Exact climate data from the past

Innovative method opens up new perspectives for reconstructing climatic conditions of past eras

GOETHE UNIVERSITY FRANKFURT

Corals precipitate their calcareous skeletons (calcium carbonate) from seawater. Over thousands of years, vast coral reefs form due to the deposition of this calcium carbonate. During precipitation, corals prefer carbonate groups containing specific variants of oxygen (chemical symbol: O). For example, the lower the water temperature, the higher the abundance of a heavy oxygen variant, known as isotope 18O, within the precipitated carbonate. Unfortunately, the 18O abundance of the seawater also influences the abundance of 18O in the calcium carbonate – and the contribution of 18O from seawater cannot be resolved when determining temperatures based on carbonate 18O abundances alone.

A great step forward was the discovery that the isotopic composition of the precipitated carbonate allows temperature determinations independent of the composition of the water if the abundance of a specific, very rare carbonate group is measured. This carbonate group contains two heavy isotopes, a heavy carbon isotope (13C) and a heavy oxygen isotope (18O) which are referred to as “clumped isotopes”. Clumped isotopes are more abundant at lower temperatures.

However, even with this method there was still a problem: The mineralization process itself can affect the incorporation of heavy isotopes in the calcium carbonate (kinetic effects). If unidentified, the bias introduced by such kinetic effects leads to inaccurate temperature determinations. This particularly applies for climatic archives like corals and cave carbonates.

An international research group led by Professor Jens Fiebig at the Department of Geosciences at Goethe University Frankfurt has now found a solution to this problem. They have developed a highly sensitive method by which – in addition to the carbonate group containing 13C and 18O – the abundance of another, even rarer carbonate group can be determined with very high precision. This group also contains two heavy isotopes, namely two heavy oxygen isotopes (18O).

If the theoretical abundances of these two rare carbonate groups are plotted against each other in a graph, the influence of the temperature is represented by a straight line. If, for a given sample, the measured abundances of the two heavy carbonate groups produce a point away from the straight line, this deviation is due to the influence of the mineralization process.

David Bajnai, Fiebig’s former PhD student, applied this method to various climatic archives. Among others, he examined various coral species, cave carbonates and the fossil skeleton of a squid-like cephalopod (belemnite).

Today, Dr. Bajnai is a post-doctoral researcher at the University of Cologne. He explains: “We were able to show that – in addition to temperature – the mechanisms of mineralization also greatly affect the composition of many of the carbonates that we examined. In the case of cave carbonates and corals, the observed deviations from the exclusive temperature control confirm model calculations of the respective mineralization processes conducted by Dr. Weifu Guo, our collaborator at the Woods Hole Oceanographic Institution in the USA. The new method, for the first time, makes it possible to quantitatively assess the influence of the mineralization process itself. This way, the exact temperature of carbonate formation can be determined.”

Professor Jens Fiebig is convinced that the new method holds great potential: “We will further validate our new method and identify climatic archives that are particularly suitable for an accurate and highly precise reconstruction of past Earth surface temperatures. We also intend to use our method to study the effect that anthropogenic ocean acidification has on carbonate mineralization, for instance in corals. The new method might even allow us to estimate the pH values of earlier oceans.” If all this succeeds, the reconstruction of environmental conditions that prevailed throughout Earth’s history could be greatly improved, he adds.

###

From EurekAlert!

70 thoughts on “Exact climate data from the past

  1. We also intend to use our method to study the effect that anthropogenic ocean acidification has on carbonate mineralization, for instance in corals.

    I’m rather sure they have the conclusion already written, “Worse than previously thought” all they have to do is massage the data to get there.

    • I am reasonably certain the Oceans will never become acidic from anthropogenic impacts, so acidification will never be a problem…

    • And as normal the generation and maintenance of the original data will be under the control of the group trying to show that their hypothesis is correct. So we know we can trust the data and the results???

    • That was also the quote that attracted my attention. What they’re saying is that atmospheric CO2 (which balances with ocean CO2) also has an effect on carbonate mineralization. If they didn’t take that into account it would affect their temperature calculations. I wonder how many other things affect their calculations. I’m beginning to suspect that their calculations aren’t as accurate as they claim.

      While I was searching for information on ocean CO2, I stumbled on this. It highlights research showing that even non-active volcanoes spew huge amounts of CO2.

      We discovered that Katla volcano in Iceland is a globally important source of atmospheric carbon dioxide (CO2) in spite of being previously assumed to be a minor gas emitter. Volcanoes are a key natural source of atmospheric CO2 but estimates of the total global amount of CO2 that volcanoes emit are based on only a small number of active volcanoes. Very few volcanoes which are covered by glacial ice have been measured for gas emissions, probably because they tend to be difficult to access and often do not have obvious degassing vents. Through high‐precision airborne measurements and atmospheric dispersion modeling, we show that Katla, a highly hazardous subglacial volcano which last erupted 100 years ago, is one of the largest volcanic sources of CO2 on Earth, releasing up to 5% of total global volcanic emissions. This is significant in the context of a growing awareness that natural CO2 sources have to be more accurately quantified in climate assessments and we recommend urgent investigations of other subglacial volcanoes worldwide.

      As far as I can tell, that story wasn’t covered by WUWT. It should be. It has long seemed to me that the global CO2 budget is seriously misrepresented. The above link is more evidence to that effect.

      • That article is interesting, but it would have been nice if it had quantified the emissions. Unfortunately, many of its embedded links are now bad.

      • Katla, a highly hazardous subglacial volcano which last erupted 100 years ago, is one of the largest volcanic sources of CO2 on Earth, releasing up to 5% of total global volcanic emissions.

        “In 2015, human activities were responsible for a projected 32.3 billion metric tons (gigatons) of CO2 emissions. All studies to date of global volcanic carbon dioxide emissions indicate that present-day subaerial and submarine volcanoes release less than a percent of the carbon dioxide released currently by human activities.”
        https://volcanoes.usgs.gov/vhp/gas_climate.html

        Therefore Katla releases 0.05% as much CO2 as human activity.

        • JD said: “Therefore Katla releases 0.05% as much CO2 as human activity.” So multiply that by the number of other active and inactive sub glacial and undersea volcanoes (that we’re aware of) and what would we have ….. just from volcanoes?

          • As I posted. All volcanic activity produces less than 1% of the CO2 emitted by human activities. Katla produces 5% of the 1%. 1% X 5% = 0.05%

            “In 2015, human activities were responsible for a projected 32.3 billion metric tons (gigatons) of CO2 emissions. All studies to date of global volcanic carbon dioxide emissions indicate that present-day subaerial and submarine volcanoes release less than a percent of the carbon dioxide released currently by human activities.”
            https://volcanoes.usgs.gov/vhp/gas_climate.html

          • Jack Dale August 12, 2020 at 10:05 am

            As I posted. All volcanic activity produces less than 1% of the CO2 emitted by human activities.

            The article I linked calls that into doubt.

          • That article DOES NOT call that into question. It calls for further study, a typical comment is science papers.

            It deals with volcanic emissions, not total emissions. Please see: Gerlach 2001https://volcanoes.usgs.gov/vsc/file_mngr/file-154/Gerlach-2011-EOS_AGU.pdf

            The quote that your provided is not from the study to which you DID NOT link. The original study says 4%.

            ” Katla is one of the largest volcanic sources of CO2 on the planet, contributing up to 4% of global emissions from nonerupting volcanoes.”

            https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL079096

          • Really? How would you interpret …

            To put this (Gerlach’s) calculation process into perspective, the Earth is home to 1,500 land volcanoes and 900,000 seafloor volcanoes/hydrothermal vents.

            By sampling just an extremely small percent of these volcanic features it is impossible to imagine that the calculation is correct.

          • Typical Tallbloke. (You need to learn to cite sources.)

            This is one volcano on which you make you claim.

            Here is another paper for you to read. It was referenced by Gerlach.

            BTW – The output of CO2 has remained relatively constant while anthropogenic CO2 emissions have risen from 11 million tonnes per annum in 1751 to 36 billion tonnes per annum in 2013 (CDIAC data).

          • I gave you an answer.

            Roger Tattersall’s blog lacks the credence of the peer-reviewed papers to which I referred.

          • You have a naive view of the concept.

            I also get my medical advise from a trained medical doctor. My car is service by a licensed mechanic. I would not want confuse their roles.

            “Be very careful not to confuse “deferring to an authority on the issue” with the appeal to authority fallacy. Remember, a fallacy is an error in reasoning. Dismissing the council of legitimate experts and authorities turns good skepticism into denialism. The appeal to authority is a fallacy in argumentation, but deferring to an authority is a reliable heuristic that we all use virtually every day on issues of relatively little importance. There is always a chance that any authority can be wrong, that’s why the critical thinker accepts facts provisionally. It is not at all unreasonable (or an error in reasoning) to accept information as provisionally true by credible authorities.”

            https://www.logicallyfallacious.com/logicalfallacies/Appeal-to-Authority

            The first “A” of the CRAAP Test is

            Authority Authority lets us know that someone with expertise or experience in the topic is sharing their knowledge. Remember, though, that authority is contextual. Having a Ph.D. in Astronomy would not give someone authority to write about the impact of music therapy on children who have autism. The expertise or experience needs to be relevant to the topic.
            What credentials related to the topic at hand does the author have?

            – Does the author have any relevant affiliations with a respected university or organization?

            – What can you find about the author online?

            – Has the author published on this subject before?

            – Is the publication reputable?

            https://guides.library.duq.edu/informationevaluation/CRAAP

          • Perhaps we should make it a legal requirement to put up notices on your posts like is mandated on most financial adds … “Warning Jack Dale past performance is not a reliable indicator of future performance.”

            The fact is even the most famous scientists throughout history was badly wrong about something in their career and you are doing nothing except trying to establish some sort of authority which is funny.

          • Jack, I asked you to interpret a rather simple statement that can be evaluated on its own merits. You did something else and I take that to mean that you are incapable of doing so.

        • I think the point is that the previous estimates of volcanic CO2 emissions are wrong, since they only surveyed what they thought were the sources. As they look more, they find more volcanoes are sources that were not thought to be previously. Therefore, the 1% estimate is likely low and not reliable.

      • I have always suspected that the vast oceanic rifts are full of carbon emission vents that remain unaccounted for – it’s just common sense. Seeing as how oceans cover most of the planet, it would seem likely that most geologic CO2 venting occurs there as well.

        You do not need a volcanic eruption to increase a vent’s emission rate.

    • I thought it was a great summary of excellent scientific detective work, up to the point of hitting that specific sentence.

      How is it that apparently brilliant chemists, such as those doing the reported work, remain ignorant of—or intentionally interject the AGW meme that counters—the chemistry of BUFFERED ocean water (ref: Revelle Factor)?

      It is the formation of bicarbonate and carbonate ions in seawater that causes the world’s oceans to be a highly stable, strongly buffered solution with an average pH in the range of 8.1-8.2. So, adding gaseous CO2 to seawater is not, in fact comparable to adding a stable acid to an unbuffered solution in a manner that would otherwise cause a significant lowering of the solution’s pH. Anyone asserting that adding gaseous CO2 to the world’s buffered oceans (with the CO2 indeed chemically reacting with water to MOMENTARILY form carbonic acid) is equivalent to “ocean acidification” is quite simply incorrect on a fundamental scientific basis.

      BTW, the first corals appeared in the Cambrian period, about 535 million years ago, so we know that Earth’s oceans have been strongly buffered since at least that time.

    • Steve
      Yes, if they were objective researchers, they would have said something along the lines of, “We also intend to study the effect ocean pH has on carbonate mineralization, …”

      • Clyde Spencer August 12, 2020 at 9:25 am

        I thought of being more objective as you point out and doing exactly that, but as Gordon Dressler pointed out above they engaged in dogmatic propaganda. My term, not his.

    • It’s a tricky problem. More and more precision but figure out how to still qualify it with “might, maybe, probably or almost certainly” and any other weasel words that the Michael Mann/James Hansen edition thesaurus might provide.

    • 1. There is no such Epoch as the Anthopocene. 2. An alkali cannot be acidified, only made less alkali. 3. NEVER throughout the whole of Geological History which includes the Cambrian when atmospheric CO2 levels are estimated to have been around 7000ppm have the Oceans ever been acid!

      I have not yet checked what Dr. Bajnai obtained his first degree or doctorate in but seems it was not geology or chemistry or if it was I would ask in what corner of the globe was the photocopier located where he obtained his qualifications. He is also clearly referencing the shockingly bad experiment quoted by Al Goreythm where HCL was used to demonstrate calcification due to “acidification”.

      Three strikes in one sentence. Impressive!

      Is this the standard of “scientific knowledge” we are to expect from those who dip into the bottomless well of climate easy money?

      • This argument over the semantic use of acidify is ridiculous.
        Where I live we have a lot of rain (12 feet yearly on average), it drops into our ocean, and the Carbonic acid that makes up some of that rain goes into the ocean and is what? Base-ified? alkaline-ized? No you added an acid to the ocean. Acidifying is just a word to describe that process. In our area, with lots of rain, it is hard for the shellfish hatcheries to get oysters to produce shells unless they treat the water (usually with ash, or let it sit in the sun for a few hours to get the algae to convert some of the CO2).
        I know it is only a surface area issue. But none-the-less it is an issue.

  2. This is a curious claim, being able to determine formational (initial temperature) temperatures by isotopic analysis some years later. Bivalve shells, corals, gastropods, belemnite phragmacones, etc all start out as the mineral aragonite, which is calcium carbonate with an orthorhombic structure. The problem is twofold, aragonite has a poorly controlled crystal structure and commonly includes ions of barium (Ba), strontium (Sr), and magnesium (Mg) substituting for calcium (Ca), and aragonite changes to a rhombohedral structure and becomes calcite. In the process of re-organizing to calcite the substitute ions are almost all expelled as the crystal structure of calcite is much more ordered than that of aragonite. So any age determination effort which utilizes current isotopic status must account for all of the start conditions and how the isotopic content was changed during the reorganization and expulsion of contaminants process. This certainly applies to any shell from the marine environment that has undergone any burial, but may not apply to cave carbonates. I would take the paleo-temperature constructions with a little caution, where isotopic of calcite were involved.

      • The simple answer is yes; deeper water is colder and shallow water is warmer. A quick search shows a modern range from 86 degrees (F) (surface temp presumably tropics) to 30 degrees (deep ocean basin floor). However, long term temperature conditions have many confounding inputs, not the least is global temperatures.

      • Yup. What they are doing may provide a tiny, tiny snapshot of one location at one very specific point. Perhaps no indication that it was deliberately selected to provide unrepresentative info ala Mieal Mann but still not very relevant information. No doubt they will use it asfuel for more grants and catastrphic forecasts.

  3. Why do the authors of these studies always have weird names?

    Professor Jens Fiebig.

    Hmmm.. Professor Jen’s Fee = big?

    I think they’re laughing in our faces.

  4. Well it is ‘better than nothing ‘ it is frankly amazing that ‘settled science ‘ , as climate ‘science ‘ claims to be ,has be built on such a position.
    Indeed the very need for ‘models’ in the first place is because the data quality they work with is often of the standard ‘better than nothing ‘ although to be fair given that these models can always produce the ‘results you need’ their are very ‘useful’

    And this ‘better than nothing ‘ is seen from the oceans to the trees and even in the air where past claims of CO2 content are often a classic example of ‘better than nothing ‘ in action through ‘proxies ‘. These in turn have proved to be as ‘useful ‘ as models especially when you are ‘careful’ with proxies selection .
    This is merely another example of ‘better than nothing ‘ in action and although it dumps all over the ideas of data accuracy and precision which is claimed to be all important to science. This is a standard approach within climate ‘science’ due to its ability , through various means, to produce ‘supportive results ‘

    • knr … clearly you haven’t heard as I HAVE many times over. The evidence is overwhelming.
      Why aren’t you ( and people like Lindzen ) overwhelmed?

  5. I’m going to go out on a limb and guess that if this method were to clearly show the MWP, it would be disappeared. “Settled science” in action.

  6. Water temperatures cycle through a temperature range over the year. Take oysters in the Chesapeake Bay. The water temperature may range from 40F to 86F during the year and they are growing all through that range (although more slowly in the very cold water). So based on this, I guess the shell the oyster builds actually has a different chemical makeup from start to finish? How is this supposed to be measured “exactly” 5000 years from now as the shell is part of a mineral rock layer?

  7. Ron Long: Dr Gerald Friedman would be quite pleased with your succinct description of the diagenetic changes ‘inflicted’ on aragonite. Good Job!!

  8. Once you see the words Ocean Acidification, you can immediately tell that you are reading propaganda.
    There appears to be a major flaw in the article.
    You do not know the depth where the oyster grew.
    The temperature on the surface is higher than the temperature at 60 feet or 120 feet. This difference is significant – we are not talking abour 0.1F or 0.01F but 5-10F.
    Even in tropical water, you would normally put on a thin wetsuit if you were diving a wreck at 120ft.

  9. Interesting, but a method with such extraordinary claims should be validated with extraordinary rigor.
    For example, by growing corals etc. under controlled conditions in various laboratories operating with GLP rules and method pre-registration akin to what is done for pharma testing.

  10. These researchers need to go out snorkelling or scuba diving once in a while. They would find that water temperatures are variable from tide to tide, day to day and year to year in any given location, not to mention at varying depths. Taking coral samples from one or a dozen locations as a proxy for the “exact temperature” in that location just shows they don’t get out much. Maybe the approximate average within a couple of degrees….

  11. One of the main issues with the use of stable isotopic ratios to determine conditions of mineral fiormation is the same as applies to the use of radioactive isotopes in geochronology: first and foremost it has to be demonstrated that the sample has remained a closed system since its formation. Corals/carbonates seldom remain closed systems; they recrystallise readily. This is seen in cores taken through carbonate reefs.

    I doubt if it is possible to get an “exact” [lost in the translation?] live growth temperature from most samples. Rather, in the same way we can end up with a “mixed” age” that reflects aspects of the history of a dated sample, so we can end up with a temperature that is a mix of that of the growth and recrystallisation environments.

  12. You take a set of extremely sensitive and difficult measurements, then combine it with another set, then add a third, then correlate the extremely sensitive data of each and come out with a highly accurate temperature graph as long as all the assumptions and measurements were perfect.

    Heh, nothing could go wrong with this.

    First thing to do is have an independent research group take independent samples from different areas and see if the correlations match. I am betting it differs depending on which reef, what direction it is facing, what water currents are normally like, etc. Just like tree ring measurements depend on what side of the tree (upward, downward, facing the sun, protected from the sun, facing the wind, protected from the wind) you take them from.

    Complex and sensitive proxies that have more than a single uncontrolled variable will never give you the accuracy you need.

    • profound assertion.
      no evidence of course

      “First thing to do is have an independent research group take independent samples from different areas and see if the correlations match. I am betting it differs depending on which reef, what direction it is facing, what water currents are normally like, etc. Just like tree ring measurements depend on what side of the tree (upward, downward, facing the sun, protected from the sun, facing the wind, protected from the wind) you take them from.”

      Notice how skeptics are always making homework for other people
      and then making assertions
      PRIOR to anyone doing the work they suggest

      “Complex and sensitive proxies that have more than a single uncontrolled variable will never give you the accuracy you need.”

      Notice there is no evidence given for this assertion

      thats how skeptics roll.

      1. Deny the evidence we have.
      2. Suggest that someone else do something.
      3. State their conclusions as fact.

      This is why mere skepticism is not science.

      • If skeptics did the work, and didn’t come to the conclusion of “the cause”, they would be denounced as industry shills, deniers, and all sorts of other names, regardless of whether the work was done correctly and the conclusions matched the results.

        Come on, Steve, look what they did to McIntyre.

      • Mosher

        A bright, well-educated person can discern problems with research protocol, and thereby make a contribution to science.

        Many, if not most of us here, are retired. We are at a disadvantage in trying to obtain grant money to do the research, if we even wanted to. Consider the suggestions as project oversight from a senior person, aimed at those who are still involved in the daily grind of doing research.

        Where is the evidence for your assertions?

        • “Many, if not most of us here, are retired. We are at a disadvantage in trying to obtain grant money to do the research, if we even wanted to. ”

          1. you never tried
          2. lack of research money does not stop Anthony, willis, mcintyre, or me.

          you retired from a job.

          think of citizen science as an adventure

          many researchers will gladly take your volunteer labor.

          lazy

          • Mosher
            Again, where is the evidence for your assertions?

            Back before I retired, I tried numerous times to be anointed with ‘gravy.’ I was not successful, even in my areas of expertise, where I was granted a patent. So, your unsupported assumption that I never tried is about what I have come to expect from you.

            I do think of citizen science as an adventure and have been doing research on the optical constants of opaque minerals, and getting published. I have also been published here on WUWT 10 times, where my background provides me with the ability to analyze problems. It doesn’t take a PhD ichthyologist to smell a dead fish.

      • Well if the researchers were actually been doing all that themselves, but clearly they were busy writing stories and fairytales. That is how climate fabricators play.

        So I wonder what science background David Bajnai has ….. guessed it without looking “Institute of Geology and Mineralogy”. Another refugee from another field playing in the climate science field.

      • “1. Deny the evidence we have.”

        There´s nothing to deny. There´s only empty wall. All I can hear, is sound of silence.

      • “This is why mere skepticism is not science”

        Skepticism just means one is unconvinced. Skeptics don’t need to do scientific research to qualify as a skeptic. It’s up to those doing scientific research and making assertions about that research who need to provide some evidence of their assertions.

        Skeptics say: “Prove it!” to those making scientific assertions That does’t require any specific scientific research on the part of skeptics. It requires those who make assertions to prove their assertions. Skeptics assume the assertions are wrong until proven otherwise. The way to shut up the skeptics is to provide said evidence.

        Complaining that skeptics are not doing skeptcism correctly is ridiculous.

  13. The new method might even allow us to estimate the pH values of earlier oceans.

    Uh-oh. A ripe opportunity to manipulate proxy-data to make it look like today’s oceans are “worse than expected”. Bets anyone?

  14. “This group also contains two heavy isotopes, namely two heavy oxygen isotopes (18O).”

    Don’t you mean 18O and 17O?

Comments are closed.