Earths mass extinction Peter Ward

[Music]

so I want to start out with this

beautiful picture from my childhood I

love the science fiction movies here it

is this island earth and leave it to

Hollywood to get it just right two and a

half years in the making I mean even the

creationists give us 6,000 but Hollywood

goes to the chase and in this movie we

see what we think is out there flying

saucers and aliens every world has an

alien and every alien world has the

flying saucer and they move about with

great speed

aliens well don brownlee my friend and i

finally got to the point where we got

tired of turning on the TV and seeing

the spaceships and seeing the aliens

every night and tried to write a

counter-argument to it and put out what

does it really take for an earth to be

habitable for a planet to be an earth to

have a place where you could probably

get not just life but complexity which

requires a huge amount of evolution and

therefore constancy of conditions so in

2000 rewrote rare earth in 2003 we then

asked let’s not think about where earths

are in space but how long is Earth Ben

Earth if you go back to billion years

you’re not on an earth-like planet

anymore what we call an earth-like

planet is actually a very short interval

of time well rare earth actually taught

me off a lot about meeting the public

right after I got an invitation go to a

science fiction convention and with all

great earnestness walked in David Brin

was going to debate me on this and as I

walked in the crowd of 100 started Bowie

and lustily but a girl came up and said

my dad says you’re the devil

you cannot take people’s aliens away

from them and expect to be anybody’s

friends well the second part of that

soon after and I was talking to Paul

Allen and I saw him in the audience I

handed him a copy of rare earth and Jill

tarter was there and she turned to me

and she looked to me just like that girl

in the Exorcist it was it burns it burns

because Eddie doesn’t want to hear this

said he wants there to be stuff out

there I really applaud the SETI efforts

but we have not heard anything yet and I

really do think we have to start

thinking about what’s a good planet and

what isn’t

now I throw this slide up because it

indicates to me that even if SETI does

hear something can we figure out what

they said because this is a slide that

was passed between the two major

intelligence is on earth a Mac to a PC

and it can’t even get the letters right

so how are we going to talk to the

aliens and if there are 50 light-years

away and we call them up and you buf

about and then 50 years later comes back

and they say please repeat I mean there

we are our planet is the good planet

because you can keep water Mars is a bad

planet but it’s still good enough for us

to go there and to live on its surface

for protected but Venus is a very bad

the worst planet even though it’s Earth

like it even though early in its history

made very well of Harvard earth-like

life it’s sue succumbed to runaway

greenhouse that’s an 800 degrees

centigrade surface because of rampant

carbon dioxide well we know from

astrobiology that we can really now

predict what’s going to happen to our

particular planet we are right now and

the beautiful Oreo of existence of at

least life on planet Earth following the

first horrible microbial age in the

Cambrian explosion life emerged from the

swamps complexity arose and from what we

can tell we’re halfway through we have

as much time for animals to exist on

this planet as they have been here now

till we hit the second microbial age and

that will happen paradoxically

everything here about global warming

when we hit co2 down to ten parts per

million we are no longer going to have

to have plants or allowed to have any

photosynthesis and there go animals so

after that we probably have 7 billion

years the Sun increases in its intensity

and its brightness and finally at about

12 billion years after first our turd

the earth is consumed by a large Sun and

this is what’s left so our planet like

us is going to have an age at an old age

and we are in its golden summer age

right now but there’s two phase two

everything isn’t there now a lot of you

are going to die of old age but

some of you horribly enough are going to

die in an accident and that’s the fate

of a platitude earth if we’re lucky

enough if it doesn’t get hit by a pale

Bop or gets blasted by some supernova

nearby in the next seven billion years

we’ll finally be your fate but what

about accidental death

well paleontologists for the last 200

years have been charting death it’s

strange

extinction as a concept wasn’t even

thought about until Baron Cuvier and

France found this first Mastodon he

couldn’t match it up to any bones on the

planet and he said AHA extinct and very

soon after the fossil record started

yielding a very good idea of how many

plants and animals that have been his

complex life really began to leave a

very interesting fossil record in that

complex record of fossils there were

times when lots of stuff seemed to be

dying out very quickly and the

father/mother geologists called these

mass extinctions along was thought to be

either act of god or perhaps long slow

climate change and that really changed

in 1980 in this rocky outcrop near

Gubbio where walter alvarez trying to

figure out what was the time difference

between these white rocks which held

creatures of the Cretaceous period and

the pink rocks above which held tertiary

fossils how long did it take to go from

one system to the next and what they

found is something unexpected they found

in this gap in between a very thin clay

layer and that clay layer this very thin

red layer here is filled with iridium

and not just iridium is filled with

glassy cereals and has filled the quartz

grains that have been subjected to

enormous pressure shock quartz now in

this life the white is chalk and this

chalk was deposited in a warm ocean the

chalk itself is composed by plankton

which has fallen down from the sea

surface onto the sea floor so the 90% of

the sediment here is skeleton of living

stuff and then you have that millimeter

thick red layer and then you have black

rock and the black rock is the sediment

on that sea bottom in the absence of

plankton and that’s what happens in an

asteroid catastrophe because that’s what

this was of course this is the famous KT

a ten kilometer body hit the planet the

effects of it spread this very thin

impact layer all over the planet and we

had very

quickly the depth of the dinosaurs the

death of these beautiful ammonites lasts

until here and selasa furs over here and

so much else I mean it must be true

because we’ve had to Hollywood

blockbusters since that time and this

paradigm from 1980 to about 2000 totally

changed how we geologists thought about

catastrophes prior to that

uniformitarianism was the dominant

paradigm the fact that if anything

happens on the planet in the past there

were present-day processes that will

explain it but we haven’t witnessed a

big asteroid impact so this is a type of

neo catastrophism and it took about 20

years for the scientific establishment

to finally come to grips that yes we

were hit and yes the effects of that hit

caused a major mass extinction well

there are five major mass extinctions

the last 500 million years called the

Big Five they range from 450 billion

years ago to the last the KT number for

the biggest of all was the P or the

Permian extinction sometimes called the

mother of all mass extinctions and every

one of these has been subsequently

blamed on large body impact but is this

true the most recent the Permian was

thought to have been impact because of

this beautiful structure on the right

this is a buckminsterfullerene a carbon

60 because it looks like those terrible

geodesic domes of my late beloved 60s

they’re called bucky balls this evidence

was used to suggest at the end of the

Permian 250 million years ago a comet

hit us and when the comet hits the

pressure produces the bucky balls and it

captures bits of the comet helium-3 very

rare in the surface of the earth very

common in space but is this true in 1990

working on the KT extinction for ten

years I moved to South Africa to begin

work twice a year in the great karoo

desert I was so lucky to watch the

change of that South Africa into the new

South Africa as I went year by year and

I worked on this Permian extinction

camping by this Boer graveyard for

months at a time and the fossils are

extraordinary

you know gaze upon your very distant

ancestors these are mammal-like reptiles

they are culturally invisible we do not

make movies about these this is

gorgon opción or Gorgon that’s an 18

inch long skull of an animal that was

probably seven or eight feet sprawled

like a lizard probably had a head like a

lion this is the top carnivore the t-rex

of his time there’s lots of stuff this

is my poor son Patrick this is called

paleontological child abuse

hold still you’re the scale there was

big stuff back then 55 species of mammal

like reptiles the age of mammals had

well and truly started 250 million years

ago and then a catastrophe happened and

what happens next is the age of

dinosaurs it was all a mistake it should

have never happened but it did now

luckily this throwing acid on the size

of a robin egg here this is a skull

discovered just before taking this

picture there’s a pen for scale it’s

really tiny this is in the lowest

Triassic after the mass extinction is

finished you can see the eye socket you

can see the little teeth in the front if

that does not survive I’m not the thing

giving this talk something else is

because if that doesn’t survive we are

not here there are no mammals is that

close one species eats through well can

we say anything about the pattern of who

survives and who doesn’t here’s sort of

the end of that ten years of work the

ranges of stuff the red line is the mass

extinction but we’ve got survivors and

things that get through and it turns out

the things that get through

preferentially are cold Bloods

warm-blooded animals take a huge hit at

this time the survivors that do get

through produced this world of

crocodile-like creatures there’s no

dinosaurs yet just the smo saurian scaly

nasty swampy place with a couple of tiny

mammals hiding in the fringes and there

they would hide for 160 million years

until liberated by that KT asteroid so

not impact what and the what I think is

that we returned over and over and over

again to the Precambrian world at first

microbial age and the microbes are still

out there they hate we animals they

really want their world

and they’ve tried over and over and over

again and suggested me the life causing

these mass extinctions because it did is

inherently anti Guyon this whole Gaia

idea the life makes the world better for

itself and it would have been on a

freeway on a Friday afternoon in Los

Angeles believing in the Gaia theory no

so I really suspect there’s an

alternative and that life does actually

try to do itself in not consciously but

just because it does and here’s the

weapon it seems that it did so over the

last 500 million years there are

microbes which through the metabolism

produce hydrogen sulfide and they do so

in large amounts hydrogen sulfide is

very fatal to humans as small as 200

parts per million will kill you you only

have to go to the Black Sea and a few

other places some lakes and get down and

you’ll find that the water itself turns

purple turns purple for the presence of

numerous microbes which have to have

sunlight and have to have hydrogen

sulfide and we can detect their presence

today we can see them but we can also

detect their presence in the past and

the last three years have seen an

enormous breakthrough in a brand-new

field

I am almost extinct I’m a paleontologist

who collects fossils but the new wave of

paleontologists my graduate students

collect biomarkers they take the set of

it itself they extract the oil from it

and from that they can produce compounds

which turn out to be very specific to

particular microbial groups is because

lipids are so tough they can get

preserved in sediment and last the

hundreds of millions of years necessary

and be extracted and tell us who was

there and we know who was there at the

end of the Permian at many of these mass

extinction boundaries this is what we

find I saw Ernie retain its very

specific it can only occur if the

surface of the ocean has no oxygen and

is totally saturated with hydrogen

sulfide enough for instance to come out

of solution

this led Lee Kump and others from Penn

State and my group to propose what I

call the comp I pas thesis many of the

mass extinctions were caused by lowering

oxygen by high co2

and the worst effect of global warming

it turns out hydrogen sulfide being

produced out of the oceans well what’s

the source of this in this particular

case the source over and over been flood

basalts this is a view of the earth now

if we extract a lot of it and each of

these looks like a hydrogen bomb

actually the effects are even worse this

is one deep earth material comes to the

surface spreads out over the surface of

the planet well it’s not the lava that

kills anything it’s the carbon dioxide

that comes out with it this isn’t Volvos

this is volcanoes but carbon dioxide is

carbon dioxide so these are new data

about burger dive from Yale put together

and what we try to do now is track the

amount of carbon dioxide in the entire

rock record we can do this from a

variety of means and put on the red

lines here when these what I call

greenhouse mass extinctions took place

and there’s two things they’re really

evident here to me is that these

extinctions take place when co2 is going

up but the second thing that’s not shown

on here the earth has never had any ice

on it when we’ve had a thousand parts

per million co2 we are a 380 in climbing

we should be up to a thousand in three

centuries at the most but my friend

David Bautista in Seattle says he thinks

a hundred years so there goes the ice

caps and there comes 240 feet of

sea-level rise I live in a view house

now I’m going to have waterfront alright

what’s the consequence the oceans

probably turn purple and we think this

is the reason the complexity took so

long to take place on planet Earth we

had these hydrogen sulfide oceans for a

very great long period they stopped

complex life from existing we know

hydrogen sulfide is erupting presently a

few places on the planet and I throw

this slide and this is B actually two

months ago let’s throw this slide in

because here is my favorite animal

chambered nautilus it’s been on this

planets this animals for started 500

million years this is a tracking

experiment interview scuba divers you

want to get involved one of the coolest

projects ever this is off the Great

Barrier Reef and as we speak now these

Nautilus are tracking out their

behaviors to us but the thing about this

is that every once in a while

divers can run into trouble so I’m gonna

do little thought experiment here this

is a great white shark that ate some of

my traps we pulled it up up it comes so

it’s out there with me at night so I’m

swimming along and it takes off my leg

I’m 80 miles from shore what’s going to

happen to me well now I died five years

from now this is what I hope happens to

me I’ve taken back to the boat I’m given

a gas mask eighty parts per million

hydrogen sulfide I’m then throwing a

nice pond

I’m cooled fifteen degrees lower and I

can be taken to a critical care hospital

and the reason I could do that is

because we mammals have gone through a

series of these hydrogen sulfide events

and our bodies have adapted and we can

now use this is what I think will be a

major medical breakthrough this is Mark

Roth he was funded by DARPA trying to

figure out how to save Americans after

battlefield injuries he believes out

pigs he puts in 80 parts per million

hydrogen sulfide the same stuff that

survived these past mass extinctions and

he turns a mammal into a reptile I

believe we are seeing in this response

the result of mammals and reptiles

having undergone a series of exposures

to h2s I got this email from him two

years ago

he said I think I got an answer to some

of your questions so he now has taken

mice down for as many as four hours

sometimes six hours and these are brand

new data he sent me on the way over here

on the top now that is a temperature

record of a mouse who has gone through

the dotted line to temperature so the

temperature starts 225 centigrade and

down it goes down it goes six hours

later up goes the temperature now the

same mouse is given eighty parts per

million hydrogen sulfide in this solid

graph and look what happens to his

temperature its temperature drops it

goes down to 15 degrees centigrade from

35 and comes out of this perfectly fine

here is a way we can get people to

critical care here’s how we can bring

people cold enough to last till we get

critical care now you’re all thinking

yeah what about the brain tissue and so

this is one of the great challenges is

going to happen you’re in an accident

you got two choices you’re going to die

or you’re going to take the hydrogen

sulfide and say 75% of you

is safe mentally what are you going to

do do we all have to have little buttons

say let me die this is coming towards

this I think this is going to be a

revolution we’re going to save lives but

there’s going to be a cost to it the new

view of mass extinctions yes we were hit

and yes we have to think about the long

term because we will get hit again

but there’s a far worse danger

confronting us we can easily go back to

the hydrogen sulfide world give us a few

millennia and we humans children ask

those few millennia will it happen again

if we continue it will happen again how

many of us flew here how many of us have

gone through our entire Kyoto quota just

for flying this year how many of you

have exceeded it yeah I’ve certainly

exceeded it we have a huge problem

facing us as a species we have to beat

this I want to be able to go back to

this reef thank you the one question to

Peter so am i understanding you right

that what you’re saying here is that we

have in our own bodies a biochemical

response to hydrogen sulfide that in

your mind proves that there have been

past mass extinctions due to climate

change yeah every single cell in us can

produce my new quantities of hydrogen

sulfide in great crises this is what

Roth is found out so what we’re looking

at now does it leave a signal doesn’t

leave a signal in bone or in plant we go

back to the fossil record and we could

try to detect how many of these have

happened in the past

it’s simultaneously an incredible

medical technique but also a terrifying

blessing and curse

you