Redefining dangerous climate change

by Judith Curry

There is some “buzz” about a new paper and essay by Timothy Lenton on dangerous climate change.

Beyond 2C:  redefining dangerous climate change for physical systems
Timothy Lenton
Wiley Interdisciplinary Reviews Climate Change

Abstract: Most efforts to define a level of dangerous anthropogenic interference (DAI) with the climate system are framed in terms of global annual mean surface temperature change, with 2°C above preindustrial being the most widely accepted climate policy ‘target’. Yet, no actual large-scale threshold (or ‘tipping point’) in the climate system (of which there are probably several) has been clearly linked to 2°C global warming. Of those that can be indirectly linked to global temperature change, the dangerous levels are necessarily imprecise and vary, with estimates ranging from ∼1°C above preindustrial upwards. Some potential thresholds cannot be meaningfully linked to global temperature change, others are sensitive to rates of climate change, and some are most sensitive to spatial gradients of climate change. In some cases, the heterogeneous distributions of reflective (sulfate) aerosols, absorbing (black carbon) aerosols, and land use could be more dangerous than changes in globally well-mixed greenhouse gases. Hence, the framing of Article 2 of the United Nations Framework Convention on Climate Change (UNFCCC), in terms of stabilization of greenhouse gas concentrations (within a time frame), is too narrow to prevent some types of DAI. To address this, a reframed policy objective is proposed; to limit the overall magnitude, rate of change, and spatial gradients of anthropogenic radiative forcing, and resultant climate change, through restriction of emissions of anthropogenic aerosols, patterns of land use, and concentrations of short-lived, as well as long-lived, greenhouse gases.

Only the abstract to the paper is available online [link].   Nature found this sufficiently interesting to invite Lenton to write an op-ed on this, link [here].  The subheading on the Nature piece is

Targets to limit the global temperature rise won’t prevent climate disruption. Tim Lenton says that policy-makers should focus on regional impacts.

Now that is a statement I can agree with.  More that I agree with:

Global average warming is not the only kind of climate change that is dangerous, and long-lived greenhouse gases are not the only cause of dangerous climate change. Target setters need to take into account all the factors that threaten to tip elements of Earth’s climate system into a different state, causing events such as irreversible loss of major ice sheets, reorganizations of oceanic or atmospheric circulation patterns and abrupt shifts in critical ecosystems.

Such ‘large-scale discontinuities’ are arguably the biggest cause for climate concern. And studies show that some could occur before global warming reaches 2 °C, whereas others cannot be meaningfully linked to global temperature.

When Lenton gets to “what should we do about it,” he misses the mark, IMO:

I suggest that the UNFCCC be extended. The climate problem, and the political targets presented as a solution, should be aimed at restricting anthropogenic radiative forcing to limit the rate and gradients of climate change, before limiting its eventual magnitude.

The beauty of this approach is that it opens separate policy avenues for different radiative-forcing agents, and regional treaties to control those with regional effects. For example, hydrofluorocarbons emissions could be tackled under a modification of the 1987 Montreal Protocol, which aimed to halt ozone depletion. And emissions of black-carbon aerosols and ozone-producing gases could be regulated under national policies to limit air pollution. This would both break the political impasse on CO2 and help to protect vulnerable elements of the Earth system.

While his proposals acknowledges that other elements of radiative forcing  are relevant to climate change (mainly anthropogenic aerosols), he fails to include natural climate variability (e.g. forcing by the sun and volcanoes) and of course unforced natural internal variability.  Not to mention land use changes, which arguably have a dominant influence on regional climate change.

So is anyone listening to Timothy Lenton?

I have to admit that I had never heard of Timothy Lenton before this article (or if i did, the name didn’t stick in my brain).  However, on Lenton’s web page, I spotted this sentence that piqued my curiosity: “I was flattered to be listed among the ten most respected climate scientists by the Financial Times.”  So I went to the Financial Times, this links to an article entitled “Top climate scientists share their outlook” which is basically a top ten list.  The date on the article is interesting:  November 20, 2009 (the climate world as it was right before the climategate impact was felt.)  The top ten on this list are . . . (drum roll):

  • Stefan Rahmstorf
  • John Mitchell
  • Rachendra Pachauri
  • Myles Allen
  • Tim Lenton (described as James Lovelock’s annointed successor)
  • Kevin Trenberth
  • Chris Rapley
  • Susan Solomon
  • Carl Wunsch
  • Isaac Held
  • Richard Lindzen

My one word reaction:  Huh?

JC’s perspective on the dangerous climate change issue

On a previous thread “What constitutes dangerous climate change?”, my arguments were summarized as:

In my opinion, the primary reason that the UNFCCC has been unable to define “dangerous” anthropogenic climate change is because they have framed the problem and its solution to be irreducibly global.  If the problem is viewed as an aggregate of regional problems in the context of a bottom-up incremental policy approach such as that promoted by Ron Brunner, then presumably a more meaningful understanding of dangerous climate change could emerge, which would be a source of political will for actually addressing the problems.

More importantly, extreme weather events and natural climate variability have adverse impacts, which in some instances (time-space) may counter the impacts of AGW and in others may amplify the AGW impacts.  Addressing the regional impacts of natural variability in combination with possible AGW impacts would increase overall resilience to extreme weather events and climate change/variability.

IMO, the IPCC WG2 should be addressing the social vulnerability aspect in a major way, other than relegating this to a single chapter.   Unfortunately, the IPCC WG2 seems more intent on attributing adverse impacts of extreme weather events and climate variability to AGW (which the IPCC was roundly criticized for in terms of its statements of confidence by the IAC report).

In my congressional testimony, I discussed climate change winners and losers:

A view of the climate change problem as irreducibly global fails to recognize that some regions may actually benefit from a warmer and/or wetter climate. Areas of the world that currently cannot adequately support populations and agricultural efforts may become more desirable in future climate regimes. 

A serious assessment is needed of vulnerabilities, region by region, in the context of possible climate change scenarios, demographics, societal vulnerabilities, possible adaptation, and current adaptation deficits. . . This is the kind of information that is needed to assess winners and losers and how dangerous climate change might be relative to adaptive capacities.

JC summary:  Given that the words “dangerous climate change” feature prominently in the UNFCCC treaty, we should figure out what these words actually mean or at least try to come up with an operational definition in the context of the treaty.  The continued failure to do so (for lack of even trying) is just astonishing.  Most of the effort undertaken seems to be attempting to sell spurious links between death and destruction from tornadoes, tsunamies, etc to climate change.  To his credit, Lenton puts the “dangerous” issue on the table for discussion, which is a step in the right direction.

138 responses to “Redefining dangerous climate change

  1. With the perverted null, and no models for regional climate change, this is just more howling about the wolf.

  2. I understand the framing is necessarily global because regional models that are any good are far from being available ?

    As for targets as things stand all it will take will be a large volcano in 2049 and it’ll be high fives for all…

    • “As for targets as things stand all it will take will be a large volcano in 2049 and it’ll be high fives for all…”


  3. Judith: Your inability to define dangerous follows from Arrow’s impossibility theorem. There is an entry on Wikipedia:

    His 1951 book Social Choice and Individual Values is very accessible.

    Essentially, Arrow shows that society cannot agree on what is good and better. A definition of “danger” requires a notion of bad and worse. That notion cannot exist per the Impossibility Theorem. Therefore, dangerous cannot be defined.

    • thanks richard, now tell that to the UNFCCC :)

      • It is not the first time an international treaty is based on an undefinable word. They work better that way, being easier to agree to, right? “Sustainability” is my favorite.

      • Jack Hughes

        “sustainability” is a Humpty-Dumpty word …

        “When I use a word,’ Humpty Dumpty said in rather a scornful tone, ‘it means just what I choose it to mean — neither more nor less.”

      • @judith
        I have repeatedly told them (in private, in public; verbally, in writing) but there is too much momentum.

      • Skeptics work against momentum.

        Dr. Curry,
        Isn’t 2°C warmer welcomed by flora, fauna and human in general, especially winter time? What the heck with it!

    • Jonathan Gilligan

      Richard Tol: Arrow’s theorem says we can’t always arrive at an agreement. It doesn’t say we can never do so. Consider the question, “What constitutes dangerous asteroid impact.” There are clear thresholds for which consensus would be easy.

      Similarly, there are some possible outcomes from anthropogenic warming that I would bet a majority of people could agree would be dangerous (e.g., multidecadal Dust-bowl severity droughts over large parts of the inhabited continents). The difficulty with defining dangerous has more to do with the uncertainty about how likely these outcomes would be, not whether they’re desirable.

      We can see this in the response to the Stern Review: People aren’t debating whether a large drop in global GDP would be bad. They’re arguing about whether Stern is correct that it’s likely under business as usual.

      • @Jonathan
        No. Arrow should there cannot be agreement on a social welfare function.

        Your examples of local agreement on parts of the social welfare function are irrelevant because most problems (and certainly climate policy) require agreement on the entire social welfare function.

      • Jonathan Gilligan


        Thank you for the rebuttal.

        Two questions to make sure I understand you:

        (1) If you’re right that it’s impossible to define dangerous anthropogenic interference with climate, then is it equally impossible to define dangerous global nuclear war, dangerous pandemics, and so forth?

        (2) Arrow’s theorem proves that in any process for making global policy there will always be a unique individual somewhere in the world whose preferences dictate all policy choices. And that different voting schemes, all of which are equally valid, will select different individuals for this dictatorial role. So am I correct in saying that Arrow’s theorem proves that there is no way of deciding world policy that’s any better than just imposing whatever Al Gore (or Nicolas Sarkozy, or Hosni Mubarak, or David Koch) chooses on the world?

        To me, Arrow’s theorem is a bit of a mathematical curiosity. If I understand it properly—and perhaps I don’t—it doesn’t show the futility of such exercises as attempting to define “dangerous anthropogenic interference.” Rather, it illustrates the limits of using mathematical utility functions to try to describe human preferences, choices, and behavior and the limits of trying to impose a rational choice model on human decisions that we empirically know (e.g., from prospect theory) are deeply and fundamentally irrational.

        Arrow’s theorem says there’s no good way to choose a restaurant when you go to dinner with your friends and it says there’s no good way for a society to decide the best balance of laisser-faire and government regulation. It even implies that there was no good way to treat the disputed Presidential ballots in Florida in 2000.

        And yet we do make such decisions and for the most part we do so in ways that the vast majority of those involved consider legitimate (Even the vast majority of Democrats in the US settled down quickly and accepted Bush as their president).

        If a majority can agree on a decision (or a preference ranking), voting paradoxes disappear; and if the vast majority of the pubic accepts the decision as legitimate then the fact that this decision is not uniquely determined by a global utility function seems irrelevant. If a vast majority of people around the world could agree that certain things would constitute “dangerous anthropogenic interference,” then I think we could all work with that as a solid starting point for UNFCCC.

        If I am wrong about any of this, I’m happy to be corrected.

      • @Jonathan
        According to the Impossibility Theorem, a social welfare function can be constructed if (a) one or two person(s) dominate(s) or (b) one or two issue(s) dominate(s).
        The alternative, as you rightly point out, is irrationality. I agree with you that there are many irrational aspects to the actual behavior of people and governments.
        I think, however, that a democratic government should be accountable for its actions, which in turn implies that it should be able to explain its decisions. Irrationality in inexplicable.
        More to the point, even when governments act irrationally, their academic advisers should give rational advice.
        The Impossibility Theorem shows that there cannot be an objective, unobjectionable definition of “dangerous”. That does not exclude subjective definitions, or definitions that preferentially treat certain people or certain issues.
        Any claim to an objective, unobjectionable definition of “dangerous” is thus false. The academic in question is either subjective or, perhaps unwittingly, lobbying for certain people or issues.
        These problems are routinely solved in a representative democracy. That does not license academics to pretend that their subjective values are objective facts.

      • Theorems like The Impossibility Theorem are problematic, because they prove something that may be in some cases an irrelevant curiosity and in others a dominating factor.

        Valuing alternative choices for human well-being belongs certainly to the second category. How to weight differing priorities of different living people in one small country is difficult enough, and extending the consideration to the whole world and to the future generations is certainly not going to make it easier. Add to that different approaches to risks and other uncertainties, and the mess gets even deeper.

        One book that may clarify some issues and open more for reader, who tries to reach deeper than what is written in the book, is Partha Dasgupta’s “Human Well-Being and the Natural Environment”. I have mentioned it in several comments here and on my own blog. As I try to express by the first sentence of this paragraph, I do not think that Dasgupta has solved the problem, but I think that he has succeeded in presenting some ideas that help in thinking about the issue more analytically. Doing that reveals, how deficient also Dasgupta’s proposed methodologies are, but that is really, what The Impossibility Theorem tells.

        There are no unique solutions, not even something close to that. That is a problem of UNFCCC and of many other UN bodies: They are often built as if there would be something close to a unique solution to world’s major problems of human well-being. The lack of unique answers should not stop us from acting in a responsible way, but it tell’s us that we should remain critical, when we sincerely believe that solutions proposed by others and accepted by some process based on historical accidents is leading to results contrary to improvement of human well-being, as we see it.

      • “Irrationality in inexplicable.”

        The irrational may accept irrational explanations.

        The multitude do not generally have a rational function for rejecting irrational explanations.

        As agenda management arguments go, pretending the academics comprise the exclusive set of all those seeking to substitute subjective personal values for objective fact defies observed, uh.. objective fact.

        Sounds like a subjective personal value to me. ;)

        And.. Don’t I recognize this argument from a gun rights debate? What’s it doing in Climate?

        Further, we don’t have to accept that what some consider a non-danger must therefore be the general rule, if that danger is priced correctly on a fair market, or if the for the good order of markets the freedom of some to accept a danger ends where more fundamental freedoms of others begin. Why should we?

        You may accept the risk of buying into a Ponzi scheme in its early days, but the Market has the right to protect itself from that form of fraud. Sure, another, ‘better’ market might spring up to replace the current one, and in some sense infinite regress applies, but let the future claw its way into existence without the help of common criminals, if it can. If it doesn’t exist yet, it can’t have rights, and those who would benefit from its existence ought be willing to pay the switching cost within the current Market.

        All markets seek their own demise, in any event, under the democratic control of their individual participants.

        In the case of Ponzi schemes, because the downfall of the Market itself is a danger, the danger is objective and absolute, regardless of the illegitimate claims of Bernie Madoff.

        We don’t have to consider the objection of the felon in the definition of the danger.

        We don’t even have to consider the objection of complicit victims addicted to the perceived reward.

        There are objective definitions of ‘Bads’ in Markets (ie Goods in the part of their demand curve with inverted or zero elasticity of demand; the more an individual buys, the more they crave), which are, again, objective dangers.

        So, nice Theorem, but it doesn’t pay its own freight.

      • Jonathan Gilligan

        @Richard: Thank you for explaining. We have no disagreement.

        I didn’t imagine that anyone still really thought “dangerous interference” was remotely an objective term, so I misunderstood you when you said it couldn’t be defined and thought you were referring to the voting paradox aspect of Arrow’s theorem as saying that a politically legitimate definition was impossible.

        Of course the term is a subjective political term and of course any political process that defines it should be open and representative to ensure the best chance of the resulting definition being legitimate with the public.

      • @Jonathan
        I’m glad we agree. Now for the rest of the world …

      • I’m not sure I understand the relationship between an objective definition of dangerosity and the Arrow theorem. Let’s suppose for a moment that the Arrow theorem is false: does that imply that it would then be possible for the concept of dangerousity to be objectively defined?

        The relationship between being objective and being unobjectionable merits due diligence.

      • “Consider the question, “What constitutes dangerous asteroid impact.” There are clear thresholds for which consensus would be easy.”

        Not until you clearly state what it is that the asteroid impact would be dangerous to. A .1 kg asteroid impact on the hood of your car as you drive down the freeway would be exceedingly dangerous to you and anyone within say 100 meters but it would have no appreciable effect on global albedo. Talk about what might cause dangerous climate change is plagued by input uncertainty – what will cause climate to change – and output uncertainty – what effects that change in climate will have. Is an expansion of a species’ range due to global warming “dangerous” per se? Is an increase in agricultural production due to global warming “dangerous” per se? Surely it is obvious that every change is “dangerous” to something, somehow; and equally surely it must be obvious that a lack of climate change also endangers something somehow. “Dangerous” inherently subsumes some estimate of probability – so how probable are “(e.g., multidecadal Dust-bowl severity droughts over large parts of the inhabited continents)”. If they are exceedingly improbable, then they are not dangerous either.

      • Jonathan Gilligan

        @JT: Would anyone deny that a 1 cubic kilometer asteroid would be dangerous?

        I agree that small scale things can be dangerous to some people but not others, but I’m saying that even though we may disagree about those things, there should be some level of consequences that we could all agree would be very bad.

        My point was that the arguments we’re having are mostly about probabilities of things happening, not so much about whether those things are desirable if they do happen. You and I would probably agree that a multidecadal dust-bowl drought covering most of the world’s agricultural land would be very bad. We probably disagree about how likely it would be.

      • @ Jonathan Gilligan: “You and I would probably agree that a multidecadal dust-bowl drought covering most of the world’s agricultural land would be very bad. We probably disagree about how likely it would be.”
        I agree that “a multidecadal dust-bowl drought covering most of the world’s agricultural land would be very bad”, but I do not think it logical to say that because a thing would be bad if it should happen therefore we are in danger of it happening. It seems to me that the word “dangerous” is being used very ambiguously. Sometimes it means something like a measure of how much damage an event would cause if it were to happen, and sometimes it means something like a measure of how near we are to causing the happening of the damaging event, and sometimes it means something like a measure of how likely we are to cause the damaging event. When you speak of “dangerous anthropogenic interference with climate” are you speaking of the magnitude, the immanence or the probability, or are you rolling them all up into one?

  4. “When I use a word,” Humpty Dumpty said in rather a scornful tone, “it means just what I choose it to mean – neither more nor less.”

    • Wasn’t that Tweedle Dumb? In any case Alice replies, more or less “The question is can you do that?” implying correctly that you cannot. Carroll was a logician (as am I).

      • Another question: Is the UNFCCC Tweedle Dumb or Alice?

      • Yet another article arguing for “reframing.” Why didn’t anyone think of that before?

        And Humpty Dumpty wasn’t (a logician). Which is the point. Progressives who constantly want to “reframe” their issues because they have been rejected by the public are the Humpty Dumptys.

        CAGW – Climate Change – Climate Disruption – Dangerous Climate Change – Dangerous Anthropogenic Interference; if we can just give it the right label, maybe all those voters refusing our statist solutions for a problem we can’t prove exists, will be fooled enough to let us pass them anyway.

        “Yet, no actual large-scale threshold (or ‘tipping point’) in the climate system (of which there are probably several) has been clearly linked to 2°C global warming.” Yes, by all means, let’s assume there are several tipping points, and get on with planning the energy economy. Now THAT’S the climate science we have all come to know and love.

        And since when is Rajendra Pachauri a scientist, of climate or anything else? Aren’t his degrees are in industrial engineering and economics?

      • simon abingdon

        Tweedledum wasn’t dumb.

    • The question, said Alice, is can you make words mean so many different things.

      The question, said Humpty, is who is to be master – that is all.

      (paraphrased, but you can look it up)

  5. Trying to do regional forecasting is one thing, but this is simply ridiculous. In other words, one scare is not enough, so lets have an endless supply? Consider this quote: “Target setters need to take into account all the factors that threaten to tip elements of Earth’s climate system into a different state…”

    Just how many of these speculative threats are there, such that our “target setters” should take them into account? I sense a new Federal Department of Target Setting in the making. Setting targets for “land use” is especially threatening. (Kim, we need you here.)

    • randomengineer

      It’s worse than you think. This seems to be an exercise in making the target so big that it’s easier to hit it. Once a hit occurs then the target makers trot out the original target and claim that this is the one that was hit.

      This is the same approach taken by anti-abortion activists where they can’t get their desired legislative changes through, so for the next 6 elections they attempt decreasingly punitive changes until one looks like it can pass — at which point they claim universal agreement of the electorate of their original premise.

  6. I think most of us would welcome the acknowledgement that the widely used threshold of 2 degrees is not very meaningful.
    And Pielke sr will be pleased to see someone from UEA admitting that other things such as land use changes could be more important than greenhouse gases.

  7. Rachendra Pachauri is top chuff=chuff what?

    • look at Romm’s Wikipedia entry…everybody can claim to be a climate expert nowadays…

    • That was my reaction. WTF? A railroad engineer? Where’s my “top climate scientist” badge and secret decoder ring?

  8. While it’s encouraging that he realizes that multiple issues exist beyond GHGs (black carbon, etc.) and that narrowly focusing on a limit provides no safety, the idea that the UNFCCC be “extended” doesn’t make much sense. It’s failed so far when narrowly focused, I have little expectation that it would have more success on a broader front.

    I agree that looking at “winners and losers” on a finer-grained basis (regional and below) makes more sense. As does tailoring policies to more local needs.

    • the idea that the UNFCCC be “extended” doesn’t make much sense

      Depends on your purpose. Extending the UNFCCC means giving it more money, more people, more power – probably a LOT more power. Another step to global governance

      • Another step to global governance

        Oh, brother. ONE WORLD GOVERNMENT1!!!1!!!!!1, eh?

        What’s next, Bilderberg group?

      • We’ve been through this here before, Josh – get some education on the subject before shoving both feet in mouth. Google “global governance”.

  9. I just keep coming back to King Kanute when i read things like this.

    I agree that focussing on regional impacts rather than global makes more sense from a policy viewpoint, however i still bemoan the massive in-built assumptions (i.e. that cAGW is correct).

    The climate has always changed, this, i don’t think anyone can contest, so it is reasonable to say that at any given point there were always adverse climatic impacts at some part of the planet; be it too cold at the higher latitudes, too hot near the equator, sea levels up, sea levels down, etc etc.

    The problem you have with trying to expand everything to a regional level and further, trying to encorporate all the other potential climatic drivers is that you can have no hope of a clear level of attribution for any of these discrete factors.

    We STILL haven’t defined the co2 related cAGW contribution, despite 30 years and practically limitless funding- so to think that expanding the ‘scope’ of this research will do anything but hopelessly muddle the issue is well, madness.

    Yet, of course, this is not the aim. The aim is to increase the scope for ‘action’ rather than actually increase the level of knowledge on the system as a whole.

    Before we go down the road suggested above we need two things:
    1- a clear and (reasonably) quantifiable knowledge of all the natural climatic factors
    2- a clear and quantifiable knowledge of co2’s role and interaction with the natural climatic factors.

    Anything else is just posturing.

  10. Bad Andrew

    OK, so we don’t know what Dangerous Climate Change is supposed to be.

    Let’s make it simpler.

    In what area/region/locality has the climate changed at all, and when, specifically?


    • Erm… everywhere and constantly…

      • Bad Andrew


        If that is true, then you should be able to give me a specific location and time and what constitutes the ‘change’ that happened there.


      • Oh… i thought you were being flippant.. you’re actually being serious?!?!

        Ok, here’s a few:
        – Uk used to be warm enough to grow wine with massive vineries covering the countryside, it has since got colder
        -greenland actually used to be green, with viking settlements present it has since got colder
        -Europe used to be under a massive ice sheet….. it has since got warmer..

        Or were you trying to suggest somtehing else?? You can’t be trying to suggest that the climate doesn’t change. Or are you trying to suggest that recently the climate has been remarkably stable, in which case i’d agree.

      • Bad Andrew


        Yes, I was being serious. The point I’m trying to illustrate is that warmers are persistent in crying that we need to address the climate change crisis. I’d love for someone to point me to a specific example of where exactly the climate has changed, how much, and how specifically some event there should be considered a crisis.


      • Gotcha. I got completely the wrong end of the long woden thingy.

      • The argument seems to be that every weather danger we have is now x% worse that it would have been. Usually they say 5% worse since it is a small enough increment that can’t be proved. So the Russian heat wave, or the UK floods, or Katrina, or the Euro 2003 heatwave are all incrementally worse due to CC and over time we are doomed, according to the believers.

        The current issue of ‘Science’ has some article about how climate is responsible for making current food prices 5?% more expensive. I haven’t read the article but from other reports it seems like the things attributed are those events I listed above. I don’t know if they took price of oil (the more obvious reason) into consideration or the demand from the increase in population.

      • Bad Andrew

        “every weather danger we have is now x% worse that it would have been”

        And when the weather is normal/good, AGW has no effect at all. It’s amazing, the moral foresight of this phenomenon. It seemingly has a diabolical bent! Al Gore and Judith Curry save us!


      • The weather is now good, but not as good as it would have been without global warming.

  11. If I leave off James Lovelock’s name, I still count 11 names on that top 10 list. But I suppose that makes sense cuz Pachauri is not a scientist.

  12. Hector Pascal

    King Canute. Why is it impossible for seemingly intelligent and supposedly well educated people to understand the story of Canute?

    Canute ordered the tide to retreat to demonstrate to his sycophants that the power of Kings had no control over nature. This children’s story has real meaning wrt AGW. Please get it right.

  13. As I have been saying for years: The issue is not if CO2 changes or influences the climate. The issue is dangerous change.
    It is astonishing that the climate science community has declined so far to define this clearly.
    But it is not surprising at all.
    It is in fact expected, since under any reasonable definition of ‘dangerous climate change’, we are not experiencing it.
    The climate science community is being dragged kicking and whining, like Monbiot, to this realization.
    This emerging realization also puts an even harsher light on Trenberth’s phony null hypothesis.
    As to regionalized views, since the AGW community has demonstrated no meaningful ability to predict anything regionally, this is really just a dodge to to allow more conflations and fabrications about extreme weather events.

    • Or in short, they’re redefining the appearance of the Great Pumpkin to include lesser pumpkins.

      • ChE,
        The lessons of how magical thinking and inverting null hypothesis in climate science/environmentalism have created problems has implications for many other areas of human endeavor.
        I posted some links and quotes from omnologos and his blog site. I urge you to read them or better, his site.
        I believe you will find them very interesting.
        (And no, he did not pay for the tout, and neither did the Koch brothers ;^) )

      • And even squash.

      • Or pumpkin pie…..

      • Yes. They’re moving the goalposts again.

        Dealing with CC/weather on a regional basis is only makes sense – as presented here –

        But extending the reach and power of a global organization to deal with it doesn’t unless you’re hell bent on “global governance” by the UN.

  14. “It is in fact expected, since under any reasonable definition of ‘dangerous climate change’, we are not experiencing it.”

    Which is why we’re seeing all this desperate attribution. No matter the weather related catastrophe, there will be in the next 24 hours something written in the MSM to the effect that it’s related to “climate disruption” formerly climate change, formerly global warming. Even events that any sane person would agree is unrelated to climate, like earthquakes are subject to climate attribution.

    • pokerguy,
      But now we who are skeptical of the revealed wisdom of AGW are considered subhuman, with underdevelpped brains and therefore to be ignored (until a better solution comes to mind, of course).
      The believer community is on the verge of some very serious and tragic errors. I hope enough of them will realize what Monbiot is really saying to prevent the logical outcomes of this movement from happening on too large a scale.

  15. Craig Loehle

    Reasoning from wrong premises is just wrong. There is no proof except in Hansen’s mind that there are any tipping points in the climate system. 2 deg C was chosen for political reasons. Assessments of effects of climate by 2100 on agriculture, forestry, and natural ecosystems generally show positive effects when the beneficial effects of elevated CO2 on plant growth are included in the models or experiments like FACE are extrapolated. Why do we care about “irreverible loss of ice sheets” if it takes 3000 years for them to melt (and much of Antarctica never gets anywhere near the melt point of ice, with surface melting due to sunlight, not air temp, so it isn’t going anywhere soon unless you move it to higher latitudes). A warmer world will have fewer tornados, not more. And so on. This essay is simply a way to find harm in some localities when the overall harm is unlikely to be significant.

    • It seems like every time the crisis is rebranded, what we end up with is old begging of a new question.

  16. Craig Loehle

    Basing policy on regional impacts is even more foolish that basing it on global. Here is an extract from a paper I have submitted:
    Output from a climate model is often used to evaluate ecosystem response, perhaps with a regional downscaling first. These outputs are virtually always taken at face value for conducting impact studies. Any particular model, however, may have known skill and bias issues with respect to regional climates. Skill can be evaluated by matching the pattern in time or distribution of temperatures or rainfall between the model and historical data. For example, a GCM might produce skillful annual precipitation amounts, but the seasonal distribution could be very different from actual. The seasonal amounts could be critical to properly simulating plant growth. Similarly, a GCM could consistently predict temperatures too warm for a region, even though matching historical trends. This could lead to modeled impacts that are not realistic. In IPCC assessments in which global trends over 100 years are being evaluated, these skill and bias issues may not affect the calculation of trends, but at the regional/local scale for simulating ecosystem response, they cannot be ignored.
    Anagnostopoulos et al. (2010) compared six climate models at multiple scales to weather data for the contiguous USA. Model results were all warmer than the observed mean annual temperature and minimum monthly temperature by up to 4°C. This bias creates an obvious problem for any bioclimatic (niche) model used to forecast future distributions because absolute temperatures, not just trends, are critical to biological processes. This is particularly true when niche models are developed using actual (not model) climate data, which do not share the model bias. Likewise, at the continental scale they found modeled precipitation to be 36% above the true value which has implications for any model that simulates plant growth. Schliep et al. (2010) and Stephens et al. (2010) noted multiple failings in the ability of GCMs to model precipitation, including both bias and lack of skill.
    Consider a model that produces output at the dry end of what occurs in a particular region. A model of forest growth is run under constant climate, but because of the climate model’s temperature bias, the simulated forest is near the point at which drought stress would cause dieback. Under almost any additional warming, this simulated forest using this climate model would show dieback. This bias can be addressed by comparing the GCM output to local weather data and adjusting the model bias (as Ines & Hansen 2006) before simulating forest growth (for both control and impact scenarios). If it is determined that skill is lacking (e.g., rainfall frequency distribution is wildly wrong or seasonal temperatures are not proportional) then another model should be used. In any case, climate model adequacy for the intended purpose should be evaluated rather than treating model output as if it were “data.”

  17. He refers to a preindustrial temperature. What was it?

    • Cold.

      • or hot.
        dry and wet.
        calm and stormy.
        variable and unpredictable.
        In other words, just like today.

      • hunter – of course it was cold you denier, you.

        Actually I wonder why nobody has chosen to demonstrate global warming not using the size of female underwear but the simple fact that people do go to the beach nowadays whilst 150 years ago they didn’t really – plus we have no mention in Dante or Chaucer of any bikinis (would have been made of cast iron, no doubt) despite the MWP.

      • I wonder what versification Dante would have been inspired to by these sorts of iron maidens?


      • Who had time to go to the beach 150 years ago, when you had to work 17 hours a day in the summer in order to eat?

        The good old days weren’t that good.

    • I’m serious [well, sort of ;-) ]

      What does he think is the ideal temperature for the earth and how did he make that calculation?

      • The ideal temperature for the earth is the modern normal. We have been at this temperature for ten thousand years and have adapted to it. What we have adapted to and what we are used to is the ideal temperature. Any temperature above or below this would be very disruptive. People would have to relocate and our way of life would have to change. We are very lucky. Temperature is extremely stable and it will stay in this range.

  18. the signature of anthropogenic climate change is not in the temperatures being higher but in them being higher than they would’ve been (c) Science magazine

  19. Are climate scientists any better at predicting regional climate impacts over global impacts? As I recall the Australian floods were linked to climate change, but droughts were the prediction.

    This is all theoretical — or just more propaganda — until climate scientists demonstrate their ability to predict climate as well as meteorologists predict weather.

  20. Dr. Curry
    +2C may not be such a danger for humanity as suggested, it would open up to the human habitation Siberia, Northern Canada and Alaska, the largest sparsely populated fertile, rich with natural resources land masses on the Earth.
    On the other hand -2C would be disastrous, since most of the temperate zone is already over populated; only hope would be possible but not inevitable greening of Central Australia, Sahara, Kalahari, Gobi etc.

  21. Hi Judy – Thank you for alerting everyone to the article. I have just posted on this also; see

  22. Ken Denison

    Pardon my gross oversimplification here, but what evidence is there that anything man has, is, or could do can cause change broad enough to which the earth and her marvelous system of auto-correction cannot respond? Think of all the volcanoes, all of the fires, all of the other natural changes that have occurred that rarely, if ever, caused a”tipping point” (global or regional). But somehow man can?

    Is it just me or do very few people have any common sense these days? Are we so lacking in problems to solve that we need to invent “boogieman” scenarios and spend fortunes preparing for them?

    How did so many “scientists” lose there collective minds?

    • Craig Loehle

      Those not born with common sense typically get more of when forced to catch or grow what they eat, build things etc. Few people today get experience with physical objects that are uninterested in memes and fads and concepts and thus have few chances to develop practical common sense. It is noteworthy to me that I hear almost no engineers who are believers. They have experience with being wrong. Elitists never experience being wrong because they just ignore contrary evidence or spin it away.

      • Yeah, we engineers construct models of a short enough term that we have seen them blow up in our faces many times. Of particular interest to me are those engineers in computational fluid dynamics — generally for airfoils and combustion chambers — using many of the same underlying algorithms as those in climate models. I have found them to be uniformly scornful of the climate models, and incredulous that anyone would take them seriously as predictive tools. Their own much simpler models often go drastically wrong.

      • Students of computational fluid dynamics are arguably among the most sophisticated modelers available. Until climate science brings members from centers of excellence of the fluid dynamics community and statisticians of Wegman’s caliber in as collaborators, their results must be considered suspect. Until climate science produces high quality engineering studies which are subject to the same liability standards that professional engineering reports are held, their results must be considered suspect.

      • Yeah, the real world can be quite humbling.

        “Engineering is the art of modelling materials we do not wholly understand, into shapes we cannot precisely analyse so as to withstand forces we cannot properly assess, in such a way that the public has no reason to suspect the extent of our ignorance. ”

        -1946, A R Dykes, Scottish Branch, Institution of Structural Engineers

      • Ken Denison

        Funny you say that about engineers because I am one and have noticed the same.

      • Absolutely, indeed. One of the formative experiences of every young, cocky engineer is failing spectacularly. People like that usually pick themselves up and learn from the experience, and come out of the experience older, wiser, and experienced.

        The ones who don’t go into marketing.

      • Don’t get carried away my dear colleagues…there is a paper out there somewhere that DEMONSTRATES WE ENGINEERS ARE FAR-RIGHT EXTREMISTS BY NATURE.

        I kid you not.

      • They’ve obviously never been around a civil firm. Or these guys:

      • ChE –
        Not sure who those guys are – and don’t care. As engineers, they suck.

        A good friend who lived in NYC watched both planes hit the Towers. I missed the first, but watched the second. The plane that hit the Pentagon passed over my brother’s car as he was headed for a meeting in the wing that was hit. My best friend’s daughter was IN the Pentagon with a group of interns – she was the only one to survive, and she lost some body parts.

        The damage that resulted was NOT – repeat NOT – caused by explosives other than the 200,000+ lbs of jet fuel that was on board the planes when they hit. That was quite sufficient.

        As an engineer you may know that jet fuel CAN melt steel, which is precisely what happened to the Towers – and at the Pentagon. Once the structural steel in the floors of the Towers that were hit softened, then it was a simple demonstration of gravity as the upper floors collapsed right through the Tower structure and took them all down.

        And BTW – another friend was the construction supervisor for the Towers. He committed suicide afterward.

        I didn’t spend much time at that site – but it REALLY ticked me off. I’d like to think that NO competent engineer would sign on to that mess. But then I know some (very few) engineers who are acolytes of the Church of CAGW. Being an engineer is no guarantee that one is more sane, logical or rational than the average politician or psychologist – just a lot more likely.

      • steven mosher

        you build what we tell you to build, nerd.

      • yeah, most customers live according to that mistaken (but useful, to us) assumption. let’s leave them like that shall we

      • You don’t happen to have pointy hair on both sides of your head and a little white dog as a management consultant by any chance, do you?

      • “It is noteworthy to me that I hear almost no engineers who are believers”

        I’ve also noticed this. The people who actually have to make things that work in real life – or else their jobs or even lawsuits are on the line – seem to almost unanimously “face palm” at what passes muster in climate science. If climate science were bridges or planes the entire field would have been sued into oblivion years ago.

      • Stirling English

        Engineers do not know anything.

        They do not have PhDs in Radiative Physics. Some of them have never been invited into a Senior Common Room in their lives. Many have never even written one academic paper, let alone been cited hundreds of times. Some even resort to ‘experiments’ in defiance of the received wisdom.

        They are just nasty grubby individuals who just won’t believe what their better qualified and cleverer intellectual superiors tell them.

        In an ideal world there would be no engineers and the universe would work just as the theories and models predict.

      • Engineers don’t bother at all with these climate gimmicks.

      • In an ideal world, no engineer or scientist would ever have political power and no lawyer would ever be allowed to hold public office – or write laws.

        But then, in an ideal world, all machines would be weightless, last forever, have zero losses, use zero energy and output infinite work. And all dogs and children would be born already trained. :-)

      • In the real world, people born, learnt and then died, what a waste!

        So, Stirling, Jim, me and the rest of the world are wastes. LOL.

      • randomengineer

        It is noteworthy to me that I hear almost no engineers who are believers.

        Seconded — from the trenches.

        I’ve noticed another thing as well. Dangerous climate change tends to not be believed by anyone without an ultra-secure income, either. People who collect taxpayer money directly or via fiat (e.g. teachers) are far more prone to believing this stuff.

        Engineers etc tend to live in an “adapt or die” environment where one is always updating skills etc just to maintain status quo, much less differentiating oneself from the herd. Failure to maintain currency is the path to irrelevance and layoff. Engineers tend to not be funded for this by employers and are doing said skill updating on their dime and their time. Good engineers do a lot of reading etc at home. The local HS history teacher meanwhile is updating skills merely by attending fully funded “in-service” sessions in lieu of teaching that day. Insurance agents have a government mandated customer base (insurance is required just to drive!) and need merely to keep up with fairly minimal law changes, which are again taught in sessions, not via homework of the individual agents. So not only is the workday mindset different, so is the underlying approach to the job.

        It’s the approach that seems to be the driving factor. Engineers are the nexus of the double whammy — they are compelled to self-update and the job itself requires making theory practical.

      • Wile E. Coyote II

        Has anyone ever done a demographic study of climate change beliefs? That could be quite interesting. I would like to see how partisans it is, by occupation, climate region, and by IQ (of course).

        I know there have been polls but if they just ask a simple question like “do you believe in man made global climate change?” but that certainly could interpreted in many ways by an intelligent person.

      • You’d want more nuance than that. If it’s a multiple choice question, there’d be about 10 answers. This isn’t as simple as “do you believe”.

      • Wile E. Coyote II

        ‘Don’t know’ would have to be a question. It would be interesting to see how many people just agree because of public opinion. Perhaps varying degrees of knowledge could be taken into consideration.

        I just remembered a Feynman clip I once saw that helps explains the difficulties of explaining something complex to someone.

      • Wile E. Coyote II

        oops, I meant ‘don’t know’ would have to be an answer.

      • And specifically, do you believe in the greenhouse effect, and do you believe in high feedback, and tipping points, and are the glaciers all going to melt, and is Manhattan gong to be underwater, and does climate change cause tornatoes, etc. And each of those question should have “WTF is that?” as one of the answer choices.

  23. When confronted with a difficult problem, redefine and overconstrain it

  24. son of mulder

    The top ten list consists of eleven names. So they can’t count, convincing start. So 2 deg C? 6 deg C? Double CO2? Now Dangerous Anthropogenic Interference. What evidence for such tipping points? Modern Society essentially developed in 120 years (including 2 world wars) so any needed adaptation would be easy by comparison with that, given modern and evolving technologies. So any local problems would be best dealt with IF they start to occur, like with earthquakes, hurricanes, tornadoes and floods etc. And planners need to remember and apply the story of the 3 little pigs and the big bad wolf where appropriate.

    • Yeah, but one of the names was Pachauri (obviously planted on the list as a joke).

  25. maksimovich

    Given that the words “dangerous climate change” feature prominently in the UNFCCC treaty, we should figure out what these words actually mean or at least try to come up with an operational definition in the context of the treaty. The continued failure to do so (for lack of even trying) is just astonishing. Most of the effort undertaken seems to be attempting to sell spurious links between death and destruction from tornadoes, tsunamies, etc to climate change.

    Indeed crisis sells , unfortunately this is a very complex problem in the mathematical sense,and not amenable to a simplistic description.

    The assertion that say extreme events are a signature for AGW or whatever,without a meaningful study, by a number of scientists are very unhelpful.

    It is also unfortunate that a number of authors of a number of the various AGW “franchises” only have a primitive and naive understanding of the mathematical literature and the constraints implied ie the classical literature needs revision. eg Nicolis et al 2006

    In a subsequent paper 2007 the conclusions are quite succint.

    The return time of extreme events is of central importance in their prediction and in the design of appropriate protection measures against
    possible damage. We have shown that the probabilistic properties of this basic predictor generated by deterministic evolution laws —the kind of laws that govern natural systems— are completely different from those predicted by classical statistical theory.

  26. DAI – Oh goody. A brand new meaningless phrase!
    Dangerous to what?
    Seems the current flatlining of temperatures are very dangerous to the AGW crisis research-industrial-financial complex.

    • Actually DAI (or “almost DAI”) was coined by James E. Hansen of later “coal death train” notoriety, in his testimony on 26 April 2007 to the Select Committee on Energy Independence and Global Warming, U.S. House of Representatives.

      (Probably thinking that the congress members would not understand the word “anthropogenic”), he called it “Dangerous Human-Made Interference with Climate”.

      Read his testimony. It’s good for a laugh.

      Then, to come back down to the planet Earth, read the later testimony of either of the famous climate “JCs” (John Christy or our hostess here).

      Quite a contrast from Hansen’s hysteria.



  27. Hoi "Bodge" Polloi

    “I was flattered to be listed among the ten most respected climate scientists by the Financial Times.”

    Climatology: “The Unbearable Lightness of Being”…. *sigh*

  28. ‘The global coupled atmosphere–ocean–land–cryosphere system exhibits a wide range of physical and dynamical phenomena with associated physical, biological, and chemical feedbacks that collectively result in a continuum of temporal and spatial variability. The traditional boundaries between weather and climate are, therefore, somewhat artificial.’ Hurrell et al 2009

    There is an evolving paradigm of dynamical complexity in climate. This does imply sensitive dependence and Dragon Kings – defined as extreme events that occur at a chaotic bifurcation. ‘We emphasize the importance of understanding dragon-kings as being often associated with a neighborhood of what can be called equivalently a phase transition, a bifurcation, a catastrophe (in the sense of Rene Thom), or a tipping point. The presence of a phase transition is crucial to learn how to diagnose in advance the symptoms associated with a coming dragon-king. ‘

    There has been little progress on predicting Dragon Kings – such that the practicality of these prescriptions is severely limited. If they managed to define tipping points – I would take it with significant reservations. That said – phase space shifts are ubiquitous in Earth systems at all scales and may theoretically occur as a result of changes in greenhouse gases in the atmosphere and sensitive dependence.

  29. “But now we who are skeptical of the revealed wisdom of AGW are considered subhuman, with underdevelpped brains and therefore to be ignored (until a better solution comes to mind, of course).”


    That made me laugh :>) Maybe they’ll establish some sort of colony to which we can all be banished. Or better yet, we’ll all be sent to “reeducation camps.”

    Joking aside, I share your sense of urgency. I think those who expect the warmists to simply retreat in the face of an unwarming world are naive. They won’t quit, no matter what happens. If as some of the long range forecasters I respect are anticipating, the earth cools over the next two or three decades, they’ll find a way to blame “carbon” for that too…

    • If their climate theory is wrong, their climate models will be wrong and they will fail to forecast snow and cold, time and time again. This past decade has been consistent. The consensus climate scientists predict warmer, based on increased CO2, but it snows and gets colder, time after time, year after year. Look at their long range winter forecasts that are made in October each year and look at the snow and cold that has occurred in the winters that have followed. How many times can they make a forecast that is wrong and still be percieved to be right.

  30. pokerguy –
    That made me laugh :>) Maybe they’ll establish some sort of colony to which we can all be banished. Or better yet, we’ll all be sent to “reeducation camps.”

    Not sure I’m laughing. I’ve seen the “reeducation camps” coming since 1985 when I first got involved in politics wrt gun control. (True “gun control” is being able to hit your target – every time). More recently there are those who’ve proposed sending “denialists” to prison or levying heavy fines – or committing them to insane asylums. Can you guess my feelings on that one?

    Being paranoid doesn’t mean nobody’s out to get you.

  31. another version

    Just because you think you’re paranoid, doesn’t mean someone isn’t following you.

  32. I thought the whole brilliance of the 2deg thing was that the climate scientists could live with it and if we never ever got near 2deg, then we don’t ever have to do anything.

    The whole redefinition effort therefore is a renewed attempt to get climate research back on the megafunding wagon.

    Just say no. Make climate scientists fight for research funding just like every other researcher has to.

  33. Paul Vaughan

    “To address this, a reframed policy objective is proposed; to limit the overall magnitude, rate of change, and spatial gradients of anthropogenic radiative forcing, and resultant climate change, through restriction of emissions of anthropogenic aerosols, patterns of land use, and concentrations of short-lived, as well as long-lived, greenhouse gases.”

    One of my areas of specialization was ecology. Even if there was so much control over nature as presumed, deliberate pattern & process changes would benefit some species & individuals while harming others.

    “‘[…] (or ‘tipping point’) in the climate system (of which there are probably several) […]”

    Such proclamations leave few (if any) avenues for sensible discourse.

    Environmentalists appreciate nature while “environmentalists” (what they call themselves, not what they are) appreciate anthropogenic computer fantasies.

  34. Redefining global warming:

    1. real or imaginary?

    2. natural or anthropogenic?

    3. positive (good) or negative (bad)?

    4. dangerous or benign?

    5. action needed or not?

    6. mitigation or adaptation?

    7. who needs to do what by when?

    We have probably answered question #1 (if GMTA is the right indicator and is, itself reliable).

    All the other questions still remain to be answered.

    And, as JC has stated, this will probably be a series of regional questions and answers, rather than a simple global one.


    • Here is a picture of the decision process for redefining global warming.

      Redefining Global Warming Decision Process


      • if you’re doing this seriously, of course even if it’s natural we need to adapt to it if it’s dangerous

      • this is a good one, thx

      • You need another reach around line, triangle #2 doesn’t automatically go into the garbage can if CC is natural; it needs to go to another triangle, and decide if it’s negative/dangerous or not. We may need to adapt to natural climate change. And no, that doesn’t mean reducing CO2.

      • IOW, #2 needs to go to the bottom of the chart, but the action is different depending on natural or anthropogenic.

      • son of mulder

        Nice diagram. Just one additional quibble if it is found that Climate Change has an anthropogenic component and it is good then we need to take advantage of it and not put it in the trash.

    • Try my version:

      Redefining global warming:

      1. Whether real or not, is it the main issue or a sub-issue of more fundamental questions?

      2. Are these more fundamental questions at least partly man-influenced and influence-able?

      3. Is the potential ‘good’ so great that unilateral action justifies usurping the rights of those who may not condone that ‘good’, including both those who may find it ‘bad’ and those who may demand compensation for our ‘good’?

      4. Is the potential danger, regardless of the beliefs of some, sufficiently compensated for to those exposed to Risk and Uncertainty, and are those involved in the Risk consulted democratically before unilateral action undertaken?

      5. Continuing antidemocratic, risky, costly actions should be halted or not?

      6. Payment? Democratic input?

      7. Who needs to stop doing what by when?

      • A clown tumbles down
        The endless Hall of Mirrors.
        Endeavour to please.

      • That would make kim the Circus Rider? ;)

        (Google Charlie Chaplin, “The Circus” if you’re as lost reading kim as I am.)

    • Not sure we have answered 1 yet. Gerlich and Tscheuschner have argued that the notion of a global mean temperature to begin with is flawed. Certainly, if one started from scratch and had a proper think about how to properly measure global mean temperature, the measurement process and methods would be rather different from what we have now.

      So for example, how would one define and measure the mean temperature of the property they live in – inside and outside the dwelling and bounded by the property boundary to some height??

  35. Yet another expert I’ve never had time to discover and follow whose views seem to me so compellingly reasonable, well-founded and thoughtful that I must immediately doubt them all, question them all, and skeptically process them all before I feel comfortable discussing them.

    However, at the outset, the ideas are certainly not easy to dismiss.

    Isn’t much of what he says plain common sense?

    Once that common sense is on the table, isn’t it plain good sense to pursue these interesting questions where ever they lead, even if it is to conclusions we cannot foretell, or expect we may not wish to consider?

  36. Curiosity
    Is the cross we gaily bear.
    Pomegranate Seeds.

  37. Robert Hort

    Republican factory owners killed your family and friends in the catastrophic blizzards, floods, tornadoes, massive wildfires and other climate change that has been wiping out the bible-belt. This is the Climate Change that their factories created. This is the Climate Change that the Republicans lie about not existing. This is the Climate Change that they program their constituents to deny exists. This is the Climate Change that killed people, destroyed homes, further destroyed the economy that the Republican factories emissions caused so they could make profits by killing those people. Republicans deny Climate Change at all costs in order to keep their factories from having to pay to stop it. The Climate Change that is destroying massive sections of our country can no longer be hidden or denied. The issue of Climate Change is TOTALLY ONLY about Republican factories which cause Climate Change getting charged to put filters on their factories.

    • Ya know, you’re not really worth answering. But I will point out three little facts that you overlook. First is that not all factories are owned by Republicans. Second is that there is no link between Climate Change and the weather events you decry. And third is that if you had any idea what you’re talking about, you’d know that Climate Change in the sense you use it is uncertain, debatable and possibly non-existent.

      I’ll add 2 more unsolicited comments –
      1) I’m not a Republican.
      2) I rarely use this word, but you’re an idiot.

      • Jim Owen

        I know we’ve had our differences in the past, and likely will in the future..

        However, barring it coming out that this apparent troll intended parody.. and even if it does..

        I’m with you on this one, Jim.

  38. Pooh, Dixie

    The topic of this post is “Redefining dangerous climate change”. The abstract quoted reads: “… mean surface temperature change, with 2°C above preindustrial being the most widely accepted climate policy ‘target’.” The quotations go on to say: “Global average warming is not the only kind of climate change that is dangerous, and long-lived greenhouse gases are not the only cause of dangerous climate change.” and “The climate problem, and the political targets presented as a solution, should be aimed at restricting anthropogenic radiative forcing to limit the rate and gradients of climate change, before limiting its eventual magnitude.”

    However, Timothy Lenton assumes that the problem is warming, even in his title reference to “2C”. He advocates giving broader policy (i.e., political) mandates to the UNFCCC.

    History argues that Cold is more dangerous than warming (dislocation, starvation, disease, etc.). Existing UNFCCC mandates would already limit mankind’s ability to respond to Cold. These are smart people, and it is (to me) incredible that this “Black Swan” or “Dragon King” has not occurred to them. Perhaps there are other reasons that the possibility of Cold is not being considered.

    “For instance, Mr. James Mill takes the principle that all men desire Power; his son, John Stuart Mill, assumes that all men desire Wealth mainly or solely. …”

  39. The top ten list.

    I could do the research myself but I’m hoping to be spoon fed it here. Of the names I recognise in the top ten list all seem to be either atmospheric scientists or modellers. Is this true? And is this a worrying bias?