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The world today teems with life

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Wherever you look, something is alive

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Then imagine 95% of all this dying in one go

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It's not a fantasy. It did happen
250 million years ago

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It was the day, the earth nearly died

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The Karroo Basin in South Africa

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A region of hunting and inhospitable beauty

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This is an area where little grows
and man and beast struggle to survive

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But it hasn't always been like this

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Almost 300 million years ago

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during what scientists called the Permian period

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it was an oasis

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The scene would have been low-lying plains

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perhaps with mountains in the distance meandering 
rivers, lots of plants around the sides of 
those rivers low plants like ferns and so on

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and then in the background 
some trees of very unusual type

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This was a time millions of years
before the dinosaurs

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when strange and half forgotten creatures
walked the earth

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They were called thorapsids

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half mammal, half reptile

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The first creatures ever
to fullly conquer life on land

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In any one locality you'd find 50 or 60
different species of reptiles living side by side

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specialized on different diets,
different habitats and so on

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This is the skull of dicynodon

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It's sitting with the top of the skull
just here coming down to the snout

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This is a tortoise-like beak that sits under here

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Dicynodon was a hippo-sized plant eater

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Filled the niche of the cow in a modern day
pasture except these would live in herds
and roam around the Permian flood plains

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Its principle predator was dinogorgon,
the king of the Permian jungle

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These were real terrors.
The first time the world had ever seen
such top carnivores as they're called

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They had sabre teeth this sort of length

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and just like the famous sabre tooth cats
of much later

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They would leap on the backs
of these hippopotamus-sized plant

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just piercing through their thick skin
tearing the flesh

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For 30 million years
these strange creatures ruled the earth

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This was a thriving, stable world
as complete in its own way as ours is today

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Then, around 250 millions years ago,
almost every living thing suddenly died

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The fossil record shows that the rock beds
at the end of the Permian period
contained absolutely no fossils

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No signs of life at all

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This is the dead zone

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This zone represents what it was
like here after the mass extinction

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We have never found anything
that represents life in this zone

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This is what we would call barren

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There's no evidence of plant life
there's no evidence of soils - and
especially there's no evidence of animals

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This is completely dead

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We're going from this very rich place
to a biological desert

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Form a place that's like a rainforest
to a place that is composed of a few species
eking out an existence

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Scientists call this utter destruction of life
the Permian mass extinction

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Never in the history of the planet was there
a catastrophe that was so widespread,
so devastating and so all-inclusive

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The Permian mass extinction was
far more terrible than the later
extinction that wiped out the dinosaurs

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The dinosaurs extinction that happened
65 million years ago

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killed off maybe 60% of most
of the species on the planet

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There's still plenty of life around

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But I get the sense that were one to go back
to the Permian extinction right afterward
you would see virtually nothing of life

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At the end of the Permian era 95% of all life died

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It was the biggest reverse in the forward
march of evolution ever recorded

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Yet, until recently, almost nothing
was known about this extraordinary event

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Nobody could explain why it had happened

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or even whether it would happen again

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Scientists have spent years digging
in Permian rocks for clues

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Yet, wherever they looked they could find
no evidence of the cause of death

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No footsteps, no finger prints

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It seemed as if the killer had arrived
and departed without a trace

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Then in the early 1990s
they stumbled on something

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Buried under the frozen wastes of Siberia
are thousands of miles of lava

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It's an area known as the Siberian Traps

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Today the region is covered in snow and vegetation

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but below the surface are the ancient remains
of the biggest and most destructive volcanic
eruptions the world has ever witnessed

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250 million years ago hundreds of thousands
of square miles of Siberia caught fire

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One of the first scientists who looked at it
in detail was Vincent Courtillot

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I probably would have seen a curtain of red glowing
fire rising a mile high up in the atmosphere

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extending from end to end of the horizon
over a distance of hundreds of kilometers

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It's a phenomenon known as
a flood basalt eruption

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When the earth crusts splits apart and releases
curtains of lava across an entire continent

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The eruptions can last for millions of years

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Nobody is quite sure why they happen

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You get a huge eruption and another
and another 

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and maybe a lull and another bunch of 10 
and then another

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all together over a few hundred thousand years

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The earth is almost continuously spewing out
lava - until after a million years or so,
millions of cubic kilometers have erupted

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so this is a truly gigantic volcanic object
thousands, tens of thousands of times
larger than anything man has ever seen

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Courtillot now began to wonder what such
a volcanic monster would do to life on earth

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Were the Siberian Traps the Permian killer?

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Though nobody had ever seen a flood basalt
eruption he did have one clue

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Just over 200 years ago,
in a region of Iceland called Laki

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a tiny but similar eruption altered
the climate of the Northern Hemisphere

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Benjamin Franklin,
the America Ambassador in Paris at the time

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recorded the effect on Europe's climate

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The skies were clogged with volcanic ash

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It was a summer when the sun never shone

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Snow fell during August

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That winter was one of the worst winters
in living memory

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That winter of 1783/1784 there were
strange fogs, brown fogs

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snow, unusual amounts of snow fell and actually
the winter continued onto the next summer

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This was called the year without a summer

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There was no grape, no wine,
the wheat didn't ripen

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and actually that foul weather was observed
in North America and in Japan and China

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Using the evidence from Laki, Courtillot now
built a model of how the Siberian Traps
might have destroyed the world

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First there would have been eruptions sending
thousands of tons of dust and ashes into the sky

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Slowly the sun would have been blocked out

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and temperatures would have fallen

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First we'll enter a winter, a volcanic winter

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the dust and the sulphur will cool
the atmosphere after each eruption

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for years or tens of years

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It would have been like a nuclear winter

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lasting decades

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But that would have been just the beginning

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As the sky's cleared vast quantities
of gas given off by the burning lava

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would have slowly wrapped the earth
in a blanket of carbon dioxide

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an extremely powerful greenhouse gas

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Gradually, over thousands of years there
would have been massive global warming

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The carbon dioxide will lead to
a greenhouse effect and the cold
will be replaced by unusual hot time

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So you get the double hit,
you're cold for a while

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and then hot for a longer time

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So that altogether after a million years
the earth would be different

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The climate would be different and
a mass extinction would have happened

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It seemed as though Courtillot must
have found the cause of the extinction

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Here was a truly massive destructive event
that had happened at exactly the right time

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Yet the evidence was not
as straight forward as it appeared

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In America, geologist Peter Ward
was alos looking at the evidence

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He knew that to do so much damage
the change in world temperatures would
have had to have been rapid and dramatic

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You have to have a very sudden,
but very large increase in temperature

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to have done the mayhem and the destruction
that is this mass extinction

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Ward looked more closely at the data
from the Siberian Traps

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He estimated the amount of lava they'd produced

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and used this to calculate how much
carbon dioxide they would have emitted

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He then calculated what this would
have done to world temperatures

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We've looked at the Traps, the Siberian Traps

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we've tried to estimate how much gas
would have come out of them - and
how much warming would that have done

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and it turns out that in the worst case scenario,
and of course for the world it was a worst case

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they may have raised the temperature
of the earth about 5 ˇăC

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The geological record shows that when
world temperatures rise abruptly by 4/5 ˇăC

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many species will die

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but he could also see there was no evidence that
such an increase would wipe out 95% of all life

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His calculation showed that to do that would
require a much bigger increase in temperature,
perhaps double

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Well, scientist estimate that a rapid temperature
rise of maybe 10 ˇăC is going to be necessary to kill
off so many animals and plants and everything else

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5 ˇăC, the Siberian Traps with their 5ˇăC,
it would have created certainly climate change

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but a massive extinction? I don't think so

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It seemed there was a flaw in Courtillot's theory

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The Siberian eruption would have been deadly
but not that deadly

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Something even more catastrophic
must have been at work

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In 1998 the search for clues took American
geologist Mike Rampino to the Alps

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It's one of the only places in Europe
where there are Permian fossils

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Rampino had been trying to understand
the extinction for some years

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and thought one vital piece of information
was missing

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Nobody knew with any certainty
how long the extinction had taken

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He believed that if he could find this out
he'd have a clue to its identity

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Was he looking for a hit-and-run killer
or something slower?

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One of the things we'd like to know about the
Permian mass extinction was how rapid it was

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how long did it take for those,
all of those organisms to become extinct?

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He planed to use a radically new dating system

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It's based on the fact that the fossil
record charting the end of the Permian era
is preserved in a thin layer of rock

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If it could work out how long it had taken
for this rock to be deposited

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he'd know how long the extinction had taken

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The Permian rocks lie just below
the next geological period

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the Triassic

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This is the Permian/Triassic boundary,

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the boundary between the Permian rocks
below us and the Triassic rocks above us

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and this is the boundary
where the mass extinction takes place

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What we're trying to do here is to determine how
long it took for the sediments at the boundary in
which the mass extinction took place to be deposited

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Rampino's system relied on the observation
that the earth's orbit round the sun
alters minutely every 23,000 years

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This produces small changes in the climate

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This, in turn, produces distinctive bands
in the rock one every 23,000 years

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Rampino took photos of the rock bands

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and fed them into a laptop

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When I digitally enhance the photographs
I can manipulate the data
to bring out the 23,000 year cycle

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and that gives me a time-frame in which
to put the mass extinction

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It's like a giant tape measure dividing an entire
mountain into a series of 23,000 year divisions

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Rampino then fitted the layer of rock
containing the evidence of the extinction
into this pattern of cycles

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It covered less than half a cycle, 8,000-10,000 years,
far faster than anyone had thought possible

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What this tells me is that the mass extinction
took place in an astonishingly short period of time

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less than 10,000 years and possibly instantaneously

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This means that that mass extinction
was catastrophic

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To have destroyed so much of life so quickly
the killer must have been extraordinarily violent

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Rampino could think of only one thing it could be

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A mass extinction that happens at less
than 10,000 years is very abrupt

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It fits the picture of a large impact
at the end of the Permian

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Rampino was now convinced a huge meteor had
slammed into the earth 250 million years ago

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Shockwaves would have raced around the globe
instantly killing everything within hundreds of miles

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When an asteroid or comet that large hits the earth
it's the equivalent of a billion atomic bombs
going off at the same time in the same place

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Almost immediately afterwards millions of
tons of dust would have shut out of the sun

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It would all have happened very rapidly

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much faster than the climate changes
caused by a flood basalt eruption

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Temperatures would have plummeted
almost overnight

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Makes a huge crater and throws a tremendous
amount of dust and debris up
into the earth's atmosphere

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and you end up with a catastrophic situation
for life on the planet

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Rampino's calculation suggested this would've been
a far bigger, harsher, more rapid nuclear winter
than anything the Siberian Traps could have caused

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Life would have rapidly become almost impossible

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A meteor from outer space
sounds like science fiction

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but there has been a similar case

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Most scientists now accept that 65 million years ago
the dinosaurs were wiped out by just such an event

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but the Permian meteor
would have been even bigger

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The asteroid that hit the earth at the time of the
dinosaur extinction was at least 10km diameter

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The Permian mass extinction
is even more severe

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so the asteroid that hit it that time must have
been even larger, perhaps 15km in diameter

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It seemed the perfect answer

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A meteor the size of Manhattan
had wiped out most of life on earth

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Yet something didn't add up

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Nothing that size could hit the earth
and not leave a trace

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The meteor that had wiped out the dinosaurs had
left a giant fingerprint in the shape of a crater

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just off the coast of Mexico
where was the Permian crater

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No matter where they looked nobody could
find anything dating from the Permian era

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but then a scientist from London
came up with a totally new idea

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Adrian Jones models the effects
of impacts on the earth's crust

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He now suggested geologists
were searching for the wrong thing

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In a conventional view of an impact

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we have a high speed asteroid which
hits the earth's crust

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and makes a crater instantaneously which is very deep
Immediately after the crater is formed
this deep shape the compressed rock

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underneath the crater rebounds

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and the crater expands
to be a much shallower shape

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So under normal circumstance there
would be a large shallow crater

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but Johns believes that when a really massive
meteor hits the earth something else happens too

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What we think happens is that in addition
to the energy from the asteroid itself

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an enormous amount of energy is released
when the crater here is transforming
back to its shallow shape

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John's theory is that as the crust rebounds from
the impact of the meteor it generates far greater
quantities of heat than anybody had thought possible

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He built a computer model to see what
would happen to a crater if this occurred

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The impact causes a deep crater

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This rebounds to create a wider, shallower one

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but then if the meteor is very large
something new happens

219
00:24:34,385 --> 00:24:38,604
It melts the earth's crust
and lava is released

220
00:24:42,151 --> 00:24:49,039
And the final part of the model shows
that lava has filled the crater and
flowed beyond the edges of the crater

221
00:24:49,040 --> 00:24:55,310
and the original crater structure
we can see the walls here is completely
drowned by the large volume of lava

222
00:24:55,311 --> 00:24:59,842
so that there's no outward shape
of the crater visible from the surface

223
00:25:06,362 --> 00:25:11,019
It meant the Permian crater
would have entirely filled with lava

224
00:25:11,020 --> 00:25:15,267
The reason nobody had found a crater
was because there wasn't one

225
00:25:19,938 --> 00:25:22,399
It was a fascinating idea

226
00:25:22,400 --> 00:25:25,291
but was it also too neat?

227
00:25:31,670 --> 00:25:36,629
When a large meteor hits the earth
it leaves more than one fingerprint

228
00:25:38,836 --> 00:25:45,687
It also leaves a trail of shattered
rock and dust which are blasted around
the globe by the force of the collision

229
00:25:48,933 --> 00:25:53,895
If John was right the Permian meteor
should have left similar traces

230
00:25:58,271 --> 00:26:02,713
But despite looking in Permian rocks
the length and breadth of the planet

231
00:26:02,714 --> 00:26:05,252
nobody could find a single trace of the meteor

232
00:26:13,204 --> 00:26:16,651
Greg Retallack was one of those
involved in the search

233
00:26:17,215 --> 00:26:19,950
He concentrated his efforts in Antarctica

234
00:26:23,507 --> 00:26:26,221
There was definitely a missing piece
to this whole thing

235
00:26:26,222 --> 00:26:32,503
and we struggled with, to find out what
that was and the clue was in front of us
actually for quite some time

236
00:26:35,677 --> 00:26:39,965
In the middle 1990s,
he led an expedition to see what was there

237
00:26:42,161 --> 00:26:47,248
It was really the trip of a lifetime and it was
something I'd wanted to do for about 15 years before

238
00:26:48,995 --> 00:26:52,479
The team spent weeks exploring the Permian rocks

239
00:26:52,480 --> 00:26:56,115
but one bed of rock in particular
attracted his attention

240
00:26:58,489 --> 00:27:05,078
We knew it was the very latest Permian bed
and inside that bed there were quartz grains
that had some very unusual features

241
00:27:06,740 --> 00:27:09,571
Quartz is the most common crystal on earth

242
00:27:09,572 --> 00:27:12,759
It's most frequently white and translucent

243
00:27:16,883 --> 00:27:23,486
Most of the quartz is just like this grain that
I'm on now and it's a very clear grain

244
00:27:24,193 --> 00:27:27,543
Looking through the microscope the light
shines through it brightly, it looks white

245
00:27:30,021 --> 00:27:33,384
But some of these crystals weren't white or clear

246
00:27:39,115 --> 00:27:47,502
This quartz had a very strange set
of parallel fracture-like fused planes
running through it at several angles

247
00:27:49,893 --> 00:27:52,386
Something had shuttered the quartz

248
00:27:56,916 --> 00:28:01,917
Retallack knew that only a force of
enormous size could create these patterns

249
00:28:06,408 --> 00:28:09,519
It seemed there must have been a huge meteor

250
00:28:19,476 --> 00:28:23,890
It looks as though he had found the traces
everybody had been looking for

251
00:28:29,109 --> 00:28:32,505
Yet again, something didn't fit

252
00:28:36,594 --> 00:28:41,374
As Retallack looked further at
the new evidence there was a surprise

253
00:28:43,914 --> 00:28:48,960
The meteor that had wiped out the dinosaurs
had left huge quantities of shattered quartz

254
00:28:50,049 --> 00:28:53,759
It had also left traces of a metal mainly
found in outer space called iridium

255
00:28:53,760 --> 00:28:57,469
It's a common component of meteors

256
00:29:00,669 --> 00:29:06,011
When a meteor wiped out the dinosaurs 65 million
years ago it left abundant evidence of itself

257
00:29:06,012 --> 00:29:11,548
There's a thin deposit of rocks that fell out
of the atmosphere after this huge explosion

258
00:29:11,549 --> 00:29:15,072
and it has within it

259
00:29:15,073 --> 00:29:18,595
bits of quarts that are shattered by the pressure and
it has iridium which came from the asteroid itself

260
00:29:19,570 --> 00:29:24,760
Yet Retallack's samples contained
very little of either of these materials

261
00:29:25,689 --> 00:29:30,823
One would expect if the meteor solution
was the whole answer

262
00:29:30,824 --> 00:29:36,914
that we would get a bigger input of shot quartz
and iridium at the Permian/Triassic boundary

263
00:29:37,824 --> 00:29:39,914
that at the one where the dinosaurs went extinct
and it was the other way around

264
00:29:41,059 --> 00:29:45,827
No traces of iridium dust and
not much shattered quartz

265
00:29:47,094 --> 00:29:48,621
It didn't add up

266
00:29:50,889 --> 00:29:57,729
For a meteor to kill 95% of all life on earth
it should have been the size of Manhattan

267
00:30:01,265 --> 00:30:06,558
Yet the evidence suggested that if there
had been a meteor at the end of the Permian era

268
00:30:06,559 --> 00:30:09,760
it had been far too small to destroy the world

269
00:30:14,290 --> 00:30:18,913
The Permian killer had, once again,
eluded scientists

270
00:30:27,971 --> 00:30:33,805
Paul Wignall, a geologist at the University of Leeds,
had always been doubtful about the meteor theory

271
00:30:35,624 --> 00:30:40,355
It's a nice theory,
it nicely explains the end of the dinosaurs

272
00:30:40,356 --> 00:30:43,868
in the later extinction event,
but for this particular extinction
I just don't think there's any convincing

273
00:30:46,553 --> 00:30:52,359
Wignall suspected all the explanations for the
extinction had been based on insufficient data

274
00:30:54,435 --> 00:30:57,734
He also knew there was one place
he might find more

275
00:31:01,102 --> 00:31:02,609
Greenland

276
00:31:03,894 --> 00:31:07,198
It's a country known to contain Permian rock

277
00:31:07,199 --> 00:31:10,108
but always considered too difficult to explore

278
00:31:16,125 --> 00:31:20,579
In the late 1990s he took a gamble
and flew out there

279
00:31:26,751 --> 00:31:30,001
Piled all our stuff onto a helicopter,
flew out into this wilderness

280
00:31:30,002 --> 00:31:33,859
they dropped us in the middle of nowhere
and left us there for several weeks

281
00:31:41,890 --> 00:31:45,377
Their first task was to find the Permian rock

282
00:31:45,411 --> 00:31:47,592
Nobody even knew where it was

283
00:31:51,046 --> 00:31:55,191
Some of us had never been there before and
we weren't exactly sure where we needed to look

284
00:31:55,192 --> 00:31:59,977
We had a lot of exploration,
a lot of wandering around to do before
we knew what we were looking for

285
00:32:04,353 --> 00:32:07,646
But finally they found what they had come for

286
00:32:10,442 --> 00:32:13,150
It exceeded their widest dreams

287
00:32:14,561 --> 00:32:17,916
Instead of the usual narrow band of rock strata

288
00:32:17,917 --> 00:32:22,758
the sediments containing the record of the extinction
stretched for meters above and below them

289
00:32:25,630 --> 00:32:30,458
It was one of the best records of
the Permian mass extinction ever found

290
00:32:35,165 --> 00:32:38,634
We were astounded by just how much,
how much cliff there was to examine

291
00:32:38,635 --> 00:32:45,203
The whole Permian extinction story seemed to
be spread through tens of meters of cliff

292
00:32:45,204 --> 00:32:48,308
and the fossils that we could collect
were showing us a beautiful

293
00:32:48,309 --> 00:32:54,267
detailed story that was telling us a lot more
than we'd known previously about the timing
of what was going on at this time

294
00:32:57,117 --> 00:32:58,493
Yeah. come ... Yeah

295
00:33:23,924 --> 00:33:28,375
Even to the naked eye,
one thing was blindingly obvious

296
00:33:28,392 --> 00:33:31,306
The meteor theorists had got the timing wrong

297
00:33:31,864 --> 00:33:36,612
The Greenland rock showed that
the extinction had been a gradual event

298
00:33:40,443 --> 00:33:45,093
In fact, it appeared to drag on
for tens of thousand of years

299
00:33:47,779 --> 00:33:54,533
We could see that the extinction
wasn't occurring instantaneously,
but in fact was spread over several,

300
00:33:54,534 --> 00:33:57,738
a certain amount of rock, so we could see it
was being spread over a certain amount of time

301
00:34:01,752 --> 00:34:04,642
Wignall now suspected he was onto something big

302
00:34:07,396 --> 00:34:10,826
The expedition spent a month amassing samples

303
00:34:13,356 --> 00:34:16,776
They shipped back 20 crates of rock to Britain

304
00:34:20,904 --> 00:34:25,969
It seemed at last that the Permian killer
might reveal its secret

305
00:34:36,681 --> 00:34:42,071
Back in Leeds, Wignall realized he'd stumbled
on a treasure trove of fossils

306
00:34:43,063 --> 00:34:46,614
Buried in the rock samples were thousands of them

307
00:34:46,615 --> 00:34:50,166
Many so small they had to
be extracted in an acid bath

308
00:34:51,068 --> 00:34:54,090
His team was overwhelmed by what they'd got

309
00:34:56,425 --> 00:35:01,831
We were so excited with this story that
we were working weekends and just buckets
and buckets of rocks all being broke down

310
00:35:01,832 --> 00:35:05,581
we, excitingly we were just sieving them through,
getting all the fossils out

311
00:35:06,561 --> 00:35:12,218
Wignall's sediments began to reveal the most 
detailed account of the extinction ever uncovered

312
00:35:12,740 --> 00:35:16,062
There was just a huge range
of little tiny fossils in these rocks

313
00:35:16,063 --> 00:35:19,716
which were telling us in fantastic detail just
what was going on at this time

314
00:35:19,717 --> 00:35:24,920
and there was no need to guess anymore, we could
actually see the order in which things were

315
00:35:24,921 --> 00:35:28,527
going extinct and get the full extinction story right
from the beginning all the way through to the end

316
00:35:30,286 --> 00:35:34,730
For the first time he was able to work out
exactly what had happened

317
00:35:36,432 --> 00:35:38,687
It was a complete surprise

318
00:35:41,626 --> 00:35:45,579
The extinction had occurred in 3 distinct phases

319
00:35:47,051 --> 00:35:49,446
The extinction crisis first begins on land

320
00:35:49,447 --> 00:35:53,659
and what we see is species of plants,
species of animals start disappearing

321
00:35:55,180 --> 00:35:58,048
about 40,000 years this goes on for

322
00:36:00,854 --> 00:36:03,067
This was the first phase

323
00:36:03,068 --> 00:36:07,764
a period when some, but by no means all,
land species died

324
00:36:09,555 --> 00:36:18,685
And then what happens next at about 40,000-45,000 years
after the crisis has begun is that we see a really
quite sharp, abrupt extinction in the seas at this time

325
00:36:19,355 --> 00:36:24,844
so this is the marine extinction event, much
shorter and sharper than what we see on land

326
00:36:27,071 --> 00:36:32,792
So the second phase of the extinction was the
abrupt death of virtually everything in the sea

327
00:36:34,581 --> 00:36:36,653
Then came the third phase

328
00:36:36,654 --> 00:36:39,524
as the extinction moved back to the land

329
00:36:40,793 --> 00:36:44,478
Following on from that we then see
the culmination of the land extinction

330
00:36:44,479 --> 00:36:48,276
so we start losing all our typical plants
and all our typical animals as well

331
00:36:51,117 --> 00:36:58,626
and this carries on to a point of about
80,000 years after the extinction began

332
00:37:01,611 --> 00:37:07,671
Three long, slow phases,
sprawled over at least 80,000 years

333
00:37:08,789 --> 00:37:12,125
very different from how
the meteor theorists had seen it

334
00:37:16,740 --> 00:37:23,132
Yet Wignall was still no closer to understanding
why it had happened or what the killer was

335
00:37:26,307 --> 00:37:28,444
but he had found a clue

336
00:37:32,924 --> 00:37:39,724
Analysis of the rock showed that just after
the marine extinction but before
the final death of everything on the land

337
00:37:40,924 --> 00:37:45,724
there was a mysterious increase in a form of carbon,
called carbon 12

338
00:37:47,587 --> 00:37:56,651
This is normally produced by rotting plant and
animal matter, but this was a huge increase,
too big to be explained by that alone

339
00:38:03,564 --> 00:38:13,253
Wignall realized that here was a fresh piece of
evidence, something that, if he could understand
it might provide the key to the Permian riddle

340
00:38:14,757 --> 00:38:21,998
The Carbo12 increase is clearly telling us something.
It's a clue to the nature of the Permian extinction.

341
00:38:22,757 --> 00:38:28,998
There's something mysterious going on at this time,
but exactly what it is not immediately apparent

342
00:38:33,799 --> 00:38:38,171
The key to the puzzle would come from
a totally unexpected quarter

343
00:38:44,594 --> 00:38:48,215
Gerry Dickens is a geologist
working on new sources of energy

344
00:38:49,133 --> 00:38:52,254
He had no special interest in the Permian extinction

345
00:38:52,903 --> 00:38:57,340
but one evening, sitting in a bar,
he ran into a friend

346
00:38:59,684 --> 00:39:02,389
We were just sort of chatting about
what we were working on for the summer

347
00:39:03,684 --> 00:39:06,825
and he was telling me that he was working on
trying to understand how you could get

348
00:39:07,684 --> 00:39:11,825
massive of 12 carbon quickly because some
signatures had been found in the rock records

349
00:39:12,684 --> 00:39:15,825
and it was very difficult to explain,
it didn't make any sense

350
00:39:18,151 --> 00:39:20,040
Dickens was curious

351
00:39:21,151 --> 00:39:29,040
Several years earlier he'd spent time on a drilling
rig in the Gulf of Mexico prospecting for
a new source of energy called methane hydrate

352
00:39:31,858 --> 00:39:36,389
It's a gas frozen in huge reservoirs
just below the seabed

353
00:39:39,550 --> 00:39:43,571
Dickens knew this methane contained
massive quantities of carbon 12

354
00:39:44,550 --> 00:39:50,571
He also knew there were dozens of these methane
hydrate reservoirs scattered around the world's coasts

355
00:39:54,762 --> 00:40:00,257
We find 'em for instance along the coast
of south America, along central America

356
00:40:00,762 --> 00:40:06,257
all along the western coast of the US and Canada,
indications round Australia, Indonesia

357
00:40:06,762 --> 00:40:14,257
essentially anywhere along continental margins
where you get a lot of organic matter that
decays at the bottom and produces methane

358
00:40:20,599 --> 00:40:28,349
Could these massive reservoirs of methane,
he now wondered, be the source of the carbon 12
found in Permian rocks

359
00:40:28,599 --> 00:40:32,349
and if it was, how did it get there?

360
00:40:34,404 --> 00:40:36,443
Dickens started to investigate

361
00:40:39,618 --> 00:40:48,220
Naturally occurring frozen methane
is unstable and difficult to extract,
so samples were artificially created in a lab

362
00:40:52,638 --> 00:40:58,163
The big question is try to get methane from
deep down in the ocean up to the atmosphere

363
00:41:00,877 --> 00:41:04,643
He put blocks of the man-made methane
into warmed water

364
00:41:08,409 --> 00:41:13,708
The results were spectacular
So it's disassociating deep down

365
00:41:15,924 --> 00:41:22,816
Dickens found that even small pieces
of frozen methane released enormous
quantities of gas rich in carbon 12

366
00:41:24,884 --> 00:41:27,744
The experiment supported what he'd suspected

367
00:41:28,705 --> 00:41:34,422
the increase in carbon 12 could be
the fingerprint of a massive methane release

368
00:41:36,838 --> 00:41:39,216
He found something else as well

369
00:41:40,923 --> 00:41:47,443
It would only take a small increase
in water temperatures to melt the
methane and release the carbon

370
00:41:48,920 --> 00:41:59,373
To explain the amount of carbon 12 that we see in
the geologic record we need to warm up the bottom
water by somewhere in the order of about 5 ˇăC

371
00:42:01,519 --> 00:42:04,061
He published his results in 1999

372
00:42:05,302 --> 00:42:08,132
He couldn't have anticipated their effect

373
00:42:18,511 --> 00:42:24,975
5,000 miles away in England, however, Paul Wignall
read Dickens's findings with growing interest

374
00:42:27,473 --> 00:42:34,538
Suddenly realized that in fact a lot of
his ideas as to how to explain carbon 12
increases may actually apply to the

375
00:42:35,473 --> 00:42:41,538
story we're getting from Greenland. It's a kind of a
missing link in the story for the Permian extinction

376
00:42:45,369 --> 00:42:47,666
Wignall now began to speculate

377
00:42:49,911 --> 00:42:53,854
What would be the effect
on the world's climate of so much methane?

378
00:42:55,287 --> 00:42:58,898
It's one of the most potent greenhouse gases
known to man

379
00:43:03,300 --> 00:43:09,594
Wignall constructed a rough climate model using the
carbon 12 as a guide to the quantities of methane

380
00:43:11,745 --> 00:43:17,511
It's not that straightforward to work out
just how significant the impact of this methane
release would be

381
00:43:17,745 --> 00:43:25,511
but it's possible to work out the volumes emitted
using the evidence from the carbon 12 increase

382
00:43:25,745 --> 00:43:33,511
and these certainly suggest that there may have been
sufficient methane going into the atmosphere to
perhaps increase global temperatures by 4/5 ˇăC

383
00:43:36,922 --> 00:43:46,030
4/5 ˇăC, not enough to kill the world, but then
Wignall realized this was only part of the story

384
00:43:47,750 --> 00:43:53,846
For the methane to melt something must already
have raised world temperatures 4/5 ˇăC

385
00:43:54,360 --> 00:44:00,275
The methane would then have raised them
a further 5 ˇăC more to a total of 10 ˇăC

386
00:44:01,190 --> 00:44:05,586
This would have been more than enough
to kill practically every living thing

387
00:44:09,669 --> 00:44:18,824
Wignall slowly realized what the evidence
from Greenland was telling him.
There had not been one Permian killer, but 2

388
00:44:24,384 --> 00:44:31,191
Paul Wignall now put together
the extraordinary story of what might
have happened 250 million years ago

389
00:44:32,532 --> 00:44:36,813
It started, as many had thought,
with the Siberian Traps

390
00:44:41,105 --> 00:44:45,986
Thousands of miles of lava flows would have
burst from cracks deep in the earth's crust

391
00:44:46,985 --> 00:44:49,328
This was the first killer

392
00:44:52,543 --> 00:44:58,054
Imagine the world for dicynodon as he crawls out
of his hole in South Africa and looks at the sky

393
00:44:58,543 --> 00:45:04,054
It may be a bit purple, it may be
a bit blue or red because of the very
distant volcanic eruptions in Russia

394
00:45:04,543 --> 00:45:10,054
He may feel it a bit warmer at first. Year by
year progressively this gets worse and worse

395
00:45:11,569 --> 00:45:14,180
There would have been a freezing winter

396
00:45:16,477 --> 00:45:19,670
followed by slow but steady global warming

397
00:45:21,101 --> 00:45:25,109
Gradually the world would have
heated up by 4-5 ˇăC

398
00:45:28,039 --> 00:45:31,071
On land some species died

399
00:45:35,785 --> 00:45:41,187
Then the sea must have headed up.
Marine life would also have died

400
00:45:44,932 --> 00:45:47,239
Then something new happened

401
00:45:50,433 --> 00:45:54,192
The hotter water would have released
the second killer from the deep

402
00:45:55,128 --> 00:45:56,384
the methane

403
00:46:11,931 --> 00:46:18,734
This huge injection of greenhouse gas now
pushed world temperatures up a further 5 ˇăC

404
00:46:20,094 --> 00:46:23,576
The world was now 10 ˇăC hotter

405
00:46:24,094 --> 00:46:26,576
A temperature rise of 10 ˇăC
may not sound very much

406
00:46:27,094 --> 00:46:30,576
but 10 ˇăC would mean this part of the south
of England would turn into the Sahara desert

407
00:46:36,313 --> 00:46:42,818
Almost all life in every shape and form across
the surface of the globe would have died

408
00:46:47,340 --> 00:46:54,618
Here at long last was an explanation
that tied up all the loose ends and
accounted for all the evidence

409
00:46:55,909 --> 00:47:01,258
The cause of the Permian mass extinction
may finally have been found

410
00:47:11,123 --> 00:47:16,799
It would take nearly 100,000 years
for life on earth to begin to recover

411
00:47:18,406 --> 00:47:26,033
When it did, a new family of creatures ruled the world.
This was the birth of the age of the dinosaurs

412
00:47:37,213 --> 00:47:44,997
but geologists have found that one of the strange,
half mammal/half reptiles of the Permian world
did survive

413
00:47:52,418 --> 00:47:56,394
It was a cow-sized plant eater called lystrosaurus

414
00:48:01,771 --> 00:48:07,792
This strange looking creature is one of the most
important animals that ever walked the earth

415
00:48:08,471 --> 00:48:15,939
because lystrosauras was the ancestor
of all mammals and so, ultimately, of us

416
00:48:17,821 --> 00:48:27,459
We're only here today because this
odd looking creature somehow clung to life
during the mother of all distinctions

417
00:48:27,821 --> 00:48:32,459
Transcription by Hattie