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Geological Society discuss climate change evidence from the geological record

Posted on 3 November 2010 by John Cook

The Geological Society has prepared a position statement on climate change, focusing specifically on the geological evidence (here's a pdf version of the statement). The geological record contains abundant evidence on the ways Earth’s climate has changed in the past and give us vital clues on how it may change in the future. Their statement is based on geological evidence, not on recent temperature or satellite data or climate model projections. The statement is a must-read, featuring a wealth of information and many useful peer-reviewed references (my to-do list has just gotten longer). I've summarised some of their key points below:

The Earth’s temperature changes naturally over time scales ranging from decades, to hundreds of thousands, to millions of years. In some cases these changes are gradual and in others abrupt. Evidence for climate change is preserved in a wide range of geological settings, including marine and lake sediments, ice sheets, fossil corals, stalagmites and fossil tree rings. Cores drilled through the ice sheets yield a record of polar temperatures and atmospheric composition ranging back to 120,000 years in Greenland and 800,000 years in Antarctica. Oceanic sediments preserve a record reaching back tens of millions of years, and older sedimentary rocks extend the record to hundreds of millions of years.

Evidence from the geological record is consistent with the physics that shows that adding large amounts of carbon dioxide to the atmosphere warms the world and may lead to higher sea levels, greatly changed patterns of rainfall, increased acidity of the oceans and decreased oxygen levels in seawater. Life on Earth has survived large climate changes in the past, but extinctions and major redistribution of species have been associated with many of them. When the human population was small and nomadic, a rise in sea level of a few metres would have had very little effect. With the current and growing global population, much of which is concentrated in coastal cities, such a rise in sea level would have a drastic effect on our complex society, especially if the climate were to change as suddenly as it has at times in the past.

Sudden climate change has occurred before. About 55 million years ago, at the end of the Paleocene, there was a sudden warming event in which temperatures rose by about 6ºC globally and by 10-20ºC at the poles. This warming event, called the Paleocene-Eocene Thermal Maximum or PETM, was accompanied by a major release of 1500 to 2000 billion tonnes or more of carbon into the ocean and atmosphere. This injection of carbon may have come mainly from the breakdown of methane hydrates beneath the deep sea floor, perhaps triggered by volcanic activity superimposed on an underlying gradual global warming trend that peaked some 50 million years ago in the early Eocene. CO2 levels were already high at the time, but the additional CO2 injected into the atmosphere and ocean made the ocean even warmer, less well oxygenated and more acidic, and was accompanied by the extinction of many species on the deep sea floor. It took the Earth’s climate around 100,000 years or more to recover, showing that a CO2 release of such magnitude may affect the Earth’s climate for that length of time.

When was CO2 last at today’s level, and what was the world like then? The most recent estimates suggest that between 5.2 and 2.6 million years ago, the carbon dioxide concentrations in the atmosphere reached between 330 and 400 ppm. During those periods, global temperatures were 2 to 3°C higher than now, and sea levels were higher than now by 10 to 25 metres, implying that global ice volume was much less than today. The Arctic Ocean may have been seasonally free of sea-ice.

Human activities have emitted over 500 billion tonnes of carbon to the atmosphere since around 1750. In the coming centuries, continued emissions of carbon could increase the total to 1500 to 2000 billion tonnes - close to the amounts added during the 55 million year warming event. The geological evidence from the 55 million year event and from earlier warming episodes suggests that such an addition is likely to raise average global temperatures by at least 5 to 6ºC, and possibly more. Recovery of the Earth’s climate in the absence of any mitigation measures could take 100,000 years or more. In the light of the geological evidence presented here it is reasonable to conclude that emitting further large amounts of CO2 into the atmosphere over time is likely to be unwise, uncomfortable though that fact may be.

I recommend everyone read the full position statement.

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Comments

Comments 1 to 46:

  1. Start stopwatch.... How long til someone posts "paleo data is unreliable" "too many uncertainties..."
    Ho hum.
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  2. Great post btw
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  3. A couple of points about the Geological Society of London Statement.

    On page 4 it states there was a 'sudden' warming event 55Ma. 'Sudden' is a very ambiguous word in geological terms. The paper doesn't give a rate of what this warming was, but it does give a rough rate of time for the Earth to recover-100,000 years. The rate of warming could have been about as slow/fast, which would mean there would be no danger to human societies from current C02 emissions.

    They also state on page 5 that the rate of increase in C02 55Ma and also in the Jurassic 183Ma whuch lead to 'abrupt' warming, was about the same as current human c02 emission rates. 'Abrupt' is another ambiguous term in geological terms. Again, they nowhere state what the actual rate of 'abrupt' or 'slow' warming was, 55Ma and 183 Ma. If it occured over tens of thousands of years, as some research papers have indicated, there is no danger from 'similar' rates of human c0o2 emissions.

    The paper mentions the abrupt shift in climate in Greenland in ht epast, but this was not from c02 emissions.

    They mention that both the reducing c02 in the atmosphere and changes in ocean circulation patterns around Antartica drove cooler temperatures over the last 50 Ma. They don't however delineate which is the more important, but do note eleswhere that c02 follows coean circulation patterns, and does not drive them. So C02 drawdown in the last 50 Ma may have had very little effect on the growth of Antarctic Ice, but rather simply follows cooler ocean temperatures. The amount of positive feedback from c02 is not stated.

    Also:
    They nowhere mention aspects of the geological reord that do not fit the paradigm that human c02 causes rapid, onoing (little/no negative feedback) climate change.

    They nowhere mention that ocean chemistry changes in the geological record took up to tens of thousands of years during 'similar' rates of c02 emissions at 55ma and 183 Ma that they say are occuring by humans now, meanning there is no danger of human c02 emissions causing major rapid ocean acidification on human timescales.

    They nowhere mention that as oceans cool or warm, they release c02 as a function of c02 solubility with temperature. This means they haven't differentiated how much c02 follows temperature changes, and how much is causes temperature changes. They only note a correlation, and implicitly assume c02 is main driver of temperature, and not the other way round. Correlation is not causation, but they fail to mention this key aspect entirely.

    Too many holes in the paper to take seriously, and as a geologist, I am disheartened by their level of bias towards AGW, whilst not addressing the weaknesses in the science.
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  4. thingadonta - can I recommend Zeebe et al 2009 and its cites? Getting rates out of geological records is indeed difficult but the high-res Walvis ridge record would suggest <5000 years and maybe <1000 years. I cannot see how you can conclude that this means rate in past infer no danger now. In past in might be assumed that CO2 feedback raised temperatures slowly because the feedback cycle is slow (not for PETM however), but the important bit is how high did temperature go. If it went 6 degrees in 1000 year for same size pulse, then getting 6 degrees in 200 years is going to be a whole lot worse. Note that CO2 injection was 'fast' as was the temperature rise - as you would expect from the physics. Note too, contrary to what you state, that the ocean chemistry change was exceedingly fast - it is the ocean chemistry change that is marker after all. I'd say the record was on the contrary warning that you can produce very fast change. You can infer that from basic physics and chemistry as well.

    While the article might raise some questions for you, you will see that published science it is based on does not have the holes you infer. For instance, the source of CO2 is inferred from stable isotopes - its not from natural marine cycle.

    PETM has some major mysteries - what caused the depleted-O13 CO2 injection and how it was sustained. However, the effects of such a change of ocean chemistry, biodiversity and global climate are no mystery at all - they merely confirm what physics and chemistry would predict.
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  5. #3: "They nowhere mention aspects of the geological reord that do not fit the paradigm that human c02 causes rapid, onoing (little/no negative feedback) climate change."

    On the contrary, they do mention that current conditions do not fit within constraints established by the geological record. This is well-researched and very clearly presented:

    While these past climatic changes can be related to geological events, it is not possible to relate the Earth’s warming since 1970 to anything recognisable as having a geological cause (such as volcanic activity, continental displacement, or changes in the energy received from the sun). This recent warming is accompanied by an increase in CO2 and a decrease in Arctic sea ice, both of which – based on physical theory and geological analogues - would be expected to warm the climate. --emphasis added.

    Human activities affecting geological scale changes? As a geologist, that should alarm you.
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  6. Whoops, make that C13 CO2.
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  7. In its conclusion, the statement refers to a change in the position of the earth relative to the sun, prompting the release of atmospheric CO2, That may explain why ice cores show CO2 lagging temperature but I do not see how the geological record shows which was responsible for global warming - change in the earths’ position relative to the sun or increase in atmospheric CO2. How do we know if CO2 was the trigger or only the amplifier?

    Should we be concerned that in the absence of a shift in the earths’ position relative to the sun, rising atmospheric CO2 is begining to increasingly trigger-happy?
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  8. #4 scaddenup
    "...but the important bit is how high did temperature go. If it went 6 degrees in 1000 year for same size pulse, then getting 6 degrees in 200 years is going to be a whole lot worse."

    No, the important thing is the rate, not the magnitude, that is basic physics.

    We don't know that it went 6 degrees up in 1000 years at 55Ma, let alone 6 derees in 200 years. You are mixing up AGW dogma with what we do and don't know. The question is: what is the rate, not: "the rate is X....therefore its going to be worse".

    Many AGW proponents do this, they confuse results with theories, and theories with results: if you are trying to determine a projected outcome of an unknown rate, you dont approach the issue by saying: this is the outcome therefore this is the rate.
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  9. For the record, if temperatures rose by 6 degrees in the space of 1,000, then that equates to an average rate of +0.06 degrees *per decade*. By contrast, recent warming has occurred at the rate of between +0.12 per decade(last 60 years) to +0.16 per decade (last 30 years)-which represents a much more rapid rate of warming-in spite of the lack of the obvious forcings in past climate change events (like long-term volcanism & Milankovitch cycles).
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  10. Agnostic - if the primary forcing is change in solar than CO2 amplifies this through a slow feedback. The orbital variation that changes solar is happening all the time - but it is very slow and so are CO2/CH4 feedbacks. However, at PETM, you had a massive injection of CO2 (probably originally CH4 that then oxidized). Whatever the initial trigger, it was this that warmed it.
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  11. Thingadonta - what you dont see in the PETM data is anything resembling much a lag between the rapid CO2 rise and the rapid temperature rise. BOTH went up (and ocean acidified) fast enough to test limits of rate determination in analysis from sediment cores. Maybe it was 1000, maybe 5000, MAYBE less??. But not 10000. The important thing is that the record confirms what you would expect from the physics - shove a whole lot of methane into the atmosphere and temperature are going rise quickly. We are seeing that kind of temperature rise now.
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  12. "By contrast, recent warming has occurred at the rate of between +0.12 per decade(last 60 years) to +0.16 per decade (last 30 years)-which represents a much more rapid rate of warming-"

    Yes, but you can't project this rate indefinitely, you would be assuming linearity. To determine whether such a linearity assumption is correct, you need longer time scales, such as the geological record. (Eg Negative feedbacks can kick in- such as a dolomite precipitation increase in the oceans to offset acidity).

    The geological record shows that such earth processes generally take longer time scales, meaning that it is "highly likely" (to borrow an IPCC term) that the linear assumptions of AGW projections, based on empirical data on the timescales of recent decades, cannnot be projected into the future with any deree of certainty.

    This is exactly why the Royal Society has retracted its position on Climate Change recently, stating we cannot know, or project, with any degree of reliability of certainty, what is going to happen in climate in the next 100 years, based on skeptical scientific objections based on data like the geological record, from its own members.
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  13. Again, look at the data. No, you cant assume linearity - the models dont. However, the PETM data does show you that betting on geological negative feedbacks is futile. The temperature went up with the CO2 injection, all the way to 6 degree which accords with models. The geological negative feedback to reduce it happened over 100,000 year time scale. Look at the figures in that paper I referenced. So far you betting on some great unknown invalidating physics models that work perfectly well for the geological record. Sounds like a very high risk proposition to me.
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  14. Thingadonta @12,

    "Negative feedbacks can kick in- such as a dolomite precipitation increase in the oceans to offset acidity"

    Can, could, might. Can we deal with reality please? Also, please support your assertions with facts and numbers from the reputable literature. Really, making such unsubstantiated assertions boils down to nothing more than wishful thinking on your part.

    "This is exactly why the Royal Society has retracted its position on Climate Change recently"

    Simply not true. Honestly, I don't think it is worth engaging you if you are going to blatantly misinform like this.

    I could critique more of your misinformation (e.g., claims about simply extrapolating current temperature trends, or nonsensical claims about linearity), but perhaps someone else might have more patience than I do.
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  15. What a load of hogwash, Thingadonta. When talking about future impacts, we aren't even looking at geological time-frames. Nor can we assume that the same negative feed-backs will come into play (as the current warming is outside of the natural cycles). Indeed, given that two of the key feedbacks from warming will be *positive*-like our oceans having reduced CO2 uptake & a reduced ice-albedo effect-its likely the future trends are an *underestimate*. If the warming trends we've seen-during a period of solar quiescence-are anything to go by, though, then the best case scenario doesn't look very promising (namely a further warming of approximately +1.0 to +1.5 degrees between now & the end of this century). If, however, the sun leaps into a period of increased activity (which also suggests reduced cloud albedo) & those other positive feedbacks I mentioned come into play, then the worst case scenario becomes an "all bets are off" situation. Now, *you* might be prepared to gamble our future in order to protect the profits of the fossil fuel industry, but many of us would prefer to adopt a more rational position!
    Also, please stop repeating that piece of Denialist Propaganda about the Royal Society retracting its position on Climate Change. Those of us that were paying attention know full well that they did nothing more than reiterate the case for AGW, & the reality of future uncertainty. What they did say, though, was that "though things might not turn out as bad as we think, they might also turn out *worse* than we think". Funny how the denialists never mention that bit!
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  16. For the record, Thingadonta, a retraction would read like this: "we unreservedly apologize to the people of the world for asserting that anthropogenic greenhouse gas emissions are the primary cause of recent global warming. There is, in fact, insufficient evidence to back this claim. We also apologize for asserting that global warming will persist into the future-if CO2 emissions fail to be curbed." Now, I've read their document fairly closely, & I see no such retraction. So if you're going to make that claim, could you at least quote the relevant passage?
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  17. From the comments policy:

    'No accusations of deception. Any accusations of deception, fraud, dishonesty or corruption will be deleted. This applies to both sides. Stick to the science. You may criticise a person's methods but not their motives.

    •No ad hominem attacks. Attacking other users or anyone holding a different opinion to you is common in debates but gets us no closer to understanding the science. For example, comments containing the words 'religion' and 'conspiracy' tend to get deleted. Comments using labels like 'alarmist' and 'denier' are usually skating on thin ice.•No politics. Rants about politics, ideology or one world governments will be deleted.

    •No profanity or inflammatory tone. Again, constructive discussion is difficult when overheated rhetoric or profanity is flying around.'

    Now from Marcus:

    'What a load of hogwash, Thingadonta.'

    and

    'Now, *you* might be prepared to gamble our future in order to protect the profits of the fossil fuel industry, but many of us would prefer to adopt a more rational position!'

    I'm sorry to say it but none of this passes for civilised discourse. It certainly doesn't fit in with my interpretation of the comments policy. Of course, it's pretty normal for the blogosphere - hence, people are desensitised. I'm picking out Marcus today but other commentators on other threads can be just as feral.
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  18. IIRC the 120 and 183 million year ago events referenced in the article are closely related to anoxic oceanic events that created the conditions for the formation of some of the worlds most famous oil provinces. Ironic really.
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  19. thingadonta at 14:54 PM on 3 November, 2010
    This is exactly why the Royal Society has retracted its position on Climate Change recently,
    = = = = = = = = = = =
    You may be working to a different definition to retraction to me, all I seen was a clarification.
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  20. Oh, and further on projecting linearly. You seem to be assuming that rates of temperature will DECREASE because of some possible negative feedback. However, the evidence is that most of the feedbacks are positive. Furthermore AR4 models mostly didnt include carbon-cycle feedbacks as they are slow (but positive). So no, cant project linearly - the heating rate may INCREASE as carbon-cycle feedback cut in- and they come into play long before geological negative feedbacks do.We sure hope that current thinking on methane hydrates hasnt over-estimated their stability.
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  21. My main point is this.

    Strong AGW proponents generally look at the geological record and claim that what is going on now is faster than before, so things are generally going to get worse then before (or just as bad as before, but only if it was bad enough before). There are several major problems with this reasoning.

    Take a look, for example, at scaddenup's post in #4 "If it went 6 degrees in 1000 year for same size pulse (at 55Ma), then getting 6 degrees in 200 years is going to be a whole lot worse."

    1. We don't know it went up 6 degrees in 1000 years at 55Ma. The resolution is not <5,000 years. 2. Even if it did, then how will it go up 6 degrees in the next 200 years (a five fold rate of increase, or a 25 times rate of increase from 5,000 years) with the same size pulse?. Shouldn't it be 5,000/1000 years?

    He takes linear projections of current rates, compares them with past unknowns up to 25 times or more that rate, and claims an outcome worse than ever. This is self-reinforcing reasoning, like a stereo mic screeching on feedback.

    The geological record generally indicates that major climate changes associated with c02 generally occur slowly, even under similar size emission rates as human c02 today. AGW proponents, see this past geological data, and the last several decades of climate changes and emission data, and based on linear projections, conclude that what is happening now has therefore never happened so fast, and so things, by inference, are going to get a whole lot worse than before.

    But there is another (more valid, for mine) possibility; the reason that climate changes haven't occurred as fast before, even with similar size c02 rate pulses (e 55Ma, 183 Ma, Zeebe et al 2009), is that there are negative feedbacks that kick in to slow the rate of climate change, which negative feedbacks have not yet been observed, understood or incorporated into the IPCC models. The time frames within the geological record, rather than imply that things are 'much worse' now, actually support this contention.

    It is the same sort of inconsistency with Lovelock's recent statements (and his recent book) about his Gaia hypothesis. He originally claimed the Earth was (like) a self-regulating organism-meaning there are negative feedbacks that negate pertubations within the Earth system. But as far as recent climate change is concerned, he has now abandoned these negative feedbacks, and claims, in contradiction to what he said before, and the basic foundation of his whole idea, that the Earth, essentially doesn't self-regulate and there are essentially no effective negative feedbacks.

    He also can't claim the rates are now too severe for the Earth to 'cope', because these same feedbacks operated in previous similar climate perturbations, which he himself has described.

    These sort of inconsistencies will come throuh the major journals with time, because they are irrefutable. The mics are screeching too loud for people not to ask the sound be turned down.

    The basic foundation of the geological record, as noted by Darwin and Lyell, is gradualism. The geological record is fundamentally a slow process (yes, with major pertubations, described like a soldier's life-long periods of boredom punctuated by short periods of terror). The catastrophists (for mine, similar to today's AGW proponents) were the ones who were resisting evolution by natural selection, not the gradualists, partly because they wanted to speed things up, and partly because they couldn't handle natural change, as opposed to human-controlled change.

    For mine, the same sort of mentality has unfortunately infused today's climate change science.
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  22. I actually don't get what Thingdonta is on about here at all. As scaddenp says, it's clear from the data that the run up in temperatures was faster prior to the PETM than was the reduction was slow afterward and that ocean chemistry changes were relatively fast. If Thingdonta is going to question those points he/she needs to provide some references for us to look at.

    I also don't get the whole argument that the geological record reveals that things always chagne slowly. The sudden changes in northern hemisphere temps during the last glacial cycle (ocean current shifts) clearly shows that the geological record, when sufficiently time resolved, can reveal very fast and large dynamics - faster even than todays. That such sudden and large changes are not often observable in much of the geological record says more about the limits of that record than it does about the time scale and amplitude of actual dynamics.

    I also thought the report was pretty clear on a number of points that thingadonta seems to think it ignored - like the role of CO2 as an amplifier rather than a driver of glacial interglacial dynamics, of the fact CO2 has little to due with sudden climate change in Greenland. Both are completely consistent with our current thinking on the current effects of CO2 and mentioned in the text.

    As for Dolomite deposition in response to increasing CO2 -- I'm not clear how increasing acidity through CO2 would promote Dolomite formation. I was taught that such precipitation happened when conditions become more alkaline, not more acidic. Also wouldn't formation of dolomite reduce alkalinity (and increase acidity) by removing base cations and bicarbonate? I'm confused there.
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  23. We posted those last notes at the same time. So I hope we're not talking cross purposes.

    But I still don't get how scaddenp is talking about linearity. In fact, it seems to me he is talking by definition about non-linearity. Look, the geological record suggests that our estimates of the equilibrium sensitivity of the climate to increases in CO2 are correct. It doesn't really have much to say about the time frame over which that new equilibrium is reached because of the poor temporal resolution of that data. Our current experience would obviously be more pertinent to that problem and it suggests we could reach equilibrium quickly, then stop thereabouts, unless we've changed something pretty drastic.

    It seems Thingadonta is the one assuming linear change, just over a longer time scale ala gradualism. Much geological action is gradual, like erosion, weathering, sediment deposition. But some processes aren't, like meteor impacts and hydrate releases. I don't see why we must assume all processes are gradual simply because the geological record is too coarse to reveal faster dynamics.

    BTW...while Lovelock claimed that certain negative feedback mechanisms related to life maintain the earth's climate within a range capable of preserving life, he was largely talking microbial life, not human life (or dinosaurs for that matter).
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  24. Also worth reading are some recent 'Geoscientist' letters responding to the Geol Soc position statement. See www.geolsoc.org.uk/letters
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  25. #22 Stephen Baines
    "As for Dolomite deposition in response to increasing CO2 -- I'm not clear how increasing acidity through CO2 would promote Dolomite formation. I was taught that such precipitation happened when conditions become more alkaline, not more acidic. Also wouldn't formation of dolomite reduce alkalinity (and increase acidity) by removing base cations and bicarbonate? I'm confused there."

    You are absolutely correct.
    Why would anyone say that formation of dolomite would offset acidification of the ocean by CO2?
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  26. Chris @17

    Actually Chris, I think people's responses here have been quite tempered in light of the inflammatory and highly misleading posts made by Thingadonta on this thread. Thingadonta also seems to be trying to insinuate that the Geological Society is purposefully omitting some key components/processes of the earth-atmosphere system with the intent mislead people or that they do not know what they are talking about. In reality though, it seems that it is Thingadonta's misunderstanding of the science which actually seems to be the problem here.

    Rather ironic....and so the faux debate and manufactured doubt continues.
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  27. Thingadota - You are trying to have it both ways. If fast changes in the past triggered fast warming - that is the likely scenario now. If slow gradual feedbacks brought earth back to what we would consider a temperate climate over 100s of thousands of years, that is the likely scenario now.

    Yet you would like us to believe that there will be FAST feedbacks, and SLOW changes (even though we are ALREADY witnessing fast changes).

    So do you have ANY published science to back this up? Or should we relegate this to the "wishful thinking" bin? I admit I like your ideas - you lift the rather harsh penalties that mother nature seems to have in store for us.

    But acting on your theories, when reality is otherwise, would be the height of folly.
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  28. Thingadonta: "there are negative feedbacks that kick in to slow the rate of climate change." You're absolutely right. The source of the problem dies.
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  29. Good for the Geological Society. I consider is to be a duty of every scientist to come out to inform the public about their findings on this critical issue.
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  30. thingadonta... It also strikes me as a foolish strategy to bet the farm on factors yet to be observed, or understood, on the chance that these are going to somehow kick in to save us from a major crisis.

    It's rather like living the big life, racking up charges on a dozen credit cards, with the assumption that you're going to win the lottery at the last minute.
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  31. chriscanaris #17

    I'm sorry to say it but none of this passes for civilised discourse. It certainly doesn't fit in with my interpretation of the comments policy. Of course, it's pretty normal for the blogosphere - hence, people are desensitised. I'm picking out Marcus today but other commentators on other threads can be just as feral.

    Does misrepresenting the stance of the Royal Society also count as an affront to "civilised discourse"? Or do these lamentations apply only to commenters who are irked by the reiteration of a thoroughly debunked talking point?

    I agree with Albatross @26. The patience on display in this thread — and at SkS generally — is remarkable. There's a lot to be said for maintaining a civil tone, but as I see it, making a consistent effort to get one's facts straight is equally essential to civilized discourse.

    Also, there's a basic inconsistency in lamenting the decline of civilized discourse online while referring to other commenters as "feral." That's a rather aggressive and basically uncharitable characterization, isn't it? Perhaps even "inflammatory" or "overheated"?
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  32. Thingadonta #21

    It is the same sort of inconsistency with Lovelock's recent statements (and his recent book) about his Gaia hypothesis. He originally claimed the Earth was (like) a self-regulating organism-meaning there are negative feedbacks that negate pertubations within the Earth system. But as far as recent climate change is concerned, he has now abandoned these negative feedbacks, and claims, in contradiction to what he said before, and the basic foundation of his whole idea, that the Earth, essentially doesn't self-regulate and there are essentially no effective negative feedbacks.

    This strikes me as a frivolous misreading of Lovelock, who was talking about homeostatic mechanisms in terms of preserving planetary conditions that are suitable for life per se, rather than preserving specific species, let alone a specific level of human civilization. As far as I know, he has never claimed that homeostatic imbalances are impossible, or that negative feedbacks can't be overwhelmed, or that having created dinosaurs, Gaia was obliged to nurture them forevermore.

    Echoing DSL @28, Lovelock's response to your criticism would probably be that one possible "negative feedback" in this case would be the collapse of industrial civilization, after which earth would eventually stabilize in a new homeostatic state. You may disagree with that idea, but it's not inconsistent with Lovelock's theories, which he's taken some pains to argue are not teleological in the sense that your human-coddling concept of "self-regulation" seems to be.
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  33. The statement by the Geological Society of London now makes it "two for two" from the oldest, most prestigious professional organisations of geologists on the issue of climate change. Read this policy statement from the Geological Society of America, recently revised and released in the April of this year and here for further details on development of the statement, references, and responses to criticisms made by some members prior to release.

    These statements reflect the fact that many, many geologists recognise the immensity of changes to Earth's climate and oceans that will result from the burning of fossil fuels in the recent past, present and foreseeable future.
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  34. Thingadonta - Please lets have some clarity about what I claim (or more importantly the published science claims).

    "1. We don't know it went up 6 degrees in 1000 years at 55Ma. The resolution is not <5,000 years."

    The resolution claimed by Kennett and Stott (data source for Zeebe) is about 800 years. However there are a lot of factors to consider in the both the temperature and CO2 proxies and I would say that it is safer to claim that both the CO2 and temperature rose together over a time period of less than 5000 years.

    "2. .... Shouldn't it be 5,000/1000 years?"
    I am claiming that climate response for that impulse of CO2 was 6 degrees and that the record such as we have is consistent with known physics. I see no evidence in the record for some negative feedback that might save us. I do not claim that you can infer maximum rates from this record - I infer those physical models.

    "He takes linear projections of current rates"

    I do nothing of the sort. I would infer rate from climate modelling and these do not give any support for linear projection.


    "The geological record generally indicates that major climate changes associated with c02 generally occur slowly"

    They do? Where is your evidence? The PETM data I pointed to show warming was rapid to point of stretching the resolution of the records. Have you looked at that data? The trouble with geological records is that resolution issues constrain lowest possible rate of warming but make it hard to constrain the highest possible rate. If temperature jumps from x to y in between two samples then rate must be faster than (y-x)/sample resolution but you cant tell how much faster. What you can say is that they are consistent with physics which would predict a rapid rate.



    "AGW proponents, see this past geological data, and the last several decades of climate changes and emission data, and based on linear projections"

    I havent seen such assertions. Can you point me to publications making such linear projections please?

    "there are negative feedbacks that kick in to slow the rate of climate change, which negative feedbacks have not yet been observed, understood or incorporated into the IPCC models."

    This is entirely possible but where is the evidence for them? Certainly not in the PETM data.

    "But as far as recent climate change is concerned, he has now abandoned these negative feedbacks,"

    No, a recognition that while they exist, they operate on timescales that do not prevent mass extinctions and not fast enough to prevent climate disruption to human activities.

    "The catastrophists (for mine, similar to today's AGW proponents) were the ones who were resisting evolution by natural selection, not the gradualists"

    This is completely irrelevant to climate change. The rapid acidification of ocean at PETM isnt catastrophic enough for you?

    For my money, climate theory rests on known physics. Geological records support the inferences of climate theory.
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  35. For the record, Chris Canaris, you will note that I have *never* resorted to ad hominem attacks against you-or ever accused you of deception-largely because you seem willing to have an intelligent debate about the issues. Thingadonta-& several others who post here-instead resort to the usual tactics of denial for its own sake-even to the point of repeatedly misrepresenting the science. My ultimate point is still valid though-that in spite of any uncertainties, the warming of the last 30 years alone (against the backdrop of a relatively quiet sun) suggests that a BAU approach is extremely unwise-if not downright fatal-especially as most of the negative feedbacks we know of from geological time take centuries to millenia to take effect-wheras the positive feedbacks (like reduced ice-albedo, reduced CO2 uptake by a warming ocean & the melting of clathrates) occur in the space of decades. If I were a gambling man, that knowledge would make me very wary of betting on a "She'll be right" outcome!
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  36. Re: Mike (36)

    Thanks for the link. Reading it, one can clearly see that it erodes the basement rocks upon which skeptical geologists rest their foundations. :)

    The Yooper
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  37. "The PETM carbon release rate was estimated using our initial carbon input of 3,000 Pg C and an input timescale of the order of 5,000 years (ref. 29), giving a rate of 0.6 Pg C y-1. The average carbon release rate from fossil-fuel burning and cement manufacturing from 1954-2004 is 5 Pg C y-1 (ref. 30)." Zeebe 2010 as above.
    ref.29. Röhl, U., Bralower, T. J., Norris, R. D. & Wefer, G. New chronology for the late Paleocene thermal maximum and its environmental implications. Geology 28, 927-930 (2000).
    30. Marland, G., Boden, T. A. & Andres, R. J. Global, Regional, and National CO2 Emissions (CDIAC, ORNL, US DOE, 2007).

    Interesting facts, the rate of CO2 pulse in PETM was 0.6yr compared to 5yr currently (and increasing) so that is rate of 8.3x as fast at present. CO2 levels have risen by 40% of a doubling, although this rises to ~65% with CO2e, and the total rise in the PETM was 70% of a doubling, so basically equivalent, but the rise in the PETM took 1000-5000yrs and now it has taken 200yrs although >50% in the last 30years. The rate of temp. rise as pointed out already was 0.06 per decade then and is now 0.2 per decade, or 3.3x as fast for the last 30-40 years. Also note that the temp. rise in the PETM was 5-9C, which gives a climate sensitivity of 7.1C to 12.8C which is interesting.

    So basically the same degree of heating force has been added to the earth's system at rate 8x higher than at any other time noted so far and if that rate is translated into the same increase in rate in temperature change that would be 0.06Cx8 = 0.48C per decade, considering there is 30-40 year lag in the system (meaning the current rate of rise is most reflective of CO2 conc in 1970-80 so about 330ppm) maybe things are about to speed up and the rate of current warming does seem to be accelerating in general trend over the last 50 years or so.

    Also it seems when something is heated slowly things occur steadily yet when heat is added quickly things seem to occur in a more choatic way and the harder you push a choatic system the more interesting and dramatic the changes of state are. In the case of earth's chaotic system these interesting changes mean interesting weather patterns and it does appear that new weather patterns are emerging or rare ones occuring more often (Arctic dipole and continental winter cold pattern (http://www.arctic.noaa.gov/reportcard/ArcticReportCard_full_report.pdf)).

    Anyway time will tell exactly how fast the earth can warm to a very sudden and very large (in terms of % of doubling) increase in one of its a basic warming influencing. And it is rate of rise that seems to be related to mass extinction induction and at present the earth's eco-systems aren't that healthy.
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  38. Re: chriscanaris (17)

    In large part I think you are off-base a bit with your points about Marcus' comment. Calling a spade a spade is not ad hominem. When someone posts a comment that is wrong, it is then not wrong to point out the error.

    Where I think you have a bit of a point is in the bit about accusations of fraud and deception. In the process of pointing out error, sometimes it is in the error itself where fraud and deception may lie. "Skeptics" repetition of errors so soundly debunked that every subsequent re-emergence of the meme requires a "rebunking" of the myth rises to the level of fraud/deception on the part of the "skeptic".

    So in the case of Marcus' calling out of thingadonta, as pointed out by several, the meme being called out has been rebunked many times. In this case, I would posit allowing for a human reaction of vexation on the part of Marcus in his wording of his comment and let it go by.

    Note: I do not use "" when applying the appellation of skeptic to you, chris. For the most part, I find you to be internally consistent in your skepticism.

    I'll win you over to the side of light someday. ;)

    The Yooper
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  39. ranyl (38)

    Are you saying we have already sown the seeds of our own destruction?
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  40. Agnostic,

    "Are you saying we have already sown the seeds of our own destruction?"

    The seeds are sown but hard times only inevitable if we ignore the situation and leave things to carry on as BAU rather than taking this seriously and initiating actions that remove CO2 from the atmosphere and putting in place plans to adapt to what is already likely to occur.

    Although they are no easy tasks as removing CO2 does mean stopping using fossil fuels in a very short time frame (political suicide) and predicting what is actually going to occur isn't easy as new weather patterns are emerging.
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  41. ".....although the best estimate from the end of the last glacial
    is that the temperature probably started to rise a few centuries before the CO2
    showed any reaction." p.4

    And then it goes on to talk about the positive feedback from CO2 after the temperature had already risen.

    "This was accompanied by major climate change around the northern
    hemisphere, felt particularly strongly in the North Atlantic region. Each warm and
    cold episode took just a few decades to develop and lasted for a few hundred years.
    The climate system in those glacial times was clearly unstable and liable to switch
    rapidly with little warning between two contrasting states. These changes were
    almost certainly caused by changes in the way the oceans transported heat
    between the hemispheres." p.4

    It was talking about 10C changes during an ice age. This could be looked at as statements of a rapid rate of change.

    I think the paper makes the point that the greenhouse effect is primarily due to the influence of gases in the atmosphere and didn't have anything to say about changes in albedo of the oceans. I haven't heard of any papers that reconstruct ocean albedo over these time frames or temperatures in the tropics.

    An ice age itself implies that massive amounts of energy have been removed from the oceans by evaporation/convection/condensation which kind of bypasses the greenhouse atmosphere.

    Finally, ranyl #41 made the comment, "Although they[sic] are no easy tasks as removing CO2 does mean stopping using fossil fuels" which is mistaken. Planting trees in the Sahara has been suggested as means to both remove all AGG and supply a growing population with food and building materials. This was suggested by the Weizmann Institute in Israel. Plant a tree already. This solution is no more difficult than stopping the use of fossil fuels and doesn't have the negative feedback of reducing food production.
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  42. Chriscanaris, quick review: when someone says a bunch of hogwash, calling the hogwash by its name does not constitute an ad-hom argument, so long as no comment is made on the person.

    When someone says anything (hogwash or not), accusing the person saying it of being bad, then using that to invalidate what they say constitute an ad-hom argument.

    For instance, when Monckton goes blaring that Prof. Abraham looks like a lobster in order to distract from Abraham's critics of his inconsistencies and inaccuracies, that constitutes an ad-hom.
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  43. TOP -"I haven't heard of any papers that reconstruct ocean albedo over these time frames or temperatures in the tropics."

    As always, try WG1 IPCC. Chapter 6. You will see there the relative forcings from albedo, sea level change, GHG, etc. Papers from which calculations were made in the references.

    Evaporation/convection/condensation moves heat around vertically and horizontally. The only way for energy to leave the earth is via radiation.
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  44. Comment # 3 (thingadonta) made little sense to me. A key misconception comes at the end:
    "Too many holes in the paper ...."

    It is not a paper, it is a statement. Even if it were a paper it would only justify the new research within itself, and use references for established science just as the statement does. It is quite appropriate for a position statement to be based on (not try to re-establish) established science. It would be strange for a position statement to try to re-establish its scientific basis.

    If thingadonta wants a rehash of all climatology, the IPCC AR4 WG1 report is one place to start.
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  45. Denialism - everyone needs to be aware of it these days. While Freud's idea may come into it sometimes, the current concept is of rhetorical methods used to create an appearance of endless argument over matters that are already established. See the link for many specific methods.

    One simple direct method is to always argue as if nothing is known, and each new paper is obliged to prove everything from scratch. Since this is not possible in a single paper, the paper may be called "biased" for not doing what it was not intended to and could not do. This method is familiar to me from evolution denial.

    The series of comments above in this thread gives me the impression that the regular group here is more susceptible to denialism than it would be if the concept were kept in mind.
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  46. There's a special issue of the Philosophical Transactions of the Royal Society B (Biological Science) — “Biological diversity in a changing world” out. Open access.

    One of the articles therein, The future of the oceans past by Jeremy B. C. Jackson closes with this:
    " There is an urgent need for immediate and decisive conservation action. Otherwise, another great mass extinction affecting all ocean ecosystems and comparable to the upheavals of the geological past appears inevitable."
    and
    "The question is whether we can overcome our apathy, ignorance, corruption and greed to act responsibly, or wait for catastrophe to strike."
    Sheesh! What's next, the Past Through Tomorrow?

    The Yooper
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