'Broken world' blamed on Carbon

From the University of Leeds , 250 million year old certainty where there was none before, now megasized.

Tropical collapse caused by lethal heat

Extreme temperatures blamed for ‘Dead Zone’

Scientists have discovered why the ‘broken world’ following the worst extinction of all time lasted so long – it was simply too hot to survive.

The end-Permian mass extinction, which occurred around 250 million years ago in the pre-dinosaur era, wiped out nearly all the world’s species. Typically, a mass extinction is followed by a ‘dead zone’ during which new species are not seen for tens of thousands of years. In this case, the dead zone, during the Early Triassic period which followed, lasted for a perplexingly long period: five million years.

A study jointly led by the University of Leeds and China University of Geosciences (Wuhan), in collaboration with the University of Erlangen-Nurnburg (Germany), shows the cause of this lengthy devastation was a temperature rise to lethal levels in the tropics: around 50-60°C on land, and 40°C at the sea-surface.

Lead author Yadong Sun, who is based in Leeds while completing a joint PhD in geology, says: “Global warming has long been linked to the end-Permian mass extinction, but this study is the first to show extreme temperatures kept life from re-starting in Equatorial latitudes for millions of years.”

It is also the first study to show water temperatures close to the ocean’s surface can reach 40°C – a near-lethal value at which marine life dies and photosynthesis stops. Until now, climate modellers have assumed sea-surface temperatures cannot surpass 30°C. The findings may help us understand future climate change patterns.

The dead zone would have been a strange world – very wet in the tropics but with almost nothing growing. No forests grew, only shrubs and ferns. No fish or marine reptiles were to be found in the tropics, only shellfish, and virtually no land animals existed because their high metabolic rate made it impossible to deal with the extreme temperatures. Only the polar regions provided a refuge from the baking heat.

Before the end-Permian mass extinction the Earth had teemed with plants and animals including primitive reptiles and amphibians, and a wide variety of sea creatures including coral and sea lillies.

This broken world scenario was caused by a breakdown in global carbon cycling. In normal circumstances, plants help regulate temperature by absorbing Co2 and burying it as dead plant matter. Without plants, levels of Co2 can rise unchecked, which causes temperatures to increase.

The study, published today [19 October 2012] in the journal Science, is the most detailed temperature record of this study period (252-247 million years ago) to date.

Sun and his colleagues collected data from 15,000 ancient conodonts (tiny teeth of extinct eel-like fishes) extracted from two tonnes of rocks from South China. Conodonts form a skeleton using oxygen. The isotopes of oxygen in skeletons are temperature controlled, so by studying the ratio of oxygen isotopes in the conodonts he was able to detect temperature levels hundreds of millions of years ago.

Professor Paul Wignall from the School of Earth and Environment at the University of Leeds, one of the study’s co-authors, said: “Nobody has ever dared say that past climates attained these levels of heat. Hopefully future global warming won’t get anywhere near temperatures of 250 million years ago, but if it does we have shown that it may take millions of years to recover.”

The study is the latest collaboration in a 20-year research partnership between the University of Leeds and China University of Geosciences in Wuhan. It was funded by the Chinese Science Foundation.

###

For more information:

‘Lethally hot temperatures during the early Triassic greenhouse’ by Yadong Sun (University of Leeds and China University of Geosciences), Michael Joachimski (University Erlangen-Nurnberg, Germany), Paul B. Wignall (University of Leeds), Chunbo Yan (China University of Geosciences), Yanlong Chen (University of Graz, Austria), Haishui Jiang (China University of Geosciences, Lina Wang (China University of Geosciences) and Xulong Lai (China University of Geosciences) is published in Science on 19 October 2012. For a copy please view the web page http://www.eurekalert.org/jrnls/sci/ or contact the Science press team, phone +1 202-326-6440 or email scipak@aaas.org

For interviews please contact Esther Harward, University of Leeds press office, phone +44 113 343 4196 or email e.harward@leeds.ac.uk

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Does anybody remember when Asteroids where the culprits du-jour and the Permian extinction plus lack of new species blamed on them?

jgmccabe

“This broken world scenario was caused by a breakdown in global carbon cycling. In normal circumstances, plants help regulate temperature by absorbing Co2 and burying it as dead plant matter. Without plants, levels of Co2 can rise unchecked, which causes temperatures to increase.”
Seems like a rather bizarre claim! Do they have proof, or is this just wishful thinking?

LazyTeenager

It is also the first study to show water temperatures close to the ocean’s surface can reach 40°C –
———–
Looks like you’re right guys. The science is not settled.

This is ridiculous.
That 50 to 60 degrees might be uninhabitable for most mamals, doesn’t mean we should be afraid of the sunrise, which can cause temperature increases of 30 degrees, nor the moderate rises in temperature that occurred from 1980 to the mid 90’s.
The whole thing is one big non sequitur.

Tucker

So, are they saying that the broken CO2 cycle caused the extinction, or that it caused the 5 million year gap in tropical life? Seems to me that any discussion about this extinction event and subsequent re-start has to include a mention of the Siberian Traps.

Todd

“Nobody has ever dared say that past climates attained these levels of heat. Hopefully future global warming won’t get anywhere near temperatures of 250 million years ago, but if it does we have shown that it may take millions of years to recover.”
Is this Professor Wignall’s way of saying it’s worse than we thought?

steveta_uk

Shame the seas were only a few inches deep back then, else the cooler water below would have been a refuge too.

At that time atmospheric CO2 levels were falling from the 8000ppmv of the Ordovician, with its prolonged ice age, so if temperatures were rising then CO2 may not be the culprit. As for hot sea water, I have seen fish swim in the very shallow waters round Bahrein with temperatures really too hot for me to swim though they were small fish and quite lethargic due to low O2 levels. There would certainly be a species quiet period after a mass extinction as the survivors sorted out a new food chain and sourced feeding areas but any mass extinction would not happen over night but over a period of perhaps thousands of years but certainly hundreds.

Garacka

How good is the temperature versus oxygen isotope correlation?
(I should know after following this site for so many moons.)

Brian H

Nothing but ferns and shrubs on land? How did they survive? And why didn’t they proliferate and “take over”?
I suspect logic leaps and lapses.

MangoChutney

begs the question what caused the release of all that carbon in the first place, dino farts?

Graham

“Without plants, levels of Co2 can rise unchecked, which causes temperatures to increase.”
Beyond about 540ppm CO2 levels would make no difference, plus one would have to assume relative humidity in that era was > 10% which would mask any CO2 effect anyway.
Whatever caused this temperature rise, it could not have been CO2.

“levels of Co2 can rise unchecked, which causes temperatures to increase”
—————————————————————
And pain causes tumors, so we can treat cancer with aspirin. We can only pray that the curative magic of aspirin has no plateau at a relatively low level.

I’ve probably misunderstood this, but they seem to be saying that rising CO2 levels caused the temperature rise, but that the rise in temperature caused the plants and animals to die so that the CO2 was not sequestered …?

TimTheToolMan

I’d love to see the paper. My first instinct is to think its ridiculous to believe they can use oxygen isotopes to determine climate when the world was so different. Who knows what the weather patterns and ocean currents that existed at the time were doing? Also what other factors were involved in the O2 isotope redistributions at the time of the mass extinction? And how did this effect their determination of temperature vs isotope ratio?
And the one bugbear that always annoys me is that they always paint the “it was the warming (by CO2) what did it” but never go on to suggest the mechanism for coming back from that situation.
And of course did they really paint that global doom picture from a single proxy, in a single region? Ouch.

Paul Coppin

New science PhD degrees have apparently joined their colleagues over in Sociology as being nothing more than a bad joke at public expense. Redefining “dumb” (PhDs from the 80s through 2000s) and “dumber” (graduate students of those foementioned PhDs). A complete collapse of western rational education.

hoppy

So on the one hand you have “extreme” temperatures and no fish alive in the tropics and then on the other they are sampling teeth from these same non-existent fish…..
…or is this just another unprecedented extreme extrapolation from a non-proven hypothesis?

Russ in Houston

Coral and shellfish survived? I thought the CO2 was causing them to die.

oldseadog

I hate to say this, but if the data are from two tons of rock from just one place, isn’t this a bit like taking rings from just one tree?

Paul Coppin

Edited to add: the Ph.D needs to be redefined as the Cb.D – “Doctor of Confirmation Bias”.

John Silver

“The dead zone would have been a strange world – very wet in the tropics but with almost nothing growing. No forests grew, only shrubs and ferns. No fish or marine reptiles were to be found in the tropics, only shellfish, and virtually no land animals existed because their high metabolic rate made it impossible to deal with the extreme temperatures”
So the zone wasn’t dead then. It was like the Sahel, more or less.

Otter

‘This broken world scenario was caused by a breakdown in global carbon cycling. In normal circumstances, plants help regulate temperature by absorbing Co2 and burying it as dead plant matter. Without plants, levels of Co2 can rise unchecked, which causes temperatures to increase.’
In other words, NOT likely to happen again.
Not that they will bother to mention that part.

John Gorter

So we had fish and conodont animals in the dead zone, according to that map. I will wait to read the paper, but colour me skeptical.
John Gorter

Steve Keohane

Looks like that world would have no global ocean circulation, no way to dump heat at the poles as is the current set up. Not the same world….

elftone

Confirmation bias at its worst. The *only* thing that can be said is that the proxy indicated higher temperatures – the rest is conjecture.

michael hart

lol
Of course, you could also claim that when the world is warmer there are more species to go extinct due to other causes. The last time I checked, there have been precisely zero recorded mass-extinctions on cold planets like Jupiter…..

So, are they saying that the Sun went through a very active millions of years?
Geocarb IV, I believe, has the planet topping out at 22 deg C, typical of a warm body operating by thermodynamic principles in response to a heat source, the Sun. How does their physics handle a much hotter body obeying the Stefan-Boltzmann law? Something is wrong or missing here, but CO2, or any gas, can back radiate this kind of power. The upper troposphere would have to be at 1000s of deg C to even have the energy supply to heat the surface to this temperature, let alone the time. Days were shorter then, too.
As CO2 cannot do what they say (remembering that Venus is so hot, not because of 95% CO2, but due to 90 atmospheres of gravitational work being done on the atmosphere) and these reported temperatures go against thermodynamics, methinks they need to go back and start over.
As calcium carbonate is less soluble in warm water than cold, there would have been rampant deposition going on as calcium leached to the waters and the seas and concretions would result. CO2 would probably not have been all that high, indicated in other works as rising from a very low state, which probably correlated with the actual extinction, at about 2000 ppm and then decreasing to about 1200 ppm CO2.
They pay no attention to the very unusual 30 million years of cold and CO2 at a dangerously low 250 ppm, starting 20 million years BEFORE the cold spell and persisting throughout the cold spell, that preceded this ramping up of temperature and CO2. It’s pretty clear that we have little idea of what was happening in this period.
Nope, it had to be CO2 and not 30 million years of record LOW temperatures. “Please, sir, can we have more funding?”

So they ignore all the places where its very hot and there is life such as near hydrothermal vents and Death Valley and where does this massive CO2 get produced from very little few animals.

H.R.

Given the position of the land masses as shown it looks like the hot water just swirled around in the big bathtub-like area in the middle and the heated water couldn’t flow up to the poles. In our current configuration, the ‘bathtub’ of the Carribean is open at the top and bottom instead of closed in like the basin seen in the illustration.
What broke the heat wave; a crack in the wall of the landmass? That’s my guess.

Espen

So they’re trying to blame the temperature on the CO2? What if the continental configuration of the Pangaea continent was responsible for the temperatures – and the CO2 would be a consequence, not a cause?

DirkH

According to the wikipedia, CO2 levels were not extraodinarily high.
http://en.wikipedia.org/wiki/File:Phanerozoic_Carbon_Dioxide.png
“Sun and his colleagues collected data from 15,000 ancient conodonts (tiny teeth of extinct eel-like fishes) extracted from two tonnes of rocks from South China. Conodonts form a skeleton using oxygen. The isotopes of oxygen in skeletons are temperature controlled, so by studying the ratio of oxygen isotopes in the conodonts he was able to detect temperature levels hundreds of millions of years ago.”
First they say everything died but they had no problems finding conodonts? How did the fish survive to form teeth to record the temperature when everything died?

Bill Illis

I’ve commented on this before. During the hottest periods of Pangea (265 Mya, not 251 Mya during the Permian extinction), temperatures rose to +10.0C and it probably got too hot for complex life in the Paleo-Thethys sea on the eastern side of Pangea.
Now part of this is because it was a relatively shallow, enclosed sea on the western side of the then very large Pacific at the time. The trade winds would have blown the warm equatorial waters across the Pacific into the Paleo-Thethys and just like the ENSO operates today, there would have been periodic ENSO-like spikes in the ocean there (something like the Pacific Warm Pool is today).
So, shallow, enclosed sea, western-side of the Pacific – temperatures would have sometimes got to +14.0C compared to today’s maximums in this area of 32.0C. ie, Very hot ocean. There is evidence of large sea life die-offs during this time but it is as much related to geography as it is to anything else.
The Permian Extinction, happened later when temperatures fell by up to 8.0C and it was caused by the Siberian Traps volcanoes. A new study published recently shows this point.
http://phys.org/news/2012-10-geochemical-analysis-chinese-permian-triassic-mass.html
http://geology.gsapubs.org/content/40/11/963.abstract

No, oxygen isotopes in skeletons are NOT temperature controlled. The isotopes in precipitation are DEW POINT controlled. And that essentially voids all temperature conclusions from d18O and d2H.
Please read this.
https://dl.dropbox.com/u/22026080/non-calor-sed-umor.pdf
Andre

Just an engineer

Hate to have to point out the bleeding obvious, but there aren’t a lot of species living in Death Valley either!

P. Solar

Oxygen isotope ratio’s relation to water temperature is presumably being extrapolated here since we don’t have anywhere on Earth to collect the calibration data for 50 -60 C sea water.
Also authors don’t seem to know a shark when they see one to judge from that labels under the icons in the figure.
“This broken world scenario was caused by a breakdown in global carbon cycling. ”
Oh, so they have solved one of the most persistent problems Earth’s history, what caused the mass extinctions. CARBON. We should have guessed really.
Still, scary stuff, uh?

Leo Morgan

The essence of skepticism is to not be too ready to believe a claim, while not being so intellectually dishonest as to deny evidence.
In order for me to find this plausible, they would need to answer many questions.
We are assured that levels of CO2 and heat much lower than that reported will prevent the formation of shellfish shells and corals. If the reported shellfish did have shells, is there an explanation for this apparent contradiction?
Does geochemical evidence confirm that there are not other causes of the isotope readings they report? Was there a ‘nearby’ supernova, and if so would that explain their results? Were their samples taken from a region with high natural radioactivity, and might that influence their results? Does other geochemical evidence support the ‘ultra-high CO2’ theory?
Do plant fossils from outside the ‘dead zone’ exhibit adaptation to high CO2?
I’d like to see replication of their results using other instruments.
They are not questions that impact on their measurements, but I’d be interested to know their judgment on the following issues: What do they consider to be the ‘tipping point’ for this temperature flip? How quickly do they think the temperature changed? Why do they think natural selection did not cope with the change? What were the arrangements of the continents and Ocean currents 250 million years ago? What was the physical basis of the earlier assumption that ‘sea-surface temperatures cannot surpass 30°C’ that they report, and why do they believe that did not apply?

Geoff Withnell

Do they speculate as to how the high temperature regime ended?

Rich

“but this study is the first to show extreme temperatures kept life from re-starting in Equatorial latitudes for millions of years.”
and
“Without plants, levels of Co2 can rise unchecked, which causes temperatures to increase”
and then:
“No forests grew, only shrubs and ferns. No fish or marine reptiles were to be found in the tropics, only shellfish”
Don’t shrubs and ferns absorb CO2? Don’t shellfish count as life?

Alan the Brit

Then again, they could be wrong, with bold statements about carbon dioxide causing global warming! So, in fact, no real improvement of casues & attribution as far as I can see! Ho hum. Do I detect a puter model somehwee buried in the debris???

anna v

Hmmm:
Sun and his colleagues collected data from 15,000 ancient conodonts (tiny teeth of extinct eel-like fishes) extracted from two tonnes of rocks from South China. Conodonts form a skeleton using oxygen.
Fishes?
Then how could they grow to leave their teethe when in the same breath:
It is also the first study to show water temperatures close to the ocean’s surface can reach 40°C – a near-lethal value at which marine life dies and photosynthesis stops.

Some sort of oxymoron, but as I have no access to the paper I will wait for those who have.

Kasuha

Strange thing is, historical records of CO2 concentrations which show a sharp increase 250 millions years ago do not suggest any sharp decrease 5 millions years later. Apparently Earth somehow managed to recover without CO2 concentrations reduced.
http://en.wikipedia.org/wiki/File:Phanerozoic_Carbon_Dioxide.png
Or perhaps there were more factors involved than CO2….?

Pamela Gray

So is this paywalled? Without reading the paper, is this a Mannian trick? Find a proxi that seems to say hot but only use the teeth from a certain region and a certain animal and then only the ones that come with a hockey schtick? We can’t know unless the paper is available for public review. Was it paid for by us? Or was it privately funded with private cash from private citizens? Loved the plug for interviews at the end of the press release.
It concerns me that Ph.D.’s were awarded. How many rode into the Ivory Tower on this paper?

Let me see, they know the land temperatures because the teeth of sea creatures… Right.

John Silver

There are places in the Atacama desert today that doesn’t even have bacteria.
How does this zone differs from the desert zone of today, Sahara, Arabian Desert and so on?

Mr Shawn

The findings of this publication are very interesting, however we should be more concerned now about how treat the whole issue of Climate change. in some of the African countries critical temperatures have been, Chad recording a maximum of 47.6 °C in 2010, Algeria recording the highest temperature ever recorded since 1931 in Africa with 51.0 °C in 2011. We are not very far from reaching lethal temperature, the question is how long until we cross that line. I really think that this is a great work of Science and it can go a long way in helping us understand Climate change and take appropriate actions to minimize the impact.

NoAstronomer

“Until now, climate modellers have assumed sea-surface temperatures cannot surpass 30°C.”
Why on earth would anyone think that?
http://en.wikipedia.org/wiki/Fran_Crippen
And don’t universities teach students to justify their assumptions any more?
Mike.

Anyone who is in the know on this issue accepts that it was aliens – just watch the movie “Battle: Los Angeles” to see how thorough they can be regarding destruction of the environment /sarc
“Nobody has ever dared say that past climates attained these levels of heat.”
I attribute that absence to there being no empirical evidence to support the “dare,” but seemingly, any “climate scientist” can create a computer simulation today and assert “x” as being real with impunity. But if it’s dares that make “science” today, then I’m asserting it was aliens that influenced the heat – humanity or its progenitors were not around to add the anthropogenic signal; therefore, it must have been a xenopogenic influence. I have no empirical evidence to support the assertion, but nobody has ever dared say that past climates attained these levels of heat due to alien influence.

Espen

Btw. in the Persian Gulf sea surface temperatures of up to 36 degrees have been measured, and land temperatures in the area have exceeded 50 degrees, so it’s not all that different.

. . . Conodonts form a skeleton using oxygen. The isotopes of oxygen in skeletons are temperature controlled, so by studying the ratio of oxygen isotopes in the conodonts he was able to detect temperature levels hundreds of millions of years ago.

How are the isotopes of oxygen in skeletons “temperature controlled”? Not doubting; just asking.
/Mr Lynn