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Plimer’s homework assignment

Filed under: — gavin @ 24 August 2009

Some of you may be aware of George Monbiot’s so-far-unsuccessful attempt to pin down Ian Plimer on his ridiculous compendium of non-science. In response to Monbiot’s request for explanation and sources for some of Plimer’s more bizarre claims, Plimer has responded with a homework assignment that is clearly beyond even his (claimed) prowess. This is quite transparently a device to avoid dealing with Monbiot’s questions and is designed to lead to an argument along the lines of “Monbiot can’t answer these questions and so knows nothing about the science (and by the way, please don’t notice that I can’t cite any sources for my nonsense or even acknowledge that I can’t answer these questions either)”. (Chris Colose and Greenfyre have made similar points). It’s also worth pointing out as Andrew Dodds has done that each question is actually referencing a very well known contrarian and oft-debunked argument, but dressed up in pseudo-scientific complexity.

However, as a service both to Plimer and Monbiot (as well as anyone else interested), we give a quick scorecard on the relevance, actual scientific content (whether the questions can actually be answered) and sources for discussion for each of the, to be charitable, ‘odd’ questions. For relevance, we grade each question on a scale from 0 to 5, 0 being irrelevant to the issue of detection and attribution of 20th Century climate change, 5 being extremely relevant. For scientific content, we rate the reasonableness of the question posed (i.e. does it make any sense at all), from A to F (A being a very well posed question, F making no sense). For sources, we generally point to a paper or discussion that addresses the real issue.

  1. From the distribution of the vines, olives, citrus and grain crops in Europe, UK and Greenland, calculate the temperature in the Roman and Medieval Warmings and the required atmospheric CO2 content at sea level to drive such warmings. What are the errors in your calculation? Reconcile your calculations with at least five atmospheric CO2 proxies. Show all calculations and justify all assumptions.
    • Relevance: 0 – poor. Basic logical fallacy. The existence of prior warm periods that may have been caused by different effects (such as solar changes, orbital variation, continental configuration etc.) does not imply that the human-caused increase in CO2 is not causing warming now.
    • Scientific Content: D – phenology (the distribution and timing of species) can potentially be useful for tracking climate changes, but it is just one of many different types of proxy information available, and has its own regional, temporal, and seasonal limitations. Even more problematic, it is well known that the patterns of surface temperature variability during the “MWP” – more accurately, the Medieval Climate Anomaly (MCA) – and LIA periods were spatially quite heterogeneous, and a record at one or two locations generally tells us very little if anything about global patterns. Even a cursory examination of the relevant recent literature (for instance, Osborn and Briffa, 2006) reveals that the pattern of warmth during the Medieval era was far regional in nature, and does not approach the truly global scale of warmth evident in recent decades.
    • Sources: Greater extent of vineyards today in England than in medieval times. Ice core records. Incoherence of the Medieval warm period.
  2. Tabulate the CO2 exhalation rates over the last 15,000 years from (i) terrestrial and submarine volcanism (including maars, gas vents, geysers and springs) and calc-silicate mineral formation, and (ii) CH4 oxidation to CO2 derived from CH4 exhalation by terrestrial and submarine volcanism, natural hydrocarbon leakage from sediments and sedimentary rocks, methane hydrates, soils, microbiological decay of plant material, arthropods, ruminants and terrestrial methanogenic bacteria to a depth of 4 km. From these data, what is the C12, C13 and C14 content of atmospheric CO2 each thousand years over the last 15,000 years and what are the resultant atmospheric CO2 residence times? All assumptions need to be documented and justified.
    • Relevance: 0 – pure misdirection.
    • Scientific Content: F – We know what CO2 and CH4 levels have been over the last 15,000 years and they oscillated within about 10 ppmv (CO2) and 100 ppbv (CH4) of their Holocene values since the start of the current era – until the industrial period (around 1750) since when CO2 has increased by 35%, and methane concentrations have more than doubled. In each case the values being measured today are way higher than anything measured in 800,000 years of ice core records, and likely higher than anything since the Pliocene (~3 million years ago). The idea that bacterial methane production at 4km in the Earth’s crust has anything to with this is laughable.
    • Sources: IPCC FAQ is all that is required. Do volcanoes produce more CO2 than human activity? Not even close.
  3. From first principles, calculate the effects on atmospheric temperature at sea level by changes in cloudiness of 0.5%, 1% and 2% at 0%, 20%, 40%, 60% and 80% humidity. What changes in cloudiness would have been necessary to drive the Roman Warming, Dark Ages, Medieval Warming and Little Ice Age? Show all calculations and justify all assumptions.
    • Relevance: 3 – clouds certainly have an effect on climate and understanding their variability is the subject of much research.
    • Scientific Content: F – The question makes no sense. Clouds at 0% humidity? Is humidity supposed to be globally uniform? And where should these cloud changes occur? The change for low-level clouds will be of the opposite sign to changes in high level clouds, and changes in the Arctic will give different answers than changes in the tropics. It should go without saying that Plimer is mistakenly assuming that he has accurate information for global temperatures over 2000 years.
    • Sources: Cloud Feedbacks in the Climate System.
  4. Calculate the changes in atmospheric C12 and C13 content of CO2 and CH4 from crack-seal deformation. What is the influence of this source of gases on atmospheric CO2 residence time since 1850? Validate assumptions and show all calculations.
    • Relevance: 0 – completely irrelevant.
    • Scientific Content: F – for those that don’t know ‘crack-seal deformation’ is a geologic process that causes the veins of crystals/minerals etc. in many rock types. (see here). Its relevance to atmospheric concentrations and isotopic composition is absolutely zero. It has no influence on atmospheric residence time – whether since 1850 or at any time in the past.
    • Sources Discussions of the actual carbon cycle and the real influences upon it.
  5. From CO2 proxies, carbonate rock and mineral volumes and stable isotopes, calculate the CO2 forcing of temperature in the Huronian, Neoproterozoic, Ordovician, Permo-Carboniferous and Jurassic ice ages. Why is the “faint Sun paradox” inapplicable to the Phanerozoic ice ages in the light of your calculations? All assumptions must be validated and calculations and sources of information must be shown.
    • Relevance: 0 – (again). The acknowledged climate changes in the past caused by natural events in no way implies that human effects are negligible today. Does the existence of forest fires caused by lightning imply that arson can never happen?
    • Scientific Content: C – There is a lot of interesting science related to deep time, but any discussion of such changes must be prefaced with the acknowledgment that our knowledge of greenhouse gases, temperatures or any other potential forcing or response is very limited compared to what we know about climate today or even in the last ice age. Given that we don’t know precisely what CO2 levels were (let alone CH4, N2O, ozone, aerosols, ice sheet configurations, vegetation distribution etc.), the attributions of climate change at this distance is speculative at best.
    • Sources: The faint young sun paradox.
  6. From ocean current velocity, palaeotemperature and atmosphere measurements of ice cores and stable and radiogenic isotopes of seawater, atmospheric CO2 and fluid inclusions in ice and using atmospheric CO2 residence times of 4, 12, 50 and 400 years, numerically demonstrate that the modern increase in atmospheric CO2 could not derive from the Medieval Warming.
    • Relevance:1 – There are amplifying feedbacks between climate and CO2 – which are most evident in the long ice cores from Antarctica, but this argument is trivial to dismiss without any recourse to ocean current velocities etc.
    • Scientific Content:D – You can calculate the change in CO2 per deg C global warming over long (multi-centennial) timescales from the ice age data – it’s roughly 100ppmv/5ºC = 20 ppmv/ºC. The increase in atmospheric CO2 in the last 200 years is now about 110ppmv, implying that any natural driver would have need to have been more than 5ºC natural warming in recent centuries. This would have been noticed by someone.
    • Sources: None required.
  7. Calculate the changes in the atmospheric transmissivity of radiant energy over the last 2,000 years derived from a variable ingress of stellar, meteoritic and cometary dust, terrestrial dust, terrestrial volcanic aerosols and industrial aerosols. How can your calculations show whether atmospheric temperature changes are related to aerosols? All assumptions must be justified and calculations and sources of information must be shown.
    • Relevance: 4 – aerosols are an important climate forcing, and their history through time (even in the 20th Century) are quite uncertain.
    • Scientific Content: C – Calculating the impacts of aerosols is quite hard, first because we don’t have great records for their distribution through time and space, and secondly there are uncertainties in how the mix with each other and how they interact with clouds. Forcing estimates for the human-caused changes in aerosols over the 20th Century therefore have quite large uncertainties associated with them and are a principle reason why attempts to constrain climate sensitivity from the recent record along have not been very successful. Volcanic effects are however quite well characterised, and actually provide one of the many lines of evidence for why GCM simulations are reasonable since they get the right magnitude and character of the volcanic effects on climate. However, there is no evidence whatsoever for large changes in interstellar dust changes in recent millennia and trying to pin recent warming on that is really grasping at straws.
    • Sources: Climate sensitivity and aerosol forcings.
  8. Calculate 10 Ma time flitches using W/R ratios of 10, 100 and 500 for the heat addition to the oceans, oceanic pH changes and CO2 additions to bottom waters by alteration of sea floor rocks to greenschist and amphibolite facies assemblages, the cooling of new submarine volcanic rocks (including MORBs) and the heat, CO2 and CH4 additions from springs and gas vents since the opening of the Atlantic Ocean. From your calculations, relate the heat balance to global climate over these 10 Ma flitches. What are the errors in your calculations? Show all calculations and discuss the validity of any assumptions made.
    • Relevance: 0 – again more misdirection. The throwing around of irrelevant geologic terms and undefined jargon is simply done in order to appear more knowledgeable than your interlocutor. The argument appears to that climate is changing due to tectonically slow changes the direct heat input from ocean sea floor spreading. This is absurd.
    • Scientific Content: F.
    • Sources: Definition of ‘flitch’.
  9. Calculate the rate of isostatic sinking of the Pacific Ocean floor resulting from post LGM loading by water, the rate of compensatory land level rise, the rate of gravitationally-induced sea level rise and sea level changes from morphological changes to the ocean floor. Numerically reconcile your answer with the post LGM sea level rise, oceanic thermal expansion and coral atoll drilling in the South Pacific Ocean. What are the relative proportions of sea level change derived from your calculations?
    • Relevance: 2 – pretty much irrelevant.
    • Scientific Content: C – isostatic issues in sea level are important on long time scales, and there is still an effect today from the deglaciation 15000 years ago. It contributes a decrease of about 0.3 mm/yr to the global sea level rise, compared to 3 mm/yr total (i.e. about 10%). If the idea was to imply that current sea level rise is simply the response to the deglaciation, then it was completely misleading.
    • Sources: Reconciliation of the sea level rise, thermal expansion and ice melt.
  10. From atmospheric CO2 measurements, stable isotopes, radiogenic Kr and hemispheric transport of volcanic aerosols, calculate the rate of mixing of CO2 between the hemispheres of planet Earth and reconcile this mixing with CO2 solubility, CO2 chemical kinetic data, CO2 stable and cosmogenic isotopes, the natural sequestration rates of CO2 from the atmosphere into plankton, oceans, carbonate sediments and cements, hydrothermal alteration, soils, bacteria and plants for each continent and ocean. All assumptions must be justified and calculations and sources of information must be shown. Calculations may need to be corrected for differences in 12CO2, 13CO2 and 14CO2 kinetic adsorption and/or molecular variations in oceanic dissolution rates.
    • Relevance: 5 – the carbon cycle is actually a key issue.
    • Scientific Content: A – understanding the carbon cycle given multiple constraints on the carbon fluxes (including some of the issues raised in the question) is important in showing that the ~35% rise in CO2 since ~1750 is in fact anthropogenic. This has been shown numerous times to be consistent with the known human emissions, increases in oceans and terrestrial carbon, the decrease in 14C content of the atmosphere, the decrease in 13C content in the atmosphere, the decrease in O2 in the atmosphere.
    • Sources: Read the FAQ.
  11. Calculate from first principles the variability of climate, the warming and cooling rates and global sea level changes from the Bölling to the present and compare and contrast the variability, maximum warming and maximum sea level change rates over this time period to that from 1850 to the present. Using your calculations, how can natural and human-induced changes be differentiated? All assumptions must be justified and calculations and sources of information must be shown.
    • Relevance: 4 – detection and attribution of climate change is an important issue.
    • Scientific Content: B – First principles calculations of climate variability are most closely approximated by GCMs and multiple modelling groups have done various Holocene simulations. Attribution of any climate changes requires model simulations with and without each particular forcing and for the Holocene, this involves changes in the orbit, greenhouse gases, solar, meltwater regimes, ice sheet change, aerosols etc. and a comparison of the signature of the responses with patterns observed in the real world. However, comparable data to 20th Century sea levels or temperature changes are not available going back to the beginning of the Holocene.
    • Sources: Attribution of mid-Holocene hydrologic changes to orbital forcing. Attribution of patterns of cooling at 8.2 kya to drainage of Lake Agassiz. Attribution of pre-industrial variability over the last millennia to solar and volcanic forcing (IPCC Ch8, p680+).
  12. Calculate the volume of particulate and sulphurous aerosols and CO2 and CH4 coeval with the last three major mass extinctions of life. Use the figures derived from these calculations to numerically demonstrate the effects of terrestrial, deep submarine, hot spot and mid ocean ridge volcanism on planktonic and terrestrial life on Earth. What are the errors in your calculations?
    • Relevance: 1 – irrelevant. Has nothing to do with current causes of species extinction nor sources of CO2.
    • Scientific Content: D – insufficient data exist to infer atmospheric composition, nor the sources of any hypothesised fluxes. We think that it is likely that mass extinctions are probably bad for “planktonic and terrestrial life on Earth” with very little error.
    • Sources: This is a good intro to the P/T extinction event which is fascinating even if mostly irrelevant to today.
  13. From the annual average burning of hydrocarbons, lignite, bituminous coal and natural and coal gas, smelting, production of cement, cropping, irrigation and deforestation, use the 25µm, 7µm and 2.5µm wavelengths to calculate the effect that gaseous, liquid and solid H2O have on atmospheric temperature at sea level and at 5 km altitude at latitudes of 20º, 40º, 60º and 80ºS. How does the effect of H2O compare with the effect of CO2 derived from the same sources? All assumptions must be justified and calculations and sources of information must be shown.
    • Relevance: 3 – radiative transfer is a key issue.
    • Scientific Content: F – the question as it stands makes no sense. How can using fossil fuel emissions of CO2 allow you to calculate the impact of total H2O? And why only three wavelengths? You would need the whole atmosphere distribution of water (in all three phases and which doesn’t exist outside a model) in order to calculate the radiative fluxes, and a full GCM to calculate all the other fluxes that influence the temperature. If Plimer is actually alluding to the impact of the direct injection of water vapour into the atmosphere from the combustion of hydrocarbons, then this makes even less sense since the perturbation time for water vapour is measured in days (rather than decades to centuries for CO2) and the relative importance of anthropogenic fluxes is much much less.
    • Sources: Importance of water vapour and clouds compared to CO2 for the total greenhouse effect (roughly, 50%, 25% and 20% once overlaps are apportioned). Complete irrelevance of anthropogenic addition of H2O. Calculation of radiative forcing for anthropogenic CO2.

In summary, the relevance of these questions is extremely low, and even when the basic question deals with an issue that is relevant, the question itself is usually nonsensical and presupposes many assumptions that are certainly not a given (at least in the real world). In fact, for the couple of cases where the scientific content is high, the answer is in contradiction to Plimer’s unstated assumptions. The most obvious use of these questions to support a ‘we don’t know everything, so we must know nothing’ type of argument, which is a classic contrarian trope, and one that is easily dealt with.

These questions have as much to do with a debate on human caused climate change as tribbles have to do with astrobiology. Both are troubling, but for very different reasons.


285 Responses to “Plimer’s homework assignment”

  1. 51
    CM says:

    Lynn (#36), with respect, did you read the whole of Mr Sacks’s rant? Global warming is a hopelessly lost cause so we have to leave behind 10,000 years of civilization and look to the hunter-gatherers? The best strawman-making efforts of the denialist camp pale in comparison.

  2. 52
    Paul says:

    Would like to point out that the Romans were in the UK for between 400 and 500 years (it wasn’t a short ‘Iraq’ type occupation). Now I don’t know what the situation was regarding breeding grape varieties back then, but a few hundred years is quite some time to develop growing techniques in a different climate, if not new breeds. Plus of course I’m not sure there are any records as to the quality of grapes and wine produced in Britain. Until recently British wine has been rubbish (even with warmer climates, it still isn’t brilliant), yet people still bought some of it.

    So given that a Roman is based in Britain, a long way from home, the quality might not have been so important.

    What is often ignored is not whether grapes are grown at all, but what the grapes taste like.

    Here is an interesting page about cool and warm climates for wine production:
    http://tablascreek.typepad.com/tablas/2007/06/cool_climate_ho.html

    So basically what i’m suggesting is that Plimers analysis is very, very rough and ready, it ignores culture, human adaption and acceptance of different standards in a product.

    More useful would be research into species that weren’t farmed during that period and migrated naturally.

  3. 53
    RW says:

    You say, in regards to question 8, “The throwing around of irrelevant geologic terms and undefined jargon is simply done in order to appear more knowledgeable than your interlocutor”. Really this applies to the whole thing. These questions clearly aren’t aimed at generating constructive debate; all these “justify all assumptions” and “show all calculations” only expose the whole thing as a craven attempt to appear clever.

    I haven’t seen anything about this from the usual deniers. Given that Plimer’s subtext is “if you can’t answer these, you aren’t competent to have an opinion”, and that none of the usual deniers could make sense of these ridiculous questions either, I guess they don’t want to touch it with a bargepole. I’m amused at their dilemma.

  4. 54
    Chris says:

    re #41

    Relevant to your point about the quality of Medieval British wine, Paul, I think it’s true that much of the impetus for wine growing in those periods was to serve religious ceremony and for medicinal purposes (it had been worked out already in the Medieval period that treating wounds with wine was quite effective). Presumably good quality quaffable wine was imported for the well to do, and local plonk was entirely sufficient for religious and therapeutic purposes!

    http://www.englishwineproducers.com/history.htm

  5. 55
    Jeffrey Davis says:

    The best strawman-making efforts of the denialist camp pale in comparison.

    Well,no. Unless you think hysteria is worse than deception. It isn’t at all clear that he’s even wrong. (To the extent that he implies knowledge of the effects of AGW, he’s wrong, but it isn’t clear that AGW won’t lead to war, famine, etc. The Department of Defense, that old silly environmental group, has issued warnings about war, famine, and other kinds of civil unrest.) Deception — particularly paid deception — is a whole other realm of Bad Behavior.

  6. 56
    Lynn Vincentnathan says:

    CM #40, I was also thinking about that, and I’m thinking what he might mean is that we have to change our approach to the world, get away from this idea that the only way we can make it or get ahead is to exploit — whether that be exploit people or nature. I don’t think he means we should get back to hunter and gatherer lifestyles (which would be impossible, since they require so much land per person); but maybe we can learn something from their world view, maybe incorporate some of their tenets.

    Now, as an anthropologist, I can say that there is a much wider variety of world views among band-level hunting and gathering societies than among civilizations, so maybe the ole stereotype of the ideal or noble hunter and gatherers would do — respect the land and nature. Some H&G societies thank the animals they kill for giving them sustenance, and perform religious ceremonies right after the kill or before; and some horticulturalists chant as they plant and tend their crops. The susbsistence/economic/religious/kinship/etc were all one, unlike today’s separate spheres for each “component” of our lives. Maybe we need an awe and reverence for this earth and for life in general, maybe we could chant or pray interiorly as we engage in our “economic” workaday activities — to the God of our religions, or if an atheist, then to the great “Not Me” (since most of what we are comes not from ourselves but from others and from nature and the environment, etc.).

    Roy Rappaport (I’ve quoted him before re the environment and economy – see #26 http://www.realclimate.org/index.php/archives/2009/08/a-biased-economic-analysis-of-geoengineering ) also presented a conference paper in 1976, titled (I think), “The Religious Dimension of the Environmental Movement,” in which he called for just such a religiouslike reverence and awe for the environment, since the complexities are so great and we cannot really completely understand everything scientifically about the world’s ecosystem.

    And in a way, over the past centuries and millennia we’ve come to believe we are the conquerers of nature, but that sort of rings hollow under the circumstances we are facing with global warming and all the other harms we’ve caused to the environment, to our home (oikos, eco), our life, Life.

    And I am guilty of what Adam Sacks accuses. I’ve been trying to convince people to do the right thing environmentally bec for the most part it is also the economic sensible thing to do, when I really should have engaged in the much more difficult task of trying to change their world view. Because, anyway people have not responded to economic incentives. There is a deep perversity there, a willfulness of “I” that will admit no error, that fears all others as enemies to exploit and dominate lest one be exploited and dominated. That’s what needs to be addressed. That’s the true cause of global warming (and many many other problems).

  7. 57

    I was just thinking… what would Yoda say about Ian Pilmer?

    hmm… the irony is strong with this one?

  8. 58
    Jay Moynihan says:

    His questions made me think of,

    “Bring me….a shrubery!”

    Knights that say knee scene, from the Monty Python film “The Holy Grail”.

  9. 59
    David Erickson says:

    Re: “warming in the pipeline” (#42, #35, #17) The Uof Rochester press release (http://rochester.edu/news/show.php?id=3420) seems to imply that the finding of this paper is that the net heat stored in the ocean is not increasing. That was what raised alarm bells for me. The statement “the team says their data shows the oceans are not continuously warming—a conclusion not consistent with the idea that the oceans may be harboring ‘warming in the pipeline’” is vague…the oceans may not be continuously warming, but what about the net heat content? If there is no “warming in the pipeline” then are they saying that the net heat of the ocean is constant? Are they saying if warming due to greenhouse gases was mitigated, that the ocean would not continue to warm the atmosphere?

  10. 60
    Ike Solem says:

    Plimer is just using the rhetorical tactic of dodging the question by presenting another list of questions, which he himself is unable to answer. The goal is little more than the perpetuation of doubt – but, there’s no longer so much doubt in the public mind about the reality of fossil-fueled global warming, or about the ability of renewable energy to replace fossil fuels entirely.

    Climate change is no longer much of a scientific question, other than for the finer points and the long-term projections. The issue is not whether global warming is happening, but rather whether political and economic approaches can rapidly replace fossil fuels with renewables.

    Plimer would have to explain polar warming, tropospheric warming, increased drought, changing precipitation patterns, the water vapor feedback response, rapidly melting alpine and tropical glaciers, rising sea levels, diminishing sea ice, warmer spring and winter temperatures, shifting animal and plant populations – the list is pretty irrefutable, and the physical models match the observations – so what science is missing?

    The next stage will involve listening to another train of Plimers telling the world that there is no plausible replacement for fossil fuels, period, regardless of the effects of global warming – but that debate, unlike the climate ‘debate’, barely makes the pages of any newspapers today, and when it does, usually it’s just a one-sided coal/oil industry perspective.

    Renewables are much more of a direct threat to entrenched energy interests than is the discussion over climate change, because the next stage after that is the removal of coal-fired power plants and the elimination of oil imports. This would result in large-scale disruption of the global economic order, which today is largely based on control of fossil fuel reserves.

    However, the Plimers of the world are reluctant to take up the argument on energy – because you really can calculate the energy available from the sun, compare it to energy available from fossil fuels, and conclusively demonstrate that solar power and other renewables are capable of meeting human energy needs in the absence of fossil fuels. Unlike with climate, you can do experiments over and over and don’t have to rely on ice core records for observational data – and anyone who says you can’t get energy from solar is easily refuted by taking them to a large solar power plant.

    If our government were to decide that renewables were a good idea, then we’d institute federal feed-in tariffs, which essentially ensure higher prices for renewable-based electricity generators by taxing fossil fuels and subsidizing renewables – a standard and successful approach outside of the United States. What you have now, instead, is a government that is pulling itself apart – some sections are grudgingly supporting renewables, and others (like the State Department) are going all-out for new fossil fuel deals.

    Unfortunately, U.S. trade and domestic policy remains dedicated to the expansion of global fossil fuel use, not to its rapid reduction – witness the bipartisan governmental support for Canadian tar sand imports to the U.S. – despite claims of concern over global warming, the permit for a tar sand oil pipeline to the U.S. was just quietly granted.

    This seems like a disorganized and deranged approach to the problem, at best.

  11. 61
    Mark says:

    Jay, it’s the Knights who say “Nii!”.

    Sheesh.

    Kids today…

  12. 62
    Chris says:

    re #54

    David, the data used by the Uni. Rochester pair (abstract below) is the data on ocean heat content. So they use the Domingues et al (2008) ocean heat content data and the Levitus et al (2009) heat content data that I refered to in my post #42 (they also analyse heat content measures from the short ARGO series and a short term CERES data set).

    Since the long term data sets (Domingues and Levitus) show substantial long term ocean heat uptake, the Rochester authors can’t argue against substantial ocean heat uptake during the last 30 odd years.

    A slightly different point is being made. I’ve had just a quick read of the paper. The authors are returning to the idea (a bit like the Swanson/Tsonis paper discussed here)…..

    http://www.realclimate.org/index.php/archives/2009/07/warminginterrupted-much-ado-about-natural-variability/

    …that the oceans are displaying regime shifts, with a period (1960-1975) when the oceans were (supposedly) losing heat, a period (1975-2000) when the oceans were acquiring heat, and a period (since 2001) when the oceans have been (supposedly) losing heat. They analyze these data in relation to an apparent top of the atmosphere radiative forcing which is apparently negative/poitive/negative during these “regimes”, but recognise that this is an unlikely interpretation and more likely the observations relate to ocean current changes (the PDO) along the lines of Swanson/Tsonis.

    A cursory reading of their paper highlights at least two problems (one a lu-lu!) with their analysis:

    1. since both Levitus and Domingues determine substantial ocean heat uptake in the period 2000-2005, it’s difficult to justify a negative heat uptake since 2001 that is required by their supposed climate regime shift at around the year 2001. Their analysis of this relies on the very short term ARGO record for which there is still uncertainty about reliability. In essence they are resorting to the dreary “it hasn’t warmed for a few years and so global warming has stopped”.

    2. The second problem is a howler. It relates to “warming in the pipeline”. The authors arrive at this as follows:

    a. they notice that the ARGO data has a strong seasonal component (the measured heat content goes up and down sinusoidally with the seasons) see my link to the skepticalscience site in post #34 to observe this.

    b. They point out that this means that the oceans have a fast response time to changes in radiative forcing.

    c. Ergo! If the oceans respond quickly there can’t possibly be any mechanism for any delayed ocean response to radiative forcing. No “heat in the pipeline”!! (wild applause!)

    I’ve read that bit of their paper three times and I’m pretty sure that’s their “argument”, astonishing as it may seem.

    here’s the abstract of the paper:

    D.H. Douglass, R. S. Knox (2009) “Ocean heat content and Earth’s radiation imbalance” Physics Letters A 373 3296-3300

    Abstract: “Earth’s radiation imbalance is determined from ocean heat content data and compared with results of direct measurements. Distinct time intervals of alternating positive and negative values are found: 1960–mid-1970s (−0.15), mid-1970s–2000 (+0.15), 2001–present (−0.2 W/m2), and are consistent with prior reports. These climate shifts limit climate predictability.”

  13. 63

    #35 David Erickson (#17, #42)

    I just took a look at the article. My first thought was are they considering the whole picture?

    They said the net flow of heat changed three times, well,as Chris (post #42) pointed out, that is well known. We had increases in the early part of the 20th century, then around mid century we put up an aerosol shield that could cause cooling, and then in the mid-seventies, we stopped that (due to little problems such as global threat to crop production) and the climate began warming again. That’s three times. It is clear that the temps have shifted:

    http://www.ncdc.noaa.gov/sotc/get-file.php?report=global&file=glob&byear=2009&bmonth=1&year=2009&month=7&ext=gif

    http://www.ncdc.noaa.gov/oa/climate/research/anomalies/index.php

    but is their analysis comprehensive enough to cover all the bases for attribution for the shift (cause/effect)?

    My second thought regarded:

    “it analyzes more completely the data sets the researchers believe are of the highest quality, and not those that are less robust.”

    Was this a cherry pick for cause, or are they using the most relevant data? Or is it a combination of changes in the heat content and cherry picking? In reality there is the possibility that the most robust (depending on their definition) data might not be the best data; as this would need to be understood in context of the GCM’s. Do they mean robust in the sense of number of data points (which might lack modeling accuracy, such as using the data sets that were later to be found to have instrumentation error), or do they mean robust in the sense of data integrity based on source, or, or, or…

    Based on the nature of the article as written I have doubts about the paper itself.

    The funniest line is:

    “a conclusion not consistent with the idea that the oceans may be harboring “warming in the pipeline.”

    The oceans are not harboring warming in the pipeline as far as I can tell, oceans just react (with various delay factors). They may simply have a fundamental misunderstanding of what is causing the warming. It’s not the oceans that drive climate, it’s the sun, combined with radiative forcing potential within our atmosphere combined with earths surface (absorption and reflective qualities). This of course includes natural cycle forcings such as Milankovitch cycles and human induced alterations of land surface and atmospheric concentrations of GHG’s and aerosols.

    It may just be a mistake of the person that wrote the news item (one would hope). The oceans absorb heat slowly because oceans are deep and big. Little (big) thing called thermal inertia.

    On the other hand, the oceans are the reason why there is ‘warming in the pipeline’ because of that thermal inertia. When you consider the atmospheric lifetime of Co2, combined with thermal inertial, that is better understood.

    Last but not least:

    Douglass further notes that the team found no correlation between the shifts and atmospheric carbon dioxide concentration.

    Well, that’s funny. There are none so blind as those that choose not to see. It’s easy not to find something. You know what the say, ‘myopia is bliss’, or something like that.

    From this single line one can might easily deduce that they probably ignored a tremendous amount of established science and related causes in relation to the scope of the view.

    - GHG’s/Aerosols combined effects
    - Surface and Atmospheric Radiative Forcing
    - GCM’s
    - Charney and related work

    But what the heck do I know. I have not read the paper and I rarely believe things I read in the press unless I have a knowledge or understanding base of the subject. So for now I will call it an estimated guess and we will see how it plays out :)

  14. 64
    Christopher Hogan says:

    Regarding #37, your point is well taken, but it’s not correct so say that the Arbor Day (current data) map looks like the USDA 1965 map. They appear systematically different to me, as described below.

    First, I finally found a copy of the USDA 1965 map here:

    http://www.garden.bsewall.com/images/zones/1964_Map_US.htm

    Comparing that with the Arbor Day Foundation map cited above (set to current data), I believe the maps are systematically different.

    In particular, the entire center of the country appears much warmer, while the coasts do not.

    Draw a line from Texas through the middle of the Dakotas. Every zone appears shifted northward … about half-a-Dakota to a Dakota or so, more as you go northward.

    For example, in the USDA 1965 map, the ND/SD stat line is on the Zone 4/Zone 3 boundary. In the 2006 map, ND is entirely in Zone 4. Go down to Texas. In the 1965 map, the northernmost square part of TX is entirely in Zone 6. In the 2006 Arbor Day map, it is entirely in Zone 7. And so on, right up that line.

    Whereas on the East Coast, it’s more of a mixed bag. Where I sit in Virginia, the two maps are essentially identical. But where the 1965 map splits PA into Zones 6 and 5, mid-state, the 2006 Arbor Day may places PA squarely in Zone6, with bit of 7 on the southern border.

    So, while your points are well taken — that the 1990 map was colder than the 1965 map (which I didn’t know), and that conservatism in the defense of nursery stock is no vice, I disagree with the 2006 maps is merely a return to where the 1965 map stood. To the contrary, looking at them side-by-side, at least in so far as I care to do so, the zones on the Arbor Day foundation map are shifted significantly northward on average. Not perhaps as dramatically as they are relative to the 1990 may, but, fairly dramatically in the center of the country, and to a lesser extent on the coasts.

    In short, I think the 2006 climate zone map prepared by the Arbor Day foundation appears warmer then either the 1990 or 1965 USDA maps. If you can find a better image of the 1965 map that differs substantially from the one I found, I’ll change my mind. Otherwise, that’s how the maps look to me.

  15. 65
    Lynn Vincentnathan says:

    RE #51, and speaking of the devil that causes global warming….I just got this reference in my email — http://www.ourfuture.org/blog-entry/2009083313/self-help-book-societies .

    It’s about how more equal societies among the developed nations far outperform on many levels the more steeply hierarchical nations, like the U.S. They don’t mention global warming or efforts at mitigating global warming or facing the scientific truths about it, but that would fit very well here.

    It’s sort of why so many in Americans are not only against health care reform (and have socially constructed it as some evil death machine), but also why they don’t want to face up to global warming and mitigate it. Why denialists and contrarians run rampant. (People tend more to fight over peanuts than really important things.)

    I also thought of another thing that would apply both to the U.S. and Australia. These are both wild west frontier societies. There is a history, ethos, and continuing myth of struggling against nature to make a go of it, including the fight against the indigenous peoples or anyone else blocking our way to happiness and fulfillment; and a history of throwing off authoritarian rule, the father, the other. This is a history (and all countries have their own bloody histories) that we need to overcome by reconciling with nature and humanity, even if we’re deathly afraid to do so, because we’ll end up being the suckers and losers. But we (including Plimer) need to be brave and reconcile.

  16. 66
    Jeffrey Davis says:

    re: 54

    I don’t know what the Rochester team was looking at since current ocean temps are the highest on record. If the oceans were losing heat there’d be a previous high record, right?

  17. 67
    Joe Hunkins says:

    This is a very impressive post!

    I was not up on Prof. Plimer’s arguments against warming but addressing the talking points of critics directly is always helpful and the responses Plimer is now obligated to post will be interesting.

    I do have a big beef with a zero relevancy ranking for the MWP however. As with many skeptic concerns the issue there is the influence of general rather than specific natural variability. Adequate modelling of natural variability is essential to tease out the AGW “signal”. The MWP debate is hardly over given how difficult it still seems to be to determine the regional and temperature variations of that period. Also, if MWP temps were higher or close to present temps it weakens the already very shaky “climate catastrophe coming” line taken by some, present company excluded.

    [Response: You are mistaken. The issue is why any period was warmer not whether. If solar was much higher than today then, we'd expect warmer temperatures and it wouldn't make any difference to our expectations for the future. As for consequences, the issue is not the temperatures today, but the likely temperatures in the future which are unquestionably warmer than any medieval values. - gavin]

  18. 68
    Kay Schmidt says:

    In the Plimer homework discussion, there’s an “it’s” that should be “its”
    and in last question and answer, the word should be “principal.”
    I say this because suvh small errors weaken perceived reliability of the writing.

  19. 69
  20. 70
    Theo Hopkins says:

    Does anyone know about “mast years” as a possible temperature proxy?

    Here in Devon, SW UK, it’s clearly going to be a (good) mast year.

    That’s to say there will be loads of hazel nuts and acorns. This in my experience happens about once in some five years. As far as I know (I don’t know much) mast years relate to temperature (perhaps in spring?). Other fruit bearing trees seem to be doing better than usual – blackthorn (sloe)and(English)maple. This is just my observation: I have no records to back myself up. Happens I run a woodland as a retirement hobby, I’m there a lot, and I see what I see.

    Historically, these mast years were very important as in a good mast year pigs would be herded in woodlands for acorns and what we still call “beech mast” and the mast they ate fattened them well (perhaps for Christmas?).

    Are there records of good mast years? Monasteries kept pigs so may have records of good mast years or super fat pigs?

    Pigs as proxies?

  21. 71
    Michael says:

    Re 6: Interesting that Plimer is an anti-creationist who debated Duane “Galloping” Gish:

    Ian Plimer, head of the Geology department at the University of Newcastle, Australia, debated Gish in 1988. Plimer considered the debate to be political rather than scientific, and thus refused to argue genteelly about scientific minutiae. Instead, Plimer debated Gish in a street-fighting style which a Sydney Morning Herald reporter described as going in “boots and all, aiming for the opponents kneecaps”. “Professor Plimer mocked, ridiculed and challenged every tenet that the movement holds dear, and made a string of blunt personal accusations about some of its more prominent members.”
  22. 72
    GFW says:

    I don’t know if this really belongs here, but someone above mentioned the 1934 US temperature record. I recently was thinking “Why so hot in the US but nowhere else at that time?” And then I thought “Dust Bowl!” As is well documented, agricultural practices on the great plains at the time worked for above-average rainfall, but when the drought occurred, those practices left dry plowed fields open to wind erosion. Vast clouds of dirt blew across the nation, starting in 1933. Would not the effect of those “black clouds” be much like carbon black aerosols, only stronger? In other words, could the high temperatures of the 30s, and the record in 1934 be significantly attributable to an anthropogenic feedback, kicked off by a naturally occurring drought and more modest natural temperature variation?

  23. 73
    Bob says:

    RE #53:

    Actually, it’s more like

    “What is your name?”
    “What is your quest?”
    “What is the air speed velocity of an unladen swallow, when taking into consideration the increased (or decreased) density of the air as a result of theoretical but as yet unproven anthropomorphic contributions to the CO2 concentrations, as well as related atmospheric components, such as humidity, temperature and altered prevailing winds resulting from such concentrations, and any impacts that living in such conditions may have had on the overall genetic selection, health and therefore flight acumen of any likely subject swallow? And please show all work. And no cheating.”

  24. 74
    Hank Roberts says:

    Theo, you’ll find a lot in Google Scholar searching on “mast year” — no simple answer!

  25. 75
    Chris Dudley says:

    I have a question for George Monbiot: Given that Rajendra Pachauri has said that he is supportive of a goal of 350 ppm, below the current concentration of carbon dioxide in the atmosphere http://news.yahoo.com/s/afp/20090825/sc_afp/climatewarmingunipccpachaurico2

    How much carbon do we need to leave in the ground now? http://www.monbiot.com/archives/2009/05/06/how-much-should-we-leave-in-the-ground/

  26. 76
    Bryan Oakley says:

    Re: #6 Bob Ward

    Be careful painting such a broad brush.
    I’m sure many geologists read and appreciate R.C., myself included!

    Great point by point debunking guys!
    Keep it up!

  27. 77

    “Mast” in contemporary North America is important for wildlife such as deer and bear, hence also for hunters and wildlife managers.

  28. 78
    James Staples says:

    People like Ian Plimer, and the CRAP they have been putting out there in the Public Eye, are why I mention RealClimate.org as much and as often as possible when commenting, blogging, chatting with lunk-heads on the train, etc..
    I see he seems to ‘get on TV – a LOT’. Hmmmmm. I wonder whose hosting those programs? Exxon Mobile? Haliburton? The ‘Clean Coal’ Consortia?
    Like the lady said, you are AWESOME.

  29. 79
    Theo Hopkins says:

    Hank @ #74

    Thanks for suggestion to check out mast years on Google Scholar.

    Here in Devon in the UK woodlands (as opposed to forests) are mostly are owned by farmers over generations and what “mast years” are all about is through folk law (or generational experience). So I was intrigued to find so much research on the subject.

    Enough there with first two hits (“mast year” and “temperature”)(but I may be using confirmation bias) to make me wonder if, indeed, old records of masting could be a temperature proxy.

  30. 80
    Nick Gotts says:

    Lynn Vincentnathan@67,
    The book your link reviews, Richardson and Pickett’s The Spirit Level: Why more Equal Societies Almost Always Do Better does indeed deal with AGW, arguing that greater inequality increases the pressure for conspicuous consumption; and that above a certain level, increasing GDP per capita does not improve quality of life. While there’s no data directly on the relationship between GHG emissions and inequality, it does show that low emissions are compatible with desirable outcomes such as low infant mortality and high HDI (Human Development Index) – despite the latter including per capita GDP along with life expectancy and education levels. More equal societies also recycle more. Much material from the book is available at http://www.equalitytrust.org.uk/

  31. 81
    dave p says:

    About the last 200 years, it’s accepted that the Earth’s temperature rose after the early 19th century due to natural causes. At the time emissions were too slight to make a difference. It is only in the mid to late 20th century that greenhouse gas concentrations became high enough to effect the climate.

  32. 82
    David B. Benson says:

    dave p (81) — NOt accepted by me. Both emissions and land use change rose from around 1750 CE onwards. From the data obtainable from the Carbon Dioxide Information Analysis Center at ORNL it seems that yearly emissions of CO2 have risen approximatly exponentially from around 1800 CE onwards. From the Arrhenius approximation, that implies an approximately linearly increasing forcing from CO2 alone.

    Methane is another matter and of course the matter of aerosols is difficult to ascertain before the modern instrumental period. But to provide some regional data, Swiss glaciers have been measured for a long time; in 1850 CE the glaciers stopped growing and by around 1880 CE had begun to retreat; by the 1950s the retreat was 4 m/y.

  33. 83
    Pete H says:

    Hi,

    I saw this pass by today and wanted to share it. Perhaps you RC folks will sign up as Defense Attorneys:

    Quote of the day:

    “It would be evolution versus creationism. It would be the science of climate change on trial.”

    William Kovacs, senior vice president for environment, technology and regulatory affairs for the U.S. Chamber of Commerce, about a requested trial on climate change.
    - Los Angeles Times

    (I picked this up thanks to Headwaters News; original story here: http://www.latimes.com/news/nationworld/nation/la-na-climate-trial25-2009aug25,0,901567.story

    -PJH, an amateur who’s paying attention

  34. 84
    William says:

    dave p @81 – are you sure about that? Any evidence or modelling results to support your assertion?

  35. 85
    Josie Wexler says:

    Thanks for this post. Excellent stuff.

    A question. You say:

    “There is a lot of interesting science related to deep time, but any discussion of such changes must be prefaced with the acknowledgment that our knowledge of greenhouse gases, temperatures or any other potential forcing or response is very limited compared to what we know about climate today or even in the last ice age. Given that we don’t know precisely what CO2 levels were (let alone CH4, N2O, ozone, aerosols, ice sheet configurations, vegetation distribution etc.), the attributions of climate change at this distance is speculative at best.”

    Hansen’s 2008 paper “Target Atmospheric CO2 Where Should Humanity Aim?” seems to be using deep time (the early Cenozoic) to make calculations about what will happen in the future. Would this caveat apply to this? Eg. to what degree should the conclusions in this paper be regarded as highly speculative? (this is a genuine question, not insinuation). Thanks!

    [Response: The higher uncertainties when dealing with deep time do need to be propagated into the final answers and that does mean that it is hard to come to precise numbers. Hansen et al are making a conservative best guess. - gavin]

  36. 86
    Craig Allen says:

    I’m a graduate of the University of Adelaide where Plimer works. All past exam papers are lodged with the University’s Bar-Smith Library. If any readers are in Adelaide, please entertain us by nipping down to the Bar-Smith, photocopying the last exam he inflicted on his students (the librarians, or any random science student will show you where to find them) and posting some of the questions here for us to compare.

  37. 87
    Hank Roberts says:

    dave, was that meant to be tongue in cheek humor?
    p:

    Ruddiman

  38. 88
    Steve Bloom says:

    Re #s 9 and 21 referring to Lindzen’s latest, James Annan has some comments here.

  39. 89
    John Pollack says:

    Re: #64 (#16, #40)
    I agree that the 2006 Arbor Day Foundation plant hardiness zone map is warmer than the 1965 USDA map. I didn’t mean to imply otherwise. Unfortunately, I don’t know of a website with a large 1965 map; I’m using my old paper copy. I also agree that it is a nice illustration of climate change for U.S. residents, considering that I spent hours poring over the old map in my youth, and how it helped arouse my interest in climate.

    My concerns are that an averaging period shorter than 30 years may be too short for the intended purpose of the map, even if 30 years does have the effect of downplaying recent mild winters. I am firmly convinced of regional U.S., as well as global, warming. However, I don’t want to get trapped into saying that our winter temperatures will rise without any reversal. When challenged with the “if this is global warming, how come it’s still so cold in the winter?” type of question, I respond that “10 below (F) is the new 15 below.” That works for my area – Nebraska.

  40. 90
    Peter Backes says:

    I think these bogus homework assignments are a clever distraction cooked up by a bunch of cynics that are heavily invested in hip wader futures and soon-to-be beachfront property in Kansas.

    Or maybe that’s just me being cynical?

  41. 91
    Mike Strong says:

    None of you see it do you? The bias? The immediate raising of the hairs on the backs of your necks at the hint of any opinion that disagrees with your ideaology.
    The fact that this topic starts with ” bizarre ” or “ridiculous”…means you already concluded your opinion before you even give in to listening a little… and that you may be wrong. God I am pissed off at all of this point-counterpoint stuff…yelling at each other on blogs…discounting the possibility that both sides might be just a little-bit correct.
    If this was a court of law with a good judge, you would need to stick to the facts. Present your argument. Wait for the judgement. But the AGW supporters and the deniers are so high and fricking mighty, they just lob shells at each other. You might as well be the Sunnis agains the shiites in Iraq. Idiots all of you. Fighting amoung yourselves instead of understanding the problem: manmade or not. A problem or not.

    Get back to science. Evidence. Fact versus counter-fact. Peer review. Verification.

    This blog is SUPPOSED to be REAL CLIMATE. It is anything but. It is the Rush Limbaugh of AGW supporters. Shame on all of you who ignore what we scientists and engineers were taught: report the data and kill the bias.

    I am sooooo sick of this crap.

    Your dad. A scientist and engineer with manners.

    Mike Strong

  42. 92
    naught101 says:

    the decrease in 14C content of the atmosphere, the decrease in 13C content in the atmosphere,

    Decreases? Is that relative to 12C, or absolute? If the latter, what are the causes?

    [Response: Relative to 12C. You keep track of the isotopic ratios use 'delta' units, which are the essentially the relative difference of the air with respect to a fixed standard i.e. d13C = 1000*(Ratio_in_air/Ratio_in_standard - 1) in permil (D14C is similar but not identical). Both these ratios have gone down over the last century - d13C because fossil fuels are biogenic (and biology discriminates against 13C), and D14C because 14C is radioactive (half life ~5700 yrs) and is almost zero in any fossil fuel because it is so old. Thus in both cases the addition of fossil-fuel derived carbon dilutes the isotope ratios in the air. - gavin]

  43. 93
    Garry S-J says:

    David B. Benson (#82).

    You mention emissions re Arrhenius – but don’t you mean concentration?

    William (#84):

    dave p’s comment seems to be broadly consistent with the conclusions of the IPCC’s 4th assessment report, which argues anthropogenic effects only came to dominate temperature trends in the latter half of the 20th century. That’s based on a lot of modelling work, obviously.

    eg, from Ch 9 of the Climate Change 2007 The Physical Science Basis:

    “No climate model using natural forcings alone has reproduced the
    observed global warming trend in the second half of the 20th
    century. Therefore, modelling studies suggest that late 20th
    century warming is much more likely to be anthropogenic than
    natural in origin, a finding which is confirmed by studies relying
    on formal detection and attribution methods (Section 9.4.1.4).
    Modelling studies are also in moderately good agreement with
    observations during the first half of the 20th century when both
    anthropogenic and natural forcings are considered, although
    assessments of which forcings are important differ, with some
    studies finding that solar forcing is more important (Meehl et al.,
    2004) while other studies find that volcanic forcing (Broccoli et
    al., 2003) or internal variability (Delworth and Knutson, 2000)
    could be more important.”

    etc etc

  44. 94
    ilajd says:

    “Hansen et al are making a conservative best guess” Most honest sumation of climate modelling I have yet seen on this site.

    [Response: What climate modelling do you think Hansen et al (2009) result is based on? Unlike you, I have actually read the paper. - gavin]

  45. 95

    #63 John P. Reisman

    Sorry, I messed up the names on that last post

    That was too #35 Garry S-J and #54 David Erickson

    En addendum, I would add that ocean oscillations drive weather as it relates to regional climate and has an influence on climate in general (as a subsystem influencing a parent system), but I would not consider it a driver of ‘global climate’ per se, but rather a climate responder with inertial mechanisms that cause variation on the trend of positive, neutral, or negative radiative forcing path in relation to their respective spheres of influence.

    PS Maybe Yoda would have said of Pilmer ‘the irony is thick with this one’ instead of strong?

  46. 96
    Doug Bostrom says:

    Mike Strong 25 August 2009 at 10:16 PM

    “Get back to science. Evidence. Fact versus counter-fact. Peer review. Verification.”

    Add: “Avoid equivocation” and you’ve succinctly summarized RC’s method. All the desirable features you mention are components you’ll find in the “official” RC articles.

    Describing Pilmer’s controversial opinions as “bizarre” seems to me entirely in keeping with avoiding equivocation. When Pilmer flings himself off the precipice representing the edge of his expertise, he assumes bizarre positions while plunging downwards into the abyss of self-humiliation. Gavin procedes to show exacly how bizarre he appears using facts and evidence provided via peer reviewed work subject to verification. You ask, RC delivers. Where’s the problem?

    (Comment threads here are another matter entirely. These are presumably provided as a means of answering honest or at least sincerely presented questions. They seem populated mostly by a rabble of such as myself and are of questionable value, or at least fairly dilute in useful content)

  47. 97
    pete best says:

    Re #85 These deep time papers talking about the time after the PETM heat spike when India collided with Asia and began the weathering of CO2 which after 20 million years or so started the first glaciations of Antartica 34 million years ago and which to have become permanent around 15 million years ago and eventually led to glaciation of Greenland and Arctic sea Ice formation. The recent web site 350.org was founded on the basis of these papers by James Hansen and his co authors. It also potenitally sheds light on both short term and long term climate feedbacks and sensitivity and the image of earth sensitivity of 6C for a pre industrial doubling of CO2 in our world up from the original charney limit of 3C.

    The amount of CO2 beign emitted by humans on our timescales is so quick that no natural process will assist us in mitigating CO2 apart from the one that are happening today (Ocean and vegetation) both of which might be starting to absorb less leaving more in the atmosphere. Antartica according to the conservative estimates began to develop its ice sheets at around 425-475 ppmv of CO2 and the Arctic even lower which potenitally explains its reaction to 390 ppmv C02 today.

  48. 98
    Tim Osborn says:

    Re: Dave P (#81) and follow-ups #82, #84, #93:

    Tett et al. (2007: The impact of natural and anthropogenic forcings on climate and hydrology since 1550. Climate Dynamics 28, 3-34) reports some model-based results relevant to when natural and anthropogenic forcings might have influenced the warming since the “Little Ice Age”.

    Caveats: this is just one model and one estimate of past forcings.

    Some relevant quotes from our abstract:

    “These simulations suggest that since 1550, in the absence of anthropogenic forcings, climate would have warmed by about 0.1 K.”

    “Comparing the simulation driven by anthropogenic and natural forcings with the natural-only simulation suggests that anthropogenic forcings have had a significant impact on, particularly tropical, climate since the early nineteenth century.”

    “Changes in tree-cover appear to be responsible for some of the local and hydrological changes as well as an increase in northern hemisphere spring snow cover.”

    See our full paper here:

    http://www.springerlink.com/content/xg6116h0t30g26g2/

  49. 99

    #67 Joe Hunkins

    I took a look at your blog and read your July 23, 2009 post “Hot Air and the Co2 Problem”

    So you are saying that the top climate researchers at RealClimate are

    “waxing very philosophically about climate catastrophes and defending even the most flagrant propaganda points in the film “An Inconvenient Truth” and in the papers by James Hansen, NASA’s top climate spokesperson and an often cited proponent of pending climate catastrophes.

    and

    “Comments at RealClimate are even worse – personal abuse and reckless pseudo-science are tolerated when they support the case for catastrophic warming while reasoned questions are often moderated or attacked irrationally if they challenge the prevailing groupthink.”

    You also speak in the item how Bjorn Lomborg has been attacked as an “enemy of reason”

    I’m curious then if you can refute using ‘reason’ the assertions in my page on Lomborg, “The Copenhagen Distraction”

    http://www.ossfoundation.us/projects/environment/global-warming/myths/the-copenhagen-distraction

    You seem to be caught up in the scientists are making money on climate so they are biased in the results they are showing. You are presenting an inappropriate argument.

    Generally speaking, institution and government scientists make the same amount of money no matter what they study. Grant funding, unlike bailout money, goes to equipment and research work, not salaries and golden parachutes. That argument simply does not stand.

    Contrary to your points as noted:

    - MWP was not higher than today
    http://www.ossfoundation.us/projects/environment/global-warming/myths/images/temperature-records/2000yrs_models_ipcc_6_1_large.jpg/view

    - MWP presents indications of ‘potentially’ strong feedbacks (if you have a better notion of the mechanism please let me know, I’m willing to examine) to less forcing than today, thus indicating larger amplification potential than occurred during MWP, which would then translate deeper into the ‘climate catastrophe’ you seem to be arguing against.

    If, as you state:

    “the science behind global warming hysteria is much weaker than advertised”

    Please provide substance to the statement. I would like to know ‘just the facts’ you have collected.

  50. 100

    Mike Strong #91,

    perhaps you might want to consider that the text of the post was not written in the order it appears… that “bizarre” and “ridiculous” are conclusions drawn from, and after, looking at the questions.

    Why don’t you give it a try, as a scientist, engineer and gentleman? There’s only thirteen of them. Please let us know, for every question,

    1) whether you understand the question;
    2) if you do, whether you find it well-posed;
    3) if you do, your answer. And don’t forget to justify your assumptions and show your calculations and sources where asked to.

    I’m sure George Monbiot would greatly appreciate your valuable contribution.


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