The Climate Wars 1 of 3 Fight for the Future 2008 subtitle

In 1972, a group
of eminent scientists
sat down to write a letter to
the President of the United States.
They were frightened.
The Earth's climate
seemed to be going haywire.
They worried that war, pestilence
and famine were on the way.
For the first time, climate change
had become a hot political topic.
The letter warned the President
he had to prepare
not for global warming,
but for the complete opposite -
a new ice age.
Yup, 36 years ago,
a lot of leading scientists
really thought that an ice age
was just around the corner.
And yet today, they're all
apparently convinced
that global warming is
the big threat.
But if scientists were
so wrong back then,
how can we be sure
they've got it right today?
In this series, I'm going to
explore some simple, big questions.
How do we know
the climate is warming up?
How do we know
humans are causing it?
And how do we know
what's going to happen next?
As the story
of global warming has unfolded,
we've learnt of the very nature
of scientific truth
and about how
that has been falsified,
manipulated, twisted,
and even bought.
manipulated, twisted,
and even bought.
As close to scientific
fraud as you can get.
This is the story of how science
discovered global warming...
.. perhaps the greatest
challenge we've ever faced.
Whoa! Yes!
That was a bumpy landing!
This is me, lain Stewart, geologist,
and lecturer at Plymouth University.
Oh, look!
Little crystals.
Oh, we don't want to know.
But I'm also a husband and a dad,
so I've got a professional and a
personal interest in global warming.
That there, that's limestone...
I don't care!
.. that there's a sandstone.
I don't care!
And that is... You don't care.
Whoa, watch it.
You know, the kids tease me that
geology is just boring old rocks,
but what they don't get - well,
not yet at least -
is that it's really about how
the planet works.
is that it's really about how
the planet works.
is that it's really about how
the planet works.
I don't think you can be
interested in that,
and not be worried about
what kind of future they're in for.
I'm used to studying how the planet
changes over millions of years -
I'm used to studying how the planet
changes over millions of years -
the gradual wearing down
of cliffs by the sea,
the remorseless drift
of the continents,
the slow building of mountains.
The idea that something is happening
that could fundamentally change
the planet within my kids' lifetime
is extraordinary
and actually quite frightening.
But there's another reason
why I'm fascinated
by the scientific
discovery of global warming.
It's a story where many
of the key developments
fit into my own lifetime.
It begins back in 1970s,
when I was just a little kid.
The way I remember,
pretty well everything
was depressing in the '70s.
The haircuts were dodgy, the films
were mostly disaster movies...
.. and Britain was in
a state of near anarchy.
Everything was falling apart.
Including the planet.
Earth was running out of resources,
acid rain was killing
the lakes and forests...
.. overpopulation was going
to lead to mass starvation.
This was a time of ecological
doom mongering on an epic scale.
'Harriett, look at this.
'Just about everyone we know
is a polluter!'
If you asked me now what
the chances are of civilisation
reaching the turn of the century, I'd
have to say 1 or 2% if we're lucky.
And there was one more scare story -
The threat of a new ice age.
In 1974, this major
BBC documentary explored
the conviction of some scientists
that ice was on the march.
Besides the risk
of somewhat cooler weather
in the decades ahead,
there's the ever-present threat
of a big freeze.
there's the ever-present threat
of a big freeze.
'We should be preparing ourselves
for a long period of colder seasons. '
'Already the Russians are building
ice breakers as fast as they can. '
'Will a new ice age claim our lands
and bury our northern cities?'
Unless we learn otherwise,
it would be prudent
to suppose that the next ice age
could begin to bite at any time.
It didn't turn out quite like that,
did it? The world didn't end.
You have to say in the 1970s,
the environmentalists
were wide of the mark on
quite a few counts.
When it comes to the
question of the next ice age,
When it comes to the
question of the next ice age,
even the scientists got it wrong.
But that doesn't mean to say
that the science was bad.
For years, climate scientists had
been doing what scientists do...
.. Gathering data,
collating it, analysing it.
And they'd noticed something.
The planet was cooling down.
In the 1960s, Britain shivered
as a succession of bitter winters
followed one after another.
followed one after another.
A barrier of snow
on one main road
defied even the snow ploughs.
Squads of workmen
had to tackle it the hard way.
It wasn't just Britain.
Scientists had linked together
weather reports
from around the world,
and it seemed clear
Britain's cold winters
were part of a global trend.
And there was a theory to explain
why the Earth was cooling.
And there was a theory to explain
why the Earth was cooling.
Because this was the era
of King Coal.
Throughout the 1950s and '60s,
the world economy boomed.
Power stations poured
smoke into the air.
And before global warming
came along, burning fossil fuel
was responsible for a very
different climate-scare story...
.. Global cooling.
A drop in temperature large enough
to cause a new ice age.
But how could pollution
lead to cooling?
The theory was simple.
Smoke from power station chimneys
formed a layer of sooty particles
Smoke from power station chimneys
formed a layer of sooty particles
Smoke from power station chimneys
formed a layer of sooty particles
in the atmosphere.
These particles blocked some of the
sun's rays from reaching the Earth,
leading to a slightly dimmer,
and therefore cooler, planet.
It seemed to make perfect sense.
Some of the brightest
young scientists of the day
signed up to the new theory.
One of them was Steve Schneider.
In a famous paper in 1971, he said
that global temperatures could
decrease by over three degrees.
And he pointed out that if this
happened, it could be enough
to trigger a new ice age.
It all seemed to fit together.
The climate was cooling, and
there was a theory to explain why.
But it didn't last.
There's a saying in science,
along the lines of,
"There's nothing so sad
as a beautiful theory
destroyed by an ugly fact. "
And in 1976,
along came an ugly fact.
The summer of 1976
broke all records.
MUSIC: "Heat Wave" by Linda Ronstadt
'Blazing heat
and woodland fires
'have destroyed hundreds of acres
of Surrey in the last two days. '
'If water isn't saved in
the home, jobs will be affected. '
At it happens, I remember
the summer of 1976 really well.
I was 12 and I was on
a family holiday to Llandudno.
And I remember it for two reasons.
One was that my brother
got pooed on by a seagull.
Still makes me chuckle!
But the second was,
it was just so damn hot!
And not just here.
Across the world, 30 years
of cooling came to an abrupt end.
The planet began to warm up.
And as the warming trend
strengthened, it became clear
that the science behind
the ice-age theory was flawed.
For the scientists who had been
associated with the coming ice age,
it was a chastening experience.
Well, nobody likes to be wrong,
But remember, I never said,
"I predict that we're gonna
induce an ice age. "
What I said was, "Under these
assumptions, this is what you get. "
Other scientists say
that could trigger an ice age.
You know, it's easy
to criticise Schneider,
but to me, there was nothing
wrong in what he did.
This is how science works.
You've got a theory,
you look for evidence,
if the evidence doesn't fit,
you change the theory.
The ice-age theory was based
on what was known at the time.
When new data came in,
Schneider changed his mind.
With cooling off the agenda,
the question now was very different.
Why was the planet warming up?
For many years,
a group of scientists
had been working
on an alternative theory
about what was happening
to the climate.
Now, their time had come.
The roots of this alternative theory
lay with an obsessional genius
by the name of Dave Keeling.
If the scientific discovery
of global warming has a hero,
then Keeling is probably it.
MUSIC: "California Dreamin'"
by The Mamas And The Papas
In 1956, a young Dave Keeling
arrived here,
at San Diego's premier
academic institution -
the Scripps Institution
of Oceanography.
Keeling had a simple desire -
to be outside.
Preferably
in wild and beautiful places.
It's not unlike the reason
that I took up geology.
The difference is that unlike me,
Keeling turned into
a genuine, scientific hero.
As a kid, Keeling put together
a lovingly crafted scrapbook
of photographs from around
the world that inspired him.
Now, as a researcher, he looked for
a way to combine his love of science
with his love of the outdoors.
And in the late 1950s, he found it.
He would focus on a problem that
scientists were just beginning
to worry about - measuring the level
of carbon dioxide in the atmosphere.
Studying carbon-dioxide levels
in the atmosphere
had little to commend itself
to an ambitious, young scientist.
But Keeling didn't care.
He got the chance to throw his
sleeping bag in the back of the car
and take off to all these
amazing locations,
all in the name
of scientific research.
So off he went,
visiting all sorts
of wonderful places,
all in an apparently obscure quest
to measure carbon-dioxide levels
in the atmosphere.
It may not have attracted
much attention at the time,
but Keeling's project
turned out to be
one of the most important pieces of
scientific research ever conducted.
Keeling died in 2005, but today
his son Ralph continues his work.
Keeling died in 2005, but today
his son Ralph continues his work.
So how did Keeling senior
measure carbon dioxide?
This is a hollow, glass sphere
wrapped in tape, this snaky thing
is a valve for opening or closing.
It's like a stop cock.
It is in fact a stop cock.
The flask is evacuated in the lab,
so all the air that's in it
is sucked out of it.
So it's a vacuum?
It's a vacuum in here right now.
And then one simply ships this
or carries it to a location
where one wants to get an
air sample, and you hold it up
and you expose it to the atmosphere.
Now the tricky bit,
the only really tricky bit
is to make sure you don't
contaminate it,
either by having something nearby
like a car or your own breath,
so attention has to be given
to obtaining a clean sample.
Of course, air coming out
of your mouth could get in there.
So do you just not breathe in? Yeah.
Shall I show you how it works?
Does it take long?
No, no, it's quite simple.
You simply face into the wind,
hold your breath...
HISSING
So there we have the sample.
I heard it. I can tell it's full.
But it turned out getting the
sample of air was the easy bit.
Much trickier was working out how
much carbon dioxide was in there.
Others had tried to do it before,
but their figures differed wildly.
The key to Keeling's success was
his obsessive attention to detail.
This was a man who kept logs of all
his phone calls throughout his life.
Even as a young boy,
he kept a meticulous record of his
watering rota in the family garden.
Now he brought all
his obsessive analytical zeal
to the problem of how much
carbon dioxide
was inside his flasks of air.
He abandoned the hills,
and moved into a lab.
And rather magically, it turns
out his equipment is still here.
This is pretty much the exact
apparatus that Keeling used
to extract carbon dioxide
and to measure
its concentration in the atmosphere.
It may look like a museum piece,
but this works.
In fact, all the modern instruments
that measure carbon dioxide
are calibrated
or standardised with this.
In 1958, Keeling's complicated
network of glass tubes
delivered the first truly accurate
measure of how much carbon dioxide
was in the atmosphere.
It was a technical triumph.
But Keeling wasn't satisfied.
more and more carbon dioxide
into the atmosphere -
from cars, power stations,
into the atmosphere -
from cars, power stations,
factories and aircraft.
He wondered if this meant that the
level of carbon dioxide in the air
would change over time.
The only way to find out
was to keep doing his measurements,
year after year.
Not everyone could see the point.
Over the years, there were many
attempts to cut his funding.
But Keeling battled on.
He saw the value of keeping it
going because it was documenting
He saw the value of keeping it
going because it was documenting
an essential phenomenon of the time.
Creating a baseline against
which you compare other processes.
Right. If he hadn't stuck with it
we wouldn't have that record.
And I don't think
the rest of the community
appreciated as well as he did
that this was going to be something
people would look back to and say,
"Wow, that was important".
So he already had a vision
of people like us
talking about him 50 years on.
I think he was really playing to an
audience a generation or two later.
In that sense, he
was out of his time.
What Keeling's dogged persistence
led to was one of the most iconic
images in the whole global warming
debate - a graph.
And this is what Keeling produced.
His measurements started in 1958
at 315 parts per million
carbon dioxide in the atmosphere.
And the first thing you notice
is the rise and fall each year
which is the seasonal variation
in carbon dioxide.
Even in these early years,
you can spot a rising trend,
but you only get a true picture
of the power of this graph
when you track the changes
through the decades.
when you track the changes
through the decades.
Here, today - 2008,
we're at 386 parts per million.
This relentless year-on-year rise
in carbon dioxide
is the one undisputed piece
of evidence
in the whole
global warming debate.
It meant that nobody could
argue with one simple statement -
the human race has steadily
increased the amount carbon dioxide
in the air.
The significance of Keeling's
discovery is simple,
because carbon dioxide
is a remarkable gas.
I can show you how carbon dioxide
affects the Earth's climate
using this heat-sensitive
camera which is purring away here,
a candle, this glass tube,
which is hooked up
to this rather large
canister of carbon-dioxide gas.
Now, if I light the candle
you'll see that on the monitor
the camera picks up
the flame perfectly, look at that,
the hottest bits are glowing white.
Now watch what happens when
I turn on the carbon dioxide.
Just keep your eye on the flame.
The gas is invisible so you
don't see it filling the tube.
But as it comes in you should
see the candle start to disappear.
There it goes. Look at that.
What's happening is that
the carbon dioxide in the tube
is effectively trapping the heat.
The candle's warmth
no longer reaches the camera.
Instead it's absorbed by
the carbon dioxide inside the tube.
That's exactly how carbon
dioxide works in the atmosphere.
It traps heat, preventing it
from escaping into space,
and warms the atmosphere
in the process.
The more carbon dioxide there is in
the air, the more heat is trapped.
This is the greenhouse effect.
As the temperatures rose
in the 1970s,
Keeling's carbon dioxide graph
seemed to provide
the perfect explanation.
But what of the cooling
period in the 1950s and '60s?
It turned out that for a while
the cooling effect of soot
from smokestack chimneys
had cancelled out the warming
caused by carbon dioxide.
But that didn't last long.
The relentless rise in
carbon dioxide
soon took over
as the dominant factor.
So now, scientists focused on
a different possibility
- not a new ice age,
but the complete opposite...
.. Global warming.
The abrupt change
didn't go unnoticed.
At the highest levels
of the American government,
officials pondered whether
global warming was the new threat.
They turned for advice to the elite
special forces
of the scientific world -
a secret, shadowy organisation
known as Jason.
Every year, an elite bunch
of scientists gather
in this building
in a desirable suburb of San Diego.
They've been meeting
for more than 50 years.
But these are no
ordinary scientists.
These are the Jasons.
A select group chosen
for their intellectual brilliance
A select group chosen
for their intellectual brilliance
and their patriotism.
Their mission - to provide secret
advice to the American government
on matters scientific.
'A few hundred miles apart,
fallout patterns can overlap... '
Most of what they do today, and have
always done, is to do with defence.
'Tests on army's Nike Zeus
continued in the last year... '
But in 1978, they were asked
to investigate
the growing evidence
for global warming.
the growing evidence
for global warming.
One Jason remarked that
it made a bit of a change -
instead of finding ways
to destroy the world,
now they were being asked
to save it.
In the 1970s, being a Jason
was just about the best job
going in American science.
Every summer, the Jasons
all moved out to San Diego
to devote six whole weeks
to working with the other Jasons.
They were paid so much that they
could rent a house by the beach,
so their kids could spend the
summers gambolling in the waves,
looked after by their wives,
whilst their menfolk
got on with saving the world.
Or destroying it,
depending on the year.
Then in the evenings, the husbands
would join their families
to recharge their batteries.
The fact is, it was less James Bond
and more like Club Med.
It's the kind of science
I'd like to get into!
So it was that in 1978 the Jasons
got to work on global warming.
There was one potential problem.
Few of them knew anything
about climate.
The Jasons decided to build their
own computer model
of the global climate system.
They called it,
"The Jason Model Of The World. "
They didn't lack confidence,
those boys.
Not everyone was amused.
Bona fide climate
scientists grumbled
that a bunch of amateurs
were trespassing on their territory.
The Jasons ignored them.
And what came out of it
was a report.
And even though it's yellowed
with age, it's quite remarkable.
What's most impressive
is that it makes predictions.
That's what science is all about,
trying to test out your theories.
And with the benefit of hindsight,
the Jason report got it
pretty well spot on.
Here, for example,
right at the start -
CO2 concentrations in the atmosphere
expected to double by 2035.
Well, the models today
suggest maybe 2050.
Well, the models today
suggest maybe 2050.
Then over here, it talks about
temperature rises of 2-3 degrees
by the end of the 21st century.
That's pretty much what
the predictions are today.
And they suggested that polar
regions would warm
by more than the average, perhaps by
as much as much as 10 or 12 degrees.
by more than the average, perhaps by
as much as much as 10 or 12 degrees.
Again, close to current thinking.
You know, for a 30-year-old
document, this isn't half bad.
But back in the '70s, the
Jason Report was explosive stuff.
So the American Government
commissioned another one,
this time by climate scientists.
this time by climate scientists.
And it came up
with very similar conclusions.
Clearly, something
needed to be done.
But then something happened that
always confuses scientific issues.
Politics got in the way.
Well, there's never been a more
humbling moment in my life.
In 1980, a new President
arrived at the White House.
Ronald Reagan was pro business
and unashamedly pro America.
Ronald Reagan was pro business
and unashamedly pro America.
I aim to try and tap
that great American spirit.
He knew that the US was already
in the environmental dog house
because of acid rain.
And if global warming turned
into a major problem,
there was only going to be
one bad guy.
The US was by far
the biggest producer
of greenhouse gases in the world.
If the President wasn't careful,
global warming could become a stick
to beat America with.
So Reagan commissioned a third
report about global warming.
The man he chose to lead it
was Bill Nierenberg.
Nierenberg was the perfect choice.
He'd made his name working on
the Manhattan Project,
developing America's atom bomb.
He went on to run the
famous Scripps Institution...
'... Dr William Nierenberg,
director of the institution. '
.. where he'd built up
the Climate Research Division.
And he was a Jason.
No-one could question Nierenberg's
scientific credentials,
or his academic integrity.
It was a fine choice
by the President.
Like Reagan, he was a fervent
believer in the free market.
Nierenberg called in lots
of experts, did his research,
and produced a report that spookily
enough chimed pretty much completely
with the President's beliefs.
Nierenberg accepted
that some warming was likely.
But he argued that any warming that
came our way would happen slowly,
so society would have
plenty of time to adapt.
Human ingenuity
would see us through.
There was nothing to fear,
and certainly no need to act to
reduce emissions of carbon dioxide.
It was just what
Reagan wanted to hear.
A presidential aide reputedly
asked a leading climate scientist,
"How long before global warming
becomes a major problem?"
The considered reply, "40 years. "
The aide quipped,
"Get back to me in 39."
Global warming
was duly kicked into the long grass.
And at this stage,
in the early '80s,
it was easy to sympathise
with Nierenberg's view.
Global warming was still just
a prediction, and the science
was in its infancy,
so no-one could be sure how
big a problem it was going to be.
And all around
there was evidence from history
that a changing climate was really
nothing to be frightened of anyway.
After all, it's something humans
have always had to cope with.
You only have to drive out to
the edge of the Californian desert
You only have to drive out to
the edge of the Californian desert
to find clear evidence
that climate varies naturally.
I'm standing on the edge
of an ancient waterfall.
It might be dry barren rock
now, but thousands of years ago
a roaring torrent of water
cascaded its way through here,
carving out this massive ravine.
But that water has long since gone.
It's difficult to imagine what
it must have been like
when the water was in full flow,
but I certainly
couldn't have stood here.
The normally jagged rock has been
smoothed to a polish,
and those potholes there have been
churned out by the turbulent water
This is a fossilised river.
But it's not just
a geological relic.
There is plenty of evidence
here to back up Nierenberg's case.
I bring my students here,
not just to show them
the river-sculpted rocks,
but for something else
equally intriguing.
The clues are all around, like these
small flakes of dark volcanic glass
called obsidian
that Native Americans used
to fashion arrowheads
and spear points.
And art like this over here
carved into the rock,
looks like an elk
or a deer of some kind.
It's all evidence that a
large community lived and worked
around the river here.
If you stay here long enough
you can just imagine them
chipping away in the veil
of the spray and roar of the falls.
DISTANT CHATTER AND LAUGHTER
Then the climate must have changed,
the river stopped,
and the people moved on.
It's this process
of natural climate change
which lay at the heart
of Bill Nierenberg's case.
Humans have lived with climate
change for thousands of years.
All that's changed is how we cope.
The key is adaptation.
In the past when the rains went,
so did the people.
In the past when the rains went,
so did the people.
Today, we can do
much better than that.
Today, we can do
much better than that.
The Hoover Dam was
built in the 1930s
to tame the mighty Colorado river.
If you ever wanted a symbol
of what human ingenuity
and sheer bloody mindedness
can achieve, then this is it.
Mind you, it's a bit unnerving
to think that behind this concrete
wall is a hundred miles of lake.
to think that behind this concrete
wall is a hundred miles of lake.
Lake Mead has helped
the Western United States
conquer the cycle
of drought and flood
that used to
afflict this desert region.
It's a powerful symbol of our
ability to ride out climate change.
Especially when you realise
that today,
the lake is in the 8th year
of a major drought.
As you'd expect,
the lake level has dropped.
You can see a band
of light-coloured rock
that's been exposed
as the water has fallen.
It's only when you get
into these narrow canyons
that you get a sense of just how
far the water has fallen.
This light-coloured rock here
is what was once covered
by the water and it stretches up
for about a hundred feet.
It's like a giant bathtub ring.
But so far at least,
the Hoover Dam has done its job.
Despite the drought, Las Vegas
and the other desert cities
of the American West
are doing just fine.
You know, the lake level
is always yo-yoing up and down.
In the 1980s it reached its
during the 1950s and 1960s
the level was way down here.
But even in those
really bad droughts,
the lake never ran out of water.
For 70 years, Lake Mead has kept the
American West supplied with water.
For Nierenberg,
this was living proof
that human ingenuity could overcome
the gradual creep of climate change.
Modern society,
far from being ever-more
vulnerable to climate change,
was actually more
robust than it had ever been.
So there was no need
to fear climate change.
It was an optimistic message that
resonated with the political times.
Nierenberg went on to set up one
of the leading think tanks
that would fight the whole idea
of global warming
and help create what became known
as the sceptic movement.
The global-warming sceptics
argued that the Earth's climate
system was simply
too vast for humans to change.
They claimed there was still
very little evidence
humans were causing
the climate to warm up.
And they suggested that
any warming that did happen
was likely to be slow
and therefore easy to cope with.
These ideas have remained central
to the global-warming debate
ever since.
But as the 1980s advanced,
all three arguments came under
sustained scientific attack.
all three arguments came under
sustained scientific attack.
What shook the sceptics' argument
was some more of those ugly facts.
And by the mid 1980s,
ugly facts were piling up
at an alarming rate.
Ugly fact number one would
challenge the reassuring notion
that climate change would be slow,
and therefore easy to cope with.
It had its origins
in one of the coldest
and remotest places on Earth -
Greenland.
More than 80% of Greenland's
surface is covered in ice.
It's the largest body of ice on
Earth, outside Antarctica.
Today, despite its remoteness,
scientists come here
from all over the world
scientists come here
from all over the world
to study the effects of
climate change on the ice.
to study the effects of
climate change on the ice.
But 50 years ago,
at the height of the Cold War,
virtually no-one did
scientific research on Greenland.
Except the American military.
The ice sheet under my feet
is up to two miles deep.
50 years ago,
the Americans decided the perfect
place to build a military base
was down there - inside the ice.
Officially they called it Camp
Century because it was 100 miles
from the coast, but the men who
built it gave it a different name -
The City Under The Ice.
More than 200 people lived here.
It was a massive project.
Huge convoys used to grind their
way from the coast up onto the ice,
laden with supplies
for Camp Century.
They used to call them heavy swings.
When it was finished,
Camp Century had a library,
a hospital, and even a gym.
And what powered it all?
What else but a nuclear
power station?
I know it's hard to believe,
but they buried a nuclear reactor
inside the ice.
Now hear this.
With all five control rods withdrawn,
6.24 inches, PM 2A went
critical at 06520.
Camp Century was built
to do research into fighting
in cold-weather environments.
But that's not what made it famous.
Today, there's nothing left of
the City Under The Ice.
They took out the nuclear reactor
and abandoned the camp
somewhere up there.
But what happened at Camp Century
would eventually -
almost by accident -
lead to a scientific revolution.
It was a revolution that would
challenge a scientific
article of faith -
the idea that climate could
only change exceptionally slowly.
Because Camp Century
saw the beginning
of an entirely new branch
of science -
using samples of ancient ice
to reconstruct
the climate of the past.
The Greenland ice sheet is made up
by year after year of snowfall.
As snow falls, it captures a record
of the conditions in the atmosphere,
which then gets preserved
in layers of ice.
So many traces from the past
are buried in the ice.
There's ash from big volcanic
eruptions like Krakatoa...
.. dust from Ice-Age dust storms
as far away as Mongolia...
.. and even traces of lead from
smelting during the Roman Empire.
It's all blown in by the wind,
carried down by the snow
and buried down there.
Even more importantly,
as snow falls,
it captures an indirect record
of the temperature
at the time it was falling.
And the ice preserves this
temperature information.
So scientists drilled down
to retrieve long cylinders of
ancient ice known as ice cores.
Now, they could use these ice cores
to create a record
of past temperatures.
In effect,
they could travel back in time.
And in the mid 1980s, they began
to realise that the old idea,
that climate
always changed slowly...
.. couldn't be more wrong.
Today this freezer
in Denver in the United States
stores many of the ice cores that
have been drilled around the world.
I don't think I've
ever been as cold in my life.
The cores that are stored in
these silver tubes are at minus 35C.
They're so valuable that
there's back-up systems in place
to make sure the freezer keeps
working if there's a power cut.
Even so, the guys that work here
carry bleepers 24 hours a day
to tell them if there's
been a power failure.
And I know you don't want
to know this, but the fluid
in my nostrils has just frozen up.
HE SNIFFS
It's been said that these ice cores
are like having a weather station
in Greenland for
the last 100,000 years.
By chemically analysing the ice,
it's possible to reconstruct
the climate counting back
through tens of thousands of years.
the climate counting back
through tens of thousands of years.
In the early 1980s, most scientists
believed, as this graphs shows,
that the climate changed only
very slowly and gradually,
through the Ice Age
and up to the present warm period.
But the ice cores
told a completely different story.
The climate seemed to be jumping
all over the place from warm to cold
and back again.
What the ice revealed was
hard to believe.
In the past 100,000 years,
there had been literally dozens
What's more, the changes
didn't happen gradually.
In most cases, they occurred
in just a few short years.
Scientists realised that they'd
fundamentally misunderstood
how the climate works.
Far from changing
with imperceptible slowness,
it was now beginning to dawn on them
that the climate could change big,
it could change often,
and it could change fast.
You know, the discovery of
abrupt climate change
unleashed a previously-hidden
literary talent
among climate scientists -
a talent for metaphor.
Climate was an angry beast,
and we, it was said,
were poking it with a stick.
Alternatively, climate was
a flickering switch,
turning on and off
between hot and cold periods.
But, regardless of
the metaphor you plumped for,
it was clear that global warming
could mean some nasty surprises.
We might wake up one day
to find that global warming
had triggered a sudden, massive
shift in climate -
like the ones revealed
in the ice cores.
But in the 1980s,
this idea was still controversial.
Many scientists - not just sceptics
- argued that the theory of rapid
climate change was still unproven.
And the sceptics
had another argument.
They said that something as
vast and complicated as the global
climate system was simply too
big for we humans to influence.
A new discovery
was about to change all that.
but from a social revolution.
After all, this was the 1980s.
I was at university,
studying hard of course,
and one thing I remember is it
was the era of big hair.
A new age of consumerism.
The trouble was, packed within
the consumer lifestyle
was an environmental time bomb -
aerosols.
Aerosols owed their existence
to one of the unluckiest men
in scientific history.
Thomas Midgley invented CFCs...
.. the gases that were used in
aerosols and in fridges.
Before that, he'd come up with
the idea of putting lead in petrol.
The trouble was,
CFCs had a terrible secret.
They appeared to be good news -
inert, safe, cheap to manufacture.
But when they floated up
to the top of the atmosphere,
they turned into something deadly.
They destroyed a vital gas
that protects us all
from lethal solar rays.
They destroyed ozone.
In 1984, British scientists
working in Antarctica
discovered that the ozone layer
that protects the planet
had a huge hole in it.
Studies from space show
that the hole, in blue and pink,
is growing year by year,
and last year,
spanned the whole
Antarctic continent.
The culprit is most probably
chloro or fluoro carbons
used in aerosols and fridges.
used in aerosols and fridges.
Faced with the rapidly growing
health risks, the world acted.
Midgley's CFCs were banned,
at about the same time
that his other great invention,
that his other great invention,
lead in petrol,
was also being banned.
Poor old Midgley ended up
victim of his own inventive
genius in one final way.
In 1944, he contracted polio.
In order to keep working,
he devised a pulley and harness
that would lift him out of bed.
But one day,
he got tangled in the harness
and was strangled
by his own contraption.
Surely there's never been
a more unlucky scientist.
The hole in the ozone layer
proved beyond doubt
that humans were capable of causing
catastrophic damage to very
significant parts of the atmosphere
and in a very short space of time.
Another part of the sceptic's case -
the idea that the atmosphere
was simply too vast
for us to have any serious
effect on it - had crumbled.
And in the 1980s, there was one
final ugly fact that challenged
the sceptics' view that climate
change was nothing to worry about.
'The heat wave broke 88 high
temperature records
across the nation since Sunday. '
'New York City was one of
12 cities that suffered
and sweltered in record high
temperatures. '
'Temperatures in some places
went as high as 109 degrees. '
Through the 1980s, the temperature
of the planet kept rising,
building on the warming that
had first begun in the 1970s.
'The 80s have brought us the four
hottest years in the last 100.'
'At least 60 cities reported... '
Almost every year broke records.
'Daily temperatures in the
90s, even in the hundreds. '
The question for scientists was
whether this was just a natural
variation, or whether it was due
to man-made emissions
of carbon dioxide -
the greenhouse effect.
In 1988, one man,
top NASA scientist Jim Hansen,
decided he knew the answer.
And he wanted the whole world
to hear what he had to say.
His chosen forum was an
American congressional inquiry.
Gentlemen, thank you very much
for being here, Dr Hansen,
if you'd start us off
we'd appreciate it.
Mr Chairman, committee members...
You'll have to talk
right into the microphone.
These are not high-tech microphones,
you have to pull it right over.
Bit of an inauspicious start.
But he warms up nicely.
I would like to draw
three main conclusions. Number one,
the earth is warmer in 1988
than at any time in the history
of instrumental measurements.
Number two, global warming
is now large enough
that we can ascribe,
with a high degree of confidence,
a cause-and-effect relationship
to the greenhouse effect.
And number three,
our computer climate simulations
indicate that the greenhouse effect
is already large enough
to begin to affect the probability
of extreme events,
such as summer heat waves.
You know, you have to say
this was as much political theatre
as scientific evidence.
It was Hansen himself that
suggested he give his evidence
at the end of June, figuring
that the weather would be hot.
He wasn't disappointed - they
were in the middle of a heat wave.
So people were in the mood
to write about global warming.
He'd also checked the press
were going to be there that day,
and that he was the
first person giving testimony.
This man wanted to make news.
And he saved the best till last.
Altogether, this evidence represents
a very strong case,
in my opinion, that the greenhouse
effect has been detected
and it is changing our climate now.
It was pretty explosive stuff.
Essentially, what Hansen was
saying was that global warming
was no longer a prediction.
It was now an observation.
For the first time,
a leading scientist had stepped off
the fence and told the world
global warming had arrived.
'All of us must begin to face up the
fact that if we continue emitting
'vast quantities of greenhouse gases,
we're going to face
'vast quantities of greenhouse gases,
we're going to face
'a global temperature rise larger
than anything experienced
in human history. '
Hansen succeeded.
Thanks to him, global warming
became an overnight sensation.
'The time for action to respond
to the impending warming is now. '
Hansen later admitted that he'd
weighed up the risk of being wrong
against the costs of saying nothing,
and decided
that he had to speak out.
'Most scientists would rather not
make a definitive statement.
'But the public
doesn't always understand that. '
I mean, if you say on the one hand
this and on the other hand that,
it makes the public think, well,
we don't know enough to draw
a conclusion.
And that... that can be,
er, unhelpful in terms of when
you do need to have policy changes.
Basically,
Hansen stuck his neck out -
not something that
we scientists are famous for.
I don't think I'd have
the nerve to do it.
favours the brave,
because Hansen's testimony has
stood the test of time pretty well.
Within a few months of Hansen's
evidence, the United Nations
had helped set up an international
committee to examine global warming,
the Intergovernmental Panel
On Climate Change.
And politicians jumped on board too.
Margaret Thatcher became
the first world leader to warn
about the dangers of global warming.
The danger of global warming
is as yet unseen, but real enough
for us to make changes and sacrifices
so that we do not live at the expense
of future generations.
That prospect is a new factor
in human affairs.
It's comparable in its implications
to the discovery
of how to split the atom.
Indeed, its results
could be even more far reaching.
No generation has
a freehold on this earth.
All we have is a life tenancy
with a full-repairing lease.
All we have is a life tenancy
with a full-repairing lease.
By the early 1990s,
it looked like the scientific
battle was pretty well over.
The idea that a new
ice age was on the way had been
comprehensively overturned.
Scientists and politicians agreed
that humans were altering
the climate.
And something had
to be done about it.
Global warming had
well and truly arrived.
And then along came the most
familiar of plot twists -
the backlash.
And what a backlash it was.
In the 1990s, global warming was
to become the biggest scientific
controversy of my lifetime.
In a way, Jim Hansen
had been too successful.
His high-profile testimony
galvanised all those who,
for whatever reason,
disagreed with taking action
to prevent climate change.
'It's just not true. '
It was the beginning of
an organised fight back,
driven by a band
of maverick scientists...
Global warming is not a crisis.
.. supported by powerful
businesses and politicians.
And they would subject the whole
idea of global warming
to a new and searching critique.
Next time, the sceptics fight back!
How a scientific consensus
turned into a vicious battleground.
And how science itself
was ultimately the winner.