Europe: A Natural History

Europe 3 billion years ago...

Born of violence and upheaval...

Scoured by wind-blasted deserts...

Swallowed by the oceans...

And cloaked in tropical swamps...

These sweeping changes laid the foundations

for the most diverse of Continents.

But then, some two and a half million years ago,

this virgin world faced a fresh assault.

Triggered by the most unusual combination

of cosmic and global events,

Europe was now confronted by a radical change in climate.

The landscape was transformed beyond recognition...

...locked in a tomb of ice.

These were the Ice Ages, a raw and challenging time.

This onslaught of climatic change had a profound impact on the land.

How did this new era of extremes shape the Europe we know today?

The Alps - the very heart of Europe.

Millions of visitors come here every year

to enjoy the exhilaration of winter...

...a glimpse of a time when much

of Europe was gripped in the big freeze.

Remnants of the Ice Ages are found right across the continent,

but this is the most spectacular...

...The Matterhorn... an iconic pyramid of rock

jutting almost 4,500 metres into the sky.

Travel back through time, over a period of

just twenty thousand years,

and the landscape was very different indeed.

An island in a sea of ice.

Only its tip would have been visible.

Back then, conditions in the

Alps and in northern Europe were extremely harsh.

Relentless icy storms swept the land.

Temperatures plunged to well below minus 50 degrees Celsius.

What triggered this climatic onslaught?

As the Earth goes about its orbit,

its pathway periodically shifts taking it closer to...

or further away from... the sun.

As well as this - in a rhythm of its own...

the Earth's axis tilts.

About two and a half million years ago

these factors combined to cause cooling in Europe's higher latitudes.

Summers became shorter...

...and winters more severe.

But cold alone does not constitute an Ice Age.

This chill was dramatically intensified by a range of other events...

one of which happened thousands

of kilometres away on the far side of the Atlantic.

As North and South America began to join,

they blocked the flow of water from the Atlantic to the Pacific,

diverting a warm, tropical current back towards Europe:

The Gulf Stream was born.

And with it came masses of moisture-laden air.

When these clouds reached the colder atmosphere of northern Europe,

they delivered enormous quantities of snow.

As temperatures plummeted, survival became increasingly hard.

A whole new cast of cold-adapted animals moved in...

rather like today's Musk oxen... with their shaggy,

windproof coats and stocky frames.

In the ever-shortening summers,

animals like reindeer too would have eked out

a living on lichens and mosses.

But as temperatures dropped below minus 40 degrees

Celsius even these hardy creatures would have

been forced south to warmer climes.

Year after year, snow built upon snow,

compacting into solid ice, engulfing the continent.

Even the sea began to freeze.

The expanse of ice acted like a giant mirror,

reflecting the sun's warmth back into space.

Colossal ice sheets up to two thousand metres

thick spread across the continent covering Siberia,

Scandinavia and Scotland.

We now know how far south the ice sheet reached,

thanks to evidence found in some surprising places.

During the construction of the London Underground

in the late 19th century,

scientists unearthed unusual sediment patterns

in the very centre of London.

They revealed that the edge of the northern ice sheet was more

or less here - at the Finchley Road tube station.

Just imagine how London might have looked about half

a million years ago when the Ice Ages were at their most extreme.

Other glacial deposits indicate that the edge

of the ice spanned the European continent...

...touching on Amsterdam...

...and also Berlin...

A freeze-up of this scale will change the whole shape of a continent.

This is the North Sea, off the coast of Holland.

Although this may seem a normal fishing trip,

these Dutch trawler men aren't after sole or plaice.

They're actually scientists on an unusual mission,

in search of a far more intriguing catch.

Among the piles of starfish, crabs and driftwood

they find the long-submerged remains of a far larger animal.

When bones like these were first hauled out more than a century ago,

they were presented to a local doctor for identification.

He declared them to be clear evidence of Noah's flood.

Whatever your belief about Noah,

the doctor was right about the flood

because these are the bones of land animals...

massive ones at that... woolly mammoths.

What are they doing in the middle of the North Sea?

During the Ice Ages the sea level was around 100 metres lower than today.

Back then the North Sea was all dry land...

its water locked up in the ice sheets

to the north and in mountain glaciers.

These Mammoth bones tell us something else, too:

Not all of Europe was buried in ice.

The North Sea was one vast green valley... a tundra.

Standing 3 metres tall and wrapped in dense fur,

woolly mammoths were well adapted to life on these cold,

grassy plains, which they shared

with relatives of today's Saiga antelopes.

Their over-sized noses help to warm the chilly air as they inhale,

and to preserve precious moisture as they breathe out.

Saigas came to Eurasia from

North America across the Bering Straits,

an important land bridge when sea levels were lower.

And with them came Przewalski's horses...

the ancestors of our modern horse.

As the climate kept changing,

the edge of the ice sheets shifted, and so did entire eco-systems.

But the most surprising ice age immigrants came from the South.

Here in London during the 1830's,

builders constructing Nelson's column in

Trafalgar Square made some extraordinary discoveries.

They unearthed the bones of some very un-ice age

and indeed un-European animals:

Hippos, rhinos, hyenas, and even lions.

Around 120,000 years ago,

Western Europe must have looked more like East Africa.

Over the past 2? Million years,

the climate has sea-sawed from subtropical to arctic and back again.

These warm "interglacial periods"...

lasting as long as 100,000 years...

have allowed plenty of time for new waves

of life to establish themselves on the continent...

before being driven back again by the next cold spell.

This thermal pulsing was rapid and extreme,

with at least 20 different climatic cycles.

Right now we're enjoying one of the warmer periods in between.

It's a sobering thought that this extreme climatic

change has not been an exception, but the rule.

The last major glacial period began 115,000 years ago.

It was to have an immense impact in shaping the continent we know today.

Back then, much of the land would have been inhospitable.

Natural shelters were highly prized.

One ice age creature totally depended on these caves: The cave bear.

In an ice age winter, deep caves were vital for hibernating bears.

But their peace... and indeed their future...

was about to be shattered by others who also sought refuge here.

Neanderthals - ice age specialists like the cave bear.

They braved the continent's harshest climate ever.

For over 150,000 years,

Neanderthals remained Europe's top predators.

But now a new force was on the move...

a force destined to have a profound impact on the continent.

Modern humans - our ancestors.

Some 40,000 years ago Homo sapiens began to advance

into Asia and Europe from their homelands in Africa...

living a nomadic existence... following the migratory herds.

For these inventive and adaptable hunters, this new land,

in spite of its harsh climate, offered a wealth of big game.

Although Neanderthals and modern humans certainly crossed paths,

in this vast continent encounters between them must have been rare.

Yet for Neanderthals, time was running out.

Their populations were shrinking.

About 30,000 years ago they vanished from the face of the land,

possibly decimated by disease or conflict

or an inability to deal with climate change.

15,000 years ago the shape of the Earth's orbit...

and the tilting of its axis...

would come to spell the end of the last great Ice Age.

In the northern hemisphere summers now became longer...

and winters less severe.

As temperatures rose rapidly in Northern Europe...

by as much as 10 degrees Celsius in less than a century...

the melt gathered momentum.

Massive volumes of water,

a hundred thousand years worth of snowfall,

cascaded off the ice sheets.

This great melt swelled vast river networks.

Old rivers found new courses where the ice had once been.

Violent torrents carried a massive cargo of debris,

filling low-lying valleys with rubble, thus creating Europe's plains.

Rivers like the Elbe and Volga would have been many times

their current size and power.

From the smaller ice caps of the

Alps and Pyrenees to the great northern ice sheets,

rivers flowed in spate.

Much of this melt water was trapped before it reached the sea.

Tens of thousands of new lakes were created.

The most impressive of them all - 18,000 square kilometres...

is Lake Ladoga on the Finnish-Russian border,

Europe's largest body of freshwater.

Free from the weight of the Scandinavian ice cap,

the land began to rise, cutting Lake Ladoga off from the sea.

Today, it is a remote natural refuge...