Earth's mass extinctions | Peter Ward

Translator: Niels Justus Reviewer: Anders Finn Jørgensen

So, I want to start out with

Jeg begynder med

this beautiful picture from my childhood.

dette dejlige billede fra min barndom.

I love the science fiction movies.

Jeg elsker science fiction film.

Here it is: "This Island Earth."

Her er den: "Denne Ø kaldet Jorden."

And leave it to Hollywood to get it just right.

og overlad blot Hollywood om at gøre det rigtigt.

Two-and-a-half years in the making.

Fremstillingen tog to et halvt år.

(Laughter)

(latter)

I mean, even the creationists give us 6,000,

Altså - selv creationisterne giver os 6.000 år,

but Hollywood goes to the chase.

men Hollywood vil ikke stå tilbage.

And in this movie, we see what we think is out there:

I den film ser vi, hvor vi tror er derude:

flying saucers and aliens.

Flyvende tallerkner og rumvæsner.

Every world has an alien, and every alien world has a flying saucer,

Enhver planet har et rumvæsen, og alle fjerne verdener har en flyvende tallerken

and they move about with great speed. Aliens.

og de bevæger sig med stor hastighed.

Well, Don Brownlee, my friend, and I finally got to the point

Don Brownlee - min ven - og jeg

where we got tired of turning on the TV

blev til sidst trætte af at tænde for fjernsynet

and seeing the spaceships and seeing the aliens every night,

og se rumskibe og rumvæsner hver aften,

and tried to write a counter-argument to it,

og prøvede at skrive et mod-argument mod det,

and put out what does it really take for an Earth to be habitable,

og vise, hvad der virkelig skal til, for en Jord kan være beboelig.

for a planet to be an Earth, to have a place

For at en planet kan være Jorden, kan være et sted

where you could probably get not just life, but complexity,

hvor man sandsynligvis vil have ikke blot liv, men kompleksitet

which requires a huge amount of evolution,

som kræver en enorm evolution,

and therefore constancy of conditions.

og derfor konstante livsbetingelser.

So, in 2000 we wrote "Rare Earth." In 2003, we then asked,

I år 2000 skrev vi bogen "En Sjælden Jord". Vi spurgte dengang:

let's not think about where Earths are in space, but how long has Earth been Earth?

Tænk ikke på hvor Jorden befinder sig i rummet, men på hvor længe har Jorden været Jorden ?

If you go back two billion years,

Hvis man går 2 milliarder år tilbage

you're not on an Earth-like planet any more.

så er man ikke på en Jord-lignende planet.

What we call an Earth-like planet is actually a very short interval of time.

Dét vi kalder en Jord-lignende planet, findes faktisk kun i et meget kort tidsrum.

Well, "Rare Earth" actually

Bogen "En Sjælden Jord", lærte mig faktisk

taught me an awful lot about meeting the public.

en masse om at møde offentligheden.

Right after, I got an invitation to go to a science fiction convention,

Jeg fik straks en invitation fra en science fiction kongres.

and with all great earnestness walked in.

og med den største seriøsitet jeg gik jeg på scenen.

David Brin was going to debate me on this,

David Brin skulle debattere med mig,

and as I walked in, the crowd of a hundred started booing lustily.

og som jeg gik på scenen, begyndte en flok på hundrede at buh'e lystigt.

I had a girl who came up who said, "My dad says you're the devil."

Der var en pige, som kom op og sagde "Min far siger at du er djævlen selv".

You cannot take people's aliens away from them

Man kan ikke tage folks rumvæsner fra dem

and expect to be anybody's friends.

og forvente at de forbliver ens venner.

Well, the second part of that, soon after --

Vel, efter debatten

and I was talking to Paul Allen; I saw him in the audience,

hvor jeg talte med Paul Allen

and I handed him a copy of "Rare Earth."

og gav ham min bog "En Sjælden Jord",

And Jill Tarter was there, and she turned to me,

og Jill Tarter var den, og hun vendte sig mod mig,

and she looked at me just like that girl in "The Exorcist."

og så på mig med et blik, akkurat som pigen i "Eksorcisten"

It was, "It burns! It burns!"

"Det brænder ! Det brænder !"

Because SETI doesn't want to hear this.

SETI vil ikke høre om det her.

SETI wants there to be stuff out there.

SETI vil have, at der er 'noget' derude.

I really applaud the SETI efforts, but we have not heard anything yet.

Jeg bifalder faktisk SETI, men vi har ikke hørt noget endnu.

And I really do think we have to start thinking

Jeg mener vi skal begynde at tænke på

about what's a good planet and what isn't.

hvad der er en god planet og hvad der ikke er.

Now, I throw this slide up because it indicates to me that,

Jeg viser dette billede, fordi det viser mig,

even if SETI does hear something, can we figure out what they said?

at selvom SETI faktisk måtte høre noget, kan vi så regne ud hvad de sagde ?

Because this was a slide that was passed

Fordi dette billede blev sendt

between the two major intelligences on Earth -- a Mac to a PC --

mellem to store intelligenser på Jorden: en Mac og en PC.

and it can't even get the letters right --

Og de kan ikke engang på bogstaverne på plads.

(Laughter)

(latter)

-- so how are we going to talk to the aliens?

Så hvordan skal vi kunne tale med rumvæsner ?

And if they're 50 light years away, and we call them up,

Og hvis de er 50 lysår borte og vi kontakter dem

and you blah, blah, blah, blah, blah,

og man blah blah blah blah

and then 50 years later it comes back and they say, Please repeat?

og så kommer det tilbage 50 lysår senere med "Kan I gentage det ?"

I mean, there we are.

Så har vi håret i postkassen.

Our planet is a good planet because it can keep water.

Vores planet er en god planet, fordi den kan opbevare vand.

Mars is a bad planet, but it's still good enough for us to go there

Mars er en dårlig planet, men den er stadig god nok til at man kan rejse derhen

and to live on its surface if we're protected.

og til at leve på dens overflade, hvis man er beskyttet.

But Venus is a very bad -- the worst -- planet.

Men Venus er meget dårlig - den værste - planet.

Even though it's Earth-like, and even though early in its history

Selvom den er Jord-lignende, og selvom der i sin tidlige historie

it may very well have harbored Earth-like life,

meget vel kan have Jord-lignende liv,

it soon succumbed to runaway greenhouse --

så bukkede den under for en løbsk drivhus-virkning

that's an 800 degrees [Fahrenheit] surface --

der er ca 400 °C på overfladen,

because of rampant carbon dioxide.

p.gr.a. en voldsom kuldioxid.

Well, we know from astrobiology that we can really now predict

Vi ved fra astrobiologien, at vi nu forudsige,

what's going to happen to our particular planet.

hvad der vil ske med vores planet.

We are right now in the beautiful Oreo

Vi er lige nu i de dejlige periode for livs-muligheder

of existence -- of at least life on Planet Earth --

- i det mindste for planeten Jorden -

following the first horrible microbial age.

som fulgte efter den første horrible mikrobiologiske tidsalder.

In the Cambrian explosion, life emerged from the swamps,

I den Cambriske eksplosion, opstod livet fra sumpene

complexity arose,

kompleksitet opstod

and from what we can tell, we're halfway through.

og så vidt vi ved, så er vi halvvejs igennem.

We have as much time for animals to exist on this planet

Der kan eksistere dyr på denne planet

as they have been here now,

i lige så lang tid, som de allerede har eksisteret,

till we hit the second microbial age.

før vi kommer ind i den anden mikrobilogiske tidsalder.

And that will happen, paradoxically --

Og de vil ske, paradoksalt nok -- i betragtning af alt,

everything you hear about global warming --

hvad du hører om den globale opvarmning--

when we hit CO2 down to 10 parts per million,

når vi når CO2 på 10 dele pr. million.

we are no longer going to have to have plants

Vi vil ikke længere have planter

that are allowed to have any photosynthesis, and there go animals.

som kan have nogen fotosyntese, og så ryger dyrene ud.

So, after that we probably have seven billion years.

Efter det har vi sandsynligvis syv milliarder år.

The Sun increases in its intensity, in its brightness,

Solens intensitet stiger,

and finally, at about 12 billion years after it first started,

og endelig, efter omkring 12 milliarder år siden sin begyndelse

the Earth is consumed by a large Sun,

opsluges Jorden af en stor Sol,

and this is what's left.

og dette er, hvad der er tilbage.

So, a planet like us is going to have an age and an old age,

Så en planet, som os, vil have en alder og en høj alder,

and we are in its golden summer age right now.

og vi befinder os i sin gyldne sommer-alder lige nu.

But there's two fates to everything, isn't there?

Men der er to skæbner til alt, er der ikke?

Now, a lot of you are going to die of old age,

En masse af jer vil dø af alderdom,

but some of you, horribly enough, are going to die in an accident.

men nogle af jer, kedeligt nok, vil dø i en ulykke.

And that's the fate of a planet, too.

Og det er også en planets skæbne.

Earth, if we're lucky enough -- if it doesn't get hit by a Hale-Bopp,

Jorden, hvis vi er heldige nok --hvis den ikke bliver ramt af en Hale-Bopp,

or gets blasted by some supernova nearby

eller bliver sprængt af en supernova i nærheden

in the next seven billion years -- we'll find under your feet.

i de næste syv milliarder år--. er under vore fødder.

But what about accidental death?

Men hvad med død ved et uheld ?

Well, paleontologists for the last 200 years

Palæontologer har i de sidste 200 år

have been charting death. It's strange --

kortlagt død. Mærkeligt nok

extinction as a concept wasn't even thought about

så var udslettelse som begreb, slet ikke tænkt på

until Baron Cuvier in France found this first mastodon.

indtil Baron Cuvier i Frankrig fandt denne første mastodon.

He couldn't match it up to any bones on the planet,

Han kunne ikke matche det med nogen knogle på planeten,

and he said, Aha! It's extinct.

og han sagde: Aha! Den er uddød.

And very soon after, the fossil record started yielding

Og meget snart derefter, begyndte fossilerne at give

a very good idea of how many plants and animals there have been

en meget klar idé om, hvor mange planter og dyr, der har været

since complex life really began to leave

siden kompleks liv virkelig begyndte at efterlade

a very interesting fossil record.

et meget interessante fossile spor.

In that complex record of fossils,

I det komplekse spor af fossiler,

there were times when lots of stuff

der var tidspunkter, hvor masser af ting

seemed to be dying out very quickly,

syntes at dø ud meget hurtigt,

and the father/mother geologists

og far/mor geologerne

called these "mass extinctions."

kaldt disse "masseudslettelser."

All along it was thought to be either an act of God

Alt sammen mentes at være enten en handling af Gud

or perhaps long, slow climate change,

eller måske lange, langsomme klimaændringer,

and that really changed in 1980,

og det ændredes for alvor i 1980,

in this rocky outcrop near Gubbio,

i dette klippefremspring i nærheden af Gubbio,

where Walter Alvarez, trying to figure out

hvor Walter Alvarez, forsøgte at finde ud af

what was the time difference between these white rocks,

hvad tidsforskellen var mellem disse hvide klipper,

which held creatures of the Cretaceous period,

som indeholdt skabninger fra kridttiden,

and the pink rocks above, which held Tertiary fossils.

og de lyserøde klipper ovenfor, som indeholdt tertiære fossiler.

How long did it take to go from one system to the next?

Hvor lang tid tog det for at gå fra det ene system til næste?

And what they found was something unexpected.

Og hvad de fandt, var noget uventet.

They found in this gap, in between, a very thin clay layer,

De fandt, i dette mellemrum, et meget tyndt lerlag,

and that clay layer -- this very thin red layer here --

og dette lerlag--dette meget tyndt rødt lag her--

is filled with iridium.

er fyldt med iridium.

And not just iridium; it's filled with glassy spherules,

Og ikke bare iridium; Det er fyldt med glasagtig spherules,

and it's filled with quartz grains

og det er fyldt med kvarts korn

that have been subjected to enormous pressure: shock quartz.

der har været udsat for et enormt pres: "chok kvarts".

Now, in this slide the white is chalk,

I denne dias er det hvide kridt,

and this chalk was deposited in a warm ocean.

og denne kridt var deponeret i et varmt hav.

The chalk itself's composed by plankton

Kalken selv er sammensat af plankton

which has fallen down from the sea surface onto the sea floor,

der er sunket ned fra havoverfladen til havbunden,

so that 90 percent of the sediment here is skeleton of living stuff,

således at 90 procent af sedimentet her er skelettet af levende ting,

and then you have that millimeter-thick red layer,

og så har man det millimeter-tykke røde lag,

and then you have black rock.

og så har du sort klippesten.

And the black rock is the sediment on the sea bottom

Og den sorte klippesten er sedimentet på havbunden

in the absence of plankton.

i fravær af plankton.

And that's what happens in an asteroid catastrophe,

Og det er, hvad der sker i en asteroid-katastrofe,

because that's what this was, of course. This is the famous K-T.

fordi det er selvfølgelig, hvad det var. Dette er den berømte K-T.

A 10-kilometer body hit the planet.

En 10-kilometer stort legeme ramte planeten.

The effects of it spread this very thin impact layer all over the planet,

Virkningerne af det spredte dette meget tynde lag fra kollisionen, over hele planeten,

and we had very quickly the death of the dinosaurs,

og så fulgte meget hurtigt dinosaurernes uddøen,

the death of these beautiful ammonites,

døden af disse smukke Ammoniter,

Leconteiceras here, and Celaeceras over here,

Leconteiceras her og Celaeceras her,

and so much else.

og så meget andet.

I mean, it must be true,

Jeg mener, det må være sandt,

because we've had two Hollywood blockbusters since that time,

fordi vi har haft to Hollywood blockbustere siden dengang,

and this paradigm, from 1980 to about 2000,

og dette paradigme, fra 1980 til omkring 2000,

totally changed how we geologists thought about catastrophes.

ændrede totalt, hvordan vi geologer tænkte i katastrofer.

Prior to that, uniformitarianism was the dominant paradigm:

Forud for det, var enheds-princippet det dominerende paradigme:

the fact that if anything happens on the planet in the past,

det faktum, at hvis der skete noget på planeten i fortiden,

there are present-day processes that will explain it.

så er der processer i nutiden, der vil forklare det.

But we haven't witnessed a big asteroid impact,

Men vi har ikke oplevet en stor asteroide-kollision,

so this is a type of neo-catastrophism,

så dette er en slags "neo-katastrophism",

and it took about 20 years for the scientific establishment

og det tog omkring 20 år for den videnskabelige establishment

to finally come to grips: yes, we were hit;

at fatte: Ja, vi blev ramt;

and yes, the effects of that hit caused a major mass extinction.

og ja, virkningerne af dette hit forårsagede en større masseudslettelse.

Well, there are five major mass extinctions

Der findes fem større masseudslettelser

over the last 500 million years, called the Big Five.

i de sidste 500 millioner år, kaldet De Store Fem.

They range from 450 million years ago

De spænder fra 450 millioner år siden

to the last, the K-T, number four,

til den sidste, K-T, nummer fire,

but the biggest of all was the P, or the Permian extinction,

men den største af alle var P eller Perm-udslettelsen,

sometimes called the mother of all mass extinctions.

undertiden kaldet moderen til alle masseudslettelser.

And every one of these has been subsequently blamed

Og hver eneste af disse er efterfølgende begrundet

on large-body impact.

med en kollision med et stort himmellegeme.

But is this true?

Men er det sandt?

The most recent, the Permian, was thought to have been an impact

Den seneste, Perm, blev anset for at have været en kollision

because of this beautiful structure on the right.

på grund af denne smukke struktur til højre.

This is a Buckminsterfullerene, a carbon-60.

Dette er en Buckminster-fulleren, en carbon-60.

Because it looks like those terrible geodesic domes

Fordi det ligner disse frygtelige geodætiske kupler

of my late beloved '60s,

fra mit elskede 60'erne,

they're called "buckyballs."

kaldes de "buckyballs." (fodbolds-molekyle)

This evidence was used to suggest

Dette bevis blev brugt til at foreslå

that at the end of the Permian, 250 million years ago, a comet hit us.

at en komet ramt os i slutningen af Perm for 250 millioner år siden,

And when the comet hits, the pressure produces the buckyballs,

Og når kometen rammer, frembringer trykket buckyballs,

and it captures bits of the comet.

og det indfanger dele af kometen.

Helium-3: very rare on the surface of the Earth, very common in space.

Helium-3: meget sjælden på overfladen af jorden, meget almindelig i rummet.

But is this true?

Men er sandt?

In 1990, working on the K-T extinction for 10 years,

I 1990, mens jeg arbejdede på K-T udslettelsen i 10 år,

I moved to South Africa to begin work twice a year

rejste jeg til Sydafrika for at arbejde to gange om året

in the great Karoo desert.

i den store Karoo ørken.

I was so lucky to watch the change of that South Africa

Jeg var så heldig at se ændringen af det Sydafrika

into the new South Africa as I went year by year.

til det nye Sydafrika, som årene gik.

And I worked on this Permian extinction,

Jeg arbejdede på Perm udslettelsen,

camping by this Boer graveyard for months at a time.

og camperede ved denne Boer kirkegård i flere måneder ad gangen.

And the fossils are extraordinary.

Fossiler er noget ekstraordinært.

You know, you're gazing upon your very distant ancestors.

Man stirrer på sine meget fjerne forfædre.

These are mammal-like reptiles.

Disse er pattedyrs-lignende krybdyr.

They are culturally invisible. We do not make movies about these.

De er kulturelt usynlige. Vi laver ikke film om disse.

This is a Gorgonopsian, or a Gorgon.

Dette er en Gorgonopsian eller en Gorgon.

That's an 18-inch long skull of an animal

Det er en 46-cm langt kranium af et dyr

that was probably seven or eight feet, sprawled like a lizard,

der sandsynligvis var syv eller otte meter lang, udstrakt som en øgle,

probably had a head like a lion.

og sandsynligvis havde den et hoved som en løve.

This is the top carnivore, the T-Rex of its time.

Dette er den øverste kødæder, T-Rex af sin tid.

But there's lots of stuff.

Men her er der masser af ting.

This is my poor son, Patrick.

Dette er min stakkels søn, Patrick.

(Laughter)

(Latter)

This is called paleontological child abuse.

Dette kaldes paleontological børnemishandling.

Hold still, you're the scale.

Stå stille, du er skalaen.

(Laughter)

(Latter)

There was big stuff back then.

Der var store ting dengang.

Fifty-five species of mammal-like reptiles.

55 arter af pattedyrs-lignende krybdyr.

The age of mammals had well and truly started

Pattedyrenes tidsalder var godt og grundigt begyndt

250 million years ago ...

250 millioner år siden...

... and then a catastrophe happened.

... og så skete der en katastrofe.

And what happens next is the age of dinosaurs.

Dernæst kom dinosaurernes tidsalder.

It was all a mistake; it should have never happened. But it did.

Det var en fejltagelse. Det burde aldrig være sket. Men det gjorde det.

Now, luckily,

Nu, heldigvis,

this Thrinaxodon, the size of a robin egg here:

denne Thrinaxodon, med størrelse af en rødkælk, her:

this is a skull I've discovered just before taking this picture --

Dette er et kranium, som jeg havde opdaget, lige før jeg tog dette billede--

there's a pen for scale; it's really tiny --

der er en kuglepen som skala; Det er virkeligt lille--

this is in the Lower Triassic, after the mass extinction has finished.

Dette er i nedre Trias, efter at masseudslettelsen var slut.

You can see the eye socket and you can see the little teeth in the front.

Man kan se øjenhulen og man kan se de små tænder foran.

If that does not survive, I'm not the thing giving this talk.

Hvis den ikke overlever, så er jeg ikke den ting, som giver dette foredrag.

Something else is, because if that doesn't survive, we are not here;

Noget andet må være det, fordi hvis den ikke overlever, så er vi ikke her;

there are no mammals. It's that close; one species ekes through.

der vil ingen pattedyr være. Det er meget tæt på; én art lirkes gennem.

Well, can we say anything about the pattern of who survives and who doesn't?

Kan vi sige noget om mønstret af hvem der overlever, og hvem der ikke gør?

Here's sort of the end of that 10 years of work.

Her er en slags slutning af de 10 års arbejde.

The ranges of stuff -- the red line is the mass extinction.

Områderne for tingene -- den røde linje er masseudslettelsen.

But we've got survivors and things that get through,

Men vi fik overlevere, og ting der kommer igennem,

and it turns out the things that get through preferentially are cold bloods.

og det viser sig at de ting, der kom igennem, var fortrinsvis koldblodede.

Warm-blooded animals take a huge hit at this time.

Varmblodede dyr bliver et kæmpe hit på dette tidspunkt.

The survivors that do get through

De overlevende, der kom igennem,

produce this world of crocodile-like creatures.

frembragte denne verden af krokodille-lignende skabninger.

There's no dinosaurs yet; just this slow, saurian, scaly, nasty,

Der er ingen dinosaurere endnu; blot denne langsomme, krybdyrsagtige,

swampy place with a couple of tiny mammals hiding in the fringes.

skællet, grimme, sumpede sted, med et par små pattedyrsom i udkanten.

And there they would hide for 160 million years,

Og der de ville skjule sig i 160 millioner år,

until liberated by that K-T asteroid.

indtil de befries af at K-T asteroide.

So, if not impact, what?

Så hvis der ikke var nogen kollision, hvad var det så ?

And the what, I think, is that we returned, over and over again,

Jeg tror, at vi vendte tilbage, gang på gang,

to the Pre-Cambrian world, that first microbial age,

til den Pre-Cambrianske verden, den første mikrobielle tidsalder,

and the microbes are still out there.

og mikroberne er stadig derude.

They hate we animals.

De hader os dyr.

They really want their world back.

De ønsker virkelig deres verden tilbage.

And they've tried over and over and over again.

Og de har forsøgt igen og igen og igen.

This suggests to me that life causing these mass extinctions

Det får mig til at tro, at livet forårsager disse masseudslettelser

because it did is inherently anti-Gaian.

fordi det er i sagens natur anti-Gaia.

This whole Gaia idea, that life makes the world better for itself --

Hele denne Gaia idé, at liv gør verden bedre for sig selv --

anybody been on a freeway on a Friday afternoon in Los Angeles

har nogen på en motorvej på en fredag eftermiddag i Los Angeles

believing in the Gaia theory? No.

troet på Gaia teorien? Nej.

So, I really suspect there's an alternative,

Så, jeg tror virkelig, at der er et alternativ,

and that life does actually try to do itself in --

og at livet faktisk forsøgte, at gøre det af med sig selv --

not consciously, but just because it does.

ikke bevidst, men bare fordi det gør det.

And here's the weapon, it seems, that it did so over the last 500 million years.

Og her er våbnet, som det lader til, at det brugte det i de sidste 500 millioner år.

There are microbes which, through their metabolism,

Der er mikrober, som gennem deres stofskifte,

produce hydrogen sulfide,

producerer svovlbrinte,

and they do so in large amounts.

og de gør det i store mængder.

Hydrogen sulfide is very fatal to we humans.

Svovlbrinte er meget giftigt for os mennesker.

As small as 200 parts per million will kill you.

Så lidt som 200 dele pr. million vil dræbe én.

You only have to go to the Black Sea and a few other places -- some lakes --

Man behøver kun at gå til det sorte hav eller et par andre steder--nogle søer--

and get down, and you'll find that the water itself turns purple.

og dykke ned, og man vil opdage, at vandet, i sig selv, bliver lilla.

It turns purple from the presence of numerous microbes

Det bliver lilla fra tilstedeværelsen af talrige mikrober

which have to have sunlight and have to have hydrogen sulfide,

som skal have sollys og skal have hydrogensulfid,

and we can detect their presence today -- we can see them --

og vi kan spore deres tilstedeværelse i dag - vi kan se dem--

but we can also detect their presence in the past.

men vi kan også spore deres tilstedeværelse i fortiden.

And the last three years have seen

Og de sidste tre år har det været

an enormous breakthrough in a brand-new field.

et enormt gennembrud i et helt nyt felt.

I am almost extinct --

Jeg er næsten uddød--

I'm a paleontologist who collects fossils.

Jeg er en palæontolog, der indsamler fossiler.

But the new wave of paleontologists -- my graduate students --

Men den nye bølge af palæontologer -min graduate studerende-

collect biomarkers.

indsamler biomarkører.

They take the sediment itself, they extract the oil from it,

De tager selve sedimentetet, de udvinder olien fra det,

and from that they can produce compounds

og ud fra det, kan de frembringe forbindelser

which turn out to be very specific to particular microbial groups.

der viser sig for at være meget specifikke for bestemte mikrobielle grupper.

It's because lipids are so tough, they can get preserved in sediment

Fordi lipider er så hårdt, kan de forblive konserveret i sedimenterne

and last the hundreds of millions of years necessary,

og holde i hundreder af millioner af år,

and be extracted and tell us who was there.

og udvindes og fortælle os, hvem der var der.

And we know who was there. At the end of the Permian,

Og vi ved, hvem der var der. I slutningen af Perm,

at many of these mass extinction boundaries,

på mange af disse masseudslettelses-grænser,

this is what we find: isorenieratene. It's very specific.

Dette er, hvad vi ser: isorenieratene. Det er meget specifikt.

It can only occur if the surface of the ocean has no oxygen,

Det kan kun ske, hvis havets overflade ingen ilt har,

and is totally saturated with hydrogen sulfide --

og er helt mættet med svovlbrinte--

enough, for instance, to come out of solution.

nok, for eksempel, til at komme ud af opløsningen.

This led Lee Kump, and others from Penn State and my group,

Dette førte Lee Kump, og andre fra Penn State og min gruppe,

to propose what I call the Kump Hypothesis:

til at foreslå, hvad jeg kalder Kump hypotese:

many of the mass extinctions were caused by lowering oxygen,

mange af de massive udslettelser, blev forårsaget af et sænket ilt-niveau, af et høj CO2-niveau.

by high CO2. And the worst effect of global warming, it turns out:

Og den værste virkning af global opvarmning, viste sig at være

hydrogen sulfide being produced out of the oceans.

den hydrogensulfid, som produceres i havene.

Well, what's the source of this?

Hvad er kilden hertil?

In this particular case, the source over and over has been flood basalts.

I dette tilfælde, har kilden igen og igen været en oversvømmelse af lava.

This is a view of the Earth now, if we extract a lot of it.

Dette er en visning af jorden nu, hvis vi fjerner en masse.

And each of these looks like a hydrogen bomb;

Og hver af disse ligner en brintbombe;

actually, the effects are even worse.

faktisk er virkningerne er endnu værre.

This is when deep-Earth material comes to the surface,

Det er når dybtliggende materiale, kommer op til overfladen,

spreads out over the surface of the planet.

breder sig over overfladen af planeten.

Well, it's not the lava that kills anything,

Det er ikke den lava, som dræber noget,

it's the carbon dioxide that comes out with it.

Det er den kuldioxid, der kommer med den.

This isn't Volvos; this is volcanoes.

Dette er ikke Volvo'er; Dette er vulkaner.

But carbon dioxide is carbon dioxide.

Men kuldioxid er kuldioxid.

So, these are new data Rob Berner and I -- from Yale -- put together,

Dette er nye data som Rob Berner og jeg -- fra Yale -- har sat sammen,

and what we try to do now is

og hvad vi forsøger at gøre nu er

track the amount of carbon dioxide in the entire rock record --

at spore mængden af kuldioxid i klippelagene.

and we can do this from a variety of means --

og vi kan gøre dette med en bred vifte af metoder,

and put all the red lines here,

og sætte alle de røde linjer her, da disse

when these -- what I call greenhouse mass extinctions -- took place.

--hvad jeg kalder drivhus-masseudslettelse--fandt sted.

And there's two things that are really evident here to me,

Og to ting, som virkelig er klart for mig, er,

is that these extinctions take place when CO2 is going up.

at disse udslettelser finder sted, når CO2 går op.

But the second thing that's not shown on here:

Men den anden ting, der ikke er vist her:

the Earth has never had any ice on it

Jorden har aldrig haft nogen is på det

when we've had 1,000 parts per million CO2.

når vi har haft 1.000 parts per million CO2.

We are at 380 and climbing.

Vi er på 380 og stigende.

We should be up to a thousand in three centuries at the most,

Vi burde nå de tusinde i løbet af tre århundreder,

but my friend David Battisti in Seattle says he thinks a 100 years.

men min ven David Battisti i Seattle mener 100 år.

So, there goes the ice caps,

Så der forsvinder iskapperne,

and there comes 240 feet of sea level rise.

og her kommer 80 meters havstigning.

I live in a view house now;

Jeg bor i et hus med udsigt;

I'm going to have waterfront.

Jeg vil få mig en strandgrund.

All right, what's the consequence? The oceans probably turn purple.

Okay, hvad er konsekvensen? Havene bliver sandsynligvis lilla.

And we think this is the reason that complexity took so long

Og vi mener, dette er grunden til, at komplekst liv tog så lang tid,

to take place on planet Earth.

for at finde sted på planeten jorden.

We had these hydrogen sulfide oceans for a very great long period.

Vi havde disse hydrogensulfid-oceaner over en meget lang periode.

They stop complex life from existing.

De hindrer komplekst liv i at eksistere.

We know hydrogen sulfide is erupting presently a few places on the planet.

Vi ved, at hydrogensulfid lige nu bryder ud et par steder på planeten.

And I throw this slide in -- this is me, actually, two months ago --

Jeg viser dette dias -- det er faktisk mig for to måneder siden--

and I throw this slide in because here is my favorite animal, chambered nautilus.

Jeg viser dette dias i fordi her er mit favorit-dyr, chambered nautilus.

It's been on this planet since the animals first started -- 500 million years.

Den var på denne planet, da dyrene først begyndte--500 millioner år.

This is a tracking experiment, and any of you scuba divers,

Dette er et sporings-eksperiment. Hvis nogen af jer dykkere,

if you want to get involved in one of the coolest projects ever,

ønsker at blive involveret i et af de fedeste projekter nogensinde,

this is off the Great Barrier Reef.

Det ligger ved Great Barrier Reef.

And as we speak now,

Og mens vi taler nu,

these nautilus are tracking out their behaviors to us.

sporer vi disse nautilus'ers adfærd.

But the thing about this is that every once in a while

Men det hænder

we divers can run into trouble,

at vi dykkere løber ind i problemer,

so I'm going to do a little thought experiment here.

så jeg har tænkt mig at lave et lille tankeeksperiment her.

This is a Great White Shark that ate some of my traps.

Dette er en stor hvid haj, der åd nogle af mine fælder.

We pulled it up; up it comes. So, it's out there with me at night.

Vi trak den op. Her er den. Så det er mig derude om natten.

So, I'm swimming along, and it takes off my leg.

Så - jeg svømmer, og det tager mit ben.

I'm 80 miles from shore, what's going to happen to me?

Jeg er 80 km fra kysten. Hvad vil der ske med mig?

Well now, I die.

I dag ville jeg dø.

Five years from now, this is what I hope happens to me:

Fem år frem i tid, og dette er, hvad jeg håber vil ske for mig:

I'm taken back to the boat, I'm given a gas mask:

Jeg bliver taget tilbage til båden, jeg får en gas-maske:

80 parts per million hydrogen sulfide.

80 dele pr. million hydrogensulfid.

I'm then thrown in an ice pond, I'm cooled 15 degrees lower

Jeg bliver så lagt i et is-bad. Jeg bliver kølet 15 grader ned

and I could be taken to a critical care hospital.

og kunne blive taget til intensiv behandling.

And the reason I could do that is because we mammals

Og grunden til at jeg kan gøre det er, fordi vi pattedyr

have gone through a series of these hydrogen sulfide events,

har været igennem en række af disse hydrogensulfid-begivenheder

and our bodies have adapted.

og vores krop har tilpasset sig.

And we can now use this as what I think will be a major medical breakthrough.

Vi kan nu bruge dette til, hvad jeg tror vil blive et større medicinsk gennembrud.

This is Mark Roth. He was funded by DARPA.

Dette er Mark Roth. Han blev finansieret af DARPA.

Tried to figure out how to save Americans after battlefield injuries.

Han forsøger at finde ud af hvordan man kan redde amerikanere efter skader på slagmarken.

He bleeds out pigs.

Han tapper svin for blod.

He puts in 80 parts per million hydrogen sulfide --

Han tilfører 80 vægtdele pr. million hydrogensulfid--

the same stuff that survived these past mass extinctions --

det samme, som overlevede de seneste masseudslettelser--

and he turns a mammal into a reptile.

og han forvandler et pattedyr til et krybdyr.

"I believe we are seeing in this response the result of mammals and reptiles

"Jeg tror, vi i denne reaktion, ser resultatet af pattedyr og reptiler

having undergone a series of exposures to H2S."

efter at have gennemgået en række eksponeringer af H2S."

I got this email from him two years ago;

Jeg fik denne mail fra ham for to år siden:

he said, "I think I've got an answer to some of your questions."

Han sagde, "Jeg tror, jeg har fundet et svar på nogle af dine spørgsmål."

So, he now has taken mice down

Han har nu han kølet en mus

for as many as four hours, sometimes six hours,

i så meget som fire timer, sommetider seks timer,

and these are brand-new data he sent me on the way over here.

og disse er splitter-nye data som han sendte mig på vej herover.

On the top, now, that is a temperature record of a mouse who has gone through --

På toppen, er der en temperatur-optegnelse for en mus, der har været igennem--

the dotted line, the temperatures.

den stiplede linje, temperaturerne.

So, the temperature starts at 25 centigrade,

Temperaturen starter ved 25 Celsius,

and down it goes, down it goes.

og det går ned , det går ned.

Six hours later, up goes the temperature.

Seks timer senere, går det op i temperatur.

Now, the same mouse is given 80 parts per million hydrogen sulfide

OK - den samme mus gives 80 dele pr. million svovlbrinte

in this solid graph,

i denne solide kurve,

and look what happens to its temperature.

og se hvad der sker med temperaturen.

Its temperature drops.

Dens temperatur falder.

It goes down to 15 degrees centigrade from 35,

Den går ned til 15 grader Celsius fra 35,

and comes out of this perfectly fine.

og kommer helt fint ud af det.

Here is a way we can get people to critical care.

Her er en måde vi kan få folk til intensivbehandling.

Here's how we can bring people cold enough to last till we get critical care.

Sådan kan man gøre mennesker kolde længe nok indtil de kan få intensivbehandling.

Now, you're all thinking, yeah, what about the brain tissue?

Nu, tænker i alle: Ja, men hvad med hjernevævet?

And so this is one of the great challenges that is going to happen.

Det er en af de store udfordringer, der kommer til at ske.

You're in an accident. You've got two choices:

Du er i en ulykke. Har du to valgmuligheder:

you're going to die, or you're going to take the hydrogen sulfide

Du vil dø, eller du vil tage svovlbrinte

and, say, 75 percent of you is saved, mentally.

og, lad os sige, at 75 procent af dit mentale jeg vil bevares.

What are you going to do?

Hvad vil du gøre?

Do we all have to have a little button saying, Let me die?

Har vi alle har en lille knap der siger, lad mig dø?

This is coming towards us,

Det er på vej,

and I think this is going to be a revolution.

og jeg tror, at det vil blive en revolution.

We're going to save lives, but there's going to be a cost to it.

Vi kommer til at redde liv, men der vil være en omkostning ved det.

The new view of mass extinctions is, yes, we were hit,

Det nye syn på masseudslettelser er: Ja, vi blev ramt,

and, yes, we have to think about the long term,

og ja, vi skal tænke langsigtet,

because we will get hit again.

fordi vi vil blive ramt igen.

But there's a far worse danger confronting us.

Men der er en langt større fare, som konfronterer os.

We can easily go back to the hydrogen sulfide world.

Vi kan nemt komme tilbage til hydrogensulfid-verdenen.

Give us a few millennia --

Om et par årtusinder--

and we humans should last those few millennia --

og menneskeheden burde vare de par årtusinder--

will it happen again? If we continue, it'll happen again.

Vil det ske igen? Hvis vi fortsætter, vil det ske igen.

How many of us flew here?

Hvor mange af os fløj hertil?

How many of us have gone through

Hvor mange af os har opbrugt

our entire Kyoto quota

hele vores Kyoto kvote

just for flying this year?

bare ved at flyve i år?

How many of you have exceeded it? Yeah, I've certainly exceeded it.

Hvor mange af jer har overskredet det? Ja, jeg har helt sikkert overskredet det.

We have a huge problem facing us as a species.

Vi har et kæmpe problem, som vi står over for som en art.

We have to beat this.

Vi er nødt til at vinde over dette.

I want to be able to go back to this reef. Thank you.

Jeg vil gerne tilbage til dette rev. Tak.

(Applause)

(Bifald)

Chris Anderson: I've just got one question for you, Peter.

Chris Anderson: Jeg har lige fået et spørgsmål til dig, Peter.

Am I understanding you right, that what you're saying here

Jeg forstår dig ret, at hvad du siger her

is that we have in our own bodies

Vi har i vores egne kroppe

a biochemical response to hydrogen sulfide

en biokemisk reaktion på svovlbrinte

that in your mind proves that there have been past mass extinctions

der efter din mening beviser, at der har været masseudslettelser i fortiden,

due to climate change?

på grund af klimaændringer?

Peter Ward: Yeah, every single cell in us

Peter Ward: Ja, hver enkelt celle i os

can produce minute quantities of hydrogen sulfide in great crises.

kan producere små mængder hydrogensulfid i store kriser.

This is what Roth has found out.

Dette er, hvad Roth har fundet ud af.

So, what we're looking at now: does it leave a signal?

Så, hvad vi ser på nu: Efterlader det et signal?

Does it leave a signal in bone or in plant?

Efterlader det et signal i knogler eller planter?

And we go back to the fossil record and we could try to detect

Og går vi tilbage til fossil-optegnelserne og kan vi prøve at fastslå,

how many of these have happened in the past.

hvor mange af disse, der er sket i fortiden.

CA: It's simultaneously

CA: Er det samtidig

an incredible medical technique, but also a terrifying ...

en utrolig medicinsk teknik, men også en skræmmende...

PW: Blessing and curse.

PW: Velsignelse og forbandelse.