"Extreme global warming" in the ancient past

Ancient global warming: but which came first, the temperature or the CO2?

From the National Oceanography Centre, Southampton (UK)

The image shows the the scientific drilling ship JOIDES Resolution docked in Hobart, Tasmania. Credit: John Beck, IODP

Variations in atmosphere carbon dioxide around 40 million years ago were tightly coupled to changes in global temperature, according to new findings published in the journal Science. The study was led by scientists at Utrecht University, working with colleagues at the NIOZ Royal Netherlands Institute for Sea Research and the University of Southampton.

“Understanding the relationship between the Earth’s climate and atmospheric carbon dioxide in the geological past can provide insight into the extent of future global warming expected to result from carbon dioxide emission caused by the activities of humans,” said Dr Steven Bohaty of the University of Southampton’s School of Ocean and Earth Science (SOES) based at the National Oceanography Centre in Southampton.

It has been known for some time that the long-term warmth of the Eocene (~56 to 34 million years ago) was associated with relatively high atmospheric carbon dioxide levels. However, scientists were previously unable to demonstrate tight-coupling between variations in atmospheric carbon dioxide and shorter-term changes in global climate.

To fill this gap in knowledge, the authors of the new study focused on one of the hottest episodes of Earth’s climate history – the Middle Eocene Climatic Optimum (MECO), which occurred around 40 million years ago.

Algae use photosynthesis to harvest the energy of the sun, converting carbon dioxide and water into the organic molecules required for growth. Different isotopes of carbon are incorporated into these molecules depending on the environmental conditions under which algae grow. Ancient climate can therefore be reconstructed by analysing the carbon isotope ratios of molecules preserved in fossilised algae.

The researchers took this approach to reconstruct variations in carbon dioxide levels across the MECO warming event, using fossilised algae preserved in sediment cores extracted from the seafloor near Tasmania, Australia, by the Ocean Drilling Program. They refined their estimates of carbon dioxide levels using information on the past marine ecosystem derived from studying changes in the abundance of different groups of fossil plankton.

Their analyses indicate that MECO carbon dioxide levels must have at least doubled over a period of around 400,000 years. In conjunction with these findings, analyses using two independent molecular proxies for sea surface temperature show that the climate warmed by between 4 and 6 degrees Celsius over the same period.

“We found a close correspondence between carbon dioxide levels and sea surface temperature over the whole period, suggesting that increased amounts of carbon dioxide in the atmosphere played a major role in global warming during the MECO,” said Bohaty.

The researchers consider it likely that elevated atmospheric carbon dioxide levels during the MECO resulted in increased global temperatures, rather than vice versa, arguing that the increase in carbon dioxide played the lead role.

“The change in carbon dioxide 40 million years ago was too large to have been the result of temperature change and associated feedbacks,” said co-lead author Peter Bijl of Utrecht University. “Such a large change in carbon dioxide certainly provides a plausible explanation for the changes in Earth’s temperature.”

The researchers point out that the large increase in atmospheric carbon dioxide indicated by their analysis would have required a natural carbon source capable of injecting vast amounts of carbon into the atmosphere.

The rapid increase in atmospheric carbon dioxide levels around 40 million years ago approximately coincides with the rise of the Himalayas and may be related to the disappearance of an ocean between India and Asia as a result of plate tectonics – the large scale movements of the Earth’s rocky shell (lithosphere). But, as explained by Professor Paul Pearson of Cardiff University in a perspective article accompanying the Science paper, the hunt is now on to discover the exact cause.

###

The researchers are Peter Bijl, Alexander Houben, Appy Sluijs, Henk Brinkhuis, Gert-Jan Reichart (Utrecht University), Jaap Sinninghe Damsté and Stefan Schouten (NIOZ Royal Netherlands Institute of Sea Research) and Steven Bohaty (SOES). The research was funded by the Netherlands Organization for Scientific Research Utrecht University and Statoil, and used samples and data provided by the Ocean Drilling Program (ODP).

Publication: Bijl, P. K., Houben, A. J. P., Schouten, S., Bohaty, S. M., Sluijs, A., Reichart, G-J., Sinninghe Damsté, J. S. & Brinkhuis, H. Transient middle Eocene atmospheric CO2 and temperature variations. Science 330, 819 – 8215 (2010).

DOI: 10.1126/science.1193654

http://www.sciencemag.org/cgi/content/full/330/6005/819

Science Perspective:

Pearson, P. N. Increased atmospheric CO2 during the middle Eocene. Science 330, 763-764 (2010). DOI: 10.1126/science.1197894

http://www.sciencemag.org/cgi/content/short/330/6005/763

h/t Dr. Leif Svalgaard

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105 thoughts on “"Extreme global warming" in the ancient past

  1. So they don’t know what the rise in co2 was caused by, but they know enough about its cause to say it wasn’t caused by the initial increase in temperature?
    I’ll grant it to these scientists, they can indulge in some pretty neat doublethink when they need to.

  2. C02 does not in of itself create Energy (heat or otherwise).
    The only energy we get from burning fossil fuels is the solar energy stored in them.
    Gravity causes the sun to undergo thermonuclear reaction and generate the energy.
    Once it is used, it escapes, as Earth wants to shed the excess back into space in order to be in equilibrium.
    Earth does not have the mass to hold it’s breath (received solar energy) as long as the massive Sun does, though life itself has conspired to store it chemically…. for our benefit.
    Some folks just can’t resist kicking a gift horse in the mouth. Ingrates.

  3. Isn’t it obvious? The dinosaurs must have had an advanced civilisation (Post their 65 million year ago supposed demise) that was pumping CO2 into the atmosphere!
    Either that, or we have to accept that volcanic action plays a larger part in CO2 emmissions than the AGW folk want to admit.

  4. Pardon my ignorance, but is it possible that the increased incidence of CO2 was the result of the inferred temperature change?

  5. “The change in carbon dioxide 40 million years ago was too large to have been the result of temperature change and associated feedbacks,” said co-lead author Peter Bijl of Utrecht University. “Such a large change in carbon dioxide certainly provides a plausible explanation for the changes in Earth’s temperature.”

    And so, personal opinion is elevated to scientific fact.

  6. I don’t see how this can work. Eocene Earth is Ice free. This means it is hotter because the Earth’s albedo is much lower.
    There is no way it is possible to prove that extra CO2 in an already hot earth causes 4-6C of warming.

  7. OK this is my take:
    From my press release: Scientists find a close correspondence between the temperature and frequency of people wearing short sleeved cloth, suggesting that wearing short sleeves plays a major role in seasonal warming during the spring-summer period,” said expert. The researchers consider it likely that the occurrence of people wearing t-shirts during the late spring resulted in increased seasonal temperatures, rather than vice versa, arguing that the increase in t-shirt sales played the lead role.

  8. So they are looking for evidence to support their preconceived theory of global warming? Whatever happened to impartial science?

  9. Blast paywall.
    “We found a close correspondence between carbon dioxide levels and sea surface temperature over the whole period”
    but which came first?

  10. Meaningless and does not bear the interpretation put on it. It is no surprise that CO2 levels and temperature were closely coupled but with inadequate temporal resolution who is to say which is cause and which is effect. And at a time of great geological upheavals too.
    Kindest Regards.

  11. If we take the simple explanation that ratios of certain isotopes used in climate reconstruction are fractionated through physical mechanisms such as evaporation from sea; if then we see studies reaching back 40 million years; can we not ask why the repetition of processes has not homogenised isotopes to such an extent that it is invalid to assume uniformitarianism?

  12. There are some doubts about the thermometer readings from this year. There is reason to believe that historical thermometer readings are being subtly adjusted all the time. Proxy records for the last thousand or so years are highly confusing and some are quite dodgy. But we know what the temperature in relation to CO2 was 40 million years ago. We know that there wasn’t some other explanation for an apparent correlation other than CO2 theory. Who could have a problem with that?

  13. In a system with liquid water and gases like CO2 there will always be a strong coupling of temperature and gas-concentration above the watersurface. That’s basic physical chemistry with the causation temperature first then CO2-concentration. On the other hand huge amounts of CO2 could have been produced during the colliding phase of India and Asia by enhanced volcanic activity. This would create an amount of additional CO2 temporarily outside equilibrium with water and the rocks it has come from. Equilibrium with water is a quick process, rocks need a lot of time until they are washed to sea producing buffers for CO2. So keep on drilling guys and be careful with time and causation.

  14. It´s disapointing… They so sure to point out CO2, watching their graph, im not so too see a cause-effect relationship in that way… But it’s curious the earth had over 4000 ppm of CO 2 and we are still alive…

  15. They used algae and plankton. Sea life. Did they account for the change in PH balance of the oceans from the extra CO2 in the air? And I thought that these lifeforms were in mortal peril from current CO2 levels?
    ……….

  16. “Their analyses indicate that MECO carbon dioxide levels must have at least doubled over a period of around 400,000 years. In conjunction with these findings, analyses using two independent molecular proxies for sea surface temperature show that the climate warmed by between 4 and 6 degrees Celsius over the same period.” So CO2 levels “at least doubled over 400,000 years and temperatures rose between 4 and 6 C. CO2 has gone up from 280 to 390ppm over the last 100 years leading to a 0.7C or so increase in global temperatures so the AGW argument goes. It would seem that 4-6C is a bit of an exaggeration using the same logic. 400,000 years to double CO2 is not what I would call rapid and could easily be the result of a sequence of natural events. They appear to be starting from the premise that CO2 is the culprit and ending with confirming that as the likely cause.

  17. Here we go again… Another paper based on speculation, assumptions about proxies and a world that 40 billion years ago was a completely different to what we find today.
    “Their analyses indicate that… ”
    “…using two independent molecular proxies for sea surface temperature…”
    “The researchers consider it <b<likely …”
    “Such a large change in carbon dioxide certainly provides a plausible explanation for the changes in Earth’s temperature.”
    “The rapid increase in atmospheric carbon dioxide levels around 40 million years ago approximately coincides with the rise of the Himalayas and may be related to the disappearance of an ocean between India and Asia as a result of plate tectonics…”
    Lots of weasel words but few facts. It is also interesting that on the worst case guess of a rise of even 6C over 400,000 years, this equates to a rise of 0.00015C per decade… How alarming is that! This paper is a FAIL.

  18. The sea floor is lifted over a very large area and turned into mountains. Yet nothing could account for the rise of CO2. OK, how about 2 simple possibles:
    1) All that crustal movement lets volcanoes dump a load.
    2) If that sea floor had methane clathrate (as we find all over the world now) there would be one heck of a load of outgassing when it was lifted and dried… then oxidized.
    I think they need to learn to never say never…

  19. 4-6 degrees celsius from a doubling or tripling over 400,000 years.
    What were the levels of CO2 at that time period?

  20. OMG here we go again. The co2 must have caused the increase in temperature because an increase in temperature would not have resulted in the increase in co2 that we observe.Could the co2 and temperature have increased at the same time for different reasons?The argument that we keep hearing here is that temperature has a small effect on co2 over time but this also true about the effect of increased co2 on temperature despite what we are told by the IPCC today.

  21. I’m fascinated. “The change in carbon dioxide 40 million years ago was too large to have been the result of temperature change and associated feedbacks,” How do they know? We don’t even know now the causative connection between atmospheric temperatures and CO2 levels, let alone the magnitude and sign of feedbacks, and I’d bet good money there were different feedbacks operating then.
    Until I see better than this I’ll stick with my hypothesis that rising temperatures release more CO2 from oceans and biomass.

  22. re post by John A says: November 11, 2010 at 12:51 am

    “The change in carbon dioxide 40 million years ago was too large to have been the result of temperature change and associated feedbacks,” said co-lead author Peter Bijl of Utrecht University. “Such a large change in carbon dioxide certainly provides a plausible explanation for the changes in Earth’s temperature.”
    And so, personal opinion is elevated to scientific fact.

    personal opinion arrived at from a whoppin’ dose of circular logic…. or gee, which came first? Perhaps instead of circular logic resulting in that personal opinion, it was personal bias resulting in the rationalization of circular logic. Either way, its clear CO2 did it, because nothing else could explain the magnitude of the result. /sarc

  23. While I am no scientist, I can read and understand English and as I see it, Jurai V sums up their ‘science’ very neatly (and with some humour). My interpretation of this paper is; we don’t understand causality but PLEASE keep that grant income rolling in

  24. Sort of interesting but!

    “We found a close correspondence between carbon dioxide levels and sea surface temperature over the whole period, suggesting that increased amounts of carbon dioxide in the atmosphere played a major role in global warming during the MECO,” said Bohaty.
    The researchers consider it likely that elevated atmospheric carbon dioxide levels during the MECO resulted in increased global temperatures, rather than vice versa, arguing that the increase in carbon dioxide played the lead role.

    Why wasn’t it vice versa?

    “The change in carbon dioxide 40 million years ago was too large to have been the result of temperature change and associated feedbacks,” said co-lead author Peter Bijl of Utrecht University. “Such a large change in carbon dioxide certainly provides a plausible explanation for the changes in Earth’s temperature.”
    The researchers point out that the large increase in atmospheric carbon dioxide indicated by their analysis would have required a natural carbon source capable of injecting vast amounts of carbon into the atmosphere.

    Too large? What about the volcanism associated with tectonics? Forgive me but is it not plausible that the vast amounts of CO2 postulated could have derived from the magma?
    This all sounds very much like opportunistic speculation to me. In accordance with accepted scientific method these people should be asked to provide hard evidence for their suggestions, their likelys, and their plausibles. Until then please don’t expect to have this sort of alarmist speculation treated as serious scientific research. Bolding mine.

  25. Will (comment 10):
    If two substances with different specific heats are subjected to the same energy input, the one with a lower specific heat will increase temperature more.
    CO2 has a specifc heat of 0.844 kJ/kgK. 0.844 kJ of added energy will increase the temperature of 1 kg of CO2 by 1K.
    N2 has a specific heat of 1.04 kJ/kgK. 0.844 kJ of added energy will increase the temperature of 1kg of N2 by 0.88K.

  26. Temperatures were even higher during the Cretaceous period and atmospheric CO2 levels were 3000ppmv, probably due to volcanic activity. But the high temperatures have been put down to an acceleration of the plate tectonic system, cause unknown, which resulted in shallower oceans.
    Ice core research has shown a lead in temperature over CO2 of 600 to 1000 years for the past 60,000 years. Resolution in measurements 40million years back is very poor and a time of 600 to 1000 years virtually impossible to see.

  27. I agree with Uk Sceptic:-
    “Understanding the relationship between the Earth’s climate and atmospheric carbon dioxide in the geological past can provide insight into the extent of future global warming expected to result from carbon dioxide emission caused by the activities of humans,” If that ain’t a preloaded statement I don’t know what is! Surely there would have been so called mass extinction events, but according to dinosaur theory that was 65 million years ago, but then again according to others the asteroid only polished them off as their climate & landscape were a changin anyway, I know it for a fact, I saw that documentary about it all lasting an hour & a half, now what was it called again, oh yes I remember, “The Flintstones”! Who really knows, they’re all theories & most are possible, but not necessarily likley, except CO2 theory & especially the manmade stuff! Also why can’t these guys just do the simple thing & say a 5°C rise +- 1°C. Did they use a “model” to test their pest theory? I do hope not. I do have a real problem when someone models something & get the answer they expected, time to look for the glaring errors I think.

  28. So where did the CO2 go? Back into coal. Wasn’t this an explosion of life at this time, I mean we are here today are we not so was the rise that bad?

  29. 40 million years ago, India collides with Asia, rerouting of major sea-currents, still no landbridge between North and South America. Large parts of Europe, Asia, Africa and South America where still covered by shallow seas, i gues there you have it.

  30. RE: The Gray Monk says:
    “Either that, or we have to accept that volcanic action plays a larger part in CO2 emmissions than the AGW folk want to admit.”
    Volcanoes have played a very large role in changing CO2 concentrations in the past. Read a climate science textbook that looks at past climate to see; you’re looking for the carbonate-silicate cycle.
    Doubling CO2 over 400,000 years is something that volcanoes could, in principle, do. Causing a 40% increase in 150 years isn’t something they aren’t doing today. We know that, because we know that the amount of CO2 in the atmosphere is going up more slowly than humans are putting it in. We’re pumping out about 30 billion tons/year, and the amount in the atmosphere is going up ~15 billion tons/year.
    CO2 from volcanoes is around 0.15 billion tons/year (USGS).
    So to believe CO2 is coming from volcanoes, you have to do some severe intellectual acrobatics and assume modern day science is horrendously wrong when it considers things like conservation of energy…

  31. So why is there a relationship between earthquakes on the East Pacific Rise and El Nino if volcanoes don’t control the climate?

  32. Will: as well as the mistake that Red has pointed out, you must also consider that CO2 is in a mixture where it interacts pretty regularly with the other particles in the air (i.e. many times a second).
    This means that if its temperature rises above the ambient, then it will transfer heat to the other molecules quickly to try and re-establish equilibrium.
    The actual, weighted change in specific heat capacity of the atmosphere is miniscule. From 0.00028% to 0.00038% CO2 would be a miniscule change in heat capacity anyway.
    However, even that is not too relevant! What is important is the _flux_ of heat in and out. The Earth will tend towards equilibrium and the only significant way it can exchange energy with space is radiation. Given a certain heat input, the only way it can reach a new equilibrium is to radiate, and the total radiation is a function of temperature but not heat capacity.
    A lower heat capacity simply means you will obtain equilibrium more quickly. If your theory was correct, then the upper ocean would always be much cooler than the atmosphere, because it has a higher heat capacity. This isn’t true.
    The website you posted is pseudoscientific rubbish. It completely misunderstands the greenhouse effect, invents a broken ‘logic’ for how it thinks the greenhouse effect works and then confuses itself in trying to take apart this imaginary hypothesis. The author should read something beyond an introductory planetary physics textbook to see where they’ve gone wrong – for example, consider the crazy idea that absorption probability can take values OTHER than 0 or 1. Wild, I know!

  33. They’ve given the answer but ignored it:
    “We found a close correspondence between carbon dioxide levels and sea surface temperature over the whole period”
    Sea surface temperatures rise due to solar variability, orbital changes, cloud quantity and albedo variations, volcanic activity, internal ocean cycles or whatever.
    Warm sea surfaces absorb less CO2 than cold sea surfaces whilst the biosphere carries on its merry way so CO2 accumulates in the air.
    So sea surface temperature changes must even then have preceded the change in CO2 quantities just as throughout the entire subsequent ice core record.
    This is just a cynical attempt to deal with that inconvenient ice core record. If they can suggest that it was different with CO2 acting as a forcing agent at any time in the past they think that will help them to say that the current human contribution to CO2 can operate as an unnatural forcing agent notwithstanding that the natural way of things is temperature first and CO2 later.
    It’s the same strategy they used to try and explain away the cooling of the stratosphere right through the late 20th century warming spell. The stratosphere is ‘supposed’ to warm up when the sun is more active but it simply did not so the cooling stratosphere was assumed to be a consequence of human CO2 and CFCs upsetting the natural order.
    I think they are soon going to find out that the stratosphere cools naturally when the sun is more active and warms naturally when the sun is less active despite the well known uv effects on stratospheric ozone.

  34. Funny how when you start a study to prove something, such as CO2 heating the earth, you can fit the flimsy data to the answer you where looking for. The main problem I have with this study though is they are assuming the only reason that temps went up was because of CO2 only, The path of science has been long and hard but it has now arrived at the point of finding questions to the answers you want.
    Einstien would be ashamed.
    I’m also amazed that these scientists can tell us what clouds and storms where doing 65 million years ago but ask ’em about next week and they’ll not be able to give you an answer.

  35. Ulric Lyons says:
    November 11, 2010 at 3:09 am
    Any cooling under that ash cloud yet?

    People may recall the recent catastrophic failure of one of the four Rolls Royce Trent engines on a Qantas Airbus a380 flying out of Singapore bound for Sydney. Had this occurred whilst the Mt Merapi ash clouds were located where indicated in your http://www.underground link no doubt this event would now have whole extra layer of speculation as to the cause.

  36. One wonders if the actual physical impact of continents smashing into each other with enough force to create mountain ranges might have a bit of a heating effect. I mean the heat caused by all that friction around this particulary active period had to go somewhere, did it not? In this case it did not produce much volcanic activity as no subduction occurred in the Himalayas. Interestingly some folk believe the formation of the Himalayas caused the last ice age and had a role in decreasing CO2 levels.

  37. I believe that CO2 concentration is just one of a number of factors that affect the climate. I do not think we can reliably draw inferences on the past if we have yet to develop accepted theories that explain why our atmosphere is structured the way it is, how it radiates convected heat to outer space and why the well-known prehistoric climate changes have occurred. That may not be possible as long as the CO2 concentration is widely assumed, as a matter of faith, to be the primary climate driver.
    As presented here, this project has the appearance of a ‘fishing expedition’ for evidence to associate high concentrations of CO2 in the atmosphere with high temperatures in the past.

  38. As has been said the crucial evidence in this paper is the rise in sea surface temperatures. There has been other research that shows that there is a clear link between sea surface temperature and solar activity. As we know the oceans are a key source of CO2 atmospheric emissions.
    It is entirely plausible that an increase in solar activity 40 million years ago would result in warmer seas resulting in an increase in CO2. The Vostok data supports that hypothesis.

  39. @ Nial , November 11, 2010 at 3:36 am:
    You took the words out of my mouth – why did they not give the amount of CO2 at the start of their doubling, and why did they not give the amount at the end of that process of 400,000 years?
    It looks like another piece of quite nice science (carbon isotope ratios in fossil algae) being abused for political activism.
    Cancun, anybody???

  40. Skeptical Science did a big write up on this. The comments were so smug….
    However, I had recently done an article up about CO2 levels and the solubility of water.
    Clearly changing temperatures are more than enough to cause significant changes in atmospheric CO2 levels. When that is taken into account with the simple fact that CO2 levels lag at the END of an interglacial and it is clear that CO2 does not cause anything.
    CO2 was a reasonable proxy for temperature, but I will agree that it is no longer a valid proxy.
    John Kehr
    The Inconvenient Skeptic

  41. “Shevva says:
    November 11, 2010 at 3:56 am
    Sorry I have added 25 million years to their study.”
    It’s OK. In climate science, this sort of “slip” (Meaning bad data, errors in processing data and even losing original data) is par for the course. There will be an inquiry , where you supply the data you will be tested by, and they will exonerate you for any wrong-doing.

  42. “Bob of Castlemaine says:
    November 11, 2010 at 3:54 am”
    Defects are appearing in regions not affected by this ash cloud, and if it were as a result of the ash, ALL engines would experience the same, or at least similar “damage”. So far that is not the case. In this case, it is just one engine. But, yes, still, the most tested engine ever made for commercial aircraft, fails in this way. What I’ve seen suggests cracks in engine components not detected.

  43. “Understanding the relationship between the Earth’s climate and atmospheric carbon dioxide in the geological past can provide insight into the extent of future global warming expected to result from carbon dioxide emission caused by the activities of humans,” said Dr Steven Bohaty of the University of Southampton’s School of Ocean and Earth Science (SOES) based at the National Oceanography Centre in Southampton.
    Why do we fund and then have to listen to the ramblings of people educated beyond their capacity for comprehension?
    The whole lot of them should be put on a train for a field exercise at Aviemore to consider and explain a climatic phenomenon that, contrary to their past prognostications, is becoming a regular, yet unpredicted, occurance.
    See here :- http://www.cairngormmountain.co.uk/
    They could then be retrained for more useful employment – perhaps as snow plough drivers…….

  44. Hey – please stop criticising this important new scientific finding.
    It must be a scientific finding, mustn’t it?
    After all, it’s printed in Science!
    OR have I got that wrong somehow?
    /sarc off

  45. Jimbo, I was just thinking the same: even if the temperature rise was cause by co2, there was no doomsday like Hansen or Tamino and his disciples want us to believe in. Quite the contrary: 5 million years later, Antarctica got it’s permanent ice sheet.

  46. Peter Bijl of Utrecht University. “Such a large change in carbon dioxide certainly provides a plausible explanation for the changes in Earth’s temperature.”
    +++++++++++
    Remember Trickie Dickie? Plausible deniability?
    This stuff is 1/NIXON: Changing Temperatures = Plausible Attributability to CO2
    And we have to erase at least 20 minutes of the ice cores.

  47. There was a couple of a warm spikes at about 39.5 Mya and 42.0 Mya but I would put no stock at all in the CO2 estimates from this study.
    One of the CO2 estimates is 6,918 ppm (ranging from 5,560 to 8,250).
    That is just so far off the charts of where CO2 was at the time and other estimates (1,400 ppm), that it should just be thrown out. If 3.0C per doubling was correct, temperatures should have been 13.0C higher than today when it was only a few degrees higher.
    They are using a method which measures Carbon levels and different Carbon isotopes in fossil organic material and this general methodology produces wild swings in estimates including many Zeros. It is just not reliable and shouldn’t be used anymore.
    —————————-
    There was a new study published in Nature on Oct, 21, 2010 which used high resolution temperature and CO2 estimates right at the Paleocene Eocene Thermal Maximum (PETM) event – 55.8Mya.
    The study found that there was a spike in temperatures (55.81 Mya) which occurred before the CO2 increased (55.76 Mya). There might have been two pulses of warming before the CO2 spiked. Temps increased between 4C to 5C in the spike (and CO2 increased from 900 ppm to 1700 ppm in the spike noted from other sources versus this study).
    So again we have Temperatures leading CO2 (in a major warming event that has particular fascination for the pro-AGW set).
    http://www.nature.com/nature/journal/v467/n7318/full/nature09441.html

  48. How could a mere doubling of co2 cause 4 to 6 degree increase in temperature? And that apparently took 400,000 years. Why are not current temperatures off the charts now considering our rapid increase in atmospheric co2? Does this means we have 300,000 years to reduce our carbon footprint? if so maybe our agw friends could relax and take it easy for a while.

  49. Moebius says:
    November 11, 2010 at 1:31 am

    It´s disapointing… They so sure to point out CO2, watching their graph, im not so too see a cause-effect relationship in that way… But it’s curious the earth had over 4000 ppm of CO 2 and we are still alive…

    Well, it seems reasonable that cells developed at high concentrations of CO2: our lungs work with thousands of ppm, in the alveoli. Respiration is a complicated system that depends on these high values.
    There used to be a nice article in wikipedia but I can no longer find it by googling.

  50. Middle Eocene Climate Optimum …… Why do they continue to refer to the warm period as “climate optimum”? Freudian slip or Orwellian oversight?

  51. Probably, the warmer earth held a larger biomass, could that account for the extra CO2?
    Seems like we should try natural explanations before we introduce unknown mechanisms. There are already to many mysterious unknowns in climate science.

  52. I don’t get it:
    “one of the hottest episodes of Earth’s climate history – the Middle Eocene Climatic Optimum”
    A period when the climate is hot, very hot, and atmospheric CO2 is high, very high.
    A situation we are told is bad, and we should avoid.
    Don’t these people mean to say “The Middle Eocene Climatic Pessimum“?

  53. Just posing – so maybe the temperatures increased, enhancing the quantity of plant life forms and the resulting increase in vegetation caused a significant increase in CO2? Where else could the CO2 come from? Man Bear Pig?

  54. Hmm, seems devoid of science from the original news release. They seem to have started with their conclusion then worked the experiments and analyzed the results to ensure the outcome. As stated above, disappointing.
    Anyone buying the article and posting a summary with a little more depth and the quantitative results?
    It seems from a quick run through available sources (superficial, like wiki, and things I can recall quickly), the CO2 levels were between two and three times our current levels in the MECO. I cannot find evidence of a change from 800 to 1600 ppm (or other ranges). It seems the trend was a gradual reduction in CO2 from near 1000 ppm with a bump, but a small bump, not a doubling, which should be obvious. Perhaps these researchers will show sufficient rigger to establish a new understanding.
    Still, a doubling at that level could not, according to the warmist theories, produce five degrees C warming. And, as has been stated, there is likely a few hundred year lag between warming and CO2 in either direction, so resolution is certainly deficient that far back.
    I hope the effort is to increase resolution and understanding, but I fear the only goal is additional grant funding on the CAGW gravy train.
    If I may remind, the very warm early Eocene gave rise to the primates and ungulates. No one is yet predicting we will get that warm again. It seems obvious we can handle much warmer temperatures as a planet and as a species.
    And just because I like the quote so much:
    http://www.scotese.com/climate.htm

  55. I will state again what I have said many times before: its time to institute a review and recall program for PhD degrees, just like occurs for things like medical and engineering certificates.

  56. No scientist can dispute the fact that CO2 gas is released from the oceans when these warm up, (except, of course those of the warmist type). But having said that, I am ready to prove otherwise, that is; the proof that the release of CO2 from the oceans causes global warming. This will be submitted upon confirmation of that still-pending million-dollar grant that I have been begging for for the last years.
    ………
    From Wikedpedia:
    “Flora
    At the beginning of the Eocene, the high temperatures and warm oceans created a moist, balmy environment, with forests spreading throughout the Earth from pole to pole. Apart from the driest deserts, Earth must have been entirely covered in forests.”
    mmm. Not actually bad. All those forests and rich vegetation…. It’s not what AlGore preaches/prophecies in his convenient lie, sorry, i mean “Inconvenient Truth” which is a lie anyway you look at it.
    ……….
    One more shot: With all those big veggie-munching beasts roaming the eocene planet from pole to pole, the methane they produced must have hockey-sticked the eocene warming by some more degrees; like in: Kill all those cows and cattle because their methane-farting activitiies will cause global warming and destroy the planet. But I think the greenies have now actually grown out of that one too, but, come to think of it, i did not see it mentioned in their admission “Where we (greenies) went wrong” of a week or two ago.
    Oh how I will miss all this fun when the AGW fable is past its sell-by date, buried and forgotten? I think I will have to take up fishing

  57. Before I get beat up for my last statement, I know that plants take in CO2 and animals exhale CO2. Just didn’t get my coffee this morning. Sorry.

  58. If CO2 can only absorb specific bands of IR energy how come this energy is available through the whole depth of the atmosphere? The way I see it is a fixed amount of energy is absorbed and heats the air. This is a constant. Increasing CO2 simply reduces the level of complete absorption.

  59. Bob of Castlemaine says:
    November 11, 2010 at 2:30 am
    “The change in carbon dioxide 40 million years ago was too large to have been the result of temperature change and associated feedbacks,” said co-lead author Peter Bijl of Utrecht University. “Such a large change in carbon dioxide certainly provides a plausible explanation for the changes in Earth’s temperature.”
    The researchers point out that the large increase in atmospheric carbon dioxide indicated by their analysis would have required a natural carbon source capable of injecting vast amounts of carbon into the atmosphere.
    Too large? What about the volcanism associated with tectonics? Forgive me but is it not plausible that the vast amounts of CO2 postulated could have derived from the magma?

    Try reading what they say and explain how vulcanism is a “result of temperature change and associated feedbacks”.

  60. Anyone notice that the stated 4 – 6°C temperature increase is conveniently at the top end of the IPCC models predictionsprojections?
    I say this is just a sad attempt to prop up a flagging power grabhypothesis.
    DaveE.

  61. I posted the suggestion that a (much) larger total biomass would (through decomposing process) release carbon dioxide. It should also be noted that a warmer climate of course increases the speed of the decomposition.
    How do one calculate the effects on atmospheric co2 from a rotting green planet?
    Is it difficult or already done?

  62. Another two cents on this topic. There is only one time in the last 700 million years where the temperatures and the CO2 levels have been as low as they are now. That was the ice age from the middle-late Pennsylvanian to early Permian periods where the average global temperature was about 12 C and the CO2 was about 350ppm. The GEOCARB III project has the details.
    http://www.geocraft.com/WVFossils/Carboniferous_climate.html

  63. I noticed the same thing as M.E. Smith. The methane hydrates would have evaporated as well which would have increase greenhouse gas heat trapping. And, of course, there’s the evaporation of mass amounts of water. If there was tectonic heat events that affected the Indian/Asian ocean, that would have also put a lot more water (and other particulate matter, which suggests cloud formation) into the air. Depending upon the timescale of the ocean event, we could be looking at a system that would provide a lot of trapped heat to the atmosphere.
    There’s a lot of missing information here.

  64. Here is my collation of temperature and CO2 estimates over the last 45 Mys.
    All CO2 estimates available in the literature (3100 individual estimates charted at 3.0C per doubling so that they are comparable to the temperature estimates) are included in here. I’ve excluded the ones done through the Carbonate method that this paper used – the Carbonate estimates are all over the map and I would have to extend the y-axis to +15C and -15C to include them all, it is just a bunch of random up and down spikes – Berner’s GeoCarb III is not included as well because it is just low resolution every 10 million years and is better for the far distant past where there are fewer estimates available than for the more recent period).
    Correlation is very poor. One can also see that cherrypicking a short period with a short CO2 spike gives a very incomplete view of the picture and allows one to make all kinds of exagerrated claims. I think the warming event they are talking about in this paper actually happened at 42 Mya so there might be a problem as well with the dating.
    http://img232.imageshack.us/img232/8831/co2sensitivity45m.png
    Some of the geographic changes over the last 45 Mys are more relevant to the temperature history in my opinion.
    http://img837.imageshack.us/img837/695/tempgeog45m.png

  65. Seems to me the increase in CO2 is easily explained. The Tethys Sea would have been like other seas that are getting squeezed. They have a lot of limestone deposites (carbonate rock) from marine life. That in turn would have had a substantial portion of it subducted back to the mantle, melted and ejected as water and CO2.

  66. It makes sense to me that if you have warming you also have explosions in animal/insect populations, therefore rises in CO2. And that would be a lag from the temp increasing.

  67. eadler said:
    “The sea does does dissolve CO2 and some remains in solution in the liquid. This is not the only possible source of CO2 as you claim. Over a period of 400,000 years, an increase in volcanic activity could result in the increase in CO2 that was observed”
    I made no such claim, merely pointed out the implications of the close correlation that they observed between SSTs and CO2 levels.
    If a significant portion of that rise in CO2 had been from a volcanic source then the correlation with SSTs would not have been so good would it ?

  68. A case for a comet impact trigger for the Paleocene/Eocene thermal maximum and carbon isotope excursion
    “We hypothesize that the rapid onset of the carbon isotope excursion (CIE) at the Paleocene/Eocene boundary (not, vert, similar55 Ma) may have resulted from the accretion of a significant amount of 12C-enriched carbon from the impact of a not, vert, similar10 km comet, an event that would also trigger greenhouse warming leading to the Paleocene/Eocene thermal maximum and, possibly, thermal dissociation of seafloor methane hydrate. “

    Evidence for the thermal dissociation of methane hydrate during the Paleocene-Eocene thermal maximum
    “We present new high-resolution stable isotope records based on analyses of single planktonic and benthic foraminiferal shells from Ocean Drilling Program Site 690 (Weddell Sea, Southern Ocean), demonstrating that the initial carbon isotope excursion was geologically instantaneous and was preceded by a brief period of gradual surface-water warming. Both of these findings support the thermal dissociation of methane hydrate as the cause of the Paleocene-Eocene thermal maximum carbon isotope excursion. Furthermore, the data reveal that the methane-derived carbon was mixed from the surface ocean downward, suggesting that a significant fraction of the initial dissociated hydrate methane reached the atmosphere prior to oxidation. “

    Release of methane from a volcanic basin as a mechanism for initial Eocene global warming
    “We propose that intrusion of voluminous mantle-derived melts in carbon-rich sedimentary strata in the northeast Atlantic may have caused an explosive release of methane—transported to the ocean or atmosphere through the vent complexes—close to the Palaeocene/Eocene boundary.”

  69. *******
    Article says:
    Their analyses indicate that MECO carbon dioxide levels must have at least doubled over a period of around 400,000 years. In conjunction with these findings, analyses using two independent molecular proxies for sea surface temperature show that the climate warmed by between 4 and 6 degrees Celsius over the same period.
    *******
    And that’s supposed to be impressive?
    You only have to look back 15k yrs or so to see similar changes — 180 to 280 ppm during a 8-10C warmup over a mere few thousand yrs. And the CO2 rise at that time is well demonstrated by the ice-cores to be due to outgassing from warmer oceans, not the cause of the warmer oceans. And this has happened again and again during the last 2 million yrs. Wow, I’m really scared. 🙂

  70. E.M.Smith says:
    November 11, 2010 at 1:50 am
    The sea floor is lifted over a very large area and turned into mountains. Yet nothing could account for the rise of CO2. OK, how about 2 simple possibles:
    1) All that crustal movement lets volcanoes dump a load.
    2) If that sea floor had methane clathrate (as we find all over the world now) there would be one heck of a load of outgassing when it was lifted and dried… then oxidized.
    I think they need to learn to never say never…

    And I think you need to read the paper before making such comments!

  71. As the market collapses the call goes out, cash out now. Or publish now cause you will face real scrutiny next publishing cycle. The desperation and psuedo science of the article is of the standard I have come to perceive as normal for this journal, which I do not purchase anymore.

  72. John Marshall says:
    November 11, 2010 at 2:44 am
    . . .
    Ice core research has shown a lead in temperature over CO2 of 600 to 1000 years for the past 60,000 years. Resolution in measurements 40million years back is very poor and a time of 600 to 1000 years virtually impossible to see.

    The 600 to 1000 year lag between T and CO2 may simply be an artifact of how atmospheric gasses get trapped in ice.
    Gas in ice at the poles is not instantaneously trapped. It occupies the space between snowflakes and ice crystals as the snow accumulates and, as it is buried, gets compressed and recrystallizes. During this process atmosphere and buried gasses continue to interact. If the composition of the atmosphere changes, so will the as yet un-trapped gases change.
    In addition to the above there is reasonable conjecture that diffusion of gases between trapped bubbles and the atmosphere (and other bubbles) occurs, and there is also the issue of different gases diffusing at different rates.
    The faith that both sides of the AGW debate place on composition of ice trapped atmospheric gases is misplaced. Too many assumptions are made regarding the timing of concentrations.

  73. Red
    November 11, 2010 at 2:36 am
    If two substances with different specific heats are subjected to the same energy input, the one with a lower specific heat will increase temperature more.
    CO2 has a specifc heat of 0.844 kJ/kgK. 0.844 kJ of added energy will increase the temperature of 1 kg of CO2 by 1K.
    N2 has a specific heat of 1.04 kJ/kgK. 0.844 kJ of added energy will increase the temperature of 1kg of N2 by 0.88K.

    In isolation (i.e. out of context) your point would be valid. But in the context of adding CO2 to the atmosphere (99% O2 and N2) the substance with the lowest specific heat capacity will have a cooling effect as it will have to emit sooner to achieve equilibrium.
    I don’t know about the world of “post normal science” but in the real world, that process is called cooling not warming. Perhaps if you care to notice the specific heat capacity of water vapour you will see that by your own definition, your point is invalid. In the context of the atmosphere, water vapour is the main so called “greenhouse gas” yet has the higher specific heat capacity compared to CO2, O2 and N2.
    Mark
    November 11, 2010 at 3:26 am
    A lower heat capacity simply means you will obtain equilibrium more quickly. If your theory was correct, then the upper ocean would always be much cooler than the atmosphere, because it has a higher heat capacity. This isn’t true.
    It depends which part of the atmosphere you are referring to doesn’t it?
    Unless you live near the one of the poles, I think you will find that at most places on Earth the ocean IS cooler than the air directly above. Which is why most people experience a cooling off when they take a dip rather than a warming.
    Not only is most of the ocean much cooler than the (lower) atmosphere above it, but strangely, (and in contravention to the fallacious bottom up warming of the so called “greenhouse effect” hypothesis) so too is most of the Earths surface, most of the time.
    Funny that!

  74. “The researchers consider it likely that elevated atmospheric carbon dioxide levels during the MECO resulted in increased global temperatures, rather than vice versa, arguing that the increase in carbon dioxide played the lead role.”
    Not happening. Any warming would simply increase convection and lead to more efficient heat loss. We do not live in a greenhouse and their picayune view of climate and their singleminded assumptions WILL ALWAYS make them draw the wrong conclusion.

  75. The answer to the question:
    “Ancient global warming: but which came first, the temperature or the CO2?”
    depends on which warming event is being studied.
    This study focused on a period 40 million years ago, and indicated that the release of CO2 caused the warming. For other periods, studies indicate that initial warming caused a release of CO2 stored in ocean waters that boosted the initial warming effect.
    While a massive release of CO2 by volcanic action can cause an ice age to end, this is not the only manner for releasing CO2. Another manner is for an initial warming of ocean waters to cause the release of CO2 held by the oceans which added a positive feedback loop to the warming that ends an ice age.
    In 2007 the IPCC noted that temperature increases ocurred prior to increases in CO2. http://www.ipcc.ch/publications_and_data/ar4/wg1/en/faq-6-1.html
    Regardless of which came first, increasing CO2 levels results in higher temperatures than would otherwise exist due to the increase in radiative forcing from the additional CO2.
    In a previous post on this site described a study whch identified the antarctic as the source of increase in atmosphere CO2 that occurred after a temperaure increase.
    http://wattsupwiththat.com/2010/10/25/antarctic-ocean-the-big-kahuna-of-glacial-period-carbon-sinks/
    “Scientists know that during the transition from the last glacial period to the current inter-glacial period about 14,000 years ago, carbon dioxide levels rose very quickly at the same time that the age of the carbon dioxide in the atmosphere fell, as measured by radiocarbon data. That suggests carbon dioxide had been stored in the ocean and suddenly released, she said.
    One idea holds that it was building up in the Southern Ocean around Antarctica, where extensive sea ice on the surface of the ocean initially prevented the exchange of gasses into the atmosphere, Martin said.”
    As Anthony Watts has previously stated:
    “any kid in high school chemistry class knows about the solubility of CO2 in water,” which decreases as the temperature of the water increases.
    http://wattsupwiththat.files.wordpress.com/2007/11/co2-h2o_solubility.png
    A May 2010 study, described below, previously identified the southern ocean as a major carbon sink that is capable of producing a “burp” of CO2 into the atmosphere and noted that the initial warming of the ocean was followed by this “burp”.
    Skinner, L.C., Fallon, S. Waelbroeck, C., Michel, E. and Barker S., ‘Ventilation of the deep Southern Ocean and deglacial CO2 rise’ is published in Science on 27 May 2010.
    Scientists Detect Huge Carbon ‘Burp’ That Helped End Last Ice Age
    http://www.sciencedaily.com/releases/2010/05/100527141959.htm
    Excerpt:
    ScienceDaily (May 28, 2010) — Scientists have found the possible source of a huge carbon dioxide ‘burp’ that happened some 18,000 years ago and which helped to end the last ice age.
    The results provide the first concrete evidence that carbon dioxide (CO2) was more efficiently locked away in the deep ocean during the last ice age, turning the deep sea into a more ‘stagnant’ carbon repository — something scientists have long suspected but lacked data to support.
    According to Dr Skinner: “Our results show that during the last ice age, around 20,000 years ago, carbon dioxide dissolved in the deep water circulating around Antarctica was locked away for much longer than today. If enough of the deep ocean behaved in the same way, this could help to explain how ocean mixing processes lock up more carbon dioxide during glacial periods.”
    But changes in Earth’s orbit could only have acted as the ‘pace-maker of the ice ages’ with help from large, positive feedbacks that turned this solar ‘nudge’ into a significant global energy imbalance.
    Changes in atmospheric CO2 were one of the most important of these positive feedbacks, but what drove these changes in CO2 has remained uncertain.
    Scientists think more CO2 was locked up in the deep ocean during ice ages, and that pulses or ‘burps’ of CO2 from the deep Southern Ocean helped trigger a global thaw every 100,000 years or so. The size of these pulses was roughly equivalent to the change in CO2 experienced since the start of the industrial revolution.
    If this theory is correct, we would expect to see large transfers of carbon from the ocean to the atmosphere at the end of each ice age. ”

  76. Oddly, just yesterday I read a notice of a study about the end of the more-recent last great ice age which postulated that when sea ice in the Antarctic melted the [uncovered and warming] seas released vast amounts of previously trapped CO2, explaining how the global CO2 levels of the time could have shot up so rapidly while warming continued at a steady [if still “alarmong”, to cold-adapted organisms] pace.

  77. “Which is why most people experience a cooling off when they take a dip rather than a warming.”
    Actually,that is because entering water of the same temperature as the air above it cools the body (assuming both air and water are at lower than body temperature) much faster than does the air because the density of water and its heat carrying capacity cause it to extract heat from one’s body much faster than does air.
    Air directly above and in contact with water quickly adopts the temperature of the water for the same reason.
    On average taking the entire globe the areas where oceans are cooler than the air above and areas where oceans are warmer than the air above are about equal over time but with swings above and below the average due to interacting variations in both air and oceans.
    The greenhouse hypothesis doesn’t propose bottom up warming. It proposes additional downward IR warming the surface in the course of delaying the exit of the same energy to space.
    However the inability of IR to warm a body of water (as opposed to just a few surface molecules that promptly evaporate) combined with the oceanic control of surface air temperatures means that the extra IR cannot alter the equilibrium temperature of the system as a whole. Instead it just accelerates the hydrological cycle a miniscule unmeasurable amount and the extra energy from that extra downwards IR just vanishes into latent heat and is whisked away by wind and convection for a faster exit to space.
    Thus there is an equal and opposite effect that cancels the assumed extra warming from more CO2.
    As someone here keeps saying, IT’S THE WATER.

  78. There are many excellent plausible posts here by us, “deniers”. However, the real answer is still that no one knows. But in our favor, at least we “deniers” are not attempting to change public policy, spray SO2 into the atmosphere, cripple the economy, or create a system by which we can make money off of the fears of the public based upon our unproven hypotheses.

  79. This study must be from the same folks who paint dinosaurs in different colors but never tell us they are just “painting” out of their ass. What they say, “Sure dinos existed.” What they say in their emails to each other, “But we don’t really know what color they were.”
    What the authors write in the paper, “Sure CO2 existed.” What they email to each other, “But we are just “guessing” out of our ass as to why it rose and fell.”

  80. Stephen Wilde
    November 11, 2010 at 12:23 pm
    Regardless of the hairsplitting and goal-poast moving, the question is, what is the origin of the “downwelling” IR?
    As I have shown on my website with a simple reproducible experiment, it is certainly not CO2.

  81. http://www.theatlantic.com/magazine/archive/2010/12/dirty-coal-clean-future/8307
    I am reading this article now and apologize if someone else has posted it. There is this reference which caught my attention: “Now the carbon-dioxide concentration is at or above 390 ppm, which is probably the highest level in many millions of years. “We know that the last time CO2 was sustained at this level, much of the Greenland and West Antarctic ice sheets were not there,” Michael Mann, a climate scientist at Penn State, told me.”

  82. Stephen Wilde
    November 11, 2010 at 12:23 pm
    I don’t wish to split hairs but this sentence:
    “On average taking the entire globe the areas where oceans are cooler than the air above and areas where oceans are warmer than the air above are about equal over time but with swings above and below the average due to interacting variations in both air and oceans.”
    contradicts your previous sentence:
    “Air directly above and in contact with water quickly adopts the temperature of the water for the same reason.”
    Which maybe true for the first few millimetres of air above water. But beyond that we are merely making assumptions.
    One more point about the so called “greenhouse effect” hypothesis:
    “The greenhouse hypothesis doesn’t propose bottom up warming. It proposes additional downward IR warming the surface in the course of delaying the exit of the same energy to space.”
    So according to this hypothesis the surface heats air which heats the surface, right?
    In violation of all known laws of thermodynamics.

  83. Add another geologists opinion …mentioned earlier with respect to dating resolution ……
    the paper is CRAP!!!!!

  84. So essentially the temperature has gone up and down like it frakking please with no regard, what so ever, for poor massmurdering-dangerous-molecule CO2. Pfft, cheeky bastard.

  85. Interesting period of time in the not so distant geologic past.
    There was an active series of super volcanic eruptions in central North America from 44-2 MY ago. The largest was a nearly VEI9 eruption from La Garita caldera in Colorado around 28 MY ago. It left the Fish Canyon tuff, erupting over 5,000 cubic KM of stuff in a single eruption (Yellowstone x3). There is also a minor extinction event 34 MY ago. Multiple large impacts around 35 MY ago (Chesapeake Bay, Tom’s Canyon, Siberia, 2 in Australia, and a few others). Most notably, the global climate gets cooler in the mid-30s MY ago.
    I think these clowns are observing natural catastrophic changes in worldwide climate and ascribing those changes to their favorite boogeyman – manmade global warming. This is a shame, as the middle Eocene had a LOT of catastrophic stuff going on, yet no significant extinction event. Has life become more robust since the K-T boundary event? Perhaps, as the Chesapeake event (85 km wide crater), Tom’s Canyon (NJ) event (20 KM), Siberia (5 KM, 20 KM, 100 KM), Australia (8KM, 10 KM, 5 KM), Canada (8KM, 28 KM), did not annihilate life worldwide.
    There were lot of impacts in the vicinity of 35 MY ago, as there are a lot of craters on the land. Comet shower? Perhaps. Single body that fragmented and impacted on a regular basis over a few MY? Maybe. But we don’t know yet. You also had an ongoing series of supervolcanic events in North America during the period. Somewhere during the festivities, the climate changed from toasty warm with high CO2 to cold and ice ages (like present) with relatively low CO2, and these clowns blame it all on CO2????
    I think they are like the parable of the blind men and the elephant – only able to see what they want to see.
    Something (or a lot of somethings) happened in the mid-Eocene (35 MY or so ago) that changed the global climate but did not kill off significant number of species. It was a significant series of events that may or may not be directly related. Yet things on this planet measurably changed. Perhaps they ought to spend more time piecing together what happened in the mid-Eocene than trying to squeeze blood out of the manmade global warming turnip.

  86. No comments in the paper on the use of species that are supposed to be unable to withstand high levels of CO2 as proxies to prove high levels of CO2 causes warming? Did anyone read the paper? What is the PH of their assumed growth environment for the species and how does that affect the conclusion of the paper? Is the idea of acidification incorrect?

  87. Will says:
    November 11, 2010 at 2:30 pm
    So according to this hypothesis the surface heats air which heats the surface, right?
    In violation of all known laws of thermodynamics.

    Care to tell us how the laws of thermodynamics are violated by this?

  88. Philip Finck says:
    November 11, 2010 at 3:12 pm
    Add another geologists opinion …mentioned earlier with respect to dating resolution ……
    the paper is CRAP!!!!!

    So unlike most on here you’ve actually read it, care to enlighten us with a more substantive comment?

  89. The researchers consider it likely that elevated atmospheric carbon dioxide levels during the MECO resulted in increased global temperatures, rather than vice versa, arguing that the increase in carbon dioxide played the lead role.
    Thanks for being so considerate. God Bless you every one. But we would rather have data.

  90. I think it was clear that the relationship was that warmth causes CO2, that is otherwise dissolved, to rise from the oceans. So Co2 does not cause warming, warming causes more CO2.

  91. *********
    Stephen Wilde says:
    November 11, 2010 at 12:23 pm
    The greenhouse hypothesis doesn’t propose bottom up warming. It proposes additional downward IR warming the surface in the course of delaying the exit of the same energy to space.
    However the inability of IR to warm a body of water (as opposed to just a few surface molecules that promptly evaporate) combined with the oceanic control of surface air temperatures means that the extra IR cannot alter the equilibrium temperature of the system as a whole. Instead it just accelerates the hydrological cycle a miniscule unmeasurable amount and the extra energy from that extra downwards IR just vanishes into latent heat and is whisked away by wind and convection for a faster exit to space.

    ********
    Stephen, I usually agree w/you, but this assertion is puzzling. I haven’t seen any convincing explanation on why the downwelling IR would be completely converted to latent heat (evaporated water). I agree it will penetrate only a very short distance, but at such small distance scales (a few microns) the absorbed IR would just thermalize & equilibrate via conduction/mixing, which would translate to slightly higher temps of the very top of the water. I understand that evaporative cooling is occurring all the time at the surface (dependent mostly on temp & wind), but I don’t see why the evaporation would increase solely due to absorbed downwelling IR from CO2 any more than from any other IR in the general downwelling wavelengths (none of which penetrate past the “skin” of the water).
    I understand evaporation would indeed increase from a surface temp increase, but to say that all (or even most) of the downwelling CO2 IR would be converted to latent heat doesn’t make sense to me. My first guess would be that most of any downwelling IR (from CO2, H2O, etc) would be, because of what I stated above, converted to a temp increase of whatever effective short-term mixing depth occurs near the surface (a couple inches?), and that the evaporation rate would simply follow the usual temp dependence rules.

  92. Hello beng,
    Can you or anyone else show that there is any energy left over from the IR from any source not just CO2 to contribute to increased warmth in the body of water below the evaporating layer ?
    I’ve been asking for clear evidence of that for some time.
    The thing is that evaporation has a net cooling effect so every time a molecule changes state it takes out of the local environment more than the energy required to provoke the change of state. How then can there be anything left over ?
    Furthermore every photon of IR gets absorbed by a molecule within the evaporating layer so every one of the affected molecules will change state earlier than it otherwise would have done. How does the IR get any deeper to be absorbed by any molecules that do NOT evaporate.
    Note that as a result of evaporation and upward radiation there is a 0.3C cooler layer below the evaporating layer which the energy from the IR cannot cross. That cooler layer is caused by the upward energy loss being faster than the rate at which energy can come up from below.
    My assertions are usually just a challenge to someone to clearly rebut them.
    Can you do it ?
    When my assertions are not clearly rebutted I incorporate them into my comceptual model until such time as they are rebutted.

  93. Why do you scientists make things so hard? . . . when it comes to the past . . .
    First thing that came to my mind was when I read this article was the commercial production of dry ice . . . .

  94. Pardon my ignorance, but is it possible that the increased incidence of CO2 was the result of the inferred temperature change?
    BINGO!
    That’s exactly what was concluded from more recent ice cores, that the atmospheric gas composution follows the temperature record rather than the other way around.

  95. RE: “The rapid increase in atmospheric carbon dioxide levels around 40 million years ago approximately coincides with the rise of the Himalayas and may be related to the disappearance of an ocean between India and Asia as a result of plate tectonics…”
    The geology I’ve read suggests some sort of “hot spot” was able to melt away the “roots” of the Indian sub-continent, so that when it broke away from Antarctica it was able to zoom north at a speed something between twice and three times as fast as any continent “drifts” today.
    Innocent Asia was just sitting there, minding its own business, with a vast continental shelf which had been accumulating coal and oil and gas for hundreds of millions of years, when along comes this upstart chip of Antarctica and smashes into it. It seems to me very little of the coal and oil and gas in Asia’s continental shelf survived the collision. (Unless there are reserves high up in the Himalayas.)
    In other words, Mother Nature burned oil in a manner far more effective than mankind can, and leeched every bit of coal out, even from areas which would be completely inaccessible to man, and squeezed all the natural gas from the pre-collision continental shelf of Asia. One way or another, (and likely involving volcanoes and even limestone being turned to CO2,) a vast amount of “sequestered” CO2 was ejected back into the atmosphere.
    If the uptick in CO2 caused warming, and if the warming didn’t “run away” then, why should warming “run away” now?
    All that seemed to happen was the world became a warmer and lusher place, a place in many ways more kind to life, and to evolution. Mammals were able to thrive and develop all sorts of new species. The vast release of CO2 gave life a kick in the pants.
    Were it not for the release of “sequestered” carbon, a planet might become increasingly cold and sterile, with plants gasping for breath due to so little CO2 being left in the air, and an “Iceball Earth” becoming a distinct possibility.
    So…..perhaps those who like to think of Gia as having a mind that thinks, ought think in this manner:
    Gia was very worried Earth might turn into an iceball, and all life would freeze. She had to figure out some way to release a lot of sequestered carbon, but there were no continents due to collide, and no asteroids available. Therefore, in a stroke of genius, She evolved humans out squeaky little tree shrews, and, at the last possible moment and in the nick of time, burned up lots of coal, and an ice age was averted.
    At the very least, thinking in this manner would allow Moon-bats to feel much more warm and fuzzy about toasting their toes by a warm fire, and might even allow them to be thankful during a Thanksgiving dinner.

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