Study of ancient fish suggests Chicxulub asteroid strike warmed planet for 100,000 years

May 25, 2018 by Bob Yirka, Phys.org report
Artistic rendition of the Chicxulub impactor striking ancient Earth. Credit: Public Domain

A small team of researchers from the U.S. and Tunisia has found evidence that suggests a huge asteroid that struck the Earth approximately 66 million years ago caused the planet to warm up for approximately 100,000 years. In their paper published in the journal Science, the group describes their study of oxygen ratios in ancient fish bones and what it revealed.

Prior research has shown that approximately 66 million years ago, a massive asteroid struck the Earth at a point near what is now Chicxulub, Mexico. Other studies have suggested the sudden change in climate that resulted is what caused the dinosaurs to go extinct. The belief has been that the smoke and particles thrust into the atmosphere blocked out the sun causing the planet to cool for a long period of time. In this new effort, the researchers suggest the cooling period likely was shorter than thought and that it was followed by a lengthy hot spell. The researchers came to this conclusion by studying the bones and teeth of ancient .

The fish remains were sifted from sediment samples collected at a site in El Kef, Tunisia. During the time before and long after the asteroid strike, the area was covered by the Tethys Sea. The researchers looked at oxygen ratios in the fish remains as a means of determining the temperature of the water at the time that the fish died. Collecting samples from different layers allowed for building a temperature timeline that began before the and lasting hundreds of thousands of years thereafter. In looking at their timeline the group found that sea temperatures had risen approximately 5°C not long after the asteroid struck and had stayed at that for approximately 100,000 years.

The researchers suggest the strike by the asteroid very likely released a lot of into the atmosphere because the ground area where it struck was rich in carbonates. The very likely would have also ignited large long-burning forest fires which would have also released a lot of carbon into the air. The evidence suggests that the cooling after the impact was short-lived as massive amounts of carbon dioxide were released into the atmosphere setting off global warming.

The note that a lot more work will need to be done to confirm their findings. Another site will have to be found with similar evidence, for example, to prove that the warming was not localized.

Explore further: New analysis of Chicxulub asteroid suggests it may have struck in vulnerable spot

More information: K. G. MacLeod et al. Postimpact earliest Paleogene warming shown by fish debris oxygen isotopes (El Kef, Tunisia), Science (2018). DOI: 10.1126/science.aap8525

Abstract
Greenhouse warming is a predicted consequence of the Chicxulub impact, but supporting data are sparse. This shortcoming compromises understanding of the impact's effects, and it has persisted due to an absence of sections that both contain suitable material for traditional carbonate-based or organic-based paleothermometry and are complete and expanded enough to resolve changes on short time scales. We address the problem by analyzing the oxygen isotopic composition of fish debris, phosphatic microfossils that are relatively resistant to diagenetic alteration, from the Global Stratotype Section and Point for the Cretaceous/Paleogene boundary at El Kef, Tunisia. We report an ~1‰ decrease in δ18O values (~5°C warming) beginning at the boundary and spanning ~300 cm of section (~100,000 years). The pattern found matches expectations for impact-initiated greenhouse warming.

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Anonym
1.4 / 5 (9) May 26, 2018
Or the impact created massive undersea faults and volcanoes that spewed magma into the ocean, warming it from below.

This CO2 hypothesis suggests the researchers started with a goal --- posit another time when demon CO2 messed up the planet --- and lo! there it was. Or at least they claim enough evidence to warrant "a lot more work." Scientists have to eat, too.

Their conclusions are unfounded. No one has suggested that disequilibrated CO2 levels in the atmosphere persist for tens of thousands of years. Furthermore, it doesn't matter how much carbonate ocean sediment was "vaporized" : There is an upper bound to the amount of heating that can be caused by atmospheric CO2. IR saturation occurs when CO2 levels exceed 600ppm --- no further warming from CO2 beyond 600ppm because the available IR energy has all been captured.

I'll be checking RetractionWatch dot com for the rest of this story.
humy
4.6 / 5 (10) May 26, 2018
Or the impact created massive undersea faults and volcanoes that spewed magma into the ocean, warming it from below.

There is no evidence for this.
And no credible model with the maths of this calculated has so far suggested that that could have been the cause of the warming.
If you disagree, show your physics equations and maths calculations for it.
This CO2 hypothesis suggests the researchers started with a goal --- posit another time when demon CO2 messed up the planet

No, it clearly doesn't 'suggest' that. And there is no evidence to support your above conspiracy theory.
But there is evidence to support this particular CO2 theory; the rocks the asteroid hit are very high in carbonates and thus large amounts of CO2 would have been released from the impact. When carbonates are vaporized, they do indeed release CO2. This can be (and was) confirmed in the lab. The theory makes sense. It can even be viewed as yet more evidence of CO2 warming.
humy
5 / 5 (9) May 26, 2018
IR saturation occurs when CO2 levels exceed 600ppm --- no further warming from CO2 beyond 600ppm because the available IR energy has all been captured.

You lie. That is made up claptrap.
There is no clear "IR saturation" point; not at "600ppm" nor an any other specific figure.
And where did you get the "600ppm" figure from? Why not, say, 500ppm or 700ppm? That is totally arbitrary and baseless.
If you disagree, show your physics equations that say it (if 'it' exists) specifically must be at "600ppm" ...
DonGateley
not rated yet May 26, 2018
humy, if you place your cursor over a crank comment like Anonym's you will see a button at the bottom right that says "Ignore User." Do so and all you see in any article in which they comment in the future is one line saying the user is ignored. There is a button that allows you to see any particular ignored comment without changing that status if you wish. The beauty is that this is a sort of shadow ban in that ignored cranks don't know how many good folks have them ignored so they are not typically clued to change their handle. :-)
ZoeBell
1 / 5 (6) May 27, 2018
There is no clear "IR saturation" point; not at "600ppm" nor an any other specific figure.
The saturation point occurs when the most of heat gets absorbed in the upper layer of atmosphere so that it gets radiated into space back without even reaching surface of Earth. Modelling shows that for Earth atmosphere the saturation point is somewhere around 350 ppm, i.e. already lower than the present concentrations of CO2.

Scientific research shows that in the past CO2 levels were 8000ppm. You heard that right. 8000ppm. And the Earth was overrun with greenery like true Eden. Huge plants, huge flowers - this is where the thick layers of fossil carbons come from. Compare that to our present day scorched Earth. Vast areas of barren land because CO2 is so low.
ZoeBell
1 / 5 (5) May 27, 2018
By analyzing tiny fish bones and teeth, researchers determined global CO2 levels reached 2,300 ppm following the impact. Yet the Earth recovered from it during 100.000 years. For comparison, CO2 levels recently climbed above 410 ppm for the first time in millions of years.
humy
5 / 5 (5) May 27, 2018
ZoeBell

The atmosphere isn't just absorbing IR Radiation from the surface. It is also radiating IR Radiation to Space. If these two heat flows are in balance, the atmosphere doesn't warm or cool - it stays the same.
But that means, with all else equal, adding any CO2, no matter how much is already there, will cause climate warming.
Thus there's no real saturation point. The warming effect is approximately proportional to the logarithm of the concentration, so each extra ppm will do less but there is no 'cut-off' point.
humy
5 / 5 (5) May 27, 2018

http://www.terpco...yth.html

"
The Myth: CO2 is saturated. This myth states that as CO2 is added to the atmosphere that there is a point where the more CO2 will simply not impact the environment anymore ...
...
What the Science Really Says:
... they demonstrated how CO2 saturation is false by modeling the atmosphere with twice as large of a concentration of CO2 as is present now. What was found was that CO2 increases the temperature in the troposphere. With a larger increase in the troposphere than anticipated because of a radiative-convective equilibrium model. It was also found that there would be an even more dramatic increase at the higher latitudes because of the recession of the snow boundary (Wetherald). This disproves the thought of CO2 saturation as a limiting factor in climate change.
..."

Learn real science; not myths political propaganda and lies.
ZoeBell
1 / 5 (6) May 27, 2018
@Humy: Nope, you're ignoring the fact, that the heat is absorbed by CO2 only but it's radiated by all components of atmosphere in an equal way once the heated CO2 molecules exchange their energy with them. Therefore every logarithmic curve - as presented by mainstream science - must be wrong, because the absorption curve will be way more complex if modeled properly: with both saturation point, both runaway point. The Venus is different case, because 96% of atmosphere is already formed by CO2, so that the heat absorption curve of CO2 gets logarithmic with concentration there.

Try to think logically: nowhere at the Earth we can observed formation of coal, in the form of whole trees the less. That means that the CO2 sink was way more intensive in the past - yet the fauna and flora did prosper from it. The contemporary Earth looks merely like desert with compare to past.
ZoeBell
1 / 5 (5) May 27, 2018
In accordance to above the temperature profile of atmosphere is way more complex, than the logaritmic curve would allow: until the heat gets absorbed faster than it gets radiated, then the temperature of atmosphere rises in the upper layers of atmosphere, which serve like radiator of energy, until it reaches the saturation point within stratopause at the 50 km altitude. Bellow this altitude the atmosphere is heated by Earth surface, not vice-versa - which also means, that the atmosphere cools the Earth surface there - not heats it.
humy
5 / 5 (5) May 27, 2018
ZoeBell
that the heat is absorbed by CO2 only but it's radiated by all components of atmosphere in an equal way once the heated CO2 molecules exchange their energy with them.

so what?
Therefore every logarithmic curve - as presented by mainstream science - must be wrong,

look up the word "Therefore" in the dictionary and come back to us. Your assertion clearly doesn't follow from your premice.
because the absorption curve will be way more complex if modeled properly: with both saturation point, both runaway point.

No, there is no definable 'saturation point' nor 'runaway point' to complicate it. The curves are complex but still approximately logarithmic in this case and that complexity is obviously taken into account by the scientists that model it.
ZoeBell
1 / 5 (6) May 27, 2018
No, there is no saturation point nor runaway point to complicate it. The curves are approximately logarithmic
This is just a mainstream propaganda similar to claim that cold fusion or antigravity don't exist.
After the famous Arrhenius paper in 1896, where he did the first calculations of the CO2 greenhouse effect, his theory was dismissed by Angstrom with a simple experiment. He let an infrared beam pass through a tube filled with CO2 and measured the emerging light intensity. Upon reducing CO2 concentration in the tube, only a tiny difference could be found and he concluded that very few CO2 molecules are enough to completely absorb the IR beam. The conclusion was that a CO2 increase could not matter. This was the birth of the first skeptic of the then called "CO2 theory of global warming".
ZoeBell
1 / 5 (6) May 27, 2018
If the absorption curve would be logaritmic, then the increasing concentrations of carbon dioxide (CO2) wouldn't cool the middle atmosphere [Rind et al., 1998; World Meteorological Organization, 1998; Olivero and Thomas, 2001]. Ramaswamy et al. [2001] used lidar and rocket data to show that the upper stratospheric cooling trend of 1–2 K/decade increases with altitude, with the largest cooling of ∼3 K/decade near the stratopause at 50 km between 1979 and 1999. The only undeniable truth of the contemporary reality is, the mainstream science systematically and consequentially fu*s everything what doesn't fit the mainstream groupthink/paradigm. The consequence is, even after one hundred years we still have no complete model of atmosphere heating involving non-radiative transfer from CO2 molecules into another ones. Everything else is the result of propaganda, which may or may not fit the objective reality.
ZoeBell
1 / 5 (6) May 27, 2018
Intro and more info about Saturated-Greenhouse-Effect-Theory. This theory was published in standard scientific way - so I do expect, all counterarguments would link their sources published in the same way.
humy
5 / 5 (5) May 27, 2018
This is just a mainstream propaganda similar to claim that cold fusion or antigravity don't exist.
What kind of ridiculous conspiracy theory is that?
The reason why few scientist now believe cold fusion exists is that the experiment claimed to result in cold fusion didn't result in cold fusion when duplicated in other labs thus leading to the conclusion that the claim was bogus. Most of the scientists that wanted to believe cold fusion (but now obviously wouldn't) also believed and believe greanhouse theory; why not?

And What! You also believe in the existence of some kind of 'antigravity' devise? Where do you get this crap from?
humy
4.2 / 5 (5) May 27, 2018
http://www.scribd...-Theory. This theory was published in standard scientific way - so I do expect, all counterarguments would link their sources published in the same way.


https://grist.org...nd-fail/

"...
... the 'saturated greenhouse effect' myth was debunked in the early 20th century. ...
..."

This is the way good science is supposed to work;
Someone comes up with a theory. If that theory is disproved, what should happen is that the theory is dismissed by science. Anyone that continues believing that disproved theory is no longer a believer in science but in junk.
antigoracle
1 / 5 (6) May 27, 2018
More PATHOLOGICAL LIES from the AGW Cult and their Pathological "science".
So, they checked for O2 levels so that they could claim an increase in temperature and then, of course, concluded that this was due to CO2. Why not check for the very thing you are claiming? CO2 levels.
ZoeBell
1 / 5 (6) May 27, 2018
the 'saturated greenhouse effect' myth was debunked in the early 20th century
Miskolczi's work is from 2005-2007 - it couldn't be debunked before it. The publication linked by you mentions it in two paragraphs (of "data/method" supplement) - but in no way addresses results, which Miskolczi deals with. In single one paragraph it simply dismisses whole years of Miskolczi's research, computer program and pile of its results - it doesn't analyze it at all. It has no even meaning to deal with such a critique anymore - is it really the only one alarmist publication, which deals with saturation effect? How the thermal gradients of stratopause are explained by mainstream science?
humy
5 / 5 (5) May 27, 2018
the 'saturated greenhouse effect' myth was debunked in the early 20th century
Miskolczi's work is from 2005-2007 - it couldn't be debunked before it.

Actually it was. The actual relationship between CO2 concentration and warming effect was worked out by basic science and with empirical evidence well before 2005 and that relationship was approximately logarithmic and without any specific 'saturation point' thus his hypothesis can be argued to be debunked before he said it i.e. it was a none starter and it is then only a trivial task to explicitly debunk it after he said it.
barakn
5 / 5 (5) May 27, 2018
http://www.scribd.com/doc/25071473/Saturated-Greenhouse-Effect-Theory. This theory was published in standard scientific way - so I do expect, all counterarguments would link their sources published in the same way. -ZoeBell/mackita/Zephir

And yet your link is to a PowerPoint presentation, not a peer-reviewed paper. Lie much?
ZoeBell
1 / 5 (5) May 27, 2018
This is just a presentation with links to original papers (1, 2, 3). His boss for example, sat at Miskolczi's computer, logged in with Miskolczi`s password, and canceled a recently submitted paper from a high-reputation journal as if Miskolczi had withdrawn it himself. That was also one of reasons, that Ferenc finally resigned from his ($US 90,000 /year) job.

How much the reference to Galileo counts for in crackpot index? The scientific community is bunch of opportunist bastards.
humy
4.3 / 5 (6) May 27, 2018
The 'saturated greenhouse effect' hypothesis doesn't even make any physical sense because it ignores extremely basic known physics.
CO2 absorbs different wavelengths of the outgoing infrared by different amounts; some wavelengths are absorbed strongly and others only very weakly.
To keep this explanation simple, suppose we pick an exact wavelength that is such that current levels of CO2 absorb exactly 50% of it (from the ground to outer space).
Then that would mean if CO2 concentrations where to exactly double, half of that 50% of that specific wavelength of that infrared that would have otherwise radiated through directly to outer space would now be absorbed thus the total absorption would now become;
50% + 50%/2 = 75%
And then if CO2 concentrations where to exactly double again the total absorption would become;
75% + 25%/2 = 87.5%
and so on for infinitum thus it will get closer and closer to 100% absorption but will never reach 100%
therefore there is no 'saturation point'.
jonesdave
4.2 / 5 (5) May 27, 2018
This is just a presentation with links to original papers (http://ruby.fgcu....lear.pdf counts for in crackpot index? The scientific community is bunch of opportunist bastards.


And you are a non-event crank. Live with it.
jonesdave
4.2 / 5 (5) May 27, 2018
More PATHOLOGICAL LIES from the AGW Cult and their Pathological "science".
So, they checked for O2 levels so that they could claim an increase in temperature and then, of course, concluded that this was due to CO2. Why not check for the very thing you are claiming? CO2 levels.


Errrr, they do. And have been for many decades. Some chap on Hawai'i started it. Can't be bothered looking it up. It is common knowledge.
ZoeBell
1 / 5 (3) May 27, 2018
Then that would mean if CO2 concentrations where to exactly double, half of that 50% of that specific wavelength
Nope, this model neglects at least two things: A) that the atmosphere layer is not infinitely thick B) energy absorption process of CO2 is followed by energy radiative process of the rest of Earth atmosphere (not to say about water once it condenses into a droplets). You cannot argue complex model with simplistic one in similar way, like you cannot argue general relativity by Galileo physics. More complex model is simply more faithful one.
In addition, your simplistic model explains neither temperature profile of stratopause, neither the fact, the temperature of stratopause goes down when concentration of carbon dioxide increases (as linked above). The mainstream climatologists couldn't disprove saturation effect, because they actually never bothered with it seriously in full depth and complexity - for not to threat their safe jobs in alarmist research.
Try it again.
ZoeBell
1 / 5 (4) May 27, 2018
Ironically enough, the climatologists have saturation effect before their eyes for whole century - the upper layers of atmosphere are hotter than these lower ones, because most of heat gets absorbed there (and subsequently radiated into space). Whereas the greenhouse effect would lead to the opposite gradient. They climatologists never attempted to explain this quite apparent temperature discrepancy for not to threat their ideology.
antigoracle
1 / 5 (5) May 27, 2018
More PATHOLOGICAL LIES from the AGW Cult and their Pathological "science".
So, they checked for O2 levels so that they could claim an increase in temperature and then, of course, concluded that this was due to CO2. Why not check for the very thing you are claiming? CO2 levels.


Errrr, they do. And have been for many decades. Some chap on Hawai'i started it. Can't be bothered looking it up. It is common knowledge.


Another Chicken Little jackass brays.
I'm referring to the PERIOD in question, where they determined O2 levels but NOT CO2 levels.
You can't be bothered to read and comprehend...but rather bray like a jackass.
humy
5 / 5 (4) May 27, 2018
Then that would mean if CO2 concentrations where to exactly double, half of that 50% of that specific wavelength
Nope, this model neglects at least two things: A) that the atmosphere layer is not infinitely thick

How so? It clearly doesn't. You make absolutely no sense whatsoever.
B) energy absorption process of CO2 is followed by energy radiative process of the rest of Earth atmosphere

As all measurements confirm, it isn't immediately reradiated out as infrared light but rather conducted out as thermal random motion of neighbouring air molecules.
(not to say about water once it condenses into a droplets).

what has that got to do with it? Are you saying clouds complicate it? If so, yes they do but not in a way that would cause a 'saturation point' so that's still irrelevant.

In short, you have said nothing there to counter my explination.

ZoeBell
1 / 5 (4) May 27, 2018
Are you saying clouds complicate it? If so, yes they do. But not in a way that would cause a 'saturation point'.
The condensation of water vapor induces a new saturation effect, even more pronounced one: once the Earth gets covered by clouds, then it turns snow white and its albedo increases.
humy
5 / 5 (4) May 27, 2018
In addition, your simplistic model explains neither temperature profile of stratopause, ..

and it isn't supposed to because it isn't an explinations for that.
I actually happen to know the explanation for that; which is irrelevant to my first explination because that is for a different topic.

You do love constantly going completely off-track.
humy
5 / 5 (4) May 27, 2018
Are you saying clouds complicate it? If so, yes they do. But not in a way that would cause a 'saturation point'.
The condensation of water vapor induces a new saturation effect, even more pronounced one: once the Earth gets covered by clouds, .

No the Earth won't get all covered in clouds. At any point in time there will still be clearing between the clouds somewhere on Earth i.e. clear skies and about the same area of clearings. And no "new saturation effect".
Please don't make crap up.
ZoeBell
1 / 5 (4) May 27, 2018
Please don't make crap up.
LOL, this is settled science even for such an alarmists like the IPCC..:-)
ZoeBell
not rated yet Jun 03, 2018
Carbon dioxide toxicity and climate change: a serious unapprehended risk for human health This is another example of fear mongering in climate change research: the concentration levels at which carbon dioxide becomes toxic are highly above levels, which would be acceptable for life environment as a whole. The low concentrations of CO2 actually support breathing, which is why the carbon dioxide is used in medical oxygen mixtures (Carbogen409_103361.pdf)) in amounts up to 5%. The current concentrations of CO2 are 0.04%, i.e. more then one-hundred times lower.
ZoeBell
not rated yet Jun 03, 2018
BTW The above "crap" is also the basis of all attempts of alarmists for artificial cooling of Earth by creating artificial clouds from aerosols. I just like when upset alarmists downvote even their own proposals, once they're cited by their opponents... :-)

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