18:51,901 --> 00:18:56,581
and cheaper shipping route between
the Atlantic and Pacific Oceans.
223
00:19:00,901 --> 00:19:03,861
And some wildlife could benefit
from an ice-free Arctic too.
224
00:19:09,021 --> 00:19:13,100
Bowhead whales are one of just
a few whales that can live
225
00:19:13,101 --> 00:19:16,221
year-round in the Arctic
because they have no dorsal fin.
226
00:19:18,421 --> 00:19:20,621
This means they can come up
for air in small spaces
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00:19:20,622 --> 00:19:23,661
and travel easily under the ice.
228
00:19:25,261 --> 00:19:28,700
Their unique body shape used to
mean that the Arctic whales had
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00:19:28,701 --> 00:19:32,900
the seas to themselves
for most of the year.
230
00:19:32,901 --> 00:19:35,781
But now, some cousins from down south
are moving in.
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00:19:43,221 --> 00:19:46,540
Killer whales are now a much more
common sight in the Arctic.
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00:19:46,541 --> 00:19:51,180
Their tall fins make it difficult
for them to travel under ice,
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00:19:51,181 --> 00:19:55,220
but the longer summers mean they can
travel much further north
234
00:19:55,221 --> 00:19:57,821
and make the most of
the rich Arctic seas.
235
00:20:04,701 --> 00:20:07,660
For animals and people,
236
00:20:07,661 --> 00:20:11,341
it will be those that can adapt who
will thrive in a changing Arctic.
237
00:20:20,501 --> 00:20:23,420
But the loss of sea ice isn't just
an issue for the Arctic,
238
00:20:23,421 --> 00:20:27,741
because the state of the ice affects
the climate of the whole planet.
239
00:20:30,821 --> 00:20:35,700
Because it's white, the ice reflects
up to 90% of the Sun's energy.
240
00:20:35,701 --> 00:20:39,180
This is called the albedo effect
and it's why
241
00:20:39,181 --> 00:20:43,421
we often see heat haze in the Arctic,
even when the air feels cold.
242
00:20:50,221 --> 00:20:54,140
The frozen Arctic Ocean
acts as a huge reflector,
243
00:20:54,141 --> 00:20:57,740
bouncing back the Sun's heat
into space.
244
00:20:57,741 --> 00:21:01,100
Throughout history, that has helped
to cool the planet,
245
00:21:01,101 --> 00:21:05,061
but when the ice melts,
it's a different story.
246
00:21:10,621 --> 00:21:16,300
Because sea water is dark,
it absorbs most of the Sun's heat.
247
00:21:16,301 --> 00:21:19,980
In the Arctic, this can trigger
a chain reaction, as the warming
248
00:21:19,981 --> 00:21:24,741
water melts more ice, exposing more
water to the Sun's heat.
249
00:21:30,301 --> 00:21:34,020
This cycle of warming, as huge areas
start to absorb rather than
250
00:21:34,021 --> 00:21:38,260
reflect heat, is the main reason why
the Arctic, a region the size
251
00:21:38,261 --> 00:21:42,701
of North America, is warming twice
as fast as the rest of the Earth.
252
00:21:47,981 --> 00:21:50,860
So, melting sea ice is a big issue.
253
00:21:50,861 --> 00:21:53,500
But there's another kind of ice
that could have an even more
254
00:21:53,501 --> 00:21:55,421
dramatic impact on our world.
255
00:21:56,781 --> 00:21:59,141
The ice that is found on land.
256
00:22:01,861 --> 00:22:03,980
This is fresh water ice,
257
00:22:03,981 --> 00:22:07,861
formed from thousands of years
of accumulated snowfall.
258
00:22:14,021 --> 00:22:19,940
This is the front of a glacier,
quite a small one, believe it or not.
259
00:22:19,941 --> 00:22:22,420
Glaciers are like rivers of frozen
260
00:22:22,421 --> 00:22:26,660
fresh water flowing
across the surface of the land.
261
00:22:26,661 --> 00:22:29,780
This one, like most polar glaciers,
262
00:22:29,781 --> 00:22:34,260
is flowing down from a vast
inland ice sheet.
263
00:22:34,261 --> 00:22:37,100
And it's what happens to those
ice sheets
264
00:22:37,101 --> 00:22:40,581
that could radically alter
the face of the planet.
265
00:22:41,861 --> 00:22:45,780
The Greenland ice sheet is by far
the largest in the Arctic.
266
00:22:45,781 --> 00:22:47,780
It's two miles thick in places
267
00:22:47,781 --> 00:22:50,941
and six times
the size of the United Kingdom.
268
00:22:58,261 --> 00:23:02,140
Every summer, some of the surface
of the ice sheet melts,
269
00:23:02,141 --> 00:23:05,701
forming sapphire blue lakes
of melt water.
270
00:23:07,261 --> 00:23:10,140
More and more of these lakes
have been forming
271
00:23:10,141 --> 00:23:12,981
as Greenland has warmed
over the last 20 years.
272
00:23:14,581 --> 00:23:18,460
This lake has grown over several
weeks and now it's overflowing,
273
00:23:18,461 --> 00:23:20,901
carving a deep channel
through the ice.
274
00:23:27,861 --> 00:23:30,980
A network of channels criss-crosses
the ice sheet,
275
00:23:30,981 --> 00:23:34,101
but many of them
come to an abrupt end.
276
00:23:45,341 --> 00:23:48,700
Huge holes, like this,
can open up quite suddenly,
277
00:23:48,701 --> 00:23:51,021
draining the melt water away.
278
00:24:02,101 --> 00:24:06,220
Alun Hubbard is a glaciologist,
studying the enormous power
279
00:24:06,221 --> 00:24:10,060
of these waterfalls,
which are known as moulins.
280
00:24:16,817 --> 00:24:20,016
Alun is here to study where
the melt water goes
281
00:24:20,017 --> 00:24:23,216
and what effect it has on
the remaining ice.
282
00:24:23,217 --> 00:24:27,577
To do that, he needs to find a
moulin that has recently run dry.
283
00:24:33,897 --> 00:24:36,576
Just a week ago,
there was a three-mile long,
284
00:24:36,577 --> 00:24:39,416
ten-metre deep lake here.
285
00:24:39,417 --> 00:24:42,936
The weight of all that water
cracked the ice beneath
286
00:24:42,937 --> 00:24:47,457
and the late drained in just
a few hours with incredible force.
287
00:24:52,617 --> 00:24:56,537
Thousand-tonne ice boulders
were tossed about like dice.
288
00:25:03,617 --> 00:25:06,816
Alun's team have found the hole
down which the lake disappeared
289
00:25:06,817 --> 00:25:09,336
and they want to have a closer look.
290
00:25:09,337 --> 00:25:12,417
It's not a job for anyone
with a fear of heights.
291
00:25:20,546 --> 00:25:25,345
Alun wants to place a sensor
deep into the moulin to discover
292
00:25:25,346 --> 00:25:27,066
how much water is flowing
through the ice.
293
00:25:33,266 --> 00:25:36,106
As they drop,
they travel back in time.
294
00:25:38,226 --> 00:25:42,345
30 metres down and they reach
ice formed from snow that fell
295
00:25:42,346 --> 00:25:45,066
10,000 years ago,
in the last Ice Age.
296
00:25:48,226 --> 00:25:53,185
When this lake drained and the plug
got pulled and the whole lot
297
00:25:53,186 --> 00:25:59,145
flushed down through here,
this ice sheet, it rose by a metre
298
00:25:59,146 --> 00:26:03,585
as that water accessed the bed
and forced, jacked up the ice sheet.
299
00:26:03,586 --> 00:26:05,705
So, we know that the water
300
00:26:05,706 --> 00:26:10,065
in this whole plumbing cavity
system, down here,
301
00:26:10,066 --> 00:26:11,986
we know that shoots straight
through that ice
302
00:26:11,987 --> 00:26:14,905
and actually hits
the bed of the ice sheet.
303
00:26:14,906 --> 00:26:18,025
We've hit the water,
I can see the water now.
304
00:26:18,026 --> 00:26:20,226
Great. Nice work.
305
00:26:23,146 --> 00:26:27,185
This daring experiment is
measuring how the water flowing under
306
00:26:27,186 --> 00:26:30,585
the ice sheet affects the speed
with which the glaciers
307
00:26:30,586 --> 00:26:33,265
flow from it, down to the sea.
308
00:26:33,266 --> 00:26:36,665
The theory is that the water is
acting as a lubricant.
309
00:26:36,666 --> 00:26:40,346
So, the more water there is,
the faster the glacier flows.
310
00:26:42,546 --> 00:26:46,745
To the naked eye, glaciers don't
appear to move at all.
311
00:26:46,746 --> 00:26:48,026
But move, they do.
312
00:26:50,266 --> 00:26:54,386
These unique time-lapse images were
captured over the last four years.
313
00:27:07,226 --> 00:27:11,025
Through long observations,
we now know that Greenland's ice
314
00:27:11,026 --> 00:27:16,145
is flowing down to the sea twice
as quickly as it was 20 years ago.
315
00:27:16,146 --> 00:27:19,505
The speed of the glaciers
affects our sea levels
316
00:27:19,506 --> 00:27:23,866
because when they reach the water,
they break apart into icebergs.
317
00:27:25,666 --> 00:27:27,666
Occasionally, a real mega-berg
is born.
318
00:27:37,586 --> 00:27:40,386
This is the Store Glacier
in May 2010.
319
00:28:36,706 --> 00:28:39,945
75 million tonnes of ice,
that had been sitting on land
320
00:28:39,946 --> 00:28:43,026
for thousands of years,
has broken away.
321
00:28:48,266 --> 00:28:51,425
Events like this have become
increasingly common,
322
00:28:51,426 --> 00:28:54,826
as Greenland's glaciers flow faster
into the sea.
323
00:29:13,450 --> 00:29:19,169
Every single one of these icebergs
raises the sea level a small amount.
324
00:29:19,170 --> 00:29:23,649
Scientists monitoring the ice sheet
predict that Greenland might add
325
00:29:23,650 --> 00:29:28,369
as much as a half metre to world sea
levels by the end of the century,
326
00:29:28,370 --> 00:29:32,090
enough to swamp many of
the world's low-lying islands.
327
00:29:54,010 --> 00:29:59,009
99% of the Arctic's fresh water ice
is in Greenland.
328
00:29:59,010 --> 00:30:03,369
It's a staggeringly big ice sheet,
but it's just a drop in the ocean
329
00:30:03,370 --> 00:30:07,370
compared to that at the southern end
of our planet.
330
00:30:15,370 --> 00:30:19,689
In Antarctica,
there is ten times more ice,
331
00:30:19,690 --> 00:30:23,010
by far the largest
concentration of ice on Earth.
332
00:30:28,250 --> 00:30:31,209
Our exploration
of the Antarctic only began
333
00:30:31,210 --> 00:30:33,250
a little over 100 years ago.
334
00:30:39,130 --> 00:30:43,089
The study of ice retreat here was
unwittingly begun
335
00:30:43,090 --> 00:30:46,850
on an expedition led by the great
early explorer Ernest Shackleton.
336
00:30:50,970 --> 00:30:56,409
In 1916, after their expedition boat
was crushed and sunk by ice,
337
00:30:56,410 --> 00:31:02,010
Shackleton and two companions set
off to summon help in a tiny boat.
338
00:31:04,810 --> 00:31:08,769
They sailed over 800 miles
across the Southern Ocean
339
00:31:08,770 --> 00:31:12,450
to the island of South Georgia,
on the edge of the Antarctic.
340
00:31:15,930 --> 00:31:19,889
Near starving and dressed in rags,
the three men
341
00:31:19,890 --> 00:31:23,369
walked across the ice sheet at the
centre of the island, knowing there
342
00:31:23,370 --> 00:31:27,050
was a whaling base on the opposite
coast where they could summon help.
343
00:31:35,050 --> 00:31:38,809
This team of Royal Marines is
re-tracing the steps
344
00:31:38,810 --> 00:31:42,290
of that journey in tribute
to Shackleton and his men.
345
00:31:44,090 --> 00:31:48,849
But for all their efforts, they can't
exactly copy the great walk
346
00:31:48,850 --> 00:31:50,130
because the ice is not as it was.
347
00:31:53,770 --> 00:31:56,329
A number of South Georgia's glaciers
348
00:31:56,330 --> 00:31:57,610
were photographed
349
00:31:57,611 --> 00:31:59,529
by Shackleton's cameraman.
350
00:31:59,530 --> 00:32:02,369
Frozen Planet saw a dramatic change
351
00:32:02,370 --> 00:32:05,130
when they returned 94 years later.
352
00:32:22,930 --> 00:32:27,849
Most of South Georgia's glaciers
have shrunk since Shackleton's time
353
00:32:27,850 --> 00:32:29,449
and most of that has happened
354
00:32:29,450 --> 00:32:32,250
since I first went to
the Antarctic 30 years ago.
355
00:32:33,810 --> 00:32:36,729
I've been to South Georgia
several times
356
00:32:36,730 --> 00:32:40,250
and seen how greatly the glaciers
there have changed.
357
00:32:44,490 --> 00:32:46,369
This photograph of a glacier
358
00:32:46,370 --> 00:32:48,369
reaching right down to the sea
359
00:32:48,370 --> 00:32:50,489
was taken just six years
360
00:32:50,490 --> 00:32:53,290
before I first visited in 1981.
361
00:32:54,490 --> 00:32:59,170
Now, that glacier has retreated
by 400 metres away from the beach.
362
00:33:04,450 --> 00:33:08,809
Temperatures in South Georgia have
risen sharply, but the Southern
363
00:33:08,810 --> 00:33:13,410
Hemisphere's most dramatic warming
has happened a little further south.
364
00:33:14,930 --> 00:33:18,569
In recent years, stronger winds
blowing over the Southern Ocean
365
00:33:18,570 --> 00:33:23,169
have brought warmer air to the 800
mile-long finger of land that forms
366
00:33:23,170 --> 00:33:26,690
the northern extremity
of the Antarctic continent.
367
00:33:32,091 --> 00:33:36,810
Here, on the Antarctic Peninsula, the
changing wind patterns have driven
368
00:33:36,811 --> 00:33:40,170
temperatures up by nearly
three degrees Centigrade
369
00:33:40,171 --> 00:33:41,690
over the last 50 years.
370
00:33:41,691 --> 00:33:45,531
Ten times the average rate
of the rest of the planet.
371
00:33:51,811 --> 00:33:56,411
The rapid warming is having
a big effect on the birdlife.
372
00:34:11,651 --> 00:34:16,331
The Adelie penguin is the most
southerly nesting of all penguins.
373
00:34:19,131 --> 00:34:22,330
And, like the polar bear,
up in the north,
374
00:34:22,331 --> 00:34:25,931
their lives are dependent
on the sea ice.
375
00:34:27,371 --> 00:34:30,490
Adelies spend their whole lives
near ice.
376
00:34:30,491 --> 00:34:33,130
These birds have spent
the winter feeding at the ice edge,
377
00:34:33,131 --> 00:34:35,610
but now it's spring
378
00:34:35,611 --> 00:34:39,971
and they've started a long trek
over the frozen sea towards land.
379
00:34:47,571 --> 00:34:52,730
They're heading for areas
of exposed rock, where they gather
380
00:34:52,731 --> 00:34:56,411
to breed, in colonies that can be
over 100,000 strong.
381
00:35:12,971 --> 00:35:15,970
But it seems that Adelies don't
find the conditions
382
00:35:15,971 --> 00:35:18,491
on the Peninsula
to their liking any more.
383
00:35:20,891 --> 00:35:25,370
17 years ago, when I was last
in the Antarctic, there were
384
00:35:25,371 --> 00:35:30,930
large colonies of Adelie penguins
all along the Antarctic Peninsula.
385
00:35:30,931 --> 00:35:36,170
Now, warming temperatures
have meant less sea ice
386
00:35:36,171 --> 00:35:39,371
and Adelie penguin numbers
are in decline.
387
00:35:48,371 --> 00:35:51,211
Many colonies have been
emptying fast.
388
00:35:55,451 --> 00:35:57,610
It may be that penguins are starving,
389
00:35:57,611 --> 00:36:01,490
or it may be that they're heading
south to colder climes
390
00:36:01,491 --> 00:36:04,491
where there's still plenty of ice
on the sea.
391
00:36:12,771 --> 00:36:17,090
But, as in the Arctic,
while ice-loving animals are feeling
392
00:36:17,091 --> 00:36:22,091
the heat, animals that like it
a bit more cosy are moving in.
393
00:36:30,131 --> 00:36:33,810
The bright orange beaks of Gentoo
penguins are a much more common sight
394
00:36:33,811 --> 00:36:36,610
on the Peninsula these days.
395
00:36:36,611 --> 00:36:38,850
I always used to know them
as residents
396
00:36:38,851 --> 00:36:42,130
of the slightly warmer islands
north of the Antarctic.
397
00:36:42,131 --> 00:36:44,371
But they've moved south in numbers.
398
00:36:45,891 --> 00:36:49,450
There are thought to be ten times
more Gentoos on the Peninsula now
399
00:36:49,451 --> 00:36:51,011
than just 30 years ago.
400
00:37:05,158 --> 00:37:07,877
The peninsula has warmed
a great deal,
401
00:37:07,878 --> 00:37:10,558
but the same is not true
further south.
402
00:37:15,598 --> 00:37:20,438
The Antarctic continent is smothered
by the world's greatest ice sheet.
403
00:37:21,598 --> 00:37:24,237
One and half times the size of
Australia
404
00:37:24,238 --> 00:37:26,118
and up to three miles thick.
405
00:37:29,238 --> 00:37:34,438
A staggering 75% of the Earth's
fresh water is locked up in this ice.
406
00:37:38,718 --> 00:37:44,798
Global sea levels would rise by some
60 metres if all this was to melt.
407
00:37:48,798 --> 00:37:52,917
But what chance is there of
that happening here in the coldest,
408
00:37:52,918 --> 00:37:54,638
most hostile place on Earth?
409
00:38:00,558 --> 00:38:05,397
The ice beneath me, up here
on top of the ice cap, is so thick
410
00:38:05,398 --> 00:38:10,238
that I am short of breath,
simply because of the altitude.
411
00:38:11,318 --> 00:38:14,037
This is midsummer
412
00:38:14,038 --> 00:38:19,478
and the average temperature is
some 20 degrees below freezing.
413
00:38:20,558 --> 00:38:23,478
And I can tell you it feels
much lower than that.
414
00:38:24,558 --> 00:38:29,117
And even the worst predictions
don't suggest
415
00:38:29,118 --> 00:38:34,157
that the air is going to warm enough
to melt the ice.
416
00:38:34,158 --> 00:38:37,838
But now, scientists are asking
a different question.
417
00:38:39,558 --> 00:38:43,637
Could the speed at which
the Antarctic ice flows off the land
418
00:38:43,638 --> 00:38:45,838
be increased by a warmer ocean?
419
00:38:47,518 --> 00:38:49,757
Where the ice sheet meets the sea,
420
00:38:49,758 --> 00:38:53,397
scientists are going to
extreme lengths to find out.
421
00:38:53,398 --> 00:38:54,598
Firing.
422
00:39:06,078 --> 00:39:09,558
Andy Smith works
for the British Antarctic Survey.
423
00:39:10,998 --> 00:39:14,797
What we have here is one kilogramme
of pentolite explosive.
424
00:39:14,798 --> 00:39:18,077
We're going to use this
to generate a shockwave
425
00:39:18,078 --> 00:39:21,237
and record the echoes that come back
from underneath the ice.
426
00:39:21,238 --> 00:39:22,758
Firing.
427
00:39:25,638 --> 00:39:28,917
Andy is particularly
interested in mapping
428
00:39:28,918 --> 00:39:31,038
the underside of the ice
around the coast.
429
00:39:32,678 --> 00:39:36,557
Because here,
it isn't resting on land.
430
00:39:36,558 --> 00:39:40,477
It's floating on sea water,
so if sea temperatures rise
431
00:39:40,478 --> 00:39:43,238
just a little,
it can be melted from below.
432
00:39:45,318 --> 00:39:47,677
Around the coast of Antarctica,
433
00:39:47,678 --> 00:39:52,277
the glaciers have flowed out across
the sea to form immense masses
434
00:39:52,278 --> 00:39:55,678
of floating fresh water ice,
called ice shelves.
435
00:39:59,958 --> 00:40:04,157
These freeze to the land around
them, sticking fast and acting
436
00:40:04,158 --> 00:40:08,038
like bathplugs, holding back the
flow of the glaciers into the sea.
437
00:40:11,238 --> 00:40:15,637
On the Antarctic Peninsula,
a one-degree sea temperature rise
438
00:40:15,638 --> 00:40:20,078
has helped to break apart seven major
ice shelves in the last 30 years.
439
00:40:21,758 --> 00:40:24,197
This is the Larsen B ice shelf,
440
00:40:24,198 --> 00:40:28,558
three times the size of Greater
London, breaking apart in 2002.
441
00:40:30,798 --> 00:40:34,357
Afterwards, the glaciers it had been
holding back
442
00:40:34,358 --> 00:40:37,038
started flowing
up to six times faster.
443
00:40:40,118 --> 00:40:43,797
In 2008, a much larger ice shelf
at the southern end
444
00:40:43,798 --> 00:40:46,878
of the peninsula started to break up.
445
00:40:47,958 --> 00:40:51,598
It's an enormous event
that's never been filmed before.
446
00:40:54,038 --> 00:40:56,597
Andy Smith is flying
down the Peninsula to study
447
00:40:56,598 --> 00:40:59,238
this phenomenon first hand.
448
00:41:12,061 --> 00:41:14,660
As Andy's team reaches
their destination,
449
00:41:14,661 --> 00:41:18,180
the scale of what's been happening
soon becomes clear.
450
00:41:18,181 --> 00:41:21,540
Here, for thousands of years,
an area the size of Yorkshire
451
00:41:21,541 --> 00:41:25,021
has been covered by a sheet of ice
200 metres thick.
452
00:41:30,101 --> 00:41:33,021
But now,
over half of that has broken apart.
453
00:41:47,261 --> 00:41:51,980
Andy has been studying
Antarctic ice for 25 years,
454
00:41:51,981 --> 00:41:55,061
but even he is blown
away by what he's seeing.
455
00:41:56,141 --> 00:41:59,820
Now, that is pretty awesome.
That is remarkable.
456
00:41:59,821 --> 00:42:04,340
The edge of the ice shelf has just,
kind of, disintegrated.
457
00:42:04,341 --> 00:42:06,380
Some of the big pieces look like
458
00:42:06,381 --> 00:42:08,741
they could be a mile or more
in size.
459
00:42:11,101 --> 00:42:14,620
It's almost like a, sort of,
a slow motion explosion.
460
00:42:14,621 --> 00:42:17,141
It all pushes outwards very quickly.
461
00:42:24,941 --> 00:42:29,381
Every one of these huge icebergs
will slowly drift out to sea.
462
00:42:34,381 --> 00:42:39,181
To study how fast that happens, Andy
needs to get closer to the action.
463
00:42:49,495 --> 00:42:52,895
Landing on an iceberg is another
first for Andy's team.
464
00:43:07,335 --> 00:43:11,294
This satellite transmitter will help
to track the continued break-up
465
00:43:11,295 --> 00:43:14,615
of this colossal ice shelf.
466
00:43:27,215 --> 00:43:31,695
The remainder of the Wilkins
looks set to break apart soon.
467
00:43:35,175 --> 00:43:39,294
It's the latest ice shelf to
disintegrate in a wave that's been
468
00:43:39,295 --> 00:43:40,654
travelling southwards,
469
00:43:40,655 --> 00:43:44,335
playing a major role in the loss
of ice from the Peninsula.
470
00:43:45,455 --> 00:43:50,734
Next in line, and already weakening
in places, are the ice shelves
471
00:43:50,735 --> 00:43:55,775
that hold back Antarctica's gigantic
continental ice sheet.
472
00:43:56,895 --> 00:44:01,214
And it would only take a small
corner of this to slide into the sea
473
00:44:01,215 --> 00:44:03,175
to have major global consequences.
474
00:44:06,415 --> 00:44:11,214
We've only started to see changes
in the Arctic and Antarctic recently.
475
00:44:11,215 --> 00:44:15,614
So, it's hard to predict exactly what
impact these changes will have.
476
00:44:15,615 --> 00:44:19,374
But we can see for ourselves
that these places are changing
477
00:44:19,375 --> 00:44:21,975
and on a scale that is hard
to ignore.
478
00:44:29,249 --> 00:44:34,088
The Poles, North and South,
may seem very remote,
479
00:44:34,089 --> 00:44:38,648
but what is happening here is likely
to have a greater effect upon us
480
00:44:38,649 --> 00:44:42,248
than any other aspect
of global warming.
481
00:44:42,249 --> 00:44:46,488
If the Arctic sea ice
continues to disappear,
482
00:44:46,489 --> 00:44:50,888
it will drive up the planet's
temperature more quickly.
483
00:44:50,889 --> 00:44:53,848
And the melting ice sheets could
contribute to a sea level rise
484
00:44:53,849 --> 00:44:57,928
of a metre, enough to threaten
the homes of millions of people
485
00:44:57,929 --> 00:45:01,409
around the world's coasts
by the end of the century.
486
00:45:02,809 --> 00:45:07,128
We've seen that the animals are
already adapting to these changes,
487
00:45:07,129 --> 00:45:14,089
but can WE respond to what is
happening now to the frozen planet?
43385
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