All language subtitles for Mass Extinction Life at the Brink 1080p HDTV x264 AAC MVGroup org EN SUB

Narrator: IT’S HAPPENED
AT LEAST FIVE TIMES

IN THE HISTORY OF OUR PLANET.

MASS EXTINCTIONS.

DEATH ON AN UNIMAGINABLE SCALE.

Man: IT’S NOT JUST KILLING
A BUNCH OF INDIVIDUALS.

IT’S KILLING EVERY INDIVIDUAL
IN THE SPECIES

THAT MAKES THAT SPECIES EXTINCT.

Narrator: THESE CATASTROPHES
WERE RAPID, GLOBAL EVENTS,

LEAVING THEIR MARK
IN ANCIENT ROCKS.

Man: SO WHEN YOU SEE
THE RAPID DISAPPEARANCE

OF MASSIVE NUMBERS OF SPECIES
IN THE FOSSIL RECORD,

THE QUESTION THAT’S PROVOKED
EVERY BIOLOGIST IS

WHAT THE HECK HAPPENED?

WHAT’S IT TAKE TO WIPE OUT
MOST OF THE LIFE ON THE PLANET?

Narrator: AS SCIENTISTS HUNT
FOR CLUES AROUND THE WORLD,

TWO OF THE GREATEST EXTINCTIONS
MAY FINALLY BE SOLVED.

Man: MAJOR EVENTS
IN THE HISTORY OF LIFE

HAVE COINCIDED
WITH THESE EXTINCTIONS.

Narrator: WHAT MIGHT THESE
CALAMITIES TELL US

ABOUT OUR FUTURE?

ARE THE FORCES THAT RAVAGED LIFE
EONS AGO BACK AT WORK TODAY?

Man: IF ENVIRONMENTAL CHANGE
IS GREAT ENOUGH, FAST ENOUGH,

AND ON A GLOBAL SCALE,
THE ENTIRE PLANET IS IN TROUBLE.

Narrator: ARE WE ON THE BRINK
OF ANOTHER MASS EXTINCTION?

WHEN YOU WALK THROUGH

THE SMITHSONIAN’S NATIONAL
MUSEUM OF NATURAL HISTORY,

MUCH OF WHAT YOU SEE IS EXTINCT.

BUT WHILE SPECIES COME AND GO,

ON RARE OCCASIONS
THERE ARE MASS EXTINCTIONS--

RAPID EVENTS THAT WIPE OUT
THE MAJORITY OF LIFE ON EARTH.

THIS IS THE STORY OF TWO
OF THOSE CATASTROPHES--

HOW THEY UNFOLDED AND WHAT THEY
CAN TELL US ABOUT OUR FUTURE.

THE FIRST MYSTERY IS
THE DEATH OF THE DINOSAURS.

66 MILLION YEARS AGO,

GIANT PTEROSAURS
RULED THE SKIES.

[SCREECH]

WHILE BENEATH THE WAVES,

PREDATORS CALLED MOSASAURS
PROWLED THE SEAS.

AND DINOSAURS ROAMED THE LAND.

[ROARS]

THEN SUDDENLY, THEY WERE GONE.

Man: THIS IS A FEMUR
OF A TRICERATOPS.

Narrator: TO UNDERSTAND
THE CAUSES OF MASS EXTINCTIONS,

EVOLUTIONARY BIOLOGIST
SEAN CARROLL

HAS CIRCLED THE GLOBE.

Sean Carroll:
IT’S JUST HANGING OUT,

AND YOU’VE GOT AN EDGE-ON
VIEW OF THE BONE HERE.

MASS EXTINCTIONS POSE
THE GREATEST

BIOLOGICAL MURDER MYSTERIES.

WHAT KILLED THE DINOSAURS?

PERHAPS YOU’VE HEARD
THAT WE NOW KNOW.

BUT HOW DO WE KNOW?

WELL, IT REQUIRED
SOME OF THE GREATEST

SCIENTIFIC DETECTIVE WORK EVER.

AND THE TRAIL BEGAN ALMOST
HALFWAY AROUND THE WORLD.

[BELL TOLLING]

Narrator: THIS IS GUBBIO,
A SLEEPY ITALIAN TOWN.

NOT A SINGLE GIANT REPTILE
IN SIGHT.

STILL, THE PAST IS
EVERYWHERE YOU LOOK.

AND BEYOND THESE WALLS,
AN EVEN DEEPER PAST IS BURIED.

JUST OUTSIDE OF TOWN, THERE ARE
TRACES OF THE DINOSAURS’ WORLD,

ITS HISTORY WRITTEN IN
THE LAYERS OF LIMESTONE CLIFFS.

MILLIONS OF YEARS AGO,

THESE ROCKS WERE AT
THE BOTTOM OF THE SEA.

IN THE 1970s, AMERICAN GEOLOGIST
WALTER ALVAREZ

WAS STUDYING THESE
LIMESTONE LAYERS,

ANALYZING FOSSILS LEFT
BY TINY, SHELLED SEA CREATURES.

CALLED FORAMINIFERA,
OR FORAMS FOR SHORT,

THEY’RE AMONG THE MOST COMMON
OCEAN PLANKTON.

WHEN THEY DIE, THEIR SHELLS
BECOME PART OF THE SEDIMENT

AND CAN BE USED AS MARKERS
OF GEOLOGIC TIME.

BUT ALVAREZ SAW
SOMETHING STRIKING.

THEY SEEMED TO DISAPPEAR AT
THIS MYSTERIOUS LINE OF CLAY.

Walter Alvarez:
YOU COULD SEE THAT

IN THE TOP LAYER OF LIMESTONE,
THERE WERE FAIRLY LARGE FORAMS.

THEN THERE’S THIS CLAY LAYER.

AND ABOVE IT,
IN THIS LIMESTONE LAYER,

ALMOST ALL OF THOSE FORAMS
ARE GONE.

AND I THINK THAT
SORT OF WOKE ME UP,

BECAUSE THAT EXTINCTION OF
FORAMS, AS CLOSE AS WE CAN TELL,

IT’S THE SAME AGE AS
THE EXTINCTION OF THE DINOSAURS.

Narrator:
ALMOST 1,000 MILES AWAY,

THERE WAS A SIMILAR PATTERN.

ON THE ATLANTIC COAST OF SPAIN,

DUTCH GEOLOGIST JAN SMIT
WAS STUDYING FORAMS AS WELL.

THEIR FOSSILIZED SHELLS
FORMED THESE LIMESTONE CLIFFS,

JUST LIKE IN GUBBIO.

Carroll: SO RIGHT THERE
TOWARDS THE BOUNDARY?

Jan Smit: RIGHT THERE
IS THE BOUNDARY.

Narrator: THEY REPRESENT
THE GEOLOGICAL PERIOD

WHEN DINOSAURS LAST
WALKED THE EARTH.

AND LIKE ALVAREZ, SMIT FOUND
A PUZZLING CLAY LAYER

MARKING THE EXTINCTION
OF THE FORAMS.

Carroll: JAN, WHAT CAN WE TELL
ABOUT EARTH’S HISTORY

FROM JUST LOOKING
AT THESE ROCKS?

Smit: WELL, YOU CAN SEE
THE END OF THE ONE WORLD

AND THE BEGINNING
OF THE NEXT ONE.

AND YOU SEE THERE IS
A VERY SHARP,

EXTREMELY SHARP DIVIDING LINE
BETWEEN THE TWO.

Carroll: THAT GRAY BAND.

Smit: THAT’S THAT GRAY BAND
OVER THERE.

AND ALL OF A SUDDEN WE SEE
A DRAMATIC CHANGE,

WHICH WE CALL THE KT BOUNDARY.

Narrator: THE KT BOUNDARY
LIES BETWEEN

TWO GREAT AGES OF ANIMAL LIFE--

THE AGE OF REPTILES,
WITH DINOSAURS,

AND THE AGE OF MAMMALS,
AFTER THE DINOSAURS WERE GONE.

Smit: AND THE KT BOUNDARY,

IT’S RIGHT HERE WHERE
YOU SEE A CONTRAST

BETWEEN THE PURPLE AND THE DARK.

SO HERE’S PLENTY OF LIFE.

AND THERE, THE BASE
OF THE FOOD CHAIN

OF THE OCEANS DISAPPEAR,

AND EVERYTHING WHICH
IS DEPENDENT ON IT

IS TOTALLY ZAPPED
RIGHT AT THE BOUNDARY.

Narrator: VARYING IN COLOR
AND THICKNESS,

THE LAYER WAS FOUND
AROUND THE WORLD.

WALTER ALVAREZ BELIEVED
IT WAS A SILENT WITNESS

TO THE END OF THE DINOSAURS.

Alvarez: AND THAT’S WHAT’S
BEAUTIFUL ABOUT ROCKS,

IS THAT THEY LIE THERE
FOR MILLIONS OF YEARS

AND DON’T CHANGE.

AND THEY REMEMBER WHAT HAPPENED
WHEN THEY WERE FORMED.

Narrator: TO UNLOCK
THOSE MEMORIES,

ALVAREZ SOUGHT HELP

AT THE UNIVERSITY OF CALIFORNIA
AT BERKELEY

FROM A NOBEL PRIZE-WINNING
PHYSICIST--

HIS FATHER, LUIS ALVAREZ.

Richard Muller: ALVAREZ LOOKED
AT THIS LAYER,

AND HE THOUGHT THERE
MUST BE CLUES THERE.

IT WAS LIKE SHERLOCK HOLMES
SEEING SOMETHING ODD.

HE WANTED TO KNOW EVERYTHING
HE COULD KNOW ABOUT THAT LAYER.

Narrator: ALVAREZ AND HIS SON
HUNTED FOR CHEMICAL CLUES.

WHAT THEY FOUND STUNNED THEM.

THE CLAY CONTAINED HIGH LEVELS
OF AN ELEMENT

RARELY FOUND IN
THE EARTH’S CRUST--IRIDIUM.

OTHER KT SITES HAD
IRIDIUM SPIKES JUST AS HIGH.

LUIS ALVAREZ THOUGHT
HE KNEW WHY.

THOUSANDS OF ASTEROIDS
CROSS THE EARTH’S ORBIT,

AND MANY CONTAIN IRIDIUM.

WHAT IF ONE HIT THE EARTH
66 MILLION YEARS AGO?

Muller: SO LUIS ALVAREZ
HAD THIS HYPOTHESIS

THAT AN ASTEROID WOULD CAUSE
THIS DESTRUCTION.

HE HAD THE CLUE--THE AMOUNT
OF IRIDIUM AT GUBBIO.

UNDER THIS HYPOTHESIS, IT WOULD
BE SPREAD ALL AROUND THE WORLD.

SO NOW HE COULD CALCULATE
HOW MUCH IRIDIUM

THERE HAD BEEN LAID DOWN
OVER THE ENTIRE EARTH.

NOW, HE ALSO KNEW
HOW MUCH IRIDIUM

THERE IS IN ASTEROIDS
AND COMETS.

SO HE CAN NOW CALCULATE
THE SIZE OF THE OBJECT.

Narrator: THE ASTEROID
WAS SIX MILES WIDE,

WEIGHING HUNDREDS
OF BILLIONS OF TONS.

STILL, COMPARED TO EARTH,
IT WAS TINY.

HOW COULD IT WREAK SUCH HAVOC?

IT WOULD HAVE HIT AT NEARLY
50,000 MILES PER HOUR.

THE ENERGY RELEASED
WOULD BE EQUAL TO

ABOUT 100 MILLION NUCLEAR BOMBS.

[DINOSAUR GROANS]

A HUGE MASS OF
SUPERHEATED DEBRIS

WOULD HAVE BEEN BLASTED
INTO SPACE,

ORBITING THE EARTH BEFORE
RAINING BACK DOWN.

THE ALVAREZES THOUGHT THE DUST
COULD HAVE BLOCKED OUT THE SUN

FOR YEARS, DEVASTATING LIFE.

THIS WAS THE HYPOTHESIS FOR HOW
THE AGE OF DINOSAURS ENDED...

BUT THERE WAS A PROBLEM.

IF AN ASTEROID
SIX MILES IN DIAMETER

DID STRIKE THE EARTH,

WHERE WAS THE CRATER OF
THE RIGHT AGE, TYPE AND SIZE?

[TRAIN WHISTLE BLOWS]

ONE OF THE MOST PROMISING LEADS

WAS DISCOVERED ALONG
THE BRAZOS RIVER,

NEARLY 200 MILES
FROM THE GULF OF MEXICO.

66 MILLION YEARS AGO,
THIS WAS THE BOTTOM OF THE SEA.

[COW GRUNTS]

Alan Hildebrand: IT’S ACTUALLY
EASIER WITH FRESH TRACKS.

Narrator: IN THE 1980s,
GEOLOGIST ALAN HILDEBRAND

CAME TO INVESTIGATE
AN ODD MIXTURE OF ROCKS

AT THE KT BOUNDARY HERE.

Carroll: SO, THIS IS THE TYPICAL
MUD JUST FOUND IN THIS AREA?

Hildebrand: EXACTLY.

ALL WE SEE IS SEVEN MILLION
YEARS OF THIS MUD HERE.

SO, I MEAN,
WE’RE TALKING BORING.

Narrator: BUT THIS MUD WAS
FULL OF PROTRUDING BOULDERS

RIGHT AT THE BOUNDARY.

Carroll: SO YOU HAVE THIS
REALLY REGULAR MUD LAYER,

AND THEN ALL OF A SUDDEN,
THIS AREA THAT’S JUST FULL

OF THIS WHOLE MIXTURE
OF BOULDERS AND...

Hildebrand:
AND FROM DIFFERENT PLACES.

IT ISN’T JUST THE ROCK
THAT WAS HERE IN THE SEAFLOOR.

MAYBE SOME OF IT GOT PULLED
FROM DEEP WATER,

MAYBE SOME OF IT GOT
PULLED FROM SHALLOW WATER.

IT ALL GOT JUMBLED TOGETHER
AND DUMPED HERE.

Carroll: ALRIGHT, SO WHAT COULD
HAVE HAPPENED HERE

THAT WOULD EXPLAIN SOMETHING
SO DRAMATIC?

Hildebrand: WELL, IT HAD TO BE
A HUGELY ENERGETIC WAVE

IN THE OCEAN, A GIANT TSUNAMI.

Narrator:
AN ASTEROID SIX MILES WIDE

WOULD HAVE CAUSED TSUNAMIS
HUNDREDS OF FEET HIGH.

TRAVELING AT THE SPEED OF A JET,

THEY WOULD HAVE RIPPED UP
THE SEAFLOOR,

LEAVING DEBRIS IN
THE BRAZOS RIVER BASIN.

HILDEBRAND REALIZED THE STRIKE
MUST HAVE OCCURRED

NEAR THE GULF OF MEXICO.

BUT WHERE?

THE BREAKTHROUGH CAME
WHEN HE FOUND A MAP

MADE BY GEOLOGISTS
SEARCHING FOR OIL.

IT REVEALED
A GIANT BURIED CRATER

ON THE YUCATAN PENINSULA.

DISCOVERED IN 1990,
IT WAS NAMED CHICXULUB,

AFTER A VILLAGE NEAR ITS CENTER.

Carroll: THE DISCOVERY
OF THE CHICXULUB CRATER

WAS THE ULTIMATE EVIDENCE
OF THE ASTEROID IMPACT.

MOREOVER, THE CRATER WAS
THE SAME AGE AS THE KT BOUNDARY,

AND IT WAS THE SIZE PREDICTED
BY LUIS ALVAREZ.

WE NOW KNEW FOR CERTAIN WHAT
HAPPENED ON THAT HORRIBLE DAY.

I LOVE THAT LITTLE ROCK
SITTING UP OVER THERE.

Kirk Johnson: YEAH,
THAT LITTLE CAP UP THERE.

Narrator: ALTHOUGH THE TRIGGER
FOR THE EXTINCTION

HAD BEEN FOUND,

KEY QUESTIONS REMAINED.

HOW DID A SINGLE IMPACT
IN THE YUCATAN

WIPE OUT SO MUCH LIFE
ACROSS EARTH?

WHICH SPECIES VANISHED?

HOW DID THE WORLD CHANGE?

ANSWERS WERE FOUND

IN THE BADLANDS OF THE DAKOTAS
AND MONTANA,

IN THE HELL CREEK FORMATION.

ITS ERODING BUTTES HOLD FOSSILS
OF PLANTS AND ANIMALS

THAT LIVED DURING THE AGE
OF THE DINOSAURS AND BEYOND.

WHEN PALEONTOLOGIST KIRK JOHNSON
FOUND THE BOUNDARY HERE,

HE COULD STUDY THE SCOPE OF THE
EXTINCTION FAR FROM THE IMPACT.

Carroll: KIRK, HOW IMPORTANT
WAS IT TO FIND THE KT BOUNDARY

UP HERE IN NORTH DAKOTA?

Johnson: IF YOU CAN PUT
YOUR FINGER ON THE BOUNDARY

LIKE YOU CAN RIGHT HERE,

WHAT THAT MEANS IS YOU CAN ASK
THE VERY SIMPLE QUESTION,

HOW WAS LIFE BEFORE THE IMPACT

DIFFERENT FROM LIFE
AFTER THE IMPACT?

ALL YOU GOT TO DO IS LOOK
FOR THE FOSSILS BELOW

AND COMPARE THEM TO
THE FOSSILS ABOVE.

AND THAT’S WHAT WE’VE DONE HERE
FOR THE LAST 30 YEARS.

Narrator: THIS ARID LANDSCAPE
WAS ONCE A WET, LUSH FOREST.

CRACK OPEN SOME ROCKS, AND
YOU’LL SEE THE LEAVES OF TREES

THAT FLOURISHED HERE
OVER 66 MILLION YEARS AGO.

Carroll: THERE IT IS.
LOOK AT THAT.

Narrator: LOOK CLOSELY
AND YOU CAN FIND FOSSILS

OF TURTLES, FISH,
AND SMALL MAMMALS

THAT THRIVED IN THE RIVERS
AND FORESTS.

AND THEN THERE ARE THE BONES
OF THE DINOSAURS.

Johnson: SO THIS IS A PLASTERED
FEMUR OF A TRICERATOPS,

SO AROUND THE CORNER IS
A TRICERATOPS SACRUM.

Narrator: THE CLUES
TO WHAT HAPPENED HERE

LIE IN THE FOSSILS
AND WHERE THEY’RE FOUND.

Johnson: THIS IS AN ANKLEBONE OF
A SMALL, MEAT-EATING DINOSAUR.

AND NEARBY WE FOUND THIS BONE,

WHICH IS A BONE OF A MUCH LARGER
MEAT-EATING DINOSAUR.

SAME BONE.
SEE THE SIZE DIFFERENCE?

Carroll: RIGHT.

Johnson: AND YOU FIND THESE
BONES, IDENTIFY THE ANIMAL,

AND PRETTY SOON YOU START
ASSEMBLING A LIST OF DINOSAURS

THAT ARE PRESENT
AT ANY GIVEN LEVEL.

AND THE CLOSER TO THE BOUNDARY
YOU ARE,

THE MORE WE ADDRESS THE QUESTION

OF HOW LONG
THE DINOSAURS SURVIVED.

Narrator: WE NOW KNOW
THAT 22 TYPES OF DINOSAURS

LIVED IN HELL CREEK, INCLUDING
THE MIGHTY TYRANNOSAURUS REX.

IF SOME SURVIVED, THEIR FOSSILS
WOULD LIE ABOVE THE BOUNDARY.

Johnson: WE’VE NOW FOUND
SEVERAL SPECIMENS

THAT ARE VERY CLOSE
TO THE BOUNDARY.

AND REALLY WHAT
THAT’S SHOWING US

IS THAT EVEN IF
DINOSAURS ARE RARE,

IF YOU LOOK LONG ENOUGH,

YOU’LL FIND THEM WHEN THEY
WERE LIVING ON THE PLANET.

WHAT WE HAVE NOT FOUND YET
IS ANY DINOSAUR SKELETON

ANYWHERE IN THE WORLD
ABOVE THE KT BOUNDARY LAYER.

Narrator:
SO NO DINOSAUR SURVIVED

THE AFTERMATH OF THE IMPACT.

NEITHER DID 50% TO 60%
OF OTHER SPECIES.

THE CATASTROPHE WAS EVEN WORSE
THAN THE ALVAREZES HAD IMAGINED.

WITHIN 600 MILES OF THE IMPACT,
DEATH CAME QUICKLY.

Brian Toon: IF YOU TURN YOUR
OVEN ON BROIL, OPEN THE DOOR,

PUT YOUR HAND
UNDER THE GLOW BAR,

THAT’S WHAT THE DINOSAURS FELT
VERY SOON.

AND THEY WERE PROBABLY BROILED
ALIVE WITHIN AN HOUR OR SO.

Narrator: WHAT HAPPENED NEXT
WAS A CHAIN REACTION.

FALLING EJECTA IGNITED FIRES.

SOOT AT KT BOUNDARIES SHOWS THAT
NEARLY THE ENTIRE WORLD BURNED.

SMOKE FILLED THE SKIES.

[ROARS]

Toon: AND THERE MAY HAVE ALSO
BEEN A LOT OF SULFUR

BLOWN INTO THE ATMOSPHERE,

BECAUSE THE IMPACT SITE
IN THE YUCATAN PENINSULA

HAD A LOT OF SULFUR IN IT.

AND ALL OF THOSE THINGS
WERE ABUNDANT ENOUGH

TO OBLITERATE THE SUN.

Narrator: THE DESTRUCTION
TRIGGERED

A GLOBAL ECOLOGICAL COLLAPSE.

ACID RAIN DECIMATED PLANTS,
THE BASE OF THE FOOD CHAIN.

TOXIC GASES
RELEASED BY THE IMPACT

DESTROYED THE OZONE LAYER

THAT PROTECTS THE PLANET
FROM SOLAR RADIATION.

WITH HABITATS DESTROYED AND
THE CLIMATE RADICALLY CHANGED,

THE AGE OF DINOSAURS WAS OVER.

BUT AS SCIENTISTS WOULD LEARN,

THERE’S MORE THAN ONE WAY
TO PUSH LIFE TO THE BRINK.

SINCE AN ASTEROID STRIKE
ENDED THE AGE OF DINOSAURS,

SCIENTISTS WONDERED IF IMPACTS

COULD HAVE CAUSED
OTHER MASS EXTINCTIONS.

AT METEOR CRATER IN ARIZONA,

SEAN CARROLL AND GEOPHYSICIST
JAY MELOSH PONDER THE QUESTION.

Carroll: SO, JAY, ABOUT HOW MANY
TIMES HAS THE EARTH BEEN HIT

BY AN ASTEROID LARGE ENOUGH
TO CAUSE A CRATER THIS BIG?

Jay Melosh: WE LIVE
IN A SHOOTING GALLERY.

THERE ARE THOUSANDS OF ASTEROIDS

THAT CREATED THIS CRATER
AND MUCH BIGGER

CROSSING THE EARTH’S ORBIT.

THE QUESTION IS HOW OFTEN
DO WE GET HIT BY SOMETHING

BIG ENOUGH TO CAUSE
A MASS EXTINCTION?

Narrator: THE ANSWER IS
VERY SELDOM.

AFTER MUCH SEARCHING,
SCIENTISTS FOUND NO EVIDENCE

LINKING AN ASTEROID STRIKE
TO ANY OTHER EXTINCTION EVENT.

THERE HAVE BEEN AT LEAST
FOUR OTHER MASS EXTINCTIONS.

SO WHAT COULD EXPLAIN THEM?

ESPECIALLY THE MOST DEVASTATING,
WHICH ENDED THE PERMIAN PERIOD,

LONG BEFORE
THE RISE OF DINOSAURS.

ALMOST 90% OF THE PLANET’S
SPECIES VANISHED.

THAT’S WHY IT’S CALLED
THE GREAT DYING.

IN CONTRAST TO OUR WORLD,
THE PERMIAN WAS AN ALIEN PLACE.

THE EARTH HAD ONE SUPERCONTINENT
KNOWN AS PANGAEA.

THE OCEAN WAS TEEMING WITH LIFE.

THERE WERE TRILOBITES,
WHICH HAD SURVIVED FOR EONS,

AND CREATURES LIKE
THE HELICOPRION,

WITH ITS SAW-LIKE JAW.

THERE WERE NO DINOSAURS YET,

BUT CARNIVORES LIKE
THE GORGONOPSIDS,

THE FIRST ANIMALS TO EVOLVE
SABER-LIKE TEETH.

AND PLANT-EATERS
LIKE THE DICYNODONTS...

[RASPING]

...SO COMMON, THEIR FOSSILS
HAVE BEEN FOUND EVERYWHERE.

[ROARS]

THEN, SUDDENLY, THE WORLD WAS
ALMOST EMPTIED OF CREATURES.

WHAT COULD EXPLAIN IT?

IN SOUTHERN CHINA,

KEY CLUES LIE BURIED BEYOND
THESE ANCIENT MOUNTAINS.

HERE, SCIENTISTS ARE SEARCHING
FOR VICTIMS OF THE GREAT DYING

ON THE BANKS OF THE RED RIVER.

Shuzhong Shen: WHOA! BEAUTIFUL!

Narrator: UNEARTHING FOSSILS
FROM THE EXTINCTION

IS THE LIFE’S WORK OF
PALEONTOLOGIST SHUZHONG SHEN.

Shen: THIS ONE’S DIFFERENT,

BUT THOSE THREE MAY BE
THE SAME THING.

Narrator: HE’S DOCUMENTING WHICH
CREATURES LIVED AND DIED HERE.

Shen, translated:
AFTER TEN YEARS OF WORK,

WE’VE DISCOVERED THAT
THIS CROSS SECTION

HAS RECORDED THE ENTIRE PROCESS
OF THE MASS EXTINCTION.

THE DIVERSITY OF CREATURES
THAT THRIVED IN THE PERMIAN,

AND THE SUDDEN POINT WHERE
THEY DISAPPEARED QUICKLY.

[SHIP HORN BLARES]

Narrator:
A SHORT DISTANCE UPRIVER,

GEOLOGIST SAM BOWRING

HAS FOUND THE END
OF THE PERMIAN WORLD

AND THE DAWN OF THE AGE
OF REPTILES--

THE TRIASSIC PERIOD.

Sam Bowring: OH, YEAH.
BEAUTIFULLY PRESERVED. YEAH.

WHAT WE HAVE HERE IS AN EXPOSURE
OF THE PERMO-TRIASSIC BOUNDARY.

NOW, YOU MIGHT SAY,
"WHAT’S SO SPECIAL ABOUT THIS?"

YOU WOULDN’T KNOW
AT FIRST GLANCE,

BUT IN FACT, THE ROCKS TO
THE RIGHT ARE PERMIAN-AGE ROCKS,

FULL OF FOSSILS,

AND THIS BLACK SHALE,
WHICH IS THE TRIASSIC--

WHICH HAS NONE OF
THOSE ORGANISMS.

AND THE LINE BETWEEN THEM
REPRESENTS

THE GREATEST EXTINCTION
IN EARTH HISTORY.

Narrator: THE BLACK SHALE
MARKING THE EXTINCTION

REVEALS A SICK OCEAN.

WHAT POWERFUL EVENT
UNLEASHED THESE CHANGES?

TO SOLVE THE MYSTERY,
THEY NEED TO FIGURE OUT

PRECISELY WHEN
THE EXTINCTION OCCURRED.

JUST ABOVE THE BOUNDARY,
THERE MAY BE AN ANSWER.

A LAYER OF ANCIENT ASH
FROM A NEARBY VOLCANO,

FULL OF TIME-TELLING CRYSTALS
CALLED ZIRCONS.

Bowring: THE MINERAL ZIRCON,
IT’S A FAMOUS GEMSTONE.

BUT IT HAS A VERY UNIQUE
ATTRIBUTE,

AND THAT IS THAT WHEN
IT FORMS IN A MAGMA,

IT’S LIKE STARTING A CLOCK.

Narrator: A CLOCK BASED
ON RADIOACTIVE DECAY,

WHICH CAN TELL WHEN
A VOLCANIC ROCK WAS FORMED.

Bowring: SO THIS IS
THE VOLCANIC LAYER

THAT IS VERY CLOSE TO
THE PERMO-TRIASSIC BOUNDARY,

WHICH IS RIGHT HERE.

SO WE’RE GOING TO SEPARATE
ZIRCONS FROM IT.

AND WE’RE EXCITED ABOUT THIS ONE
IN PARTICULAR,

BECAUSE WE ARE GOING TO GET
THE BEST ESTIMATE

OF THE AGE OF
THE PERMO-TRIASSIC BOUNDARY.

[TRAIN WHISTLE BLOWS]

Shen: YES, THIS IS JUST HERE,
WE FOUND, ACTUALLY.

Narrator: ONCE THE TEAM
DATES THE BOUNDARY,

THEY CAN FIGURE OUT WHEN
THE EXTINCTION BEGAN.

THEN THEY CAN LOOK FOR EVENTS
THAT HAPPENED AT THE SAME TIME

AND ZERO IN
ON THE LIKELIEST SUSPECTS.

BACK IN THE U.S.,

SCIENTISTS FOLLOW
ANOTHER TRAIL OF EVIDENCE.

IN ROCKS FROM THE BOUNDARY,
THERE’S AN INTRIGUING CLUE--

A SUDDEN CHANGE
IN THE TYPE OF CARBON--

EVIDENCE OF A DRAMATIC
GLOBAL DISTURBANCE.

Jonathan Payne: WHEN WE SAW
THIS DISTURBANCE,

THIS INDICATED THAT THERE WAS
PROBABLY A RAPID ADDITION

OF A LOT OF CARBON DIOXIDE GAS
TO THE ATMOSPHERE.

AND THAT’S WORRISOME,

BECAUSE CARBON DIOXIDE
CONTROLS EARTH’S CLIMATE.

SO THE BIG QUESTION
THAT CAME UP IN OUR MINDS

IS WHERE DID THE CARBON
COME FROM?

Narrator: ONE PRIME SUSPECT
LIES IN THE VASTNESS OF SIBERIA.

AROUND 250 MILLION YEARS AGO,

A SERIES OF MASSIVE
VOLCANIC ERUPTIONS

RAVAGED MORE THAN A MILLION
SQUARE MILES OF LAND.

THE EARTH’S MANTLE
SPEWED OUT ENOUGH LAVA

TO BURY AN AREA THE SIZE
OF THE CONTINENTAL U.S.

UNDER A LAYER
AT LEAST 1,000 FEET DEEP.

HUGE AMOUNTS OF GASES,
INCLUDING CARBON DIOXIDE,

POURED INTO THE ATMOSPHERE.

SAM BOWRING AND
A TEAM OF SCIENTISTS

HAVE COME TO THIS REMOTE AREA

TO SEARCH FOR REMNANTS
OF THE ERUPTIONS,

KNOWN AS THE SIBERIAN TRAPS.

MUCH OF THE VOLCANIC ROCK
LIES BURIED UNDERGROUND.

TO REACH IT, THE EXPEDITION
WILL TRAVEL DOWN RIVERS

THAT HAVE CARVED THROUGH
THE ANCIENT LAVA.

[AIR PUMP HISSING]

Bowring: THE BEAUTY
OF BEING ON THIS RIVER

IS THAT WE ARE ABLE
TO FLOAT THROUGH TIME.

AND WE’RE GOING TO GO UP
THROUGH THE PERMIAN.

AND THEN THE LAST BIT
OF THE PERMIAN

IS COVERED WITH THIS THICK
OUTPOURING OF LAVA

THAT WE KNOW AS
THE SIBERIAN TRAPS.

AND WE NEED TO EVALUATE
ONCE AND FOR ALL,

DOES IT COINCIDE EXACTLY
WITH THE EXTINCTION,

OR IS IT POST THE EXTINCTION,

OR DOES IT SIGNIFICANTLY
PREDATE THE EXTINCTION?

Man: OH, YES!

Narrator:
AFTER DAYS OF TRAVELING,

GEOLOGIST LINDY ELKINS-TANTON
MAKES THE FIRST DISCOVERY.

Lindy Elkins-Tanton:
THAT IS LAVA.

THIS IS MATERIAL
THAT’S FILLED IN AROUND.

SEE THAT EDGE RIGHT THERE?

Narrator: A LAYER OF
ANCIENT LAVA

BESIDE ROCKS FROM
THE PERMIAN WORLD.

Elkins-Tanton: THIS IS THE FIRST
MOMENT IN THIS WHOLE TRIP

WE’VE ACTUALLY FOUND
THE LOWER-MOST LAVA

WHERE IT IS IN CONTACT WITH
THE UPPER PERMIAN SEDIMENTS

THAT IT ERUPTED ONTO.

AND SO RIGHT ON THIS INTERFACE

IS WHERE WE THINK THAT
THE EARTH STARTED TO CHANGE.

Narrator: CLUES TO THIS CHANGE
MUST BE HERE.

Man: YOU GOT SOME...
AM I KEEPING THESE?

Elkins-Tanton:
YEAH, HANG ON TO THOSE.

Benjamin Black:
THIS SAMPLE LOOKS GOOD.

Elkins-Tanton:
DOES IT LOOK GOOD?

Narrator: AS WELL AS ZIRCONS
TO DATE THE ERUPTIONS.

BUT COLLECTING THE EVIDENCE
WILL TAKE ENDURANCE.

[INSECTS BUZZING]

Bowring: THERE’S NOTHING LIKE
RIDING IN A BOAT

WITH A CLOUD OF MOSQUITOES
AROUND YOUR HEAD

AND DRIVING RAIN.

Black: YOU NEED SOME THINGS
TO MAKE YOU REALIZE

YOU’RE IN SIBERIA.

Narrator: AFTER MULTIPLE
EXPEDITIONS,

THE HUNT FOR EVIDENCE
IS COMING TO AN END.

NOW IT’S TIME TO FIGURE OUT

IF THE GREATEST VOLCANIC
ERUPTIONS IN EARTH’S HISTORY

CAUSED ITS GREATEST
MASS EXTINCTION.

IN CAMBRIDGE, MASSACHUSETTS,
THE EVIDENCE HAS ARRIVED.

WILL IT LINK THE SIBERIAN
ERUPTIONS TO THE GREAT DYING?

THE FIRST TASK--
TO ISOLATE THE ZIRCONS,

THE TIME-TELLING CRYSTALS
THAT RECORD HISTORY.

AFTER FIGURING OUT
WHEN EACH ZIRCON WAS FORMED,

THE SCIENTISTS HAVE A RANGE
OF REMARKABLY PRECISE DATES.

Seth Burgess:
IT’S AN AMAZING THING.

WHAT WE’VE BEEN ABLE TO SHOW
FROM OUR WORK IN SOUTH CHINA

IS THAT THE MASS EXTINCTION
OCCURRED VERY QUICKLY

AND OVER A VERY SHORT
DURATION HERE.

Bowring: 251.9.

Burgess: AND WE CAN SHOW
FROM OUR SIBERIA TRIPS

AND THE ZIRCONS
THAT WE’VE DATED,

THAT THE SIBERIAN ERUPTION
OCCURRED AT THE SAME TIME AS,

OR EVEN JUST A BIT PRIOR TO,

THE ONSET OF
THE MASS EXTINCTION.

AND THAT’S A VERY
IMPORTANT RESULT.

Bowring: WHEN YOU HAVE
TWO EVENTS IN EARTH HISTORY,

BOTH SHORT DURATION,
EXACTLY THE SAME AGE,

IT DOESN’T GET ANY BETTER

IN TERMS OF FINDING
THE SMOKING GUN.

Narrator: IT’S POWERFUL EVIDENCE

THAT MASSIVE VOLCANOES
IN SIBERIA

TRIGGERED THE GREAT DYING.

EVEN MORE SURPRISING IS
THE SPEED OF THE EXTINCTION.

INSTEAD OF HAPPENING SLOWLY
OVER MILLIONS OF YEARS

AS ONCE THOUGHT--

IT UNFOLDED IN LESS THAN 60,000.

BUT HOW COULD ERUPTIONS IN
SIBERIA AFFECT THE ENTIRE WORLD?

CRYSTALS WITHIN ANCIENT LAVA
MAY CONTAIN THE ANSWERS.

IN THEM, BEN BLACK HAS FOUND
TINY DROPLETS OF MAGMA

THAT, AMAZINGLY,
STILL CONTAIN GASES

FROM 250 MILLION YEARS AGO.

Black: YOU CAN SEE THE CRYSTAL
THAT WE’RE ANALYZING RIGHT HERE,

AND OVER HERE YOU CAN SEE
THE ACTUAL GASES

THAT WERE TRAPPED
INSIDE THIS CRYSTAL.

SO THE BRIGHTEST ORANGE COLORS
SHOW THE MOST SULFUR HERE.

AND THEN THESE GREENS SHOW YOU

WHERE THERE’S GASES
LIKE FLUORINE,

AND WE FIND CHLORINE, CARBON,
WHICH WOULD BE CARBON DIOXIDE.

Elkins-Tanton: SO IT’S TRILLIONS
OF TONS OF GASES

RELEASED INTO THE ATMOSPHERE.

AND WE TAKE ALL THE EVIDENCE,

AND WE PUT THEM
INTO GLOBAL CLIMATE MODELS.

AND WE ASK THE QUESTION, CAN
THAT MUCH GAS CHANGE THE CLIMATE

TO SUCH AN EXTENT THAT
IT WOULD KILL ALL THE THINGS

THAT WE KNOW THAT IT KILLED?

AND IT LOOKS LIKE
THAT’S WHAT IT TAKES

TO MAKE A GLOBAL
EXTINCTION EVENT.

Narrator: OUR PICTURE
OF THE GREAT DYING

IS NOW CLEARER THAN EVER BEFORE.

AS MAGMA ROSE TO THE SURFACE,
IT HEATED SEDIMENTARY ROCKS,

RELEASING MASSIVE AMOUNTS
OF CLIMATE-CHANGING GASES.

AMONG THEM WAS CARBON DIOXIDE,
WHICH TRAPS HEAT.

AS THE WORLD GREW WARMER,
OCEANS CURRENTS MAY HAVE SLOWED,

CUTTING OFF THE FLOW OF OXYGEN,
CREATING DEAD ZONES.

EXCESS CARBON DIOXIDE TRIGGERED
OCEAN ACIDIFICATION,

PREVENTING ANIMALS
FROM BUILDING SHELLS.

THE CHANGES WERE SO OVERWHELMING

THAT MOST CREATURES
COULD NOT ADAPT.

SO WHAT CAN EXTINCTIONS
OF THE PAST

TELL US ABOUT OUR WORLD TODAY?

Carroll: WHAT’S REALLY VALUABLE

ABOUT COMPARING THESE
MASS EXTINCTIONS,

THE KT AND THE END-PERMIAN,

IS THEY WERE CAUSED BY TOTALLY
DIFFERENT TRIGGERS, RIGHT?

AN ASTEROID FROM ABOVE
OR VOLCANISM FROM BENEATH.

BUT THEY HAD
VERY SIMILAR EFFECTS

IN TERMS OF
CATASTROPHIC DESTRUCTION

OF ECOSYSTEMS AROUND THE WORLD.

AND THERE’S
A REALLY SIMPLE LESSON

THAT’S RELEVANT TO TODAY,

WHICH IS, IF ENVIRONMENTAL
CHANGE IS GREAT ENOUGH,

FAST ENOUGH,
AND ON A GLOBAL SCALE,

THE ENTIRE PLANET IS IN TROUBLE.

Narrator: HUMANS ARE RAPIDLY
CHANGING THE EARTH.

COULD LIFE BE
AT THE BRINK AGAIN?

MASS EXTINCTIONS EONS AGO

MAY SEEM AS IF THEY HAPPENED
ON A DISTANT PLANET.

BUT THIS IS THE SAME STAGE,

EVEN IF THE ACTORS HAVE CHANGED.

WE’RE NOW IN A THIRD GREAT AGE,
KNOWN AS THE AGE OF MAMMALS.

DURING THIS TIME, LIFE REACHED
ITS GREATEST LEVEL OF DIVERSITY.

BUT THERE ARE FEARS
THAT THE WORLD COULD FACE

ANOTHER MASS EXTINCTION.

ONLY THIS TIME, INSTEAD
OF VOLCANOES OR ASTEROIDS,

THE TRIGGER WOULD BE US.

PALEONTOLOGIST ANTHONY BARNOSKY
IS INVESTIGATING

IF THE SIXTH MASS EXTINCTION
HAS ALREADY ARRIVED.

Anthony Barnosky: HUMANS USED TO
BE PART OF NATURE.

NOW WE’RE A FORCE OF NATURE.

WE HAVE TRANSFORMED 40% OF
THE PLANET FOR OUR OWN NEEDS.

AND THINGS ARE ONLY
GOING TO GET WORSE,

BECAUSE WE’RE GOING TO HAVE
THREE BILLION MORE PEOPLE

ON THE PLANET BY THE YEAR 2050.

Narrator: ACROSS THE WORLD,
VAST REGIONS OF FORESTS,

HOME TO MOST BIODIVERSITY
ON LAND, HAVE DISAPPEARED.

OTHER HABITATS
ARE ALSO VANISHING.

70 YEARS AGO,

THE AFRICAN SAVANNAH WAS HOME
TO 400,000 LIONS.

TODAY, ONLY AROUND 30,000 REMAIN
IN ISOLATED PATCHES.

Barnosky: WE’RE DOING TWO THINGS
TO OTHER SPECIES NOW.

WE’RE TAKING AWAY
WHERE THEY LIVE.

BUT WE’RE ALSO SEPARATING
THEIR NEIGHBORHOODS.

AND THE PROBLEM IS THAT
WE’RE CHANGING THE CLIMATE

AT THE SAME TIME.

SO THE NORMAL RESPONSE
OF A SPECIES

WOULD BE JUST TO MOVE
TO A NEW HOME.

THEY CAN’T DO THAT ANYMORE,

BECAUSE, IN ORDER TO MOVE
TO A NEW HOME,

THEY MIGHT HAVE TO GO
THROUGH LOS ANGELES.

Narrator: BARNOSKY BELIEVES
WE’RE CHANGING

THE EARTH’S ATMOSPHERE IN WAYS

THAT RIVAL PAST
MASS EXTINCTIONS.

JUST LIKE
THE SIBERIAN ERUPTIONS,

WE’RE RELEASING GREENHOUSE GASES
THAT TRAP HEAT.

OVER THE PAST CENTURY,

CO2 LEVELS AND GLOBAL SURFACE
TEMPERATURES HAVE CLIMBED,

STRESSING ECOSYSTEMS
ACROSS THE WORLD.

YOU CAN SEE THE WARNING SIGNS

EVEN IN ONE OF THE WORLD’S
MOST PROTECTED PLACES,

YELLOWSTONE NATIONAL PARK.

[WOLF HOWLS]

[BISON GRUNTS]

IT LIES WITHIN ONE OF
THE LARGEST INTACT ECOSYSTEMS

NORTH OF THE EQUATOR,

SHELTERING OVER 60 SPECIES
OF MAMMALS.

AMONG THEM IS THE GRIZZLY BEAR,

WHOSE NUMBERS HAVE REBOUNDED
FROM 150 TO ABOUT 600.

BUT GRIZZLIES ARE BACK ON
THE ENDANGERED SPECIES LIST.

CLIMATE CHANGE IS KILLING OFF

ONE OF THEIR KEY
SOURCES OF FOOD--

THE HIGH-FAT SEEDS OF
THE WHITEBARK PINE TREE.

ACROSS THE AMERICAN
AND CANADIAN ROCKIES,

ONCE-GREEN FORESTS
ARE BLEACHED OF COLOR,

AS WHITEBARK PINES ARE KILLED
BY A TINY ASSAILANT.

BIOLOGIST ELIZABETH HADLY
HAS STUDIED

THE YELLOWSTONE ECOSYSTEM
FOR 30 YEARS.

Elizabeth Hadly: OKAY, SEAN.

THIS IS A REALLY,
THIS IS A GREAT EXAMPLE.

SO, YOU KNOW, IF YOU LOOK UP,
YOU SEE GREEN BRANCHES,

AND THERE’S SOME CONES UP THERE.

BUT IN FACT THIS TREE
HAS JUST BEEN HIT.

AND THE EVIDENCE
ARE THESE LITTLE HOLES

THAT ARE MARKED BY RED.

Carroll: SO THE DEFENSE THAT
THIS TREE HAS IS REALLY MINIMAL.

Hadly: THAT SIGN HERE...

Narrator: THE CULPRIT IS
THE MOUNTAIN PINE BEETLE,

WHICH BORES INTO THE BARK
TO LAY ITS EGGS.

THE NEWLY HATCHED LARVAE
EAT AWAY AT THE TREE,

QUICKLY KILLING IT.

Carroll: SO THIS IS THE BEAST
CAUSING ALL THE TROUBLE.

LOOK AT THAT, NOT EVEN AS BIG
AS MY FINGERNAIL.

Narrator: BEETLES HAVE
LONG LIVED HERE,

BUT AS THE CLIMATE WARMS,

THEY’RE MOVING TO
HIGHER ELEVATIONS,

ATTACKING TREES
ONCE OUT OF REACH.

AN AVERAGE INCREASE OF
JUST A COUPLE OF DEGREES

MEANS THE WINTER IS NO LONGER
COLD ENOUGH, FOR LONG ENOUGH,

TO KILL OFF THE BEETLES.

AND IT’S ALL HAPPENING
VERY FAST.

Hadly: THIS IS WHAT AN ATTACK
LOOKS LIKE

SEVEN TO TEN YEARS LATER.

Carroll: WOW!

Hadly: THE LAST TIME I WAS HERE,

THIS WAS A DENSE, GREEN FOREST
WITH A CACOPHONY OF SOUND.

WITHIN TEN YEARS,
THIS FOREST IS SILENT.

THESE TREES ARE NOT GOING
TO PRODUCE CONES

FOR AT LEAST 50 YEARS.

THAT IS, IF WHITEBARK PINE
COMES BACK.

Carroll: SO THE CHANGE
MAY BE PERMANENT.

[SQUAWKING]

Narrator: AND BEARS AREN’T
THE ONLY LOSERS.

CLIMATE CHANGE
OF JUST A FEW DEGREES

IS THREATENING THE WEB OF LIFE.

SPECIES AROUND THE WORLD
ARE MOVING, IF THEY CAN.

EVEN MORE WORRISOME,

TEMPERATURES MAY RISE
BY 9 TO 11 DEGREES FAHRENHEIT

BY THE END OF THE CENTURY--

A RISE ALMOST AS GREAT
AS DURING THE END-PERMIAN.

Carroll: AND THE UNCERTAINTY IS
NOT THAT THE CLIMATE IS WARMING.

THE UNCERTAINTY IS WHAT
THE EFFECTS ARE GONNA BE.

THINGS THAT SURPRISE BIOLOGISTS.

UNEXPECTED CONNECTIONS.

OR, FOR EXAMPLE,
CERTAIN POPULATIONS

THAT ARE UNDER CERTAIN STRESSES
WE DIDN’T QUITE RECOGNIZE,

BUT THE NEXT STRESS
MAY PUSH THEM OVER THE EDGE.

Narrator: WHAT’S HAPPENING
ON LAND IS VISIBLE.

BUT WHAT ABOUT BENEATH THE SEA?

ALONG THE CALIFORNIA COAST,

THERE ARE SIGNS THAT THE CO2
WARMING THE ATMOSPHERE

IS ALSO DISSOLVING
INTO THE OCEANS,

CHANGING THEIR CHEMISTRY.

Barnosky: AND IT HAS
THE NET EFFECT

OF ACTUALLY MAKING THOSE WATERS
MORE ACIDIC.

AND IT’S A HUGE PROBLEM

FOR THE MARINE CREATURES
THAT LIVE THERE.

THEY RELY ON A CERTAIN
WATER CHEMISTRY.

IF THE WATERS GET TOO ACIDIC,
THEY CAN’T BUILD THEIR SHELLS.

IN FACT, WE’RE ALREADY SEEING
THAT IN THE PACIFIC NORTHWEST,

WHERE THE EMBRYOS OF OYSTERS
AND SCALLOPS CANNOT SURVIVE.

Narrator: IF THE CURRENT TREND
CONTINUES,

SCIENTISTS PREDICT THAT
BY THE END OF THIS CENTURY,

THE RATE OF OCEAN ACIDIFICATION
WILL MIRROR WHAT HAPPENED

DURING THE GREAT DYING.

BY GEOLOGICAL STANDARDS, THIS IS
CHANGE AT A BREAKNECK PACE.

Barnosky: THERE ARE PREDICTIONS
THAT WE WILL LOSE

MOST OF THE CORAL REEFS ON EARTH
BY THE YEAR 2070.

NOW, IF WE LOSE CORAL REEFS,

WE’RE NOT JUST TALKING ABOUT
NO NICE PLACES TO SNORKEL,

WE’RE TALKING ABOUT LOSS OF 25%
OF THE FISH SPECIES IN THE SEA

THAT DEPEND ON CORAL REEFS.

WE’RE TALKING ABOUT LOSS OF
10% OF THE OCEAN’S FISHERIES

THAT WE DEPEND UPON.

Narrator: HABITAT DESTRUCTION,
OCEAN ACIDIFICATION,

RISING CO2 LEVELS
AND TEMPERATURES.

HUMANS ARE ALMOST AS GOOD
AS ASTEROIDS AND VOLCANOES

AT WREAKING HAVOC.

SO HAS THE SIXTH MASS EXTINCTION
ALREADY BEGUN?

TO FIND OUT, BARNOSKY ANALYZED
RATES OF EXTINCTION

IN THE FOSSIL RECORD

AND COMPARED THEM TO DATA

TRACKING ENDANGERED SPECIES
TODAY.

Barnosky:
I HAD A SNEAKING SUSPICION

THAT IF WE WERE ABLE
TO CALCULATE EXTINCTION RATES

OVER HUMAN HISTORY
OF THE PAST FEW CENTURIES

IN THE SAME WAY WE CALCULATED
EXTINCTION RATES

IN THE DEEP-TIME
PALEONTOLOGICAL RECORD,

THAT IT MIGHT NOT LOOK SO BAD.

I WAS TOTALLY WRONG.

ONCE WE CRUNCHED THE NUMBERS,

IT TURNED OUT
WE REALLY WERE SEEING

HUGELY ACCELERATED
EXTINCTION RATES TODAY.

Narrator: IN FACT,
AT LEAST 12 TIMES FASTER

THAN SPECIES NORMALLY DIE OFF.

TODAY, A QUARTER OF ALL MAMMAL

AND ONE FIFTH OF FISH
AND REPTILE SPECIES

ARE THREATENED WITH EXTINCTION.

AMPHIBIANS ARE VANISHING
EVEN FASTER.

Barnosky: IF WE CONTINUE
TO LOSE SPECIES

AT THE RATE WE’VE LOST THEM
OVER THE LAST CENTURY,

WITHIN AS LITTLE AS 200 YEARS,

WE WOULD SEE 75% OF SPECIES
WE KNOW ABOUT

DISAPPEARING FROM
THE PLANET FOREVER.

IF WE CONTINUE DOING THINGS

PRETTY MUCH AS WE ARE
DOING THEM TODAY,

WHAT THAT MEANS IS
THE SIXTH MASS EXTINCTION

IS A VIRTUAL CERTAINTY.

Carroll: I THINK THE HARDEST
QUESTION TO ANSWER

IS WHAT DO WE DO?

PARTICULARLY WHAT DO WE DO AS
INDIVIDUALS? WHAT CAN WE DO?

WELL, ONE THING WE KNOW
THAT WORKS ARE RESERVES.

SET ASIDE A LARGE ENOUGH SPACE
OF INTACT ECOSYSTEMS,

AND ANIMALS CAN THRIVE THERE.

SO WE AT LEAST HAVE TO DO THAT.

[WOLF HOWLS]

Narrator: A GLOBAL EFFORT
IS NOW UNDER WAY

TO CONNECT WILDLIFE HABITATS
WITH LAND CORRIDORS

SO ANIMALS CAN MOVE FREELY.

ONE CORRIDOR BEING PROPOSED

WOULD RUN FROM ALASKA
TO THE YUCATAN,

AND INCLUDES YELLOWSTONE.

Barnosky: I JUST THINK
IT’S REALLY IMPORTANT

FOR PEOPLE TO REALIZE
THAT THIS ISN’T A LOST CAUSE.

HUMANITY IS AT A CROSSROADS
RIGHT NOW.

WE CAN EITHER CHOOSE TO KEEP
ENDANGERED SPECIES ALIVE

AND AVOID
THE SIXTH MASS EXTINCTION,

OR WE CAN WATCH
THE TRAIN WRECK HAPPEN.

WE HAVE A VERY NARROW WINDOW
OF OPPORTUNITY TO FIX THIS.

WILL WE DO THAT?

I LIKE TO THINK WE WILL.

Carroll: THIS IS
THE AGE OF MAMMALS,

AND WE DON’T WANT IT TO END
LIKE THE AGE OF DINOSAURS,

PARTICULARLY AT OUR OWN HANDS.

WE DON’T WANT
SORT OF THE EQUIVALENT

OF T. REX OF YESTERDAY,

THE GRIZZLY BEARS
OF NORTH AMERICA,

OR THE LIONS OF AFRICA,
OR THE TIGERS OF ASIA,

TO DISAPPEAR ONLY TO BE SEEN
AS STUFFED ANIMALS IN A MUSEUM.

SO THE QUESTION IS CAN WE--

BECAUSE WE UNDERSTAND
WHAT’S GOING ON--

DO SOMETHING ABOUT IT?