Press release from University of Göttingen: T-Rex Dinosaur teeth give glimpse of early Earth’s climate
The study shows that the late Jurassic atmosphere carried about 1,200 ppm of CO₂, about four times the pre industrial 1850 benchmark of 280 ppm. By the late Cretaceous, CO₂ it had dipped to near 750 ppm.
A previously untapped source of data sheds new light on the climate of the early Earth: fossilized dinosaur teeth show that the atmosphere during the Mesozoic era, between 252 and 66 million years ago, contained far more carbon dioxide than it does today. An international research team at the Universities of Göttingen, Mainz and Bochum made this discovery by analysing oxygen isotopes in tooth enamel. They used a newly developed method that opens up opportunities for research into the Earth’s climate history. In addition, the researchers found that total photosynthesis from plants around the world was twice as high as it is today. This probably contributed to the dynamic climate during the time of the dinosaurs. The results were published in the journal PNAS.
The research team analyzed the enamel of dinosaur teeth found in North America, Africa and Europe dating from the late Jurassic and late Cretaceous periods. Enamel is one of the most stable biological materials. It records different isotopes of oxygen that the dinosaurs inhaled with every breath that they took. The ratio of isotopes in oxygen is affected by changes in atmospheric carbon dioxide and photosynthesis by plants. This correlation allows researchers to draw conclusions about the climate and vegetation during the age of the dinosaurs.
In the late Jurassic period, around 150 million years ago, the air contained around four times as much carbon dioxide as it did before industrialization – that is, before humans started emitting large quantities of greenhouse gases into the atmosphere. And in the late Cretaceous period, around 73 to 66 million years ago, the level was three times as high as today. Individual teeth from two dinosaurs – Tyrannosaurus rex and another known as Kaatedocus siberi which is related to Diplodocus – contained a strikingly unusual composition of oxygen isotopes. This points to CO₂ spikes that could be linked to major events such as volcanic eruptions – for example, the massive eruptions of the Deccan Traps in what is now India, which happened at the end of the Cretaceous period. The fact that plants on land and in water around the world were carrying out more photosynthesis at that time was probably associated with CO₂ levels and higher average annual temperatures.
This study marks a milestone for paleoclimatology: until now, carbonates in the soil and “marine proxies” were the main tools used to reconstruct the climate of the past. Marine proxies are indicators, such as fossils or chemical signatures in sediments, that help scientists understand environmental conditions in the sea in the past. However, these methods are subject to uncertainty. By analysing oxygen isotopes in tooth fossils, the researchers have now developed the first method that focuses on vertebrates on land. “Our method gives us a completely new view of the Earth’s past,” explains lead author Dr Dingsu Feng at the University of Göttingen’s Department of Geochemistry. “It opens up the possibility of using fossilized tooth enamel to investigate the composition of the early Earth’s atmosphere and the productivity of plants at that time. This is crucial for understanding long-term climate dynamics.” Dinosaurs could be the new climate scientists, according to Feng: “Long ago their teeth recorded the climate for a period of over 150 million years – finally we are getting the message.”
The study was funded by the German Research Foundation (DFG) and by the VeWA consortium as part of the LOEWE programme of the Hessisches Ministerium für Wissenschaft und Forschung, Kunst und Kultur.
Original publication: Dingsu Feng, Thomas Tütken, Eva Maria Griebeler, Daniel Herwartz & Andreas Pack. Mesozoic atmospheric CO2 concentrations reconstructed from dinosaur tooth enamel. Proceedings of the National Academy of Sciences (PNAS) (2025). DOI: 10.1073/pnas.2504324122
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Well nuts. This sucks. Whatever happened to the reports of 6000-4000 ppm in some early parts of the dino ages? Dang drat fooey!
I think you have the Mesozoic Era confused with the first two periods of the Paleozoic, both hundreds of millions of years before dinosaurs. Studies have found 7000 ppm for the Cambrian Period and as low as 4000 ppm during the Ordovician Ice Age.
The write up misrepresents the paper it reports. High Mesozoic CO2 is not a surprise, but it’s great to have another proxy source.
Late Jurassic CO2 of 1200 ppm and Late Cretaceous of 750 ppm are actually on the low side. The report also confuses “preindustrial” with present CO2. Late Cretaceous 750 ppm is not three times present level, but is more than 2.5 times (as the paper says) the alleged 285 ppm of AD 1850.
The report also makes it sound as if T. rex and the sauropod were both Late Cretaceous dinosaurs. The sauropod was Late Jurassic.
A bit lower than GeoCarb for the late Jurassic (pink), but pretty close to GeoCarb at the end of the Cretaceous (orange).
What’s the scale on the right side meant to represent?
It appears to be a scale change for the right most section of the chart.
I could be extremely wrong here, but the “shade” in the background is, I think, some measure of ‘biodiversity’, and the scale on the R hand side is the metric for that ‘biodiversity measurement’. Likely scaled to some normal; one might need to read the original source paper to get the full flavor of the chart.
Your guess is as good as any other.
We have no means to test either hypothesis.
Isn’t the come back by alarmists that the sun wasn’t warming the Earth as much as now- so the higher CO2 back then couldn’t over heat the planet? I think I’ve seen that excuse but not sure what to make of it.
According to current theories, the sun is increasing its output by about 10% every billion years or so. So the statement by the alarmists is true, but irrelevant.
If memory serves, the theory goes something like this.
The sun converts 2 atoms of hydrogen into one atom of helium.
The one atom of helium has a tiny bit less mass than do the two atoms of hydrogen, but it takes up about half the space.
This makes the sun’s core, a little bit denser, which causes the rate of fusion to increase.
Just curious, but why is it irrelevant? I’d like to know when confronted by an alarmist over this.
It’s not irrelevant.
An increase in solar output of a few tenths of a percent, is most definitely irrelevant. Almost as irrelevant as you are.
It’s irrelevant because the increase in intensity of the sun, over the period in question, is not enough to explain the temperature difference.
One percent more power per 110 million years. Thus solar radiation is now one percent stronger than in the Early Cretaceous Epoch, ie between the Late Jurassic and Late Cretaceous.
IOW, machts nichts!
So why is Earth in an Ice Age right now ?
There are more things in heaven and earth, sir, that affect solar energy absorbed by Earth than are dreamt of by those that limit themselves to changes in solar luminosity.
Or CAGW or Climate Crisis.
Because, about 2.5 to 3 million years ago, the South American plate shifted northward and squished the Caribbean plate up against the North American plate which caused Panama to rise cutting off the mixing of Atlantic and Pacific ocean waters which changed the ocean circulations resulting in the beginning of the current ice age.
Well, perhaps. Before the tectonic plates mash-up that you mentioned (perhaps leading to the current Quaternary Ice Age), there was the “Karoo” Ice Age (during the late Paleozoic 360 to 260 million years ago) and even preceding that there was the “Andean-Saharan” Ice Age (during the Late Ordovician and Silurian periods 460 to 420 million years ago).
Neither of these involved “cutting off the mixing of Atlantic and Pacific ocean waters”.
Other factors are undoubtedly in play, such as:
— Milankovitch cycles and their resonances over multi-million-year time scales
— Variations in Earth’s atmospheric humidity and areal cloud coverage over multi-million-year time scales
— Variations in heat, greenhouse gases and aerosols released from Earth’s crust/mantle over multi-million-year time scales
— Variations in ocean circulation patterns as Earth’s land masses changed locations over multi-million-year time scales.
Ta da.
Lots of theories- I don’t think this is resolved.
And never will be, since we can’t go back in time and do millions of years of continuous studies. The best we can do is guess.
Perfect weather on Earth only occurred in 1850 when atmospheric CO2 was around 285ppmv.
The dinosaurs obviously perished because the CO2 level got too high and Earth reached a CO2 induced tipping point.
Please desist from burning fossil fuels so we avoid another CO2 induced tipping point that wipes out humans.
I think all that CO2 in dinosaur times made the planet so green and lush that the dinosaurs over ate and died of obesity. /s
No, the growth in foliage got so great, the male and female dinosaurs could no longer find each other, and that caused them to die out.
Wrong. CO2 was responsible for attracting a large asteroid that hit the earth and caused year round winter conditions for decades. CO2 is to blame.
Also, CO2 caused plants to evolve and the new species gave off pollen that caused all of the dinosaurs to have sinus infections.
Like when the ents lost the entwives
The recoded temperatures (what few there were) recorded the interval of 1850 to 1880 as the coldest in the entire 19th century.
“Dinosaurs could be the new climate scientists, according to Feng”
I’m speechless, said one man:
Toothless…
Europe’s largest wind power company has blamed Donald Trump for derailing its business model, after it announced a $9bn (£6.7bn) fundraising and its market value plunged by almost a third.– Grauniad
Oh dear,. How sad,,,
Trump did say “no more windmills!” recently, so I guess that could affect a windmill company’s market value.
Trump is right: Windmills are not fit for purpose. They are an impediment to progress. Anyone with any sense could see this.
Trump hasn’t vetoed the Chagos surrender… From this I deduce he isn’t that great at spotting a very bad deal. And if he is… he’s not much of an ally.
But we (the UK) pay not the US. (And about ten times more than he was told I suspect given that the true or truer figure has now come out.).
He will think we are ten time stupider than we were earlier.
Yep, I think you got that right, although I’m sure there’s some kind of back-story we’re not getting. Starmer can’t really be that stupid, can he?
But isn’t wind power a tenth century answer to a twenty first century non-issue. 🤷♂️
Was it a meteor, or a drop in CO2 and resulting drastic drop in vegetation what killed the dinos?
How different was atmospheric pressure in those days? It is my believe that pressure is a big factor for temperature. Otherwise why would it get colder going up a mountain? Many flying dinosaur would probably not be able to fly in today’s pressure regime. So was the atmosphere heavier in those days and did the impact 66Ma sweep a lot of atmosphere into space never to be seen again?
“did the impact 66Ma sweep a lot of atmosphere into space never to be seen again?”
There’s a good question.
No! Do you not understand gravity.? The Earth has captured the moon. It continually captures meteors and space dust.
The drop in pressure regulates how fast temperatures change as you move up or down.
Pressure plays no role in how warm the bottom of the air column is.
As the sun warms, the planet warms, with no change in atmospheric temperature.
If the sun were to cool, the planet would cool, with no change in atmospheric temperature.
As to the meteor sweeping a lot of atmosphere into space, in a word. No.
You seem to dismiss the basic PV = nRT. You also seem to dismiss the idea of conduction/convection in the earth surface-atmosphere interface. Could elaborate please.
In the ideal gas law, n (number of moles of gas) and P (pressure) are set by the mass of the atmosphere. R is a gas constant. All of these are unchanging constants when considering the whole atmosphere. (Yes, pedants, some mass is gained by meteors and some blown off by solar wind, and the average temperature affects the amount of condensible vapor, but practically speaking these are constants).
Only two of those terms are variables: temperature T and volume V. The independent variable is temperature. The dependent variable is volume. The sun heats the surface and atmosphere. Depending on how much it heats, the earth’s atmosphere either puffs up or shrinks down.
The average atmospheric pressure doesn’t change except as the mass of the atmosphere changes. If the sun’s output were to suddenly be reduced substantially, the average temperature would plunge, but the pressure would not change substantially. What would change? The volume or height of the atmosphere.
So the idea that pressure determines temperature is completely wrong. The earth’s temperature can vary from extremely cold to extremely hot with pressure only varying to the extent that there will be more or less water vapor and thus more or less atmospheric mass.
If this doesn’t convince you, then consider this thought experiment. Take an empty nitrogen gas cylinder and a full one, side by side at room temperature. One is at 1 atm and the other is at 150 atm. Both are at the same temperature. If pressure “creates” temperature then why is the full cylinder the same temperature as the empty one?
Try reading what I wrote again, My first sentence acknowledges PV=nRT.
If pressure was the only thing that mattered, then the temperature would remain constant, even if the sun were to go out.
I think that you meant to say “no change in atmospheric pressure”? (Rather than temperature)
Clearly the atmosphere is warmed both directly and indirectly by a more active sun and would cool off if the sun became less active.
How different was atmospheric pressure in those days? It is my believe that pressure is a big factor for temperature. Otherwise why would it get colder going up a mountain? Many flying dinosaur would probably not be able to fly in today’s pressure regime. So was the atmosphere heavier in those days and did the impact 66Ma sweep a lot of atmosphere into space never to be seen again?
While pressure is the measurement, the reason it gets colder as you ascend is that the air is less dense. Thermal energy (aka heat) is due to molecular kinetic energy. Fewer striking your skin, colder you feel.
It is, of course, not as simple as that, but density (aka air pressure) is a major factor.
There was no drastic drop in CO2, the drop mentioned above occurred over millions of years.
Clearly, the study of fossilized dino teeth leads to truth decay.
Awful. You made me laugh.
They did not have fluoide in their drinking water? How primitive.
How well does this proxy correlate with other proxies?
That is highly dependent on who does the correlation analysis.
Why is this surprising?
The paper says
Not surprising to me. But it is surprising to see you candidly admit that 1,200 ppm of CO₂ is not a problem.
In fact the world was lush and very, er, green….
Where did I say 1200 ppm would not be a problem? The late Jurassic period was much warmer than today.
So warmer temps didn’t cause problems, either. Noted.
No grasses though!
I believe the surprise is that the study was published. Normally anything that contradicts the global warming narrative is buried and the authors punished.
What does it contradict, and why wouldn’t it be published if it did?
It contradicts the CAGW claim that doubling CO2 from 280 ppm to 560 ppm will result in a dead planet. Oceans will boil killing marine life, severe weather occurances will be catastrophic, heat deaths will kill populations, famine will reign from crop failures, continents will drown, etc. Your own trends that show no flattening of the temperatures trends forecast that too.
Don’t be a fence sitter. Using your trends will temps increase by 6°C at 560 ppm and by 12°C or more at 1200. If you claim you don’t know, then your trends are kind of meaningless aren’t they?
“It contradicts the CAGW claim that doubling CO2 from 280 ppm to 560 ppm will result in a dead planet.”
Got it. It contradicts your own strawman.
“Using your trends will temps increase by 6°C at 560 ppm”
I am not a scientist. My “trends” as you put it are just looking at the data as us. But no. They would not suggest a 6°C rise from CO2 at 560ppm. Generally I get a trend of around 2°C per doubling of CO2. So going to 560 might see a bit under 1°C warming from current levels. But that’s not including any longer term feedbacks.
“and by 12°C or more at 1200”
If CO2 was the only factor and you accept this 1200±150 ppm for late Jurassic, you could look at how much warmer it was then as an indication. But that requires an accurate estimate if how much warmer it was then. I doubt it was 12°C warmer. More like 5-10°C warmer.
“If you claim you don’t know, then your trends are kind of meaningless aren’t they?”
Meaningless to someone who refuses to understand the point.
Well that’s disappointing.
What a fizzer.
Don’t even try to make this comment at the BBC, Guardian, NYT, WAPO, etc
1°C warming from current levels is over 2°C from pre-industrial, which would be disappointing.
But not caused by human CO2
And yes, disappointing that the planet is still very much in a COOLER period of the Holocene. Barely out of a little ice age
it’s disappointing that you continue to spew crap.
Why would better weather be disappointing?
Almost 90% of the last 12 to 15 thousand years has been warmer than it is today.
What does the word “trend” mean to you? Explain what the generally accepted meaning is to you.
Merriam-Webster
Given that your the one who keeps using trend as a term of abuse, maybe you should explain what you mean by it.
When I talk about a trend in the context of a time series, Iean exactly what Dr Spencer means – the rate of change over a certain time period.
But in this case I’m talking about the relationship between temperatures and CO2, not time. I assume that’s what you mean when you ramble on about “Using your trends will temps increase by 6°C at 560 ppm and by 12°C or more at 1200.”. I’m really not sure what your point is at this stage. Are you complaining about using the term “trend line” when the independent variable is not time? If so why did you talk about my “trends”?
Did they have pine cones back then?
I believe the single tree from the Yamal Peninsula that “settled” Mann’s proxy selections was a bristle cone pine tree.
I don’t believe so. The one tree in Yamal was a Larch, to my recollection, and was Briffa’s problem child. Mann’s Bristlecone was in the US southwest, I believe.
You’re no doubt correct Jeff.
I don’t have my copy of A.W. Montford’s book to refer to.
I recall the bristlecones were from California. I could be wrong.
Seems so.
https://en.m.wikipedia.org/wiki/Pinaceae
Speaking of tree rings.
Here is Biffa’s data from 1900 onwards.
Notice how much cooler 1990 was than the warmer period around 1940.
That’s assuming treemometers are a thing, and assuming statistical shenanigans aren’t a thing.
Apparantly not only does mr. bellman not read the science, he doesn’t even read what his fellow travelers have been saying.
So the only logic conclusion to blaim the high CO2 levels to the dinos extinction is that the meteor which wiped them out consisted of pure dry ice…well since no dino-car has been found so far…lol and sarc
I’m shure the dino tooth examined was a wisdom tooth 😉
“A previously untapped source of data sheds new light on the climate of the early Earth: fossilized dinosaur teeth show that the atmosphere during the Mesozoic era, between 252 and 66 million years ago, contained far more carbon dioxide than it does today.”
Not sure I would classify that time frame as “early Earth”.
Agreed! But when your time frame for “the Earth” is just the past two hundred years, or so, then the Upper Cretaceous is definitely, ” … early …”.
“… – that is, before humans started emitting large quantities of greenhouse gases into the atmosphere.”
So what got it to 1 200ppm before T-Rex formed a rock band? Was there a carbon capture scheme to get it down to 750ppm?
The atmosphere was originally almost pure CO2. Then plants discovered photo-synthesis, and it’s been down hill ever since. (There’s also chemical weathering to consider.)
Actually, it started out as methane.
Bacteria metabolized the methane and exhaled oxygen
Which they will still do very rapidly.
Oh, the horror of it all!! Unless we switch to windmills and solar panels for all of our electricity, dinosaurs will come back and eat all the humans.
I’m a bit shocked that this O/O isotopic study is being called new, including it’s application.
I see . . . more “settled” climate science.
I have it! Eureka! I know the answer.
The reason CO2 levels were higher is because dinosaurs were huge and the 20,000 ppm they exhaled was not 1 liter per breath, but 1 cubic meter per breath.
Check the math!
Well, anyone can conjure up something. The trick is to make people believe it.
Better check the teeth of modern climate advocacy scientists, after extraction.
How come we didn’t have a negative tipping point back then?
Well that is the “REAL” question for the warmists. One they don’t have an answer to.