Representative Concentration Pathways

by Judith Curry

“Representative concentration pathways” is the new phrase for what the IPCC used to refer to as “emissions scenarios.”  Lets take a look at the new RCP’s being used for the AR5.

The last time the emissions scenarios were updated was 2000.  For background on the IPCC emissions scenarios, see this previous post at Climate Etc.

From the CMIP5 web page

The CMIP5 forcing website links to this page for RCP, hosted by the IIASA.  this is the first time I have come across the IIASA, whose mission is

Founded in 1972, the International Institute for Applied Systems Analysis (IIASA) is an international research organization that conducts policy-oriented research  into problems that are too large or too complex to be solved by a single country or academic discipline:

  • problems like climate change that have a global reach and can be resolved only by international cooperative action, or
  • problems of common concern to many countries that need to be addressed at the national level, such as energy security, population aging, and sustainable development.

From the RCP website, links are provided to IPCC Expert Meeting Report on New Scenarios and Moss et al. (2010).

Version 2.0 of the database includes harmonized and consolidated data for three of the four RCPs. This comprises emissions pathways starting from identical base year (2000) for BC, OC, CH4, Sulfur, NOx, VOC, CO and NH3. In addition, harmonized well-mixed GHG emissions of the RCPs have been added for the period 2005 to 2100. Radiative forcing and concentrations of GHGs are given for the RCPs up to the year 2100, and are extended for climate modeling experiments to 2300 (ECPs). Wherever available, historical information is provided back to the year 1850.

Characteristics and guidance

The RCPs are not new, fully integrated scenarios (i.e., they are not a complete package of socioeconomic, emissions, and climate projections). They are consistent sets of projections of only the components of radiative forcing that are meant to serve as input for climate modeling, pattern scaling, and atmospheric chemistry modeling. As such, they jump-start the scenario development across research communities from which uncertainties about socioeconomic, climate, and impact futures can be explored. They thus constitute just the beginning of the parallel process of developing new scenarios for the IPCC’s fifth Assessment Report. By doing so, the RCPs aim at providing a consistent analytical thread across communities.

The RCPs are named according to their 2100 radiative forcing level as reported by the individual modeling teams. The radiative forcing estimates are based on the forcing of greenhouse gases and other forcing agents – but does not include direct impacts of land use (albedo) or the forcing of mineral dust.

The RCPs are not forecasts or boundaries for potential emissions, land-use, or climate change. They are also not policy prescriptive in that they were chosen for scientific purposes to represent the span of the radiative forcing literature at the time of their selection and thus facilitate the mapping of a broad climate space. They therefore do not represent specific futures with respect to climate policy action (or no action) or technological, economic, or political viability of specific future pathways or climates.

The RCPs are four independent pathways developed by four individual modeling groups. The socioeconomics underlying each RCP are not unique; and, the RCPs are not a set or representative of the range of potential assumptions. For instance, the RCPs with lower radiative forcing (RCP 6.0, RCP 4.5 and RCP 3-PD) are not derived from those with higher radiative forcing (RCP 8.5, or even RCP 6.0). The differences between the RCPs can therefore not directly be interpreted as a result of climate policy or particular socioeconomic developments. Any differences can be attributed in part to differences between models and scenario assumptions (scientific, economic, and technological). This is in particular relevant for scenario elements that are only indirectly coupled to the radiative forcing targets such as land use/land cover and air pollutant emissions.

The extension of the scenarios beyond 2100 will be done using simple algorithms intended for use as pathways to drive long-term earth-system simulation experiments and is not the result of integrated assessment analysis or modeling.

Overview in Climatic Change

An overview paper on RCP was just published in Climatic Change:

The representative concentration pathways: an overview

Detlef P. van Vuuren, Jae Edmonds, Mikiko Kainuma, Keywan Riahi, Allison Thomson, Kathy Hibbard, George C. Hurtt, Tom Kram, Volker Krey, Jean-Francois Lamarque, Toshihiko Masui, Malte Meinshausen, Nebojsa Nakicenovic, Steven J. Smith and Steven K. Rose

Abstract. This paper summarizes the development process and main characteristics of the Representative Concentration Pathways (RCPs), a set of four new pathways developed for the climate modeling community as a basis for long-term and near-term modeling experiments. The four RCPs together span the range of year 2100 radiative forcing values found in the open literature, i.e. from 2.6 to 8.5 W/m2. The RCPs are the product of an innovative collaboration between integrated assessment modelers, climate modelers, terrestrial ecosystem modelers and emission inventory experts. The resulting product forms a comprehensive data set with high spatial and sectoral resolutions for the period extending to 2100. Land use and emissions of air pollutants and greenhouse gases are reported mostly at a 0.5 × 0.5 degree spatial resolution, with air pollutants also provided per sector (for well-mixed gases, a coarser resolution is used). The underlying integrated assessment model outputs for land use, atmospheric emissions and concentration data were harmonized across models and scenarios to ensure consistency with historical observations while preserving individual scenario trends. For most variables, the RCPs cover a wide range of the existing literature. The RCPs are supplemented with extensions (Extended Concentration Pathways, ECPs), which allow climate modeling experiments through the year 2300. The RCPs are an important development in climate research and provide a potential foundation for further research and assessment, including emissions mitigation and impact analysis.

The complete paper is available online [here].

Tim Worstall @ Forbes

Tim Worstall has a post at Forbes entitled “Solving Climate Change.”  Worstall argues ironically that the solution to the climate change problem lies within the assumptions made in developing the RCP scenarios.

My general points can be made quite simply with the aid of two of their charts.

We know very well that there’s a connection between economic growth and population size. Richer countries on average have lower fertility rates so as the world becomes richer fewer children are born. So more economic growth leading to peaking and declining population really isn’t a surprise at all.

However, look at that light green line. The RCP 2.6 one, the “whew, we dodged it” one. The highest economic growth model leads to the lowest level of emissions considered. Less economic growth leads to higher emissions.

Note again that these are not my assumptions. They are those of the IPCC process. Which is something of a body blow to those telling us that we must cease economic growth if calamity is to be averted: the very assumptions built into the whole proof that climate change is something we should worry about say exactly the opposite. Economic growth is the way out, not the problem.

The second chart:

This is how much energy we’re going to use and where we’re going to get it from. We need to be more parsimonious in our use of energy, yes. We need to use less of it per unit of GDP (which is known as “energy intensity” and their desired decrease in that isn’t far off what the advanced economies already manage) but we don’t actually need to use less of it overall. Less oil, yes, but we can near double our energy consumption and still hit that “we missed the problem” sweet spot. It’s also amusing to note what a small role for solar and wind power is necessary to hit that target.

Again, I want to point out that these aren’t my assumptions, they’re not made up out of whole cloth by some denialist, these are the assumptions which the very scientists who tell us about climate change themselves think are the driving forces and likely outcomes.

Which leads to a very interesting conclusion indeed. We don’t have to stop economic growth at all, we can quite happily have around the same amount of it that we had in the 20 th century. So that’s a large number of the Green Miserablists shown to be wrong. We don’t have to reduce or even severely limit our energy consumption: we just have to get the growth in our consumption from other than the usual sources. A large number of the Energy Miserablists shown to be wrong there too.

Or, to boil it right down, the IPCC is telling us that the solution to climate change is economic growth and low-carbon energy generation.

JC’s 5 cent solution

I don’t have a solution to the climate change problem, but I do have a proposal for developing emissions scenarios.  This goes back to my previous post on emissions scenarios (the discussion on that post got hijacked by my reference to the precautionary principle.):

So how might the IPCC proceed in this regard?  First, the complicated models that develop emissions scenarios don’t seem to be necessary for forcing the climate models; simply specifying a value of CO2 concentration (with the other greenhouse gases and anthropogenic aerosol)  at 2100 along with a simple time trajectory is sufficient to force the climate model. The value of the emission models would be in establishing the “barely feasible” worst case scenario and the conditions under which this scenario might be created, and in rejecting more extreme scenarios.

The individual scenarios in the IPCC scenario suites (both SRES and AR5) are implicitly regarded as equally plausible.   Armed with Kaya’s identity (or the more sophisticated emission models), modal falsification, and the possibility distribution, it seems that there is a feasible and credible method for establishing the relative likelihood of the different radiative forcing scenarios.  Inverse modeling using Kaya’s identity could identify the number of different pathways among the various combinations of possible input variables that could result in a specific radiative forcing scenario (say +/- 10%) .   The number of different combinations of variables that would produce a particular forcing scenario would provide some sense of the likelihood of that scenario (with the barely feasible scenario having only one combination of variables, and so being the least likely).  A further embellishment could be provided by ranking the input values for at least some of the input variables in terms of their likelihood (from necessary to barely feasible).  This would provide a rationale for the size of the bar (on the possibility to necessity scale) related to that particular scenario.

This would be much simpler and cover a broader range of possibilities for understanding the model sensitivity to different magnitudes and rates of atmospheric composition change.  The overwhelming uncertainties associated with inputs to the models of representative concentration pathways don’t seem to me to justify much else.

168 responses to “Representative Concentration Pathways

  1. Tim Worstall is wrong to compare the RCP scenarios. They were drawn using different models. Any comparison is thus inconsistent. I don’t blame Tim for this. Van Vuuren et al. encourage silly inferences.

    Judith is right. There are plenty of observations on population, economic activity, energy use, and emissions. These data can be used to validate models and assign relative probabilities to the scenarios. In fact, this has been done. Google Books “Economic Scenarios for Global Change”. The application is to the SRES scenarios, but the same models were used for the RCPs.

    The IPCC cannot claim not to know this, as shown here:

    • All of the new phrases and model modifications will not change the fact: There is no valid empirical evidence for CO2-induced global warming.

      IPCC has simply confirmed that it is Big Brother’s tool of propaganda.

      I regret to speak so negatively about this part of the UN organization, but scientists have a responsibility to speak out when science is abused in this manner.

      With kind regards,
      Oliver K. Manuel
      Former NASA Principal
      Investigator for Apollo

      • Why is government science used to deceive? The answer may be revealed later today in a five-video summary of events I personally witnessed over the past 50 years, 1961-2011.

        Prior to and during World War II, psychology was used by governments to organize citizens against a common enemy – Jews, Natzis, etc.

        The victor was decided by the branch of science that produced an “event” that literally vaporized Hiroshima on August 6, 1945 – scaring politicians worldwide.

        [By coincidence, the scientist that became my research mentor, a faculty member at the Imperial University of Tokyo in 1945, went to Hiroshima to find out the nature of the frightening nuclear “event.”]

        After WWII, psychology continued as an important tool to influence “value systems, belief systems, emotions, motives, reasoning, or behavior” [].

        Our government openly formed the Psychological Strategy Board on April 4, 1951. Henry Kissinger worked there before becoming Secretary of State and National Security Advisor to Richard Nixon in the 1970s.

        Nationalism re-emerged as the Cold War, dividing the globe between communist East and capitalist West. Nuclear weapons became more destructive and difficult to transport to the other side of the globe.

        Did Kennedy announce the “Apollo” program on 20 April 1961 to show that the USA could transport a heavy, bulky H-bomb around the globe to Moscow?

        I don’t know. Ten years later Kissinger convinced Chinese leaders to join a worldwide effort to avoid the threat of mutual nuclear annihilation by ending the “space race” and uniting nations against a new common enemy – “anthropologic global climate change.”

        On January 5, 1972, President Nixon announced,

        “I have decided today that the United States should proceed at once with the development of an entirely new type of space transportation system . . ,” [Claud Lafleur, “No More Dreams, Mr. President”].

      • I just finished this summary of my career:

        A. Scientific Genesis Videos:
        1. Science vs. Propaganda

        2. Origin of the Solar System (1975)

        3. The Iron Sun (1983)

        4. Neutron Repulsion

        5. Global Warming Scam (2011)

        B. Text Summary in Dropbox:

        The Bilderberg Sun, Climategate and Economic Crisis

        Today all is well,
        Oliver K. Manuel

  2. Can anyone explain to me of what use any of these models and scenarios serve? It seems now scientists can’t even draw conclusions on what they physically observe, let alone assign any credence to what they invent. IMHO we are all a witness to the most monumental waste of intellectual and financial resources in history. That it is possible because of my dimes is galling.

    • It is in the response time of methane. Methane is highly reactive compared to the relatively inert CO2 so that Methane levels can dampen quickly to equilibrium levels if the emission sources trend to some asymptotic level.

      That is why I said below in this thread that these residence time arguments are crucial to understand what is going on.

    • The purpose of these RCP’s is the same misdirection that a magician employes. It is to focus attention and debate away from what is really important.

      This is an exercise in forced anchoring. [1] These authors assert that four independent groups (who’s individual qualifications are unknown to me) create four independent — (“can’t call them scenarios – lets call them ‘pathways’) that are of “equal probability”

      Folks, my BS detector just pegged off scale. I don’t have time to illuminate all my objections, disagreements and questions. I smell a rat and an attempt to restrict the ground of debate and investigation.

      Equally probable my foot! Just look at the Oil Consumption vs Year graph with the RCP8.5 implying that oil consumption can triple in 60 years. I work in the industry and I don’t know anyone who thinks that is possible. Yet somehow if we can triple production, it will fall off a cliff in the next 25 years. Yeah, they are equally probable pathways if and only if the probability is zero.

      Methinks we should send the RCMP after these RCP creators.


    • Chief Hydrologist

      The problem of emissions is not the same as the problem of concentrations. Emmission trajectories are frought with the difficulties especialy as to economic and technological futures. The concentration problem brings in natural variability in the carbon cycle – orders of magnitude more complex.

      • On “economic and technological futures”, see my parallel post Uncertainty of economic projections highlighting poor accuracy of economic projections. Furthermore, we are in the midst of a major transition from cheap abundant transport fuel to scarce expensive transport fuel (until we see some gamechanger technology breakthroughs.) IPCC has not addressed the underlying systemic economic bias, nor the more serious major declines in Energy Return On Energy Invested (EROEI).

      • The concept of price being a function of available supply vs. current demand seems to come to mind. Not really all the difficult of a concept.

  3. @Judith,

    Do you have some way to decode this mumbo-jumbo ?

    Why can’t these people write what they mean in plain straightforward language?

    Instead we read

    They therefore do not represent specific futures with respect to climate policy action (or no action) or technological, economic, or political viability of specific future pathways or climates.

    It looks like they just invented some numbers. Is this correct ? Why not just come clean?

  4. I googled a couple of technical terms on this site “CO2 residence time” and “convolution”. Not much on these topics, except for some sporadic mention in the comments (from me included).

    Understanding and establishing pathways is the central behavior that most interests me. The initial pathway for CO2 is fossil fuel emissions. There are OK data sources for this long-term function, the best ones coming from oil depletion analysts. How the emitted CO2 gets convolved with the residence time response function is the second significant part of the pathway. Maybe someone wants to do the fundamental ground work explaining what goes on with respect to this time behavior. This is the deep behavior that no one wants to look at, even though it involves just some straightforward math.

  5. Human being are complex, and from time to time, they malfunction; a process we call sickness.
    Now why have these modelers not applied their forensic approach to medicine? They could work out the various ‘forcing’ for various biological relevant species, Na/K/Glucose/temperature/blood flow, e.t.c. and then program a computer to spit out the optimum therapy, designed to restore the body to ‘balance’.
    These people could clean up, we pay a lot of money to restore ourselves to health.
    So why do they not apply their finely honed computing/modeling skills in other areas?

  6. Judith’s good suggestion of driving the GCMs with simple CO2 trajectories is similar to one way in which we in the climate modelling community are using the RCPs. We’d driving the models with the GHG concentrations, and using carbon cycle models within the climate models to simulate the natural carbon fluxes (atmosphere-land and atmosphere-ocean), which themselves are affected by the simulated climate change, and the residual needed to balance the carbon budget then indicates the anthropogenic emissions that would give the prescribed scenario of CO2 rise.

    Then it’s over to the economists etc to figure out what socio-economic pathways would give those emissions.

    So it’s very important that the climate model simulations driven by the RCPs are *not* regarded as predictions – just scenarios.

    • Hi Richard, thanks much for your comments.

      • Hi Judith, can I borrow your special reading glasses this weekend.

        You know – the ones that have plain english sub-titles. :-)

    • Will the AR5 IPCC report cover how likely these scenarios are? Or is it left up to the reader to guess or insert their own value judgements? For example, given how often we are told that peak oil has arrived (sooner or later those that say that will have to be right), is it genuinely feasible that we can triple oil extracts? Similarly around use of renewable energy sources (consider the recent controversy about the IPCC renewables report).

  7. It seems overly difficult for many to understand the idea of these pathways.

    Their purpose is to provide four reference points that can be used on the other hand by climate scientists when they create projections for the future climate. In this way the climate scientists can tell that my climate model produces the following four projections, when the four pathways are taken as input.

    On the other side environmental economists can study their models for the development of human societies and then tell, how their model relates to these four pathways. Is the model going to produce emissions that agree reasonably well with one of the pathways, or in which way it differs from all of the four pathways.

    The purpose is to allow these two activities to do their work and help then in providing some link between the economic models and the climate models without the need that every study must include both.

    It’s certainly true that the scenarios will be both misused and criticized on false grounds. The misuse of results is the largest problem of everything related to IPCC, but dismantling the IPCC would not prevent misuse of science.

    • Marlowe Johnson

      Well said Pekka.

    • Sorry Pekka it is not global warming or climate change which is a problem, the problem is the IPCC, which quite frankly is a joke. But of course it is no joke when the Independant Panel on Crippling Countries continues to, well, attempt to cripple countries?

    • “but dismantling the IPCC would not prevent misuse of science.”

      It would prevent the misuse of science in their particular case. This is obvious to anyone but the brain-dead.


    • You want complex?
      I am trying to disentangle hormone/hormone receptor effects, this bit is made as simple as possible;
      Test -> E2 (Aromatase)
      Test -> DHT (5α-reductase)
      DHT -> 3,17diol (three known enzymes)
      E2 is a agonist to ERa, ERb1 to Erb5; Tissue specific distribution.
      Test and DHT are agonists to AR and antagonist to ERa, ERb1 to ERb5
      3,17diol agonist to AR, ERa, ERb1 to Erb5

      All have different binding constants for all 7 common receptors,
      Androgens/estrogens change the levels of the receptors.
      ER’s bind as dimers, so you can have (ERa)2, ERaERb and (ERb)2, with different promoter/inhibitor activities.
      There are at least 24,000 androgen receptor binding sites on the human genome.
      The degree of DNA methylation alters the binding affinity.

      People who work with an actual complex system, a system that we can actually manipulate, as system that we have the ability to add and subtract genes, a system that allows metabolic quenching so we can kill the system and then measure the levels of metabolites and protein levels, in this system, NO ONE would be arrogant enough to pretend that it can be modeled from first principles.
      You cannot model a complex system if you don’t know the fluxes in steady state.

    • Combining climate models created by CAGW consensus scientists, with econometric models created by “environmental economists.” Gee, I wonder what the chances are of any combination of the above resulting in anything other than a recommendation for what the consensus progressives have been recommending all along.

      For some reason, the phrase “the blind leading the blind” comes to mind.

      The only models I trust less than unverified, unvalidated climate models, created by CAGW true believer climate scientists, are any models by any economists.that use those climate models as their starting point.

  8. What I don’t get is this:

    The breakdowns of energy sources are…

    Coal — regions that produce it want to, but folks that don’t live near it don’t want it in any part of our energy picture going forward.

    Oil — regions that produce it want to, but folks that don’t live near it don’t want it in any part of our energy picture going forward.

    Natural Gas — Environmentalists aligning with NIMBYs to prevent new sites from getting off the ground near where they live.

    Nuclear — Environmentalists aligning with NIMBYs to prevent new sites from getting off the ground near where they live.

    Biomass Energy — Environmentalists aligning with NIMBYs to prevent new sites from getting off the ground near where they live.

    Wind Energy — Environmentalists aligning with NIMBYs to prevent new sites from getting off the ground where they live.

    That just leaves solar and geothermal energy … and that isn’t going to be enough, is it.

    How can all these studies be generated and pushed forward be taken seriously if NONE of the people involved in the advocacy are willing to live next to (and share space with) any one of the various energy infrastructures that we’re going to need to have more of in order to succeed in these goals? A distressing irony.

    • It seems another exercise or study of virtually no value at the end of the day.

      As has been discussed at this site previously, no matter how much people (or certain climate scientists) fear additional atmospheric CO2, humans are not going to lower their total emissions for several decades. Spending resources endlessly studying different potential emissions scenarios is certainly a non-value added exercise. Until alternate energy production is fully economically viable that is simply a fact. The probability of this situation being certain is greatly increased due to the economics in Europe and the US.

      Nations/people will adapt to a slowly changing climate. Those nations that build proper infrastructure to prepare will adapt better than those that allocate resources elsewhere. Worldwide economics (imo) will force countries to look after their own interests to an increasing degree in the future and poorer countries will need to fend for themselves to an ever increasing degree over the next few decades.

      • This work is not an exercise of study. It’s just a step of defining four concepts that many scientists consider useful or even necessary for the planned work.

      • Pekka- you believe it is, I believe it is a waste of effort and of no value. I would most certainly not want to fund anyone in the US to perform such a study

      • I wrote that many scientists consider it useful or even necessary to have such reference pathways available. I didn’t say anything on what I think otherwise about them.

        That work was not a study. What it did was to choose four pathways different enough to cover the range of interest to most of those of need of such reference pathways. That’s all, and they try to make it understood that that’s indeed all.

      • nandhee jothi

        It is no value of anybody…. other than for those that are making a good living with this vile, “screw the folks” racket

      • Their model cranks out the projection that maximum economic activity minimizes CO2 emissions; the only way this can happen is if the most efficient energy generation sources are used. That probably means nuclear at the end of the day. On the other hand, the “pathways” may be rigged to tie prosperity and “renewables” together.

        The divil is in the details.

      • humans are not going to lower their total emissions for several decades.

        The cost of extracting Central Appalacian Steam Coal increased 17% in the last 12 months according to todays Wall Street Journal (subscription required – sorry)

        Coal power has been losing market share in the US for 10 years.
        The trend has continued for the first 4 months of 2011.

        Then we have these other trends…Vietnam is about to become a net coal importer. Indonesia…the worlds largest coal exporter is working hard on making it’s coal more expensive to export…

        The ‘end of cheap coal’ may be closer then anyone imagined.

        Humanity will lower emissions when ‘save the planet’ and ‘save my wallet’ both dictate the same action.

    • Good listing of some of the underlying pathology of AGW.

    • Scientists can determine any percetage and combination pathway they want, but they haven’t run it through any sort of sociology or psychology model– even among their own supporters.

      Environmental advocates believe that it is through the rapid deployment of these technologies and energies that the costs will go down– and I think this DOES have some merit, but two (serious) problems remain undiscussed in the advocacy community:

      1. In order for this to happen, we really need a China-like goverment structure that places energy infrastructure through edict, and allows no due process for appeal. It is this appeals and site litigation process that is a major contributor for cost overruns or infeasibility (nevermind that the most common exploiters of these processes are those who commonly self-identify as ‘environmentalists’).

      2. Environmental advocates themselves cannot agree on a SINGLE deployment location of ANY energy source listed above, with the exception of solar and geothermal power. If this can’t even happen within the advocacy community that understands the value of renewable energy, how can you expect it to be easy for people who don’t to see something like a biomass facility or a nuclear powerplant be installed nextdoor. Environmentalists can’t even get on the same page wrt Yucca Mountain. It’s just not possible that all their talk about rapid mass deployment has grounding in reality– and they themselves are part of the reason why. I, for one, have TWICE tried to help my community get a biomass facility in-place in my community when it came up for a vote (my own wife is still mad at me for it)…but if those who are environmentally conscious want to see these renewable energy facilities get deployed, they had better stand and be counted as ones who will accept them in their own backyards.

      • You make me realize another trick used to justify renewables costs. While they extrapolate implausible cost reduction curves for their pet “technologies”, they keep all alternatives fixed or growing in cost, presumably because they are “mature” and not subject to improvement.

        Nothing could be further from the truth. As a post on Jo Nova’s site pointed out recently, simply upgrading and replacing coal generators with the latest efficient burn versions slashes their emissions 30% (or 13% of the Australian total) at about an order of magnitude lower cost than a maximum renewables effort which cuts emissions by about 6%.

        Walls built of BS-bricks everywhere you turn in the AGW compound.

  9. Well, well . . . “RCP” . . . a nice, shiny new TLA.

    That should put the IPCC back on track to being an honest assembly of noted scientists doing stellar work instead of the stinky agglomeration of Greenpeace staff republishing fund raising agitprop designed to obfuscate and scare people that it is now.

    Yup . . . should work.

    • Fred:

      I see that you know what a TLA is – did you work around Intel in the 1980s? I understand that the term was coined by folks at Intel.

      I worked for an Intel distributor in the day.

      • For those not “in”, TLA is a Three-Letter Acronym for “Three-Letter Acronym”, one letter shorter than those flabby FLABs (Four-Letter ABreviations).


  10. “I don’t have a solution to the climate change problem”
    JC of course you don’t because it is impossible to have a solution when there is no problem? :-)

    Despite the newsciencespeak it is clear that all is based on models, so what is wrong with observational data? Man made CO2 emissions continue to rise global temperatures continue to fall?

    I think if I were a professional scientist outside the community I would be really concerned at the bureaucratisation created by the community to hide their failings. I think the only law the community understand is this one:-
    “Work expands so as to fill the time available for its completion”
    ref Parkinson

  11. So how might the IPCC proceed in this regard? First, the complicated models that develop emissions scenarios don’t seem to be necessary for forcing the climate models; simply specifying a value of CO2 concentration (with the other greenhouse gases and anthropogenic aerosol) at 2100 along with a simple time trajectory is sufficient to force the climate model.

    The simplicity of that approach appeals to me, but wouldn’t that neglect the other emissions listed above: “BC, OC, CH4, Sulfur, NOx, VOC, CO and NH3”?

  12. Perhaps a review of the assumption that grants the models credibility needs to be revisited.
    Two important claims of the AGW community have yet to be proven:
    1- that we are dealing with a climate that is producing dangerous weather any differently than it has in the past.
    2-that mitigation of CO2 will keep us from experiencing a climate more dangerous than the present in the future.
    This is followed by the corollary problem of mitigation, that no one has offered a realistic mitigation technology that actually achieves CO2 reduction and does not utilize nuclear energy.

  13. Simply put, these are just like case studies that MBAs do all the time. It’s probably worthwhile for short term. However long term projections to 2100 are useless. The robots will be more concerned about ET by then and we will have the greenest planet ever with all that extra heat energy and CO2. The new Planet of the Apes movie is as likely scenario as anyone’s

  14. The ‘socioeconomics’ of global warming have eclipsed the scence of global warming. For example, consider the use of the analogy of a ‘greenhouse’ to connote a problem for humanity.

    We all know that a cup of oil contains more energy than a cup of air or a cup of wind. A greenhouse proves that we can better harness the energy of the sun for the betterment fo humanity by eliminating wind–the CO2 that gardeners use to fertilize a greenhouse is irreleveant to the greater heat within a greenhouse compared to the air outside it.

    Schopenhauer obseved that the teeth are objectified hunger. We also can apply a rigorous objectivity to thoughts that have taken on a substance beyond their service to the human that is the bearer of such thoughts.

    So, let’s be objective about Western civilization’s feelings about climate change. It is now clear that in Western civilization, fear of global warming is fear of individualism.

  15. Another perfect example of disapproving of dinner guests but being overly polite because of social customs when you are in their home. Why does JC she pander to co2 regulations as a “precaution” when there isn’t the science to back the self-serving claims of statism that there is a problem?

    She is too linked to the consensus even while dissenting on the obvious hyperbole we as a society have been forced to endure. She still wants dinner invitations or she is just culturally too inside the same self-identification of the eco-green-academic left. “No-labels” is a common weasel word structure for not revealing your true cultural and political I.D..

    • cwon14,
      There is no immaculate solution to the problems the AGW community creates. There are only the tried and true tools of sticking to the truth, maintaining critical thinking skills, resisiting going with the flow and encouraging incremental steps. Just two years ago the typical description of the IPCC was ‘gold standard’. Very few informed people would describe the IPCC like that today. Instead the AGW community is playing games, like Yoram, or defending the latest discovery of a growing list of shoddy or corrupt IPCC practice as ‘not effecting the science’.
      Two years ago, it seemed inevitable that some sort of so-called carbon trade or carbon tax would be in force in a matter of months. Today pushing that tactic puts the politicos pushing it at peril of their careers.
      Two years ago Gore was the toast of the town, haughtily ridiculing skeptics, talking about his fantasy tiping points and an Earth with a fever. Today Gore’s whiney foul mouthed diatribe against skeptics and how he cannot push his AGW vision without dispute has gone viral on the internet.
      Skeptics are winning because the AGW community was wrong to claim that we are facing or will face some grave climate crisis, and no matter how many studies believers come up with to claim otherwise, the climate continues to fail to cooperate with the apocalypse.

      • That aside Hunter, how do you explain JC’s critical input of agw extremes on the one hand and her appeasment of warmists on the other?

      • My shot: Dr. Curry has selected “On Conflict Tribe Wins” in her reconcilliation options. ;)


      • Your malaprop is too kind: “a growing list of shoddy or corrupt IPCC practice as ‘not effecting the science’.” That would mean “not performing or implementing the science”.
        What they claim, of course, is that it is not “affecting the science”. In reality, it is integral to IPCC science, which would collapse without shoddy and corrupt practice.

  16. Hold on. I’m confused.

    From WUWT:

    In the IPCC modelling the set up with the most economic growth has the least emissions.

    According to many of my friends here at Climate etc., the IPCC is nothing other than a collection of frauds working in cohoots with eco-Nazis in a plot to make the world a socialist, Luddite, paradise. The entire end goal of this cabal is to reverse any economic progress and have us all back living in caves warmed by geo-thermal emissions (the smoke from wood fires releases too many particulates).

    There must be some mistake. According to many of my Climate etc. friends, there is no way that the IPCC could produce any material that indicates that economic growth is good.

    Gee. Either WUWT has wrongly concluded what the IPCC’s models show, or the constant ululating about the fast left-wing/socialist/eco-Nazi/climate scientist conspiracy is much ado about nothing.

    I wonder which it is…….

    • Yet you claim to like the IPCC. You should be welcoming some common ground to share with the skeptics.

    • Maybe quote mining and taking things out of context doesn’t lead to a logical conclusion. Regardless of what you read at wuwt what makes you think promoting inefficient politically driven green junk solutions leads to “more growth”??

      Go ask the Soviets.

      • Maybe quote mining and taking things out of context doesn’t lead to a logical conclusion.


        Are you saying that I haven’t read post after post explaining how the IPCC is part of a cabal between climate scientists and eco-Nazis to retard economic growth?


        Here’s a nice post from WUWT.

        All attempts to slow down CO2 are economic stoppers. That’s their whole purpose, for heaven’s sake!

        Are you saying that post isn’t characteristic of many similar posts I’ve read here at Climate etc. (not to mention WUWT?)


        Why would a cabal between people whose “purpose” it is to stop economic growth publish studies that show an inverse relationship between economic growth and increased emissions.

        Oh. Right. “Quote mining.”

      • I’m sure you’ve read “post after post”, but you use the phrase “many of my friends here at Climate etc” without actually saying that they are the same “many”.

        Many of my friends are men, and many are women. That doesn’t make them hermaphrodites. You need to be more specific to have a point.

      • Oops, I meant to say you use the phrase *twice* without actually saying that it refers to the same people.

      • Dagfinn – I think that you’re being a bit more literal than my post intended.

        I’m not sure I understand your post – but let me try to clarify my previous post.

        When I say “friends,” I mean in a virtual sense, and use the term “friend” to tweak some folks (I’m wouldn’t doubt that many of them wouldn’t be friends with a socialist/eco-Nazi/true-believer/warmist/dissembling/”retarded”/pissant leftist such as myself).

        I have read many posts at Climate etc. that postulate a vast left-wing, socialist, eco-Nazi, climate scientists conspiracy intended to use the theory that GW is 90% likely to be A as a cover for hidden intentions to retard global economic growth and to punish the U.S. for its evil capitalistic ways. If you doubt that such posts have been made – you’re entitled to claim otherwise. If you’re asking me to quantify “many,” let’s just say multiple such posts on virtually every thread. If you’re asking me to quantify the posts or provide examples – I’m not inclined to take the time now, but I’ll borrow an old New England saying, if you don’t like the weather [or in this case, the lack of conspiracy-denouncing posts] now, just wait a minute.

      • Joshua, those posts do indeed exist. To say just how many you will need to refine your specification. Posts which include all the claims you list are probably zero. Posts that go to the core of your list no doubt number in the hundreds, out of roughly 100,000. Moreover there is an element of truth in these extreme claims, so that percentage is fitting. You tend to ignore the simple fact that skepticism embraces a wide range of beliefs, as does warmism.

        Variation is not hypocrisy, your frequent assertions to the contrary notwithstanding. To use your language, there are many tribes here.

      • Steven Mosher

        I think he wants to avoid the real issue and make the issue some of the crazier commenters that reside here.

      • Indeed Mosh, there appears to be an underlying principle that the extremists on one side cite the extremists on the other side, to make their case. An elegant symmetry in its way. Someday we will understand all this, once the science of public debate has matured. Polarization in the face of uncertainty is a fascinating topic, the stuff or wars and all that. Not a trivial topic. Unfortunately people can’t seem to study the climate debate without taking sides, as the sociologists discussed here all seem to be doing. Where are the anthropologists when you need them? They study tribes, right?

      • David. Hans Von Storch actually has an anthropologist working with him. Guy showed up in Lisbon. Fascinating take on things. I think I ended up in the middle because looking at both sides I saw that the force was deep with both extremes, and that force was crazy. Of course, crazy can be right about the science, but the methods of debate are deeply crazy. The patterns of argumentation reminded me of academic and philosophical debates, and surprisingly epistemology has a place again. practical problem solving and conflict resolution.. not on the scene yet. Crazy wont allow what may just work.

      • Mosh, I hope you are not saying that philosophical debate is crazy. It is quite true, and very important, that the climate debate is epistemic at heart. The concept of a balance of evidence is epistemic, and not well understood. As for practical problem solving this is not that kind of problem, because the issue is whether there is a problem?

      • You need to be partisan blind to not ralize how powerful the political narrative is in both science and education in particular, the Utopianism that logical fields can’t go down the same ratholes as humanities is easily debunked;

        Try “social justice math” for example;

        “Did you know that child slavery is a common practice on cocoa farms in Ivory Coast, the world’s biggest supplier of cocoa beans? Don’t feel too bad if you didn’t know – I didn’t either until a few days ago. But now I know and so do you. I’m a huge chocoholic but now there is no enjoying a non-fair trade bar of chocolate, knowing a child may have been forced to pick the beans. There’s no going back. … Picking cocoa beans is hard and dangerous work. It takes 400 beans to produce a pound of chocolate so these kids work long and hard to get enough cocoa for even a few bars. No wonder most chocolate bars are so cheap and fair trade chocolate is so expensive.”

        Climate scence from the Phil Jones, Michael Mann, Jim Hansen, U.N., Greenpeace division is the fruit of the same tree Joshua. How is this so hard to accept or “deny”?

      • Joshua,

        Are you trying to sustain a myth that by in measure the community that has had the most impact in climate science alligned with the U.N. isn’t part of the eco-left and generally socialistically inclined?

        “Why would a cabal between people whose “purpose” it is to stop economic growth publish studies that show an inverse relationship between economic growth and increased emissions.”

        You haven’t noticed that the basic promise of socialist results by in large fail? Stalin and Mao’s five year plans next? What would you expect the eco-left to say about renewable energy goals? That they are huge wastes of capital and focus better left to markets?

        Try again Joshua, the “studies” are every bit as biased as the “science”. Retarding economic growth is by in large a sad result of the anti-business and freedom nature of the the modern left.

  17. Yet you claim to like the IPCC.


    Please explain.

    • If you like something that is now irrelevant does it make you happy or sad. Since when has the IPCC actually impacted behavior to any meaningful degree?

    • So you don’t like the IPCC?

      • Wait. First you said I claimed to “like” the IPCC, and now you’re asking me whether or not I “like” the IPCC?

        You mean that you draw silly conclusions (what does “liking” have to do with anything?) before you have the information needed to support those conclusions?

        I’m shocked. I thought that drawing conclusions without supporting data got you all “concerned.” How would that “concern” accord with your behavior?

        Try reframing your question in a way that make sense (I neither “like” nor “dislike” the IPCC), and I’d be happy to answer.

  18. If you like something that is now irrelevant does it make you happy or sad.


    What are you boyz talking about? Please explain. Who said anything about “liking” the IPCC? Me? Where?

    • Joshua,
      Do you defend the IPCC? Do you agree with their work product, do you think they are the gold standard of climate science?

      • Hunter –

        I neither “agree” or “disagree” with the IPCC’s “work product.” I read some of their work product, and I read some analysis of their work product from different perspectives. I see no more reason to categorically reject their work product than I see reason to categorically accept their work product. I’m skeptical of people who categorically accept their work product just as I’m skeptical of people who categorically reject their work product.

        I think that the IPCC broadly represents the perspective of a considerable majority of people with highly developed expertise on the topic of climate change. That, in itself, does not mean that “they are the gold standard of climate science,” however, I would imagine that some individuals who are part of the IPCC produce “gold standard” work (not having expertise myself on the topic, it is hard for me to comprehensively evaluate their work).

      • Joshua,
        Then we are in agreement, in principal.
        I think the IPCC economic analysis is realistic to the extent that it recognizes the need for economic prosperity, even though it is in the context of a naive and impossible beleif regarding renewable energy.
        You, I am certian would agree with other parts.
        What parts do you not agree with?

    • Joshua–sorry for the misunderstanding. I am not writing that you like or dislike the IPCC. I am simply writing that I believe the IPCC is now virtually irrelevant because the entire concept of “halting CO2 emissions” worldwide is DEAD. People obviously keep writing about the idea, but there is a near ZERO likelihood of any significant change due to the reality of economics.

      People who have a completely different view of how they believe the world should be different may hope or want these changes but they are not going to happen. I just hope the US stops spending funds on the topic as quickly as possible.

      • Rob –

        To riff on Mark Twain, I think that pronouncements of the death of “halting CO2 emissions,” are greatly exaggerated.

        “Halting” CO2 emissions is a bit of a straw man. Most folks involved are focused on reducing CO2 emissions. As such, limited progress is being made right now for myriad reasons – but that doesn’t mean that given continued anomalous climate change and continued accumulation of evidence linking climate change to CO2 emissions, and continued technological innovation, there won’t be greater progress in the future.

      • Joshua- If 40 years from now CO2 is at 550ppm vs 500 ppm does it matter? there is no mitigation strategy that will have any significant impact on this situation overall.

      • I agree, Joshua, although not for the reasons you give. As a political movement AGW has a huge and powerful base. This fight is not over, it is just resting between rounds.

      • David

        I agree that there will continue to be lots of talk on the topic and that there will even be projects to reduce CO2 emissions in specific areas that get implemented. Overall, I believe that the IPCC is meaningless because they will have no role in the funding of anything and not much will be funded overall.

        Ultimately, it will come down to specific projects that either will be implemented (or not) by individual nations and nations that have no money tend to not implement costly projects of marginal hypothetical benefit.

      • Rob, are you not aware that the US EPA is moving forward to regulate CO2 emissions and that their actions are based on the IPCC. If you think the IPCC has lost its power you are reading too many skeptical blogs. It is true that the public is finally aware of the debate, and that the economic downturn has put the political issue on hold for now, but that is about as far as it goes. The IPCC still holds center stage, in mainstream media and national policies.

      • David

        Yes, I actually follow what the EPA is doing pretty closely and I believe that the debate in the US will be independent of what the IPCC does. The EPA had initially been looking at implementation of regulation very quickly, but due to economics the measures seem be undergoing more reviews and delays.

        In the US today, implementation of any measure that threatens US jobs or costs funds will (imo) be delayed and delayed. This is especially true of the time between now and 11/12 since the current administration will need to appeal to middle America to be reelected.

      • I think we are looking at different timescales. I am thinking in terms of decades, not years. The economic situation is temporary. It probably does not change the long term balance of political power.

      • David

        I believe the economics in Europe are fundamentally flawed and the US is racing into the same situation if not worked pretty quickly. Demographics in Europe and the US are going to make very little money available for things other than supporting a retired population. There are simply a lot of aged people who will need to be supported and not enough people to support them. In both areas the economies have been supported by immigration, but in both areas the local populace is now concerned by this uncontrolled immigration and the rapid change to their culture.

        Over the course of decades I am not worrying about the issue as alternate energy sources become economically viable they will be adopted. In the US, I am not worried about IPCC because they do not make the decisions; Congress and the executive branch make the decisions. I agree that the EPA will force the adoption of some CO2 reducing activities. I believe these will turn out to be fairly token and or political in nature and will not ultimately result in any significant reductions in CO2 or costs to the US economy.

        The idea that the US is going to fund other nations CO2 reduction efforts is one I find “beyond belief”. In spite of the hopes of people like Martha, I just do not see that happening to any significant degree when funding is as limited as it will be for the next several years.

      • Handwaving nonsense. All by themselves China and India will blow the roof off any and all emissions projections now being bandied about. The only technologies that will impact that are those that are significantly cheaper AND readily deployable for vigorously growing industrial societies.

        It is a curious incongruity that the prophet of “ending industrial society”, Maurice Strong, has long taken refuge in Beijing, which is en route to being the hub of the greatest surge of industrialization since 19th C. Britain, scaled up 10 to 100X. Perhaps he’s onside with their preference for which industrial societies are to be deconstructed.

      • “Handwaving nonsense. All by themselves China and India will . . .”

        Small error in punctuation.

        Handwaving nonsense: All by themselves China and India will . . .”


      • Nope. Fugged, as per your usual.

  19. The idea of these “pathways” or the older SRES scenarios to have “equal probability” or that we are “ignorant” about their probabilities is a result of ignorance (or lack of competence) on the part of authors of those pathways or scenarios.
    In the case of SRES, scenarios used as exogenous (and separate) inputs population growth and GDP growth, This resulted in several inconsistencies, because population and income interact and their growth paths cannot be assumed separately. For instance, the rapid population growth of A2 is incompatible with A2 economic growth, which would induce lower fertility (besides, of course, the fact that the “high” variant of population growth used in A2 has been long superseded by lower “high” projections from the UN, and besides the fact that UN demographic projections also neglect correlation between population growth and socioeconomic development).
    In the case of RCPs, the initial idea was to posit just an emission trajectory, which could potentially be produced by a variety of socioeconomic developments (higher or lower pop growth, higher or lower GDP growth, different combinations of energy sources). Once one attempts to create socioeconomic and energy hypotheses which would generate RCP trajectories, it is easily discovered that some of the trajectories are totally or nearly unfeasible, and highly unlikely, especially those associated with higher emissions.
    Finally, it should be noted that socioeconomic hypotheses associated with the lower emission trajectories (such as the one commented upon by Tim Worstall) imply a greatly increased use of nuclear and fossil fuels, especially cooal and natural gas, and the share of renewable sources reaching much less than the “80%” claimed by the recent “renewable energy” IPCC report. I wonder, by the way, why oil should fall so precipitously while natural gas increases: is this somehow related to known reserves or other sorts of grounds?

  20. It’s always trouble when people use language to obscure what they are discussing. You would think that people genuinely concerned about communication with the public would find simpler terms, not more complex ones, to discuss their ideas. Its just another indication of the elitism rampant at the IPCC.

    • Chip- I completely agree. I find that many of those who post here and write obscurely are from academics and not industry. I believe in industry we are taught not to waste time and to make sure the reader understands your point clearly and quickly.

      • Not even sure if it’s people writing the mumbo-jumbo. Maybe it’s a computer simulation that randomises the shop-soiled talking points :-)

        “Worse than we thought”
        “Think of the children”
        “Representative Concentration Pathways”

      • At east Daleks are honest villains :-)

  21. Steven Mosher

    looks like a mess that just makes communicating the problem more difficult.

    “simply specifying a value of CO2 concentration (with the other greenhouse gases and anthropogenic aerosol) at 2100 along with a simple time trajectory is sufficient to force the climate model. ”

    I note in their writing that they argue that the pathways are not boundary cases. It would see that the vast uncertainty in pathways would dictate that you should proceed by establishing boundary cases.

  22. Steven Mosher

    If you want to have some fun look at this page

    click on an RCP, click on a GHG and then see a spatial view of it.

    C02 and deforestation is interesting

    • Steve

      What I find humerous is that I have has people point of this site as some type of new discovery in science. When it is pointed out that all they are posting is really, really rough estimates (or outright unverfied guesses) of emissions and nothing more, people still believe the data.

      • I really need to start proof reading what I type before hitting enter. Sorry for the above post.

      • Steven Mosher

        I guess I take a different view of it. I have no issue with making guesses provided the method of guessing is laid out plainly and clearly for all to see. And I have no problem with guessing provided that the boundaries are explored explicitly. In some ways the simpler and clearer the guess are the better. When guesses get packaged as “models” then I start to have issues.

      • Steve– I agree and have no problem with a guess or estimate properly labelled. What I meant to write previously is that some people do not realize that these are guesses and react a bit over the top after seeing the information

      • The method of guessing usually involves a conference at an exotic resort.
        Like a Bond film with only the baddies.

    • Waste is interesting to. It looks like Mexico, Australia, China and Greenland have no waste but Baffin Island does.

    • Some peculiarities. There’s no CO2 category, e.g., though there is one (mislabelled?) for CO. And it seems that Greenland, China, Australia, and Antarctica all will have zero sulphur emissions from landfills.

  23. Dr James Ward

    One of the biggest problems I see with emissions scenarios is the failure to recognise the growing body of published (peer-reviewed) literature on “peak oil” (and peak coal/gas). To me these relatively recent studies allow us to assign much-needed probabilities to different emissions pathways – something that should be seen as a welcome reduction in predictive uncertainty).

    I have had a paper published on this topic, freely downloadable along with review comments:

    I have also tried to engage climate scientists in this discussion but there is a prevalent view that the claims of limited fossil fuel resources are not based on credible science.


    • What the frack? Natural gas reserves have been put at 100 years and the US is the Middle East of coal. Global warming is not a problem but fear of it is. There are no problems that free enterprise capitalist cannot deal with–faster, better and more productively–than a fearmongering liberal fascist Big government bureaucracy.

      • Dr James Ward

        The notion of “100 years left” being a useful production forecasting method is well outdated, and has been since the 50s. Yet it is still used widely (e.g. BP’s Statistical Review of World Energy).

        I can see the appeal of rhetoric such as “the US is the Middle East of coal” but it is no substitute for rigorous science.

        And yes, I know, there are plenty of celebrated cases of doom-and-gloom predictions that have been shown to be wrong. This does not mean that all predictions of resource scarcity will be wrong.

      • It’s just that, to date, they have a 0% record of being right. Questions have been asked, but not answered …

      • Dr James Ward

        Hang on – how do you define a prediction “being right”?

        If the accuracy you require is, for instance, that a national peak oil model must predict the date of the peak within several months and be precise to the nearest 1,000 bbl/day, then indeed all predictions have failed and will continue to do so.

        On the other hand, if the requirement is a validation of the underlying “peak production” principle (i.e. production from large resources maturing and going into decline, and not being sufficiently offset by newer smaller resources to maintain overall growth), and if we can accept some uncertainty around the date and height of the peak, then we have many examples of regions and countries in which exactly this process has occurred for oil and other resources.

        By extrapolation, the world must eventually reach a point at which declining production outweighs growing production. Even if we only got fossil fuel predictions right to 20-30% accuracy (for the peak height) and 20-30 years (for timing), that would be a huge improvement on the enormous spread of future scenarios currently on the table via the SRES and RCP exercises. It give us something a bit more certain to plan for, mitigate, etc.

      • Still nonsense. Resource expansion and substitution through changes in technology and needs renders all “peaking” projections toothless. At least, that has been the universal experience to date. As has been said, it was not shortage of stones that ended the Stone Age.

      • Concerning oil resources the basic estimates of the amount of total crude oil resources have been stable for 50 years. Around 1960 there was enough geological data to make estimates using statistical methods so well that the estimates have essentially unchanged since.

        What has changed is the estimate of the share than can be recovered. Earlier it was estimated to be 30% of the whole resource, but 10 years ago USGA concluded that newer technology allows rising the estimate to 40% and that it’s likely that further technology development will ultimately raise it to 50%. This means that the estimate of the recoverable oil was increased by 67%.

        Even with this new estimate it appears clear that the production of conventional oil cannot grow much higher than it’s today, perhaps not higher at all, and that the production will start to decline within 30 years, if not sooner, possibly it’s already declining.

        There are other sources of oil that have helped in the recent past and continue to have an increasing share. Some of them can never grow much larger, e.g. the amount of liquids produced as a side product with natural gas. Others like oil sand in Canada have large total resource base, but are difficult to produce in very large volume. Finally there are even larger amounts of oil shale in Colorado or coal that can be liquefied, but these sources have major environmental problems and difficulties in scaling up the volumes.

        It’s so easy to claim that limits of resources will never affect us, but that’s just denying obvious facts. Humans are innovative, but the dynamics of change is such that many large problems cannot be solved in time. It’s much more difficult than getting the economy on healthy path right now.

      • So you have nothing to offer but fear itself? Those 1960 “estimates” you rely on are so out of whack with e.g. the last 10 yrs of onshore hydrocarbon discoveries that they actually illustrate the weakness of your assertions.
        Post your numbers. Lets see how “obvious” your “facts” are. The H0, by the way, is that history will continue to repeat itself, and “peak” projections will continue their 100% failure rate.

      • Pekka,
        No, estimates of reserves have not been stable over 50 years.
        By the way, I urge everyone to read “No Frakking Consensus”, linked to by our hostess and read this interesting post:
        about the media transition from covering the apocalypse of Y2K to the current apocalypse.

      • Hunter,
        Who cares about idiotically wrong predictions about peak oil?
        It is the correct ones that matter and those that are based on careful probability and statistics considerations as Pekka has stated.

        Yes, Deffeyes is a geologist that has lots of oil industry experience and has worked closely with Hubbert, but as an analyst, he is prone to shoot from the hip and use some bad analysis. One analysis in particular called Hubbert Linearization that Deffeyes popularized has no fundamental basis and is often inadequate as a heuristic. It is also constantly misinterpreted as I have shown recently here:

        Oil depletion analysis is like climate science, in that you have to separate the good stuff from the bad stuff.

    • Dr. Ward,
      Those peer reviewed papers are going to join the other peer reviewed papers predicting the same thing for the past 90 years in the trash.

      • Dr James Ward

        If you truly think that predictions have not changed in 90 years then you clearly have no interest in engaging in the evolving science of fossil fuel depletion. Interestingly, when I have tried to point out to climate change activists that there is a growing body of literature pointing to a peak and decline of carbon emissions, it is met with the same immediate dismissal. I guess you have some common ground after all.

  24. Regarding IIASA, which Dr Curry did not know of before: they are a very respected research center in systems theory and analysis. They have not worked much on climate as such, but a lot on climate change impacts. I have used their results on land use and agricultural impacts for my own work on the impact of climate change on food security and agriculture (, on which they have done the most adequate work to date (albeit using IIPCC climate projections as their starting point), via integrated assessment models (combining GCM climate models, agroecological zones, crop models and socioeconomic models (lead researcher in the Land Use program is Dr Günther Fischer). They have also worked on population projections as a function of per capita income, and on impacts of biofuels on agriculture and hunger. IIASA has several joint endeavors with FAO as regards agro-ecological zones, soil maps and other relevant matters.

    It is regrettable that the work of Fischer’s team has not developed alternatives to official IPCC climate projections, nor critiques of SRES scenarios, and it is also regrettable that several of their analyses are restricted to just one or two scenarios, usually the “worst-case” ones such as A2. However, this is just as well, because the impact on agriculture is usually more positive for scenarios implying more severe warming (since they imply more precipitation and more availability of atmospheric CO2). The A2 scenario, however, involves quite unrealistic assumptions about population, which impinges on forecasts about future food demand. Even so, and starting with a worldwide baseline of 16% undernourishment (people at risk from hunger) in 1990 (and about 14% today), they forecast its prevalence to decline sharply by 2080, to about 1% to 1.5% in all other scenarios, and only 6% for A2 (totally explained by the weird population assumptions in A2). The estimated prevalence of undernourishment (or % people at risk from hunger) is statistically non significant at values below 5% –due to variation in inter-personal dietary-energy needs and measurement error in food availability and distribution. In other words, AR4 climate projections imply for all practical purposes the disappearance of hunger in the coming decades. Moreover, this is robust across scenarios (including the worst ones), and also robust to the presence or absence of climate change (a reference projection without climate change yields very similar results), even if agricultural output growth is assumed to proceed slower than in past decades, and not to encroach on unsuitable agroecological zones (e.g. forests).

    Fischer, G., K. Frohberg, M.A. Keyzer, & K.S. Parikh, 1988. Linked National Models: A Tool for International Food Policy Analysis. Dordrecht: Kluwer.
    Fischer G., M.Shah & H. van Velthuizen, 2002a. Climate change and agricultural vulnerability. A special report, prepared by IIASA as a contribution to the World Summit on Sustainable Development, Johannesburg. Laxenburg (Austria): IIASA.
    Fischer, Günther; Harrij van Velthuizen; Mahendra Shah & Freddy O.Nachtergaele, 2002b. Global agro-ecological assessment for agriculture in the 21st century: methodology and results. IIASA RR-02-02. Laxenburg, Austria: IIASA.
    Fischer, G., M.Shah, F.N.Tubiello & H.van Velthuizen, 2005. Socio-economic and climate change impacts on agriculture: an integrated assessment, 1990–2080. Philosophical Transactions of the Royal Society, Series B, 360:2067-2083.
    Fischer, Günther; Mahendra Shah, Harrij van Velthuizen & Freddy O. Nachtergaele, 2006a. Agro-Ecological Zones Assessment. IIASA RP-06-03. Laxemburg, Austria.
    Fischer, Günther; Guy Jakeman, Hom M. Pant, Malte Schwoon & Richard S.J.Tol, 2006b. CHIMP: A simple population model for use in integrated assessment of global environmental change. The Integrated Assessment Journal 6(3):1-33.
    Fischer, Günther, Francesco N.Tubiello, Harrij van Velthuizen & David A. Wiberg, 2007. Climate change impacts on irrigation water requirements: effects of mitigation, 1990-2080. Technological Forecasting & Social Change 74:1083-1107. doi: 10.1016/j.techfore.2006.05.021.
    Fischer, Günther, 2009. World Food and Agriculture to 2030/50: How do climate change and bioenergy alter the long-term outlook for food, agriculture and resource availability? In FAO, 2009. How to feed the World in 2050. Proceedings of an Expert Meeting held in Rome, 24-26 June 2009. FAO, Rome.
    Fischer, Günther; Eva Hizsnyik, Sylvia Prieler Mahendra Shah and Harrij van Velthuizen, 2009. Bio-fuels and food security. IIASA, Laxenburg (Austria).
    Tubiello, F.N. & F.Ewert, 2002. Modeling the effects of elevated CO2 on crop growth and yield: a review. Euro¬pean Journal of Agronomy 18 (1-2):57-74. Doi:10.1016/S1161-0301(02)00097-7.
    Tubiello, F.N. & G. Fischer, 2007. Reducing climate change impacts on agriculture: Global and regional effects of mitigation, 2000–2080. Technological Forecasting & Social Change 74(7): 1030–1056. Doi: 10.1016/j.techfore.2006.05.027
    Tubiello, F.N., C. Rosenzweig, R.A. Goldberg, S. Jagtap, & J.W. Jones. 2002. Effects of Climate Change on US Crop Production: Simulation Results Using Two Different GCM Scenarios. Part I: Wheat, Potato, Maize, and Citrus. Climate Research 20 (April): 259–270.
    Tubiello, Francesco N., Jeffrey S. Amthor, Kenneth J. Boote, Marcello Donatelli, William Easterling, Gunther Fischer, Roger M. Gifford, Mark Howden, John Reilly, & Cynthia Rosenzweig, 2007. Crop response to elevated CO2 and world food supply (A comment on “Food for thought” by Long et al., 2006, Science 312: 1918–21.). European Journal of Agronomy 26: 215–223.

    • It seems when not closely supervised by the chief torturers, even the IPCC data sets and assumptions fail to justify catastrophism. Who’d a thunk?

  25. Rob Starkey is right (as are others here who have come to the same conclusion)

    IPCC “scenarios” and “storylines” for what is going to happen 100 years down the road are highly conjectural, by definition (see Taleb’s Black Swan and the “horse manure” projections of the mid 1800s).

    What is meaningful is a look at the past.

    “Carbon efficiency” of economies can be defined as the amount of wealth generated (annual GDP) divided by the amount of CO2 generated (in tons CO2/year).

    This is higher for the “industrially developed” economies, such as the European nations, Japan, USA, Canada, Australia, New Zealand ($2,000-$3,500 per ton of CO2), than it is for the developing nations: Asian “tigers”, China, India, Brazil, Russia ($600-$1,300 per ton of CO2). It is lowest for the underdeveloped nations.

    It has also increased over time, as measures to improve energy efficiency and reduce waste plus pollution have been implemented, and there is no doubt that this improvement will continue, partly as a result of increasing fossil fuel prices and other market-driven considerations.

    Population growth forecasts vary considerably, but all forecasts predict growth rates that are only a fraction of the growth rates seen from 1960 to 2000 (compounded annual growth rate, or CAGR, of 1.7%).

    During the same period 1960-2011 (essentially the length of the Mauna Loa record) atmospheric CO2 level increased by a CAGR of a bit more than 0.4% per year (or at approximately one-fourth the rate of population growth).

    Over the same period, world GDP has increased from $7.3 trillion to $62 trillion in constant dollars, or at a CAGR of 4.4% (or roughly three times the rate of population growth (data from Wiki). So it is clear that both population as well as affluence have grown considerably more rapidly than atmospheric CO2 concentrations.

    Whether one assumes a “low fertility” case with global population leveling off by 2100 at around 9 billion (CAGR of 0.3%/year) or a “high fertility” case with population growing to 12 billion (CAGR of 0.6%/year) does not really matter that much. In either case, the growth rate has already slowed down considerably, and is expected to continue to do so, as developing nations become more affluent.

    One “medium fertility” estimate by the UN puts human population at just over 10 billion by 2100 (CAGR of 0.4%/year).

    The average per capita carbon emission (1970-2011) was 4.2 tons CO2 per year. In recent years this has remained fairly constant at 4.4 tons CO2 per year. But if we assume that the per capita rate will increase to 4.8 tons CO2 per year, we would see annual emissions growing to around 50 GtCO2 by year 2100 (from today’s 34 GtCO2).

    Using the UN’s “medium fertility” population growth rate projection and the assumed higher per capita carbon footprint plus the assumption that 50% of the emitted CO2 will “remain” in the atmosphere, we arrive at an estimated atmospheric CO2 concentration of 640 ppmv by 2100.

    This represents a CAGR in atmospheric CO2 increasing from the past 0.4% per year to a future rate of 0.55% per year while population growth rate declines from 1.7% to 0.4% CAGR.

    To me this would appear to be a worst case scenario, based on the least developed economies building up energy infrastructures largely using fossil fuels, in order to pull their populations out of poverty, as China and India are doing today (thereby reducing their rate of population growth as they become more affluent and improving their carbon efficiencies) and the remaining societies continuing to improve their overall carbon efficiencies as they have already been doing.

    So what would this “worst case scenario” mean for our climate?

    If we assume that IPCC’s model-based 2xCO2 climate sensitivity estimate of 3.2°C is correct, this means we would see a “worst case” increase of temperature by 2100 of 2.3°C.

    Now I will admit that this is probably a pretty “hairy-fairy” estimate of the “worst case”, but it is as good as anything coming out of all of IPCC’s models IMHO.

    Of course, if there are any new energy technologies over the next 89 years (and there sure as hell will be), then this theoretical warming estimate is too high.

    The modelers should swallow their arrogance, take on a bit of humility, read Taleb and (above all) not forget the “horse manure” factor.


  26. In as much as none of the model scenarios can be validated, all predictions about future climate conditions amount to nothing more that, ‘Wait to see if our predictions come true; you’ll see then. Trust us!’

    GCMs cannot be offered as proof of their predictions. The models have been ‘tuned’ through the use of parameters to simply mimic observations, after the fact. Even so, their lack forecasting ability is demonstrable: they can never be validated because they fail hindcasting.

    Moreover, the statistical significance of reductionist models that are constructed in this manner can never be asserted because the degrees of freedom can never be known. McShane and Wyner have put forward 2010 research and unlike the work of UN-approved climate science, the work of M&S can be duplicated by others to verify their conclusions.

    There is no question: MBH98/99/08 (the ‘hockey stick’ graph) is scientific fraud and not just because lack of ‘backcasting’ ability is demonstrated–that had been proven before. M&S showed that the data upon which the GCMs are founded contain absolutely no global warming ‘signal’ whatsoever.

    Even Phil Jones admits that. He admits that there has been no statistically relevant global warming since 1995; and he acknowledges–as does Kevin Trenberth–that the Earth has been in a cooling trend for a decade.

    Trenberth says it’s a ‘travesty’ that ‘we can’t account for the lack of warming at the moment.’ He’s still looking for it to turn up in some deep ocean crevasse because he’s so sure he can’t be wrong. But, Trenberth is more than just wrong. The ONLY compelling convergent evidence we see is in the field of climatology the picture of collusion and corruption in the field of paleoclimate. The foi2009.pdf disclosures of CRUgate are proof of that.

    It is no longer possible for AGW ideologues to hide previous interglacial warming, hide the decline, run from the truth, dismiss the corruption of science, and continue to lie to the people. It is nothing but ‘climate porn’ to hide the decline, and then worry about where in the ocean a killer heat wave may be lurking, just waiting to surface, causing Thermageddon.

    What Trenberth is saying he fears is nothing more that the sort of fearmongering scare tactics that we’ve seen before. The global warming alarmists not only must pretend to believe that global temperatures will be warmer than now in 30-50 years–they must also pretend to believe that the Earth will be disastrously warmer. Their forecasts are exaggerations based on delusions about Climate Catastrophe.

    Moreover, rational people must accept that even if America commits economic suicide and Western civilization descends into feckless nihilism, the global warming alarmists’ predictions of doomsday will not change anything. We know that Brazil, Russia, India, China will all continue to get a good chuckle at the self-defeating and hypocritical ideology and the cultural and social dysfunction of Western socialists who have become blinded to truth by their hatred of capital and productive in their search for their secular, socialist Utopia.

    • If there is a skill set that has been polished and advanced by the AGW / IPCC Kru, it is the technique and technology of concealing and burying hidden assumptions and parameters in a rat’s nest of distractions, which then bloom and flower with the desired outcome and output, almost regardless of the real-world data input. This is described, of course, as “robust” science.

      • True, true. The IPCC defines ‘radiation forcing’ to be ‘the reduction in upward directed infrared at the tropopause due to the increase in CO2 concentration.’ UN-approved GCMs of the science authoritarians grossly exaggerate surface temperature responses to radiative forcing. How? The global warming alarmists underestimate the rate of increase of surface evaporation due to increases in temperature; they have to know that doing so is not supported by theoretical and observational evidence. Only Western government scientists have abandoned reason in this way. You have to ask yourself, ‘W H Y’ ?

        “The computer models on which the IPCC based its fourth assessment projections significantly underestimate the rate of increase of evaporation with temperature when compared to both theoretical and observational estimates… [and] projections of global temperature rise made by these contemporary computer models are nearly an order of magnitude too large. A better representation in computer models of the response of evaporation and surface latent heat exchange with temperature is a primary requirement if the uncertainty about anthropogenic global warming is to be reduced. Without this improvement the projected temperature response to anthropogenic forcing will likely continue to be exaggerated.” ~William Kininmonth

      • Interesting. I’d just been wondering what kind of change in humidity would be required to entirely squelch any temperature rise, even assuming the (one-time) increment that “back-radiation” gives to the in-transit IR flux. Latent heat of H2O is so high compared to the specific heat of a comparable mass of dry air that I assumed it wouldn’t take much.

      • Kininmonth seems to suggest that models can’t handle temperature increases properly in terms of evaporation. Given that they can handle the annual cycle well enough, how can he justify that? The annual cycle is several times larger than the century increase due to global warming. If the models weren’t doing evaporation correctly you would see it in the annual cycle.
        The quote comes from his 2010 Energy and Environment paper, which is an interesting exercise in spot the error. He doubles CO2 in a radiative model and finds that the surface doesn’t warm much because of how increased evaporation offsets this. He does not look at the top of atmosphere balance to see how it remains unbalanced under his modified state, so he hasn’t looked at radiative equilibrium, but some kind of transient response, as far as I can tell. Increased evaporation is a necessary step for increased water vapor and the positive feedback, but he didn’t consider that part.

      • “the” positive feedback which applies only at night and is far less than the daytime negative feedback.


  27. “Or, to boil it right down, the IPCC is telling us that the solution to climate change is economic growth and low-carbon energy generation.”

    Absolutely. There are some on the extreme eco-fringe who would argue otherwise, but that’s what many of us have always been saying. It’s nothing new. I’d also add that the nuclear option has to be included in low -carbon energy generation.Incidentally, James Hansen, reviled by many commentors on this blog, is saying exactly the same thing, if I understand him correctly.

    Having said that, we still do need to do a reality check, and use our calculators to work out that economic growth of 3% between now and the end of the century will mean the world’s economy will grow by a factor of 16. So low- carbon, or more correctly CO2, energy generation needs to be very low carbon energy generation.

  28. Meanwhile, the oceans are cooling, there is no end to the cooling in sight, and the earth may remain in a cooling trend for another 3 to 7 decades decades.

  29. Chief Hydrologist

    Given that carbon dioxide had very little to do with centennial warming – and the sun (including UV) was at a 1000 year high last century – cooling for 500, 10,000, 100,000 years seems in the cards.

    • So its a “given” is it? And who , if you don’t mind my asking, has done the ‘giving’?

      In addition, we have many centuries of “cooling” to come. And you’re saying this is “in the cards”? Like, you give them all a good shuffle, deal out the pack ….. ??

      Well, if that’s the case, I just don’t know why anyone has any worries about AGW at all!

      • Most ‘recent warming’ occurred in the 1976/77 and 1997/98 ENSO ‘dragon-kings’ – 0.47 degrees C. According to NASA – most of the rest happened because of cloud changes. ‘The overall slight rise (relative heating) of global total net flux at TOA between the 1980’s and 1990’s is confirmed in the tropics by the ERBS measurements and exceeds the estimated climate forcing changes (greenhouse gases and aerosols) for this period. The most obvious explanation is the associated changes in cloudiness during this period.’ In fact there was ‘relative cooling’ in the IR.

        But AGW doesn’t exist as such – instead we have abrupt change. You have asked me this question before – and I assume you are not reading or not understanding. So here is the National Academy of Sciences committee on abrupt climate change again.

        ‘Recent scientific evidence shows that major and widespread climate changes have occurred with startling speed. For example, roughly half the north Atlantic warming since the last ice age was achieved in only a decade, and it was accompanied by significant climatic changes across most of the globe. Similar events, including local warmings as large as 16°C, occurred repeatedly during the slide into and climb out of the last ice age. Human civilizations arose after those extreme, global ice-age climate jumps. Severe droughts and other regional climate events during the current warm period have shown similar tendencies of abrupt onset and great persistence, often with adverse effects on societies.

        Abrupt climate changes were especially common when the climate system was being forced to change most rapidly. Thus, greenhouse warming and other human alterations of the earth system may increase the possibility of large, abrupt, and unwelcome regional or global climatic events. The abrupt changes of the past are not fully explained yet, and climate models typically underestimate the size, speed, and extent of those changes. Hence, future abrupt changes cannot be predicted with confidence, and climate surprises are to be expected.

        The new paradigm of an abruptly changing climatic system has been well established by research over the last decade, but this new thinking is little known and scarcely appreciated in the wider community of natural and social scientists and policy-makers.’

        Oh my God – it’s worse than global warming.

        If you have a problem with chaos theory – I suggest from personal experience that you do quite a lot of study because that’s what it takes.

  30. tempterrain

    You wrote:

    Having said that, we still do need to do a reality check, and use our calculators to work out that economic growth of 3% between now and the end of the century will mean the world’s economy will grow by a factor of 16. So low- carbon, or more correctly CO2, energy generation needs to be very low carbon energy generation.

    OK. Let’s do that reality check.

    From 1960 to 2010 GDP grew by 4.4%/year compounded annual growth rate (CAGR), i.e. from $7.2 trillion to $62.9 trillion (in constant $).

    Over the same period human population grew by 1.7%/year CAGR, i.e. from 3.0 billion to 6.95 billion.

    [So GDP grew at roughly 3X population growth rate.]

    Over the same time period atmospheric CO2 concentration grew from 316 ppmv to 390 ppmv or at a CAGR of 0.43%/year.

    [This was roughly one-fourth the population growth rate.]

    A UN “medium fertility” forecast projects that human population will grow to 10.1 billion by 2100 = a CAGR of 0.4%/year.

    [This is roughly one-fourth the CAGR seen from 1960 to 2010.]

    IF GDP and CO2 continue at the same relative growth compared to population as we have seen in the past, we should see from today to 2100:

    GDP growing at 3 * 0.4 = 1.2%/year CAGR (in constant $), to $184 trillion by 2100 and:

    Atmospheric CO2 growing at 0.25 * 0.4 = 0.1%/year CAGR.

    Today’s CO2 level is 390 ppmv.

    That means that the CO2 level by 2100 would be:

    (1.001)^90 * 390 = 427 ppmv

    Using IPCC’s model-based mean 2xCO2 climate sensitivity of 3.2°C, we should see 0.4°C warming by 2100.

    But let’s say you are right, and that GDP really does grow at 3% per year until 2100 in constant $ (or 2.5 times the current rate relative to population). This means GDP would be close to $900 trillion by 2100, or over 14 times today’s level.

    On that basis, CO2 would grow at 0.25% CAGR, so by 2100 it would be:

    (1.0025)^90 * 390 = 488 ppmv

    And temperature would increase by 1.0°C, using IPCC’s model-based mean 2xCO2 climate sensitivity of 3.2°C.

    Let’s be even more pessimistic than you were and say that CO2 levels continue to increase at the same CAGR we have seen since 1960, despite the slowdown in population growth rate. We then have:

    (1.0043)^90 * 390 = 574 ppmv

    And temperature would increase by 1.8°C.

    (BTW this is very close to IPCC “scenario and storyline” B1).

    So the “reality test” tells us that a 3% CAGR for GDP until 2100 is probably on the high side, but even if it did occur, we would only see around 1.0°C warming by 2100.

    And even in the very unlikely case that we saw CO2 continuing to grow at the same exponential rate as in the past, despite a major slowdown in population growth, we would see a maximum warming by 2100 of 1.8°C.

    Forget about “Representative Concentration Pathways” gobbledygook. No matter what you call it, it is BS.


    • Max.

      You should learn how to plot graphs.

      I’m not quite sure how you’ve got less than 500ppmv, for CO2 concentrations, on current trends, by the end of the century but if you taken the trouble to plot out the data you’d see you’d got the wrong answer.

      Even we take a really optimistic view and say that the rise will be linear then you can see, from the graph, that CO2 concentrations will be higher than 500 ppmv.

      Or to use your own figures of 316 to 390ppmv in 50 years:

      That’s 14.8 ppmv increase per decade.

      So (9 *14.8) + 390 = 523.2 ppmv on a linear trend !

      So, it looks like you might have a dodgy calculator! I’ve thought that for some time now. I should buy you a new one!

      On second thoughts maybe not. I’m not sure I could cope with you and I being on the same side of the argument.

    • The 3% I have mentioned a couple of times. It factors in substantial per capita increases in income – and is necessary to feed and provide a reasonable level of development globally. Exponential growth – it is 14 times current global GDP in 2100 – so roughly 14 times current emissions if we could stay on that trajectory.

      It is utterly impossible with fossil fuel technologies – but possible with 4th gen nuclear tech or better.

      • It [14 x growth] is utterly impossible with fossil fuel technologies – but possible with 4th gen nuclear tech or better.

        Yes, you’ve said something sensible at last!

        I’d even add that it doesn’t look like renewables are going to be that significant given the scale of the task, although of course they will have their place. It looks to me that either we go nuclear, and that means we have to find a way of keeping it safe, or global society and civilisation will just face an inevitable downward spiral during the course of this century.

      • So you cannot possibly begin with anything less than a snark. You have never said anything sensible.

        This less than anything – because you haven’t even googled 4th gen nuclear. You are a clueless and worthless individual..

  31. Mrs. Curry, do you ever sleep? Or are your days 48 hours long? Tell me your secrets, please!

  32. Judith,

    Science has yet to consider that ALL current science parameters would change drastically if the solar system was non-moving.
    Ever consider how a magnetic re-news it’s energy?
    Certainly if their was no motion, their would be no forces of energy moving.

  33. Web,
    This is in response to your reply regarding peak oil.
    I would point out that that argument based on “who cares about wrong predictions” is faulty.
    Wrong predictions teach us a lot: why were they wrong? Why were they accepted at the time? How similar are current predictions to the wrong ones? How are they different?
    My conclusion is that nearly anything to do with predicting looming global resource shortages or impending catastrophism is always wrong.

  34. andrew adams


    Sorry, but your calculations for CO2 growth are nonsense – you are comparing the rate of growth in population to the growth in the absolute amount of CO2 in the atmosphere, but you should instead be comparing it with the rate of growth of our annual emissions. By your logic if the growth rate of the population fell to 0 then the rate of growth in overall CO2 levels would also fall to 0 but that’s obviously plain wrong because the existing population would still carry on emitting CO2.

    If emissions continue for the rest of the century at the same rate as over the last decade we would end up with about 578ppm by 2100, even before we allow for increases in population and GDP, so that best case scenario is slightly worse than your worst case scenario.

    • Andrew, I think you need to be careful with your use of the words “best” and “worst”. So far as we skeptics are concerned, the best scenarios are those where CO2 reaches very high levels of concentration, just so long as this does not exceed 2000 ppmv. The worst scenarios are where CO2 levels decrease. So, hopefully, your scenario for 578 ppmv by 2100 is on the low side of what will happen, and the actual value will be considerably higher.

      • Jim,

        I can only call it as I see it. The skeptics may have an entirely benign view of high CO2 levels but that seems to be based on some highly dubious assumptions, and they won’t be immune from the effects if (when) they are wrong.

        See also my reply to Brian H

      • Andrew writes “but that seems to be based on some highly dubious assumptions”

        If you read what Girma says, then you ought to realize that the skeptical view of CAGW is based on observed data, NOT “dubious” assumptions. And the benefits of adding CO2 to the atmosphere have little to do with warmer temperatures; which is a very marginal effect anyway. The benefit of CO2 is as “plant food”. Land produces a far higher yield of food crops, wiht the use of less water. With world populations increasing, this can be an enormous benefit.

      • Jim,

        No doubt in some places there will be increased yields of some crops due to excess CO2, but not all crops respond positively to increased CO2 and, more importantly, the level of CO2 is not the only variable which impacts on plant growth. I think the claims made by the skeptics in this respect are extremely optimistic and what’s more they disgregard (or rather do not accept) the negative consequences of the increased warming which will have to be balanced against any gains from increased crop yields.

      • There is really no evidence that the more “plant food” argument has any scientific merit at all.

        Besides food crops, which I would agree can probably be bred or even genetically engineered for Co2 levels, the global biosphere depends on all plant life remaining healthy. There is no doubt that plants have previously successfully adapted, by a normal evolutionary process or re-adjustment to a new optimum, to changing CO2 levels, and temperatures; but, never at such a rapid rate as is occurring now.

        There has been much discussion as to why tree ring data stopped being a useful measure of temperature in the 60’s and 70’s. Could it be that elevated CO2 levels are causing stress to forests? I’m not saying that it necessarily is; but, if it is a factor, a further question would be just how much stress can they take?

      • Do you have any biological mechanism or precedent for suggesting that elevated CO2 levels could cause stress to forests?
        In the animal kingdom, excess nutrition leads to weight gain. Why should it lead to weight loss in plants?
        Or is that pure conjecture?

      • Elevated temperatures could. You don’t see pine forests in warm climates for a reason.

      • The reason there is in the reproduction strategy.

        ‘The flowering plants (angiosperms), also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies (derived characteristics). These characteristics include flowers, endosperm within the seeds, and the production of fruits that contain the seeds.

        The ancestors of flowering plants diverged from gymnosperms around 245–202 million years ago, and the first flowering plants known to exist are from 140 million years ago. They diversified enormously during the Lower Cretaceous and became widespread around 100 million years ago, but replaced conifers as the dominant trees only around 60-100 million years ago.’

        Flowers and fruit are a great reproduction strategy – but are a little delicate.

      • There are very few plant or animal species which don’t do just as well or better in elevated temperatures.
        And even if individual trees don’t do as well, their offspring just need to live a few feet higher up the hillside to do just as well.
        Besides, using pine trees is a bad example, because they’re one of the few species which thrive in colder temperatures. They’re not common in warmer climates, not necessarily because they don’t do well but because they’re crowded out by other species. For example, you’ll find pine trees in the tropics, and doing well, but they’re not the dominant species.
        Besides, plants are far more sensitive to the availability of water than to temperature.

      • You really don’t bother to research anything at all do you? Simply relate the first thing that comes into your head and make a vague nod in the direction of science?

        Can I be bothered correcting this nonsensically simplistic nonsense?

        Carbon is the major building of cells – appearing in all cells with nitrogen and phosphorus along with micro-nutrients needed for various cell functions. The marine ratio is on average the Redfield ratio 0f 106C:16N and 1P. On land a major limiting factor is water.

        Phosphorus and micro-nutrients are derived from rock weathering and from recycling in soils. Both processes proceed faster in wet and warm conditions. Some of the weathering occurs as a result of fungus in the soils – that indeed swap through root contact nutrients obtained by the fungus for sugars created in the plants. They have a very well regulated economy. Some is the result of biologically mediated soil acidity or as the result of carbonic acid in rain. .

        It turns out that plants are very well adapted to C02 variability – reducing both the size and density of leaf stomata in response to increases in CO2.
        This both reduces gas exchange and limits water loss – a useful survival adaptation. It is happening worldwide.

        The natural fluxes of carbon are some 24 times the human flux and both natural sinks and sources vary over less than a geological age. The problem is that people have mistaken a simple narrative ‘superficially in the culturally potent idiom of objective science’ for a profound scientific insight. They are profoundly mistaken – as inevitably you are too. In your case – change one letter in idiom for the obvious explanation.

      • Jim,

        You write “So far as we skeptics are concerned, the best scenarios are those where CO2 reaches very high levels …”

        Really? If so, I’d suggest “idiots” would be a more suitable word than “skeptics”.

    • andrew adams

      Sorry, Andrew – you have got it all wrong. To put it your way – your comment is “nonsense”.

      I have looked at the actual past development of atmospheric CO2 and compared that with the actual development of both human population and GDP.

      There is absolutely no question that human CO2 emissions are generally related to the number of human beings emitting CO2.

      There is also no question that more human-caused CO2 is emitted as the GDP or wealth of a society is increased.

      During the recent period of record increase of both human population and of global GDP, human CO2 emissions did increase with the result (if Salby is falsified) that atmospheric CO2 concentrations increased.

      As a matter of fact, over this period of rapid growth of both human population and GDP, the compounded annual growth rate (CAGR) of atmospheric CO2 concentration was 0.42% per year. This was also the most recent rate of increase.

      If we assume that CO2 will continue to increase at this exponential rate until year 2100, despite all projections that point to a much lower rate of growth of both population and GDP than we have seen over the past, we arrive at a worst case scenario with CO2 at roughly 580 ppmv by 2100 and temperature increasing by 1.8°C (this is the IPCC “scenario and storyline” B1)..

      If we adjust the rate of CO2 increase proportionately to the rate of population growth, or to the expected rate of GDP growth as was posulated by tempterrain of 3%/year GAGR, we arrive at a lower temperature increase by 2100.

      It’s just that simple, adam.

      Tempterrain asked for a “reality check”. And that’s what I gave him. What you are posting is simply denial, without any realistic alternate thoughts on how atmospheric CO2 could increase as a result of the growth of human population and industrialization..

      All this “RCP” stuff cannot give us predictions, which are any better than the rough ones I just made – simply because the unknowns are far greater than the knowns.

      Remember that in the mid-1800s forecasters were predicting that the rapidly increasing number of horse carriages would result in cities like London, New York and Manchester being covered in two meters of horse manure by 1930.

      It’s “déjà vu all over again”.


      • Max,

        Andrew’s right. These reply threads seem to have got mixed up. But if you look at the reply to your original comment I’ve posted up a graph which agrees closely with his figure of 578 ppmv for CO2, under current trends, by the end of the century.

        Look – this is such a simple calculation. If you can’t get this one right, you should give up the maths and just stick to ranting about Al Gore!

      • andrew adams


        No, tt is right.

        We will get to about 580ppm by 2100 simply by continuing to emit CO2 at our current rate (about 2ppm p.a.) with our current population and level of GDP. If you allow for population and GDP growth on top of that then we will get a significantly higher figure.

  35. aa;
    Got your “best” and “worst” reversed there. 578 ppm would be fine; 1156 ppm (double that) would be even better. More CO2 and more warming = more life. Less CO2 and more cooling = more death. You seem to be in favour of the latter.

    • Brian H,

      The general assumption that warmer = more life is a very simplistic one, and is not necessarily supported by evidence from the past – see here for example –

      We analysed the fossil record for the last 520 Myr against estimates of low latitude sea surface temperature for the same period. We found that global biodiversity (the richness of families and genera) is related to temperature and has been relatively low during warm ‘greenhouse’ phases, while during the same phases extinction and origination rates of taxonomic lineages have been relatively high.

      Also, the rate at which climate changes is also important – species can adapt to gradual changes to their environment, they struggle with rapid changes. Human activity is already putting stress on biosystems – add rapid warming on top of that and the effects are likely to be severe.

      There is a nice essay here if you are interested.

    • Brian H and andrew adams

      I will not argue with Brian that (if I were a plant) I’d agree with his statement:

      578 ppm would be fine; 1156 ppm (double that) would be even better

      But 1156 ppm hardly seems physically possible.

      The World Energy Council has recently issued a report listing the proven reserves of all fossil fuels as well as the inferred possible total resources in place on this planet.

      These are:

      Proven reserves:
      Coal: 861 Gt
      Oil: 1,239 billion bbl
      Gas: 186 trillion cubic meters

      Inferred possible total resource in place:
      Coal: 2,462 Gt
      Oil: 5,078 billion bbl
      Gas: 486 trillion cubic meters

      There have been other estimates, which are both lower and higher than this, but this study is the most recent detailed breakdown I have seen.

      Once one deducts the small amount of oil and gas going into non-combustion end uses, the inferred possible total fossil fuel resources on this planet represent 2,873Gt of carbon, which would generate 10,536Gt CO2 when combusted.

      Assuming that Salby’s hypothesis of a natural cause for CO2 increase is shown to be false, and that around 50% of the emitted CO2 “remains” in the atmosphere (as has been the case over the past), this is enough CO2 to increase the atmospheric CO2 level to 1,065 ppm.

      That’s it, folks. That’s all there is.

      Will we ever “use up” all these optimistically estimates total fossil fuel resources? If we continue using them at the current rate, they should last several hundred years, despite “peak oil” (etc.) disaster scenarios being presented by scare mongers.

      But who knows what new technologies will be developed over that period?

      Certainly NOT the IPCC.

      (Meanwhile, the plants are loving it.)


  36. You have never heard of IIASA? Many of their scientists are lead authors on IPCC reports, and dozens of their scientists have contributed as members of the research community. And their scientists are among the pioneers of climate science.

    Has anyone ever heard of Paul Crutzen? He has been discussed several times on this blog and is a colleague at Georgia Tech. He has had a long and every well-known affiliation with IIASA.

    p.s. Tim Worstall’s ‘argument’ is clearly based on gross misunderstanding of the scenario storyline he tries to pretend he can discuss. Frankly, it’s not that complicated, and I am quite sure that a child in kindergarten could demonstrate more understanding. 2.6 requires very aggressive emissions reductions and energy diversification. Nor does he have the vaguest understanding of climate science – so it is not surprising that he misses the fact that the 2.6 scenario involves slightly more warming than the threshold set at Copenhagen as that to avoid dangerous warming. This is the kind of post that is so far from anything on the ‘knowledge frontier’. It is very stupid stuff. :-(

  37. Brian H and andrew adams

    [Somehow this post got stuck, so am re-posting. If it shows up twice, please delete one.]

    I will not argue with Brian that (if I were a plant) I’d agree with his statement:

    578 ppm would be fine; 1156 ppm (double that) would be even better

    But 1156 ppm hardly seems physically possible.

    The World Energy Council has recently issued a report listing the proven reserves of all fossil fuels as well as the inferred possible total resources in place on this planet.

    These are:

    Proven reserves:
    Coal: 861 Gt
    Oil: 1,239 billion bbl
    Gas: 186 trillion cubic meters

    Inferred possible total resource in place:
    Coal: 2,462 Gt
    Oil: 5,078 billion bbl
    Gas: 486 trillion cubic meters

    There have been other estimates, which are both lower and higher than this, but this study is the most recent detailed breakdown I have seen.

    Once one deducts the small amount of oil and gas going into non-combustion end uses, the inferred possible total fossil fuel resources on this planet represent 2,873Gt of carbon, which would generate 10,536Gt CO2 when combusted.

    Assuming that Salby’s hypothesis of a natural cause for CO2 increase is shown to be false, and that around 50% of the emitted CO2 “remains” in the atmosphere (as has been the case over the past), this is enough CO2 to increase the atmospheric CO2 level to 1,065 ppm.

    That’s it, folks. That’s all there is.

    Will we ever “use up” all these optimistically estimates total fossil fuel resources? If we continue using them at the current rate, they should last several hundred years, despite “peak oil” (etc.) disaster scenarios being presented by scare mongers.

    But who knows what new technologies will be developed over that period?

    Certainly NOT the IPCC.

    (Meanwhile, the plants are loving it.)


  38. Martha

    You refer to the need for very aggressive emissions reductions and energy diversification.

    Pekka is right in stating that the fossil fuel reserves of our planet are finite. This holds for oil, coal and natural gas.

    The latest estimate by the WEC (cited above) lists not only today’s “proven reserves”, but also the “inferred possible total resource in place” for oil, gas and coal. This more optimistic estimate is around three times higher than the proven reserves.

    At current consumption rates, this total resource would last us several hundred years (coal: between 350 and 400 years; oil and gas: between 150 and 200 years).

    If and when combusted, the combined carbon in all these fossil fuels would represent an increase to around 1,000 ppmv in the atmosphere over these several hundred years (if Salby is proven wrong and human emissions really are the principal cause of the increase).

    So we could see this as our “maximum ever possible worst case scenario” for AGW from CO2.

    This does not include large-scale “harvesting” of natural gas from methane clathrate deposits beneath the ocean, which WEC has ignored in its estimate.

    The fossil fuel resources will continue to become more expensive as we move from easily exploitable deposits to more difficult ones.

    And, at the same time, new competing energy technologies will be discovered and developed.

    So I think it is reasonable to assume that ”energy diversification” as you suggest will occur: we will gradually move away from being a primarily carbon-based economy, and this will occur quite naturally, without imposing direct or indirect taxes on carbon.

    As a result, I would concur with Dr. Curry’s testimony before US Congress a) that the impacts from AGW are still largely unknown, b) that AGW, even in the worst case, is not likely to become an existential problem in this century and c) that we should not rush off into actions whose unforeseen consequences we are unable to judge.

    From your posts here and elsewhere, it appears to me that you might agree with a), but do not agree with b) and c).

    So be it. Everyone is entitled to her own opinion.


    • Max

      “You refer to the need for very aggressive emissions reductions and energy diversification”

      No, I pointed out that Tim Worstall’s ‘argument’ is clearly based on gross misunderstanding of the 2.6 scenario storyline because that scenario requires (i.e., assumes) aggressive emissions reductions, and energy diversification:

      I also suggested that it is incomprehensible to me that a blog that has made the IPCC the object of scrutiny has “never heard of IIASA” when so many of their scientists are lead authors on IPCC reports, and dozens of their scientists have contributed as members of the research community, and their scientists are among the pioneers of climate science, and the person who is perhaps best know for his affiliation with IIASA is a close colleague of the blog owner.

      Given every thing else I have seen here, both intellectually and ethically, I have come to the conclusion that I no longer have any desire to participate. Overall, this blog is so uninformed and I see endless misrepresentation and dishonesty that does not lend itself to productive discussion of anything that is meaningful or important to me. At a personal level, I have also come to question Judith Curry’s fitness. I cannot hold people accountable when they show signs of being unfit, and I do care about people and that is not right.

      Take care

      • John Carpenter

        “At a personal level, I have also come to question Judith Curry’s fitness. I cannot hold people accountable when they show signs of being unfit, and I do care about people and that is not right.”

        You have to be kidding…. right?

        “Given every thing else I have seen here, both intellectually and ethically, I have come to the conclusion that I no longer have any desire to participate.”

        I guess this is goodbye then… have a good life.

      • Martha,

        For what it’s worth, I must admit I always read your posts.

      • John Carpenter


        One final parting comment…

        I find you can offer insightful and good comments that come from someone who obviously is intelligent and well read on the subject matter… but then you also have this knack of going off the track and make personal comments about Judith or whoever that are non productive to the discussion that only adds fuel to the fire. You should know by now those here that are good for ‘entertainment value’ and those that offer good insight. You cannot let a few posters who you clearly feel are charlatans prevent you from discussing topics you feel are important… you will be perceived as defeated. But resorting to insult will guarantee you will not be well received.

        Look, I am the first to admit I don’t agree with a lot of your positions.. so what…? that is what makes the discussion interesting and productive as long as the discussion does not turn to personal insult. When that happens, it is a sign to the one you are directing your comment to that your argument is weak. Insulting other peoples intelligence will not drive home any message you want them to hear… it will only succeed in driving them further toward their original point of view. Please think about these ideas and maybe you will come back another day.

      • Martha, thanks for providing me with some “exercise,” its been fun.

        For the record, I have met Paul Crutzen exactly twice, in the 1980’s. Paul Crutzen had an adjunct appt at Georgia Tech in the 1990’s (he probably held such positions at dozens of places.) Crutzen is a giant in his field, personally I pay far more attention to his published papers than I do to his various affiliations.

        As for the IIASA, well here is what they say they do:

        “IIASA’s energy and climate change research takes place within four themes:

        • transformation of the global energy system to achieve a low-carbon world;
        • reframing the greenhouse gas debate;
        • managing energy and research and development investments; and
        • improving energy use efficiency.”

        Other than reframing the greenhouse gas debate, the IIASA is outside of what I pay much attention to, and I don’t see any reason to change that.

        Be sure to check out my next post on blogospheric discourse (coming later today).

  39. “At a personal level, I have also come to question Judith Curry’s fitness.”

    Yeah, she should prolly hit the gym more often. ;)


    Martha, you really need to get a hobby.


  40. My comment will probably get lost in the mass… But I wrote a feature article for the journal Nature Climate Change explaining what the RCPs and the earlier IPCC scenarios are, and are not, meant to accomplish. In short, they are not meant to predict the future (despite their use in that way by many researchers, politicians, and others). They are meant to help understand how driving forces such as economic growth, education, and innovation may affect the planet.

    Here’s the link to my article, “Opening the Future”

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