The Vanishing Antarctica Our World

between 18-60. Now it is time for Our World. British scientists are

in ing dramatic and potentially dangerous changes to

the west Antarctic ice shelf. There is a strange and mysterious place

at the edge of our planet which most of us will never see. 1.5

times the size of the United States, it holds just ice. Now one of

Antarctica's greatest glaciers has begun to race into the ocean,

putting more ice into the sea than any other in the world. Nobody

knows what the consequences for the world's oceans will be. Just one

thing is certain: If you want It is brass monkeys out there! You

would think that after six trips to this icy continent, I would be used

to the cold but it is impossible to grow complacent about any aspect of

Antarctica. For 20 years, I have been reporting on how it has

changed. The seas around the Antarctic Peninsula have changed

almost beyond recognition, and climate change is also having a

dramatic effect. I am talking to scientists both here and in the UK

about something they are reporting as a major global concern: The

oddly named Pine Island Glacier is one of the world's largest rivers

of ice and it has almost doubled its speed in the last 30 years. Its

behaviour has left scientists confused and concerned. The ice

here is melting faster than just about anyone thought possible. We

have front-row seats here. The story begins here on the Antarctic

Peninsula. Until the 1800s, Antarctica was nothing more than a

myth and even when we discovered it was real, it retained a mythic

status. We thought of it as the last great wilderness, untouched,

unchanging. We were wrong. This man is an aero-geophysicist. In 1997 he

was working on a vast expanse of floating ice called the Larsen B.

Each ice shelf has its own character but this one has rifts

and it is likely it could go. years ago, we were sitting in a

small boat off the Antarctic Peninsula when you said this could

be the next glacier to go. How did you know? In hindsight I should

have been more forthright. There were three of us on the plane and

we could see the enormous rifts and the way it was open. After the

flight we were chatting. We all felt melancholy because we knew it

was going to go at some point. could see its number was up. Hugh

was right. So that is the place where the glacier should begin but

instead it is full of water and Larsen B is gone. It is an

extraordinary sight. In 2002, it was plain to see in the satellite

images. In March, there was heavy cloud and when it cleared the

glacier had vanished. It had become tiny shards which would eventually

float out to sea. Scientists stared at their computer monitors in

astonishment. We knew that other ice shelves had disintegrated as

well but in a piecemeal fashion. Pieces would fall off and then more

bits but this one was very different. The whole ice shelf

literally disintegrated. A complete shock? Yes, it was not expected.

soon as the weather permitted, scientists returned to the

peninsula to try to work out why it had collapsed. It did not take them

long. This is a meteorologist who tracks climate on the peninsula.

She is watching as the climate behaves in an extraordinary way.

Can you give me an overview of what has happened to temperatures?

Antarctic Peninsula is one of the fastest warming places on the

planet. Temperatures have risen by three degrees in 50 years, which is

about ten times the global average. Scientists concluded that warming

air was responsible for the glacier's demise. Climate change

had claimed its first high-profile Antarctic victim. After the

collapse of Larsen B, the focus was on the ice and who works on it. A

world-leading glaciologist remembers the time very well.

the biggest thing we have seen for many decades - an ice shelf that we

thought was permanent suddenly collapsing in a short period. It

was enormously important. This is the main research station of the

British Antarctic Survey. Scientists and support staff stay

here for stretches of up to 18 months at a time. One of their aims

is to track every move that the ice makes. Some people take a little

persuading, like this climate change scientist. I studied

oceanography and wanted to work in the tropics, somewhere warm.

Somewhere along the line I was diverted to the polar region. It is

incredible! This is something many people can only dream about. A

glacier is always on the move. Glaciers are always moving towards

the sea. You can really see that in this fissure which has opened up.

You can walk around and see that it is moving. Why are the icicles at

right angles here? The larger ones have formed over many years. They

are dripping down vertically but the ice itself is moving. When it

is quiet, you can hear cracks and creaks and groans. That is another

indication that it is moving and really quite fast. Movement is one

of the basic principles of ice. As snow falls across the continent, it

is slowly compressed into giant frozen rivers. Gravity and fresh

snowfall force these glaciers to float towards the sea. There they

edge out in vast floating platforms called ice shelves. Their tips

break into icebergs and float away to sea. Until the collapse of

Larsen B, scientists had thought that this happened very slowly.

They had a theory that an ice shelf was like a cork in a bottle,

holding back a glacier. If you take away the cork, the glacier just

hotly-contested but then the Larsen B broke away and melted. Now we

know that the ice shelf restrains the glacier behind it. If you take

away the ice shelf, the glacier will speed up. It was like pulling

a cork from a bottle. The ice shelf has stabilised the glaciers. When

it was gone, the glaciers sped up. They are still retreating at this

moment. An ice shelf floats and has no effect on sea levels, unlike the

glaciers behind them. In just six months, the glaciers dropped in

height by as much as 1.5 times the size of these peaks. Remove an ice

shelf and the glaciers behind will race to the seas. Ice can be swift

and volatile. It made them afraid of what would happen if rising

temperatures spread. The Antarctic Peninsula is a vast formation of

ice but it is dwarfed by the West Antarctic ice sheet further south.

Here the air is not warming nearly as fast, so scientists thought the

ice shelves were safe at least until now. Then something happened

which made them change their mind. 800 miles from the nearest British

base, Pine Island glacier has been tracked by satellite since the

1990s and it is acting up. It is one of the largest ice streams on

the planet - a large river on ice that drains the West Antarctic ice

shelf. It is changing very quickly. It was melting more than 100 times

faster than they had expected. Scientists did not know why and had

to go there to find out. Less than one thousandth of 1% of the world's

population has ever been to Antarctica. Science here still

pushes the limits of polar exploration. To get to this ice

shelf from the nearest base, scientists had to cross 800 miles

of the most inhospitable terrain on earth. It is a place so remote that

more people have landed on the moon. Conditions here are so tough that

only one scientist has walked on a forward floating edge of the

glacier. He was an American from NASA. The pilot was so nervous that

No one except a special robot. In January 2009, scientists sent a

remote-controlled submarine into a place no man or machine had ever

been before. In icy waters of the ice sheet its job was to collect

data from below the glacier. Adrian Jenkins is the oceanographer who is

in charge. This is a model of the submarine. It is seven metres long

and a metre in diameter. This is sophisticated technology. It is

amazing. It gives us an unprecedented view on the world

underneath the ice shelves. Frozen sea ice normally covers the bay but

a lucky break in the weather meant Adrian and the ship got within

three miles of the ice shelf. wanted to get in and we would tents

knowing this was the big moment. -- were tense. We were the first

mission below the glacier and have no idea what would come back.

the teams saw the data they were astonished. They thought the ice on

the underside of the Pine Island glacier was an kits to a ridge but

the Autosub had made its way 30 kilometres inland. The glacier had

come unstuck and it was floating. It wasn't warming air that was

causing it to melt, it was warming seas. Not just lapping against the

ice but eating away at its underbelly. It changed the way we

think about the system. It was jaw- dropping. What the submarine

revealed was the latest piece of evidence suggesting the melting of

the Pine Island glacier and the West Antarctic ice sheet may be the

largest source of global sea level rise the century. In 2007,

governments commissioned a report written by scientists which

estimated future sea-level rises around the world. By 2100, these

seas were unlikely to rise by more than 59 centimetres, they said. But

they also admitted not enough was known to fully include the ice in

west Antarctica and I think what is happening now makes that report

obsolete. David Vaughan here, I have been looking at the figures.

David will be a lead author of the next IPCC report. The predictions

are predictions of climate change are out of date when they are

published. We are working in the IPCC to begin the process of doing

that, complete and consolidated estimates. I will not prejudge the

outcome of that but everything we had seen coming out of the science

suggests Antarctic could contribute more than was known at the time of

the last report. The world's oceans could rise 30 centimetres. Great

coastal cities could be swamped by five metres of water if the West

Antarctic ice sheet follows it. events we have seen in Pine Island

glacier make us more concerned than we were five or 10 years ago. More

than a metre of sea-level rise is potentially with us by 2100.

Certainly by 2150. It seems increasingly likely the future of

these coastal cities will be shaped by a piece of ice at the end of the

Earth. It is a future scientists are struggling to bring into

clearer relief. Ed King is one of a handful of scientists who have made

it to the glacier itself. Accompanied only by an assistant

and a camera. We had all sorts of issues to do with getting cross

country into Pine Island glacier from another glacier we were

studying. It should have taken three days, it took us 11. The

weather clamped in on us, we sat in the tent seven days straight with

40-knot winds blowing past. Blizzard conditions. Things broke.

By the time we finally got to Pine Island glacier there was quite a

lot of fixing to do. Despite the extreme conditions, he has mapped

the glacier bed using radio waves. The image of the bed we have

created was eated was dar survey. It is the most detailed image of

this glacier ever created. And we can see straight away from that

there is melting going on down there. There is water being

produced and ice melting right under our feet at the moment.

pioneering results are his swansong. After 17 tough seasons on the ice

he has decided this is his final trip. It is an extraordinary place,

it has been a privilege to be able to work here. Sometimes you can

recognise that the time has come for something to end. This is that

time. I bid farewell to the situation in the Antarctic. And it

feels quite hard. For generations scientists have suffered out on the

ice, trying to unlock its secrets. Now, technology is lending a hand.

This is the wonderful world of aerogeophysics. Nothing can remain

hidden for long. We have four utility aircraft, they are work

horses for the survey. This is special in that it has been

equipped to do airport geophysics. There are cables down the wings to

the antenna. It is hoped by scanning Pine Island this play will

show what is happening deep inside the ice. -- plane. Where do you

take it? When we get the equipment installed and do a test flight and

if all goes well, off we go to Ireland and the idea is to survey

the ice shelf, the plug holding back Pine Island. -- Pine Island.

Pine Island could answer the trillion dollar question about sea

levels rising coming from the West Antarctic ice sheet. You're excited.

Excited and worried. We want to a good job. It is a huge challenge. A

huge challenge we have everything right because it is a one-shot

chance. We have limited time and weather window and we must get it

I have been have been e as a TV correspondent since the mid-1990s.

It is interesting to reflect that back then it was thought the sort

of changes we're seeing here would not happen until the time of my

grandchildren or long after that. And yet it is happening now and it

is happening much faster than thought possible. Scientists

working here say the rapid changes on the peninsular are being driven

by human activity. But they have not drawn any definite conclusions

about Pine Island for one simple reason. They just don't think they

have observed enough. Yet. We have seen dramatic changes but they are

for a short time period. They have only been monitoring what is going

on since the satellite era, the late 1970s. In terms of a time

period to understand the changes, 30 years is very difficult to get

any statistical significance. next step is to look at ice drilled

from deep down in the ice sheet to hope it will unlock the past.

cores are a fantastic resource because they show an archive of the

climate. The most interesting one is past temperatures. Liz Thomas

has spent a season during ice cores at the edge of the West Antarctic.

What we are interested in finding out is how the climate of the West

Antarctica has been changing over the last 200 years. We are

interested in the causes of whatever is happening. Is this part

of a natural cycle? So, the climate has been changing many times over

the past million years, so it is this part of natural change or is

this something that is more recent effect like something like human

induced warming and change. Everyone I spoke to about Pine

Island says the same. At the moment they have more questions than

answers. But there is one thing about which they are all in

agreement. It is one of the biggest questions facing science. Science

and society as well. Because there is potential for the changes we see

to affect all this. Regardless of the cause of the changes, it is

something, with regard to sea level rises, it will affect everyone.

does concern me. People have said to me, these things have happened

in the past, that is true and the sea level has been higher than at

the moment but back then the humans there were around were few and

minimal. But back then, the humans were few in number and were nomads.

They could move away from rising sea levels. Now we have 7 billion

people on the planet. That is a thought echoed by everyone who

works down here. It has made me think about things in a different

way. So, consider this. In a way it really doesn't matter whether you

think the changes in Antarctica are natural phenomena or global warming