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Another link between CO2 and mass extinctions of species

It’s long been known that massive increases in emission of CO2 from volcanoes, associated with the opening of the Atlantic Ocean in the end-Triassic Period, set off a shift in state of the climate which…

Mass extinctions caused by rapidly escalating levels of CO2 have occurred before. Global warming image from www.shutterstock.com

It’s long been known that massive increases in emission of CO2 from volcanoes, associated with the opening of the Atlantic Ocean in the end-Triassic Period, set off a shift in state of the climate which caused global mass extinction of species, eliminating about 34% of genera. The extinction created ecological niches which allowed the rise of dinosaurs during the Triassic, about 250-200 million years ago.

New research released this morning in Science Express has refined the dating of this wave of volcanism. It shows marine and land species disappear from the fossil record within 20,000 to 30,000 years from the time evidence for the eruption of large magma flows appears, approximately 201 million years ago. These volcanic eruptions increased atmospheric CO2 and increased ocean acidity.

Mass extinctions due to rapidly escalating levels of CO2 are recorded since as long as 580 million years ago. As our anthropogenic global emissions of CO2 are rising, at a rate for which no precedence is known from the geological record with the exception of asteroid impacts, another wave of extinctions is unfolding.

Mass extinctions of species in the history of Earth include:

  • the ~580 million years-old (Ma) Acraman impact (South Australia) and Acrytarch (ancient palynomorphs) extinction and radiation
  • Late Devonian (~374 Ma) volcanism, peak global temperatures and mass extinctions
  • the end-Devonian impact cluster associated with mass extinction, which among others destroyed the Kimberley Fitzroy reefs (~360 Ma)
  • the upper Permian (~267 Ma) extinction associated with a warming trend
  • the Permian-Triassic boundary volcanic and asteroid impact events (~ 251 Ma) and peak warming
  • the End-Triassic (201 Ma) opening of the Atlantic Ocean, and massive volcanism
  • an End-Jurassic (~145 Ma) impact cluster and opening of the Indian Ocean
  • the Cretaceous-Tertiary boundary (K-T) (~65 Ma) impact cluster, Deccan volcanic activity and mass extinction
  • the pre-Eocene-Oligocene boundary (~34 Ma) impact cluster and a cooling trend, followed by opening of the Drake Passage between Antarctica and South America, formation of the Antarctic ice sheet and minor extinction at ~34 Ma.

Throughout the Phanerozoic (from 542 million years ago), major mass extinctions of species closely coincided with abrupt rises of atmospheric carbon dioxide and ocean acidity. These increases took place at rates to which many species could not adapt. These events - triggered by asteroid impacts, massive volcanic activity, eruption of methane, ocean anoxia and extreme rates of glaciation (see Figures 1 and 2) - have direct implications for the effects of the current rise of CO2.

Figure 1 - Trends in atmospheric CO2 and related glacial and interglacial periods since the Cambrian (542 million years ago), showing peaks in CO2 levels (green diamonds) associated with asteroid impacts and/or massive volcanism. CO2 data from Royer 2004 and 2006.

Figure 2 - Relations between CO2 rise rates and mean global temperature rise rates during warming periods, including the Paleocene-Eocene Thermal Maximum, early Oligocene, mid-Miocene, late Pliocene, Eemian (glacial termination), Dansgaard-Oeschger cycles, Medieval Warming Period, 1750-2012 and 1975-2012 periods.

In February 2013, CO2 levels had risen to near 396.80ppm at Mauna Loa Atmospheric Observatory, compared to 393.54ppm in February 2012. This rise - 3.26ppm per year - is at the highest rate yet recorded. Further measurements show CO2 is at near 400ppm of the atmosphere over the Arctic. At this rate the upper stability threshold of the Antarctic ice sheet, defined at about 500–600ppm CO2 would be reached later this century (although hysteresis of the ice sheets may slow down melting).

Our global carbon reserves - including coal, oil, oil shale, tar sands, gas and coal-seam gas - contain considerably more than 10,000 billion tonnes of carbon (see Figure 5). This amount of carbon, if released into the atmosphere, is capable of raising atmospheric CO2 levels to higher than 1000ppm. Such a rise in atmospheric radiative forcing will be similar to that of the Paleocene-Eocene boundary thermal maximum (PETM), which happened about 55 million years-ago (see Figures 1, 2 and 4). But the rate of rise surpasses those of this thermal maximum by about ten times.

Figure 3 - Plot of percent mass extinction of genera versus peak atmospheric CO2 levels at several stages of Earth history.

Figure 4 - The Paleocene-Eocene Thermal Maximum (PETM) represented by sediments in the Southern Ocean, central Pacific and South Atlantic oceans. The data indicate a) deposition of an organic matter-rich layer consequent on extinction of marine organisms; b) lowering of δ18O values representing an increase in temperature and c) a sharp decline in carbonate contents of sediments representing a decrease in pH and increase in acidity (Zachos et al 2008)

The Paleocene-Eocene boundary thermal maximum event about 55 million years ago saw the release of approximately 2000 to 3000 billion tons of carbon to the atmosphere in the form of methane (CH4). It led to the extinction of about 35-50% of benthic foraminifera (see Figure 3 and 4), representing a major decline in the state of the marine ecosystem. The temperature rise and ocean acidity during this event are shown in Figures 4 and 6.

Based on the amount of carbon already emitted and which could continue to be released to the atmosphere (see Figure 5), current climate trends could be tracking toward conditions like those of the Paleocene-Eocene event. Many species may be unable to adapt to the extreme rate of current rise in greenhouse gases and temperatures. The rapid opening of the Arctic Sea ice, melting of Greenland and west Antarctic ice sheets, and rising spate of floods, heat waves, fires and other extreme weather events may signify a shift in state of the climate, crossing tipping points.

Figure 5 - CO2 emissions from fossil fuels (2.12 GtC ~ 1 ppm CO2). Estimated reserves and potentially recoverable resources.

By analogy to medical science analysing blood count as diagnosis for cancer, climate science uses the greenhouse gas levels of the atmosphere, pH levels of the ocean, variations in solar insolation, aerosol concentrations, clouding states at different levels of the atmosphere, state of the continental ice sheets and sea ice, position of high pressure ridges and climate zones and many other parameters to determine trends in the climate. The results of these tests, conducted by thousands of peer-reviewed scientists world-wide, have to date been ignored, at the greatest peril to humanity and nature.

Continuing emissions contravene international laws regarding crimes against humanity and related International and Australian covenants. In the absence of an effective global mitigation effort, governments world-wide are now presiding over the demise of future generations and of nature, tracking toward one of the greatest mass extinction events nature has seen. It is time we learned from the history of planet Earth.

Figure 6: The Paleocene-Eocene boundary thermal maximum. http://www.uta.edu/faculty/awinguth/petm_research/petm_home.html

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  1. Mark Lawson

    senior journalist at Australian Financial Review

    Um, last I checked CO2 concentrations were increasing at an average of about 2 pm/year or 0.002 per cent of the atmosphere a year (or is it 0.0002 per cent? Can someone confirm.).. sometimes more sometimes less over the past decade.. and this is going to cause mass extinctions? Its certainly not evident in the count of actual, observed species yet, and most of what can be seen may well be due to land use changes.. and scientists can distinguish these tiny movements from the fossil records to the point of declaring present changes to be a record increases? Andrew is the scientist I suppose but it seems far fetched..

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    1. Mark Lawson

      senior journalist at Australian Financial Review

      In reply to Michael Guy

      Michael - the analogy doesn't add up. CO2 isn't actually directly dangerous until you get to what 50 per cent and more? Glickson is claiming that the increase in CO2 is faster than ever seen before and very dangerous. All I'm doing is pointing out that we can't see anything in the system yet. Ther have been foercasts of mass extinctions for teh past 20 years and we still haven't seen anything. You did know that greenhouse system regularly run to 1000 ppm of CO2, right?

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    2. Mark Lawson

      senior journalist at Australian Financial Review

      In reply to Michael Guy

      Sorry - further to my other post, I meant actual greenhouses in which they grow plants.. they often take those up to 1000 ppm..

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    3. Mark Lawson

      senior journalist at Australian Financial Review

      In reply to Mike Hansen

      Mike - you did know that greenhouses (as in the glass houses used to grow plants) are regularly run to 1000 ppm? there is nothing inherently dangerous in the level of CO2 and the rate of increase seems far too small to pose a threat, particularly as we haven't seen this mass die off yet... so where is it? There have been forecasts of mass die-offs going back decades and its still not evident..

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    4. Mark Lawson

      senior journalist at Australian Financial Review

      In reply to Alex Serpo

      Alex - I seem to have struck a nerve, which is good. As for good sources of information you should read the original post. All I really said was that the increase seemed to too small to be of any real threat, and we haven't seen this mass die-off yet. You did know that greenhouses (as in the glass houses used to grow plants) can have atmospheres with 1,000 ppm CO2? Helps to grow the plants. so where is this mass die off? Is it going to happen soon. Happy to be guided by your superior knowledge.

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    5. Tim Scanlon

      Debunker

      In reply to Mark Lawson

      Ahh, the good old fallacy of small numbers.

      Carl Sagan listed this among his top fallacies to watch out for in his baloney detection guide.

      Of course, Mark won't have read any of the actual science on this, nor looked at the studies that have been monitoring levels for several decades, let alone the geological records that Andrew has presented.
      http://www.csiro.au/greenhouse-gases/
      http://www.esrl.noaa.gov/gmd/dv/iadv/graph.php?code=MLO&program=ccgg&type=ts

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    6. Mark Lawson

      senior journalist at Australian Financial Review

      In reply to Myall Tarran

      Myall - I see you're studying the issues that's good. But go back and look at the my original post. All I said was that the increase seemed too small to be of any real significance and that we haven't seen this mass die off yet. So where is this mass die off? Bear in mind that greenhouses (as in the glass houses used to grow plants) can have atmospheres with 1000 ppm of CO2, as that helps to grow the plants, so it would seem improbable to claim that plants or animals can't adapt to the higher levels.Higher temperatures? Maybe, but bear in mind that the earth already has a wide range of temperatures, and wide seasonal variations- also the earth has been cycling in and out of ice ages every 100,000 years for the past million years.. so the stuff Glickson cites is going to cause this mass die off? Very difficult to believe.

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    7. Mark Lawson

      senior journalist at Australian Financial Review

      In reply to Myall Tarran

      Another point, bye the bye, this comment "50% of anthropogenic CO2 emissions have been absorbed by the oceans" I wonder if you knew that's not based on anything but back calculation. Sure you'll find it in your textbooks and your lecturers will tell you that, but then ask them how scientists know this? Where did the figure come from? Experiment? You may be surprised at the answer.

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    8. Alex Serpo

      Garbologist

      In reply to Mark Lawson

      Mark - it's a annoyance I have a certain vocal quarter of the business community. They're anti-science. If someone came to the school where your kids where being immunized and told all the parents it would give their children autism, wouldn't you be annoyed? Misinformation makes everyone's life harder. You're responsible because journalists have an obligation not to mislead.

      As for your specific claims I won't address them. Why would anyone bother? Do you really believe that scientific institutions like the CSRIO or ANU have completely missed high school level science? How can incompetence go that high? It's a bold claim and plainly ludicrous claim.

      Remember these are the same people who check water you drink, the medicines you take and the food you eat is safe.

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    9. Danderson

      logged in via Twitter

      In reply to Mike Hansen

      Under a picture of a glowing, steaming Earth we're told that "governments world-wide are now presiding over the demise of future generations and of nature".

      Now who's really trolling?

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    10. David Bentley

      logged in via LinkedIn

      In reply to Mark Lawson

      "scientists can distinguish these tiny movements from the fossil records to the point of declaring present changes to be a record increases?"

      Yes they can

      "Andrew is the scientist"

      Yes he is

      "but it seems far fetched"..."or is it 0.0002 per cent? Can someone confirm"

      So you don't even understand the calculation or any of the other calculations relating to this iss and yet you think it's far fetched?

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    11. Felix MacNeill

      Environmental Manager

      In reply to Mark Lawson

      Mark, this post could win an award for utter bullshit. There's simply no pint in trying to refute your PRATTs. please find another way to waste a Friday afternoon.

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    12. Felix MacNeill

      Environmental Manager

      In reply to Danderson

      You are, Danderson. Maybe that's why you hide behind a pseudonym.

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    13. Dave Smith

      Energy Consultant

      In reply to Mike Hansen

      It appears that Mark thinks that the Greenhouse Effect has something to do with growing plants in greenhouses.

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    14. Danderson

      logged in via Twitter

      In reply to Felix MacNeill

      Felix, my name is David Anderson. I'm a male and live in Melbourne, and a Scorpio, for what it's worth.

      Ummmm... does that change something here? Am I less trolly if you know me better?

      Maybe you'd like to meet up for coffee, and have a chat or something. Or a movie? I wouldn't mind seeing Argo...

      Amazing how words take on new meanings when you know the author better, apparently, at The Conversation.

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    15. Myall Tarran

      PhD candidate, Palaebotany & Palaeoclimatology at University of Adelaide

      In reply to Mark Lawson

      A greenhouse is a closed, artificial system. The CO2 concentrations within that system could have no effect on the "climate" of that system, since a gardener is applying water/fertilizer/protection from herbivory and weather events. There's no cosmic gardener to make sure that we'll be fine in the face of such high atmospheric CO2...

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    16. John Nicol

      logged in via email @bigpond.com

      In reply to Felix MacNeill

      Felix MacNeill,

      I cannot understand why anyone would visit a site such as this for the sole purpose of writing very rude comments such as yours to people such as mark Lawson, who go to the effort of providing a sensible and constructive contribution to a conversation. I notice your other remarks below which are of the same base quality and spoil what would otherwise be an unbroken chain of reasoned debate. Anyone with whom you do not agree is apparently fair game - I await your response to my contribution here.

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    17. John Nicol

      logged in via email @bigpond.com

      In reply to Mike Swinbourne

      Mike,

      I don't think that Andrew Glikson would claim to be an agricultural scientist and what Mark has said is correct.

      The fact is that plants require a balanced input of all nutrients. It is NOT that they loose their ability to absorb nutrients that increased plant food is supplied, but that in order to take advantage of the increase in CO2 in the greenhouse, the additional nutrients which they are then able to utilise, need to be provided.

      This principle is basic in all farming. In…

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    18. John Nicol

      logged in via email @bigpond.com

      In reply to Mike Hansen

      Mike Hansen,

      Why is it that you must respond rudely to people who hold views with which you do not agree. What Mark is saying IS correct scientifically and you must know that. It is you who are commenting inappropriately for TC.

      You have not put forward any evidence to refute what he has said, and could not. You are just being abusive and unpleasant

      Much, much higher levels of CO2 are not a threat as mark points out - your own breath contains significantly higher levels of CO2 that will ever be in the atmosphere. John Nicol.

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    19. John Nicol

      logged in via email @bigpond.com

      In reply to Alex Serpo

      To the Optimistic Garbologist. The only reason people decline to refute arguments with which they disagree is that do not have the understanding of the topic to do so.

      There is nothing wrong with what Mark has explained and it does not contradict CSIRO at all. Nor is it misleading, otherwise you would have been able to state clearly for all of us why you believed it to be "misinformation". (BTW: Andrew Glikson is a climatologist, not a zoologist).
      John Nicol

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    20. Mike Hansen

      Mr.

      In reply to John Nicol

      I thought that Lawson had found the bottom of the barrel.

      John Nicol's claim

      "...your own breath contains significantly higher levels of CO2 that will ever be in the atmosphere"

      has proved me wrong.

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    21. John Nicol

      logged in via email @bigpond.com

      In reply to Mike Hansen

      Mike Hansen,

      Just thought you might like to know:

      Normal air:0.03% CO2; Breath exhaled ~4% ( factor of 130 increase!!!)
      "How much CO2 is emitted per breath?
      CO2 & O2 Measurementwww.mep.net.au/Dissolved oxygen and carbonation Meter for soft drinks, wine & beer.
      Ads

      View Slide Show
      Answer:
      An average adult breathes about 0.5 L of air per breath at rest. Normal air contains ~ 0.03 % of CO2 which gets enriched to 4 % of exhaled air. The difference, 3.97 % is what you exhaled. One mole of air at room temperature have a volume of ~22.4 L (use ideal gas equation p*V=n*R*T, p=pressure [bar], V=volume, n=amount in mole, R=ideal gas constant, T=temperature [Kelvin]). 1 mole CO2 is equivalent to 44 g.
      So, 0.5 L*(1 mole /22.4 L)*(44 g / mole) = 0.982 g

      One breath therefore contains ~ 1 g of exhaled CO2 "

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    22. Mike Hansen

      Mr.

      In reply to John Nicol

      John Nicol - ROFLMAO

      You have to be joking. This is the most absurd argument I have ever heard in relation to the Greenhouse effect.

      Are you suggesting that as the earth radiates infrared, the radiation passes through the inside of our mouths?

      (Even if this was the case :-), it would not make any difference as the effect also requires the adiabatic lapse rate and the mixing of CO2 in the atmosphere)

      You might want to read this. Here are the climate cranks from Monckton to Watts in their own words conceding the existence of the Greenhouse Effect.
      http://www.skepticalscience.com/The_Greenhouse_Gas_Effect_All-Star_Fan_Club.html

      John - you may also wish to stop and consider why climate science deniers are laughed at here.

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    23. John Nicol

      logged in via email @bigpond.com

      In reply to Mike Hansen

      Thank you for your response Mike Hansen. Not being of the Y generation I hjave no idea what you mean by ROFLMAO and don't care.

      However, my comment as you should have realised had absolutely nothing to do with Enhanced Green House Effect, which for your information, is spectroscopically, scientifically and by implication for climate change, quite different from the bland and somewhat banal description given in the link to Skeptical Science, a blog well known only for its wide ranging ignorance…

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  2. Ian Alexander

    Reader

    Excellent article Andrew, thanks.

    Adds another piece to the already huge pile of evidence and complements the Hansen and Sato 2012 paper on paleoclimate. The big question again seems to be ice loss and whethere it will continue to be exponential...

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  3. Tim Scanlon

    Debunker

    "Continuing emissions contravene international laws regarding crimes against humanity and related International and Australian covenants. In the absence of an effective global mitigation effort, governments world-wide are now presiding over the demise of future generations and of nature, tracking toward one of the greatest mass extinction events nature has seen. It is time we learned from the history of planet Earth."

    I agree completely.

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    1. John Nicol

      logged in via email @bigpond.com

      In reply to Tim Scanlon

      Tim,

      The history of planet earth does not place the great mass extinctions at the feet of global warming nor carbon dioxide, and Andrew Glikson is not saying this, because the more likely causes are excessive cold because of the aerosols produced by major volcanic activity to which he refers..

      The excessive carbon dioxide when the earth has been warmer is simply because CO2 is emitted from many different sources at a higher rate when the source is heated and in particular comes out of solution in water - largely sea water. The geological data shows that CO2 concentrations follow the warming - not the other way around.
      John Nicol

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    2. Tim Scanlon

      Debunker

      In reply to John Nicol

      John, I see you also fail to understand the paleoclimate and not just modern climate.

      CO2 and other greenhouse gases, are not usually the trigger and follow insolation levels (etc). But once the warming has been triggered, CO2 becomes a feedback and triggers more warming. If you had bothered to read Andrew's article or any of his previous articles, you would understand this.

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    3. John Nicol

      logged in via email @bigpond.com

      In reply to Tim Scanlon

      Tim,

      If you read Andrew's article you will see that he claims that this is the case, but there are many other studies apart from "Andrew's" which do not agree with his statements:

      1. It’s has been know that massive increases in emission of CO2 from volcanoes, associated with the opening of the Atlantic Ocean in the end-Triassic Period, set off a shift in state of the climate which caused global mass extinction of species, eliminating about 34% of genera. The extinction created ecological niches…

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    4. Tim Scanlon

      Debunker

      In reply to John Nicol

      And again, you seem to ignore the majority of information for the minority that fits your confirmation bias.

      Andrew has already offered up multiple studies in this thread and article. I'm betting you haven't read them.

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    5. John Nicol

      logged in via email @bigpond.com

      In reply to Tim Scanlon

      Tim Scanlon,

      No Tim, I have not ignored the information from Andrew's article nor from other links on this thread. From Andrew's paper, only two (2) of the references mentioned anything about carbon dioxide - they were mainly about defining periods of extinction. In the two references that cited CO2, their comments were purely speculative, assuming that the increase in CO2 caused the warming, where equally/more probably, the warming caused the increase in CO2.
      John Nicol

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    6. Tim Scanlon

      Debunker

      In reply to John Nicol

      So the ones he's going to send you are what exactly? Stuff you haven't read? Do you see my point?

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  4. Danderson

    logged in via Twitter

    Those old enough might remember when towards the end of the cold war a the so-called "nuclear winter" was coined. It was theorised that a full scale nuclear war would raise so much dirt into atmosphere that incoming solar radiation would be obstructed. The "nuclear winter" would last for a few years and wide scale extinctions were expected, and many less humans at the end of it.

    We've all heard of the asteroid impact theory of dinosaur extinction. The proposed mechanism was similar, dust particles…

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    1. Myall Tarran

      PhD candidate, Palaebotany & Palaeoclimatology at University of Adelaide

      In reply to Danderson

      There is hard evidence that volcanic/asteroid events did occur.Check out the geological record, or the palaeobotanical record for that matter. Iridium horizons are evidence of extra-terrestrial colliosn, ash horizons in sedimentary sequences attest to palaeovolcanism, plants from the fossil record at the time of the K/T event show physiognomic adaptation to the impact winter.

      There's hard evidence extinctions occured. Check out the fossil record.

      We're living through a mass extinction right now. Welcome to the anthropocene. Who cares if CO2 is the cause or not. But, there's pretty good evidence to suggest that our marine and terrestrial ecosystems will suffer as a result of evelvated atmospheric CO2.

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    2. Danderson

      logged in via Twitter

      In reply to Myall Tarran

      Myall I'm sure over the past few hundred million years there's been great variability in both our surface and climate. I don't doubt that we were once a ball of hot gas either, so it's been a long journey, to say the least. The exact timeline itself is uncertain especially WRT supposed causal relationships.

      "Who cares if CO2 is the cause or not."

      That's, kind of, missing the gist of the argument here. It's all about CO2!

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    3. Sean Lamb

      Science Denier

      In reply to Myall Tarran

      "Who cares if CO2 is the cause or not."
      Good to see the emerging generation of scientists is picking up the rigorous scientific evidential standards of their mentors.

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    4. Myall Tarran

      PhD candidate, Palaebotany & Palaeoclimatology at University of Adelaide

      In reply to Danderson

      You're right, it is all about CO2. However, we have created and entered the anthropocene. We are driving the largest mass extinction we've ever witnessed, and there are a myriad of other elements to our environmental crisis that are much less "contentious". While we're squabbling over Anthropogenic warming with the scientifically illiterate, Humanity is still filling our oceans with plastic, still cutting down the rainforests still consuming, polluting and wasting, and regradless of the influence of CO2, we're in trouble.

      Still, I can't help but feel you both took that sentence somewhat out of context...

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    5. John Nicol

      logged in via email @bigpond.com

      In reply to Myall Tarran

      Myall Terrain,

      What evidence is there that increased CO2, will cause suffering of marine and terrestrial creatures? None has been shown to suffer yet.

      Just as the models (AOGCMs) predicted continued warming over the past 16 years, none has occurred in spite of the increase in CO2 being demonstrably higher than expected. Why cannot we see an explanation from the climatologists as to why they were unable to get the prediction correct.

      Their failure demonstrates quite clearly that the models…

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    6. Myall Tarran

      PhD candidate, Palaebotany & Palaeoclimatology at University of Adelaide

      In reply to John Nicol

      I am not a landscape!

      Firstly, climatology is a continuously improving science, but it is not perfect. Science is very good at explaining things, but we barely understand the complexity of small insects, let alone the workings of other complex animals such as ourselves. And, something as vast as a planetary climate system? You'd better believe science doesn't have all the answers. You'd better believe we can't produce accurate models when we don't understand all of the parameters and variables…

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    7. Geoffrey Harold Sherrington

      Boss

      In reply to Myall Tarran

      Myall,
      Many people agree with the essence of what you write, but it does not really progress understanding. In particular, the relationship between atmospheric CO2 and increased global temperatures is very unclear. It arose in the first instance because the recorded global temperature did not match modelled predictions, so there needed to be another factor introduced to fill the gap. For Australia, it will soon become apparent that the temperature records have some rather untrustworthy elements…

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    8. Geoffrey Harold Sherrington

      Boss

      In reply to Myall Tarran

      No, not really. It's a kid's term that lacks precision and context. I use grown up terms.
      Would you care to attempt a precise definition to embarrass yourself? I'm quite confident of picking up errors you might make. Can you quote me a definition from a peer reviewed paper?

      Do you know about the actress Elizabeth Taylor? She died just over 2 years ago.
      She was described precisely as "Always the bride, never the bride's lady."
      My question also lacks precision and context. It is included as a guide. She was often peer reviewed, not always with the same outcome.

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  5. Sean Lamb

    Science Denier

    Yet more pseudo science based on CO2 reductionism.
    1. One of the markers of the periods of high CO2 levels is greater deposits of benthic foraminifera in geological strata - indicating at very least greater biomass during these periods and most likely biodiversity. Periods of low CO2 levels are associated with lower biomass deposits.

    Professor Glikson brings up a number of exceptions but invariably misinterprets them.
    2. "These volcanic eruptions increased atmospheric CO2 and increased ocean…

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    1. Felix MacNeill

      Environmental Manager

      In reply to Sean Lamb

      Sean, I will grant you that you are very obviously an expert in pseudo science.

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    2. Sean Lamb

      Science Denier

      In reply to Felix MacNeill

      Felix, I am. It must have been a difficult 24 hours for you, on the one hand you have the joy of having Julia Gillard re-endorsed, on the hand the misery of knowing that the carbon tax is almost certainly dead come September. You must have been wearing one of those smiling/tearful clown faces last night.

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    3. Felix MacNeill

      Environmental Manager

      In reply to Sean Lamb

      Wow - you really should retitle yourself as 'mind reader' except that, while you make an excellent science denier, you are crap at reading minds.

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    4. Andrew Glikson

      Earth and paleo-climate scientist at Australian National University

      In reply to Sean Lamb

      Response to Sean Lamb

      Details regarding the PETM based on evidence not on opionion are in the peer review literature, for example "An early Cenozoic perspective on greenhouse warming and carbon cycle dynamics
      "http://www.nature.com/nature/journal/v451/n7176/full/nature06588.html), where the PETM is related to the release of low 13/12Carbon as methane, not to solar maximum.

      Mass extinctions related to protracted volcanic effects have been more gradual than those related to the instantaneous asteroid impact effects.

      Volcanic eruptions, mainly in Iceland, resulted in famine in Europe a number of times, mostly due to released sulphur aerosols.

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  6. John McLean

    logged in via email @connexus.net.au

    Please retitle this piece to "Another alarmist scare about nothing much at all". Glikson provides a very clear alternative explanation for extinctions - volcanic dust and silicates in teh atmosphere blocking sunlight, which means lower temperatures and a reduction in vegetation growth. When animals start dying as a consequence of this the impact travels right up the food chain.

    Studies are now showing that planet Earth has become greener in the last 30 or 40 years. It's not due to increased…

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    1. Felix MacNeill

      Environmental Manager

      In reply to John McLean

      John, do you actually believe anyone is going to swallow a few poorly-picked cherries like this in the face of huge bodies of solid evidence?

      I guess you must just be determined to 'concludively' demonstrate that you have nothing other than insults and slogans to offer.

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  7. Andrew Glikson

    Earth and paleo-climate scientist at Australian National University

    Response to Lawson's comments

    CO2 RISE:
    Lawson writes "last I checked CO2 concentrations were increasing at an average of about 2 pm/year or 0.002 per cent of the atmosphere a year (or is it 0.0002 per cent? Can someone confirm".
    Response: The rise of CO2, currently about or above 2 ppm/year, constitutes 0.7% per-year of the original atmospheric level of 280 ppm.

    RATE OF MASS EXTINCTION
    Lawson writes "Its (mass extinction) certainly not evident in the count of actual, observed species yet…

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    1. John Nicol

      logged in via email @bigpond.com

      In reply to Andrew Glikson

      Andrew,

      While "papers" by the WWF feature heavily in the IPCC reports, it is not known to be a very reliable scientific organisation - last time I looked it was just an advocacy group with pretty way-out ideas. It is intriguing that you should find their publications meaningful..

      Just how does one determine "the natural extinction rate"? Extinctions have been well documented as having quite variable rates and one wonders which of these rates is defined as "natural!

      All predictions aside, why is it, that in the face of very confident predictions, sorry, "projections" for one or two different "scenarios" for which the IPCC at least suggested in about 1995 that the earth would continue to wam over the "next 16 years, the earth has not in fact warmed recently? Carbon dioxide I understand has increased more than expected at that time but the earth does not seem to have been told about it..
      John Nicol,

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    2. Mark Lawson

      senior journalist at Australian Financial Review

      In reply to Andrew Glikson

      Although I am flattered that Andrew has taken the trouble to respond, I regret that I must take issue..

      On the business about the rate of increase I will accept Andrew's calculation although I am still far from impressed, as my other points will show..

      As for the reference to the World Wildlife Fund report on extinction rates, the link does not work for a start.. after scratching around on the WWF site I found a bland mention of this rate and the claim that it is many times higher than any…

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  8. Andrew Glikson

    Earth and paleo-climate scientist at Australian National University

    ON THE DIFFERENCE BETWEEN GREENHOUSE GLASS CULTIVATION AND NATURAL ATMOSPHERE-BIOSPHERE CONDITIONS

    Both glass houses and atmospheric greenhouse conditions involve blocking of heat flow, which result in warmer temperature.

    In a glass greenhouse structures thermal CONVECTION to the atmosphere is blocked. Under conditions opoen to the atmosphere the thermal RADIATION is blocked.

    Under glass house conditions if no water and nutrients are supplied plants will not survfive. Under open atmospheric conditions, draughts or floods destroy vegetation and crops.

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    1. Geoffrey Harold Sherrington

      Boss

      In reply to Andrew Glikson

      Andrew, Survival in the wide world

      Plants growing naturally will die when deprived of the first essential nutrient, just as they die in artificial greenhouses if you do not add fertilizer.

      You need to address the point made by Mark Lawson that the extra CO2 added in artificial greenhouses does not harm the vast majority of plants studied. Rather, it will usually increase yield until the limit of the first nutrient shortage.

      How do you imagine we have deserts with very little plant material? There is a recent, quite relevant video presentation at
      http://wattsupwiththat.com/2013/03/08/a-bridge-in-the-climate-debate-how-to-green-the-worlds-deserts-and-reverse-climate-change/

      It provides an interesting view that desertification can be helped along by humans in a process that does not involve greenhouse gases. If this process is indeed at work as described, then you have to subtract some of the influence you currently attribute to GHG and other ill-defined theories.

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    2. Tim Scanlon

      Debunker

      In reply to Geoffrey Harold Sherrington

      Geoff, you are raising some very tired BS talking points about plants.

      The first essential nutrient to a plant is water. The next is nitrogen. CO2 isn't even on the list, why, because it is not in limiting amounts and hasn't been since plants first evolved into existence.

      The next point you raise is also rubbish. Raised CO2 in a glasshouse IS IN A GLASSHOUSE not in a real situation where water and nutrients are limiting. There are all sorts of problems with high CO2 on plant growth, and your denial talking points are not only ignoring them, but creating myths that would make any high school biology student cringe.

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    3. John Nicol

      logged in via email @bigpond.com

      In reply to Tim Scanlon

      Tim, First i must comment that I can see no reason for you to be rude to Geoffrey Sherrington. He has presented a clear case/opinion on these matters and it would be so good if you could just politely refute them if you can.

      Increases in production through the increases in CO2 are well documented in the farming world in general and there are many situations where the water exceeds that needed for a particular growth of a crop any way, but where the carbon in the soil is less than optimum and…

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    4. Tim Scanlon

      Debunker

      In reply to John Nicol

      John, my degrees in plant science, my current work with APSIM plant modelling, my current work with farmer groups on crop production, and my reading of the science, all bring me to a point where I can plainly tell you that you are wrong, as is Geoff. You may read it as rude, but that is only because blatant ignorance derived from climate denial falsehoods have no place in a discussion of this sort.

      I have already explained why this is the case. If you had bothered to read you would have seen my…

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    5. Geoffrey Harold Sherrington

      Boss

      In reply to Tim Scanlon

      Tim Scanlon,
      I spent 9 years researching links between plant growth and fertilization, some with the highly successful CSIRO Division of Tropical Pastures project to introduce legumes and grasses to Australia's beef cattle industry. You might have heard of Townsville stylo, as it was named then. I helped conduct and analyse many multivariate experiments with typically a dozen nutrients at 2 to 4 rates of application each, replicated by 2 to 4, evaluated by growth weight of roots, stems, leaves…

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    6. Tim Scanlon

      Debunker

      In reply to Geoffrey Harold Sherrington

      I see where you are going wrong, you are simply wrong to reframe what allows plant growth to occur.

      Any text book, any model, any plant scientist will list water and nitrogen as the two limiting factors for plant growth. In fact, most plant growth models can account for the majority of agronomic productivity with just those two factors. As such, your basic starting point is wrong.

      The next point you make is just agreeing with me that plants have not and will not be limited by CO2.

      The next…

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  9. Andrew Glikson

    Earth and paleo-climate scientist at Australian National University

    RESPONSE TO JOHN NICOL REGARDING MASS EXTINCTION

    Here are some references to relevant scientific papers from the peer review literature regarding mass extinction of species:

    Veron J. E. N. 2008 Mass extinctions and ocean acidification: biological constraints on geological dilemmas. Coral Reefs (2008) 27:459–472
    Diamond, J.M. (1989)Overviewof recent extinctions. In Conservation for
    the Twenty-First Century (Western, D. and Pearl, M.C., eds), pp. 37–41,
    Oxford University Press
    Pimm, S. et…

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    1. John Nicol

      logged in via email @bigpond.com

      In reply to Andrew Glikson

      Thanks Andrew. I will try to get hold of as many of these papers as I can. I believe the first is by "Charlie" Veron from AIMS who is a very strong activist.

      Even though I will probably continue to disagree with your take on Global Warming, I must say that I do appreciate that you respond to what we say and help in explaining the details of your arguments.

      However, I am also perplexed though, as indicated in a comment above, as to why you so strongly submit that carbon dioxide is to blame…

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  10. Andrew Glikson

    Earth and paleo-climate scientist at Australian National University

    THE EVIDENCE FOR MASS EXTINCTION

    Millennium Ecosystem Assessment, 2005.
    Ecosystems and Human Well-being: Biodiversity Synthesis.
    World Resources Institute, Washington, DC.
    http://www.unep.org/maweb/en/index.aspx

    Some of the key Messages

    Changes in biodiversity due to human activities were more rapid in the past 50 years than at any time in human history, and the drivers of change that cause biodiversity loss and lead to changes in ecosystem services are either steady, show no evidence…

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  11. Andrew Glikson

    Earth and paleo-climate scientist at Australian National University

    CO2 AND TEMPERATURES

    Throughout the history of Earth CO2 (and CH4) acted as both triggers as well as amplifying feedbacks of global warming, as in the following examples:

    1. Snowball Earth (850-635 Ma) - Accumulation of CO2 from volcanic activity, which could not be sequestered due to global ice cover, built to levels of tens of thousands of ppm which eventually led to the melting of ice, as represented by the "cap carbonate" which overlies the glacials.

    2. Volcanic and asteroid impacts…

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  12. Geoffrey Harold Sherrington

    Boss

    Andrew Glickson - extinct species.
    The official Australian list of Australian species has 24 birds, 4 amphibians, 28 mammals & 7 invertebrates. Many of these became extinct on small islands like Norfolk and Lord Howe, because of competition from newcomers like people. They did not all become extinct from global warming. The rate of extinction seems to have slowed as CO2 in the air is alleged to have risen. BTW, if you read the Mauna Loa papers carefully, you will see that many measurements have…

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    1. Mike Hansen

      Mr.

      In reply to Geoffrey Harold Sherrington

      We now have the CO2 measurement conspiracy theory! LOL

      "... if you read the Mauna Loa papers carefully, you will see that many measurements have been or are rejected and that hand-picked figures go into the final copy"

      Poor old Geoff does not realise that "CO2 levels are measured by hundreds of stations scattered across 66 countries which all report the same rising trend."
      http://www.skepticalscience.com/co2-measurements-uncertainty.htm

      We even have one at Cape Grim in Tasmania
      http://www.csiro.au/greenhouse-gases/

      Plus satellite measurements.

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    2. Geoffrey Harold Sherrington

      Boss

      In reply to Mike Hansen

      Mike Hansen,
      You are invited to show any error in my statement and to correct it, by data rather than smear and innuendo.
      Yes, I have been aware for decades of measurements other than the ones at Mauna Loa, but I was specifically mentioning that the ML values vary considerably with the hours of most days; and that selected vales are released.
      Ref: e.g.http://scrippsco2.ucsd.edu/publications/refgas_report_2002.pdf
      Quote:
      "In this report we have also reevaluated the volumes to be
      assigned to both the 4 cc and 5000 cc chambers, resulting in new cubic calibration
      equations for the entire period of our measurements of atmospheric CO2 back to 1957."

      While this is not an extraordinary event, it makes a nonsense out of quoting too many decimal places for concentration of CO2.

      It seems that adjustment in hindsight is endemic in the climate industry, as is exaggeration of claims of accuracy.

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    3. Tim Scanlon

      Debunker

      In reply to Geoffrey Harold Sherrington

      He did show the error in your statements. Just as I showed the error in your previous claims about temperature at Darwin.

      But keep shifting those goal posts to keep your denial intact.

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    4. John Nicol

      logged in via email @bigpond.com

      In reply to Mike Hansen

      Mike, You should probably take a little bit more time to read what people are writing. As with your response to my own comments, you appear not to appreciate that Geoffrey Sherrington is agreeing that CO2 as officially measured at Mauna Loa - the figures of which are most commonly quoted - shows that CO2 is increasing, a fact with which we all should agree. The only mystery is that the increase is only about 50% of the known increase from the burning of fossil fuel.

      Geoff's point is that, in spite of this the SST has NOT increased - and BTW neither has the overall global temperature.
      John Nicol

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  13. Andrew Glikson

    Earth and paleo-climate scientist at Australian National University

    John Nicol

    I will be happy to send you a number of key papers regarding the role of CO2 and other greenhouse gases, including my own papers, if you let me know which E-mail address to send it to.

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  14. Andrew Glikson

    Earth and paleo-climate scientist at Australian National University

    Mark

    Regarding mass extinctions, it is the demise of habitats and changes in temprature and rainfall conditions which are principal factor, closely intertwined with consequences of climate change and extreme weather events in different regions. A vast literature exists regarding the different genera and species, some of which I placed below. Estimates made by organizations such as WWF and other are mostly based on the peer review litertature.

    As an Earth and paleo-climate scientist, not being…

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