Is Climate Really Changing?

Average global temperature has risen by about 1.5°F (0.8°C) since 1910:

Warming hasn’t been the same everywhere. Land areas have warmed faster than the oceans, the northern hemisphere has warmed faster than the southern, and the Arctic has warmed faster still — just as predicted by climate scientists decades ago.

The Arctic is the “canary in a coal mine” for global warming, showing far greater change than most of the world. Arctic temperature has increased about 5.3°F (3°C) since 1880:

Meanwhile, sea ice in the Arctic is disappearing fast, not only covering less and less area, but thinning dramatically (click the graph!):

Not only are the great ice sheets in Greenland and Antarctica shrinking, so too are the vast majority of the world’s glaciers. Because of this, and because warming makes the oceans expand, sea level is rising:

Temperature isn’t the only part of climate that has changed. Patterns of rainfall have altered, so some areas are now more drought-prone, others are more susceptible to flooding, and some regions have become more vulnerable to both drought and flood. Worldwide, total drought has increased since about 1970 (lower values indicate more drought):

When it does rain, it pours. There are more deluges than before, in large part because warming temperatures have caused the atmosphere to hold more water vapor:

Storms — especially damaging storms — have become both more frequent and more severe. According to the giant re-insurance company Munich Re (who sell insurance to insurance companies), weather-related disasters have more than doubled since 1980:


Yes, climate is really changing. Rapidly. But unlike the changes which have happened in the past, modern climate change is not natural.

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110 responses to “Is Climate Really Changing?

  1. I agree with all of your analyses and interpretations, except for the last 5 words, e.g., “… modern climate change is not natural …” While it is a strong and firm statement, it neither summarizes nor concludes the presented data presented. It is a polemical and, I feel, unnecessary value judgement that does little to advance what we know, do not know, or perhaps need to know. Please note, that I do not say, that it is a wrong judgement or statement, just that it is one that is NOT supported by data and analyses.

    [Response: Although the evidence is not presented in this post, it is supported by a truly vast array of data and analysis.]

    • If you took the facts above and deducted the factual influence of 7.x billion people would then the climate be changing anywhere near a rate of what we see happening?

      “Factual influence” in reference to a throw-away society producing all kinds of massproducts e.g. from electricity to steel, plastic rubbish to fast food by using 1.3 or most probably even more earths.

      This climate change is going to change our habitat; so even the slightest hint that it could be caused by ourselves, our lifestyle or just our ignorance should meet some last resources of human intelligence demanding precautions and consequences. Instead there are discussion still ruled by question beginning with “whether?”, “if!” and “me?” or “you!”

      Really silly; mankind obviously is stuck in the early days of a Kindergarten.

      caw

    • Kudos to you, Dr. Muenchow, for the work you do (I’m a fan). But as a primary researcher in the field you are perhaps a bit close to see the Big Picture.

      Shorter Tamino: The world is warming and we are the cause.

      Longer Tamino: A synopsis of the full data and analysis (i.e., the Big Picture) is presented here.

      • jasonpettitt

        The closest I get to doing actual science is organising a count of glow-worms in a field every once in a while.

        I couldn’t tell you a thing about glow-worms: what they like for breakfast, what sort of weather they like best or what the most glow-worm friendly length of grass is. I haven’t the faintest idea, and it would be wrong to try and deduce much from my sample size of 1 site.

        But I feed my data on to someone higher up the glow-worm nerd ladder. They get to see data from lots of sites and from that lofty position can start putting together a picture of the care and feeding requirements of glow-worms that’s far more convincing than anything I ever could.

        (also, top post Mr. Tamino)

    • Andreas Muenchow wrote: “While it is a strong and firm statement, it neither summarizes nor concludes the presented data presented.”

      True, for the data presented here in this specific post, as Tamino acknowledged, but surely you are aware that there is far more data than that contained in this specific post that does in fact support the assertion that current observed climate change is not due to natural forcings, so I take your comment as constructive criticism to either include the data that supports Tamino’s last assertion, or leave it out of the post.

    • I agree with all of your analyses and interpretations, except for the last 5 words, e.g., “… modern climate change is not natural …”

      There has been much response to Andreas Muenchow already, but there’s one small point that I’d like to develop.

      If the observed climate change is not due to humans then to where is the expected anthropogenic impact, as predicted by basic physics, disappearing? To deny human involvement not only does one have to demonstrate the “natural” forcings that are warming the planet, but also the natural forcings that are countering the human contribution.

      This leads to a rather paradoxical conclusion that “nature” is apparently simultaneously warming and cooling the planet.

      Ockham would cut the throat of anyone who tried to push that barrow past him.

      • I think you make a really good point.

        But it seems to have passed through unnoticed.

        Reminds me of a comment you made some time ago on Skeptical Science – observing that the test of GCM accuracy is not to compare actuals with the original forecast … but to re-run the models using the actual values of input parameters observed over the forecast period; and see what the models compute.

    • It is a polemical and, I feel, unnecessary value judgement…

      With all due respect for Dr, Muenchow’s scientific credentials, no it isn’t a value judgment. It’s a simple factual statement, no more involving values than “Average global temperature has risen by about 1.5°F (0.8°C) since 1910:”. Apparently it’s a factual statement that Dr, Muenchow considers to be debatable but that’s a different matter. Value judgments don’t come into the matter until we start considering the likely consequences of climate change and the extent to which we should adapt to them or try to prevent them.

    • As has been pointed out, there are problems in the position that people aren’t causing global warming. 1) Something is. 2) GHGs provide a mechanism that’s supported by quantum mechanics AND which has been observed and measured in the laboratory. (So, it’s safe to say than an increase in GHGs has produced an enormous amount of energy.)

      So.

      1) What else is warming the planet? (Remember there’s no secret ingredient called “Natural Variation”. There must be an increase in the natural variation of some forcing.)
      2) What mechanism has vamoosed the energy produced by the increase in GHGs which simultaneously disposes of the energy and which acts as a prophylactic so that it doesn’t warm the atmosphere.

      Happy hunting.

  2. An excellent summary and the status of the changes being seen. The Arctic in particular is seeing enormous changes with the decline in sea ice being only the most visible. As to the causes of the changes being seen– proof of that would take a different sort of post but the most telling evidence by far is the incredible increase in ocean heat content. A sure sign that increased greenhouse gas concentrations are the culprit, especially as the stratosphere has generally been cooling.

  3. From where did you find the sea level rise data?

    There is a spike upwards in the last datapoints (last months?) that do not appears in the SLR graphs of U. of Colorado, CSIRO and AVISO.

    [Response: It is the latest global composite of tide gauge data from Church & White.]

  4. Mark Harrigan

    Tamino. Clearly you are misguided. After all – its all due to “Stochastic Resonance” surely! The physics of increased heat being retained by the planet due to the addition of GHGs is irrelevant when compared with the statistics. Isn’t it? Isn’t it? Please?

  5. It’s interesting that the Pretend Skeptics, who shout “The climate is always changing!”, are even more shrill to tell the world it isn’t changing.

  6. Andreas Muenchow

    One summary of the vast array of evidence supporting the conclusion that “modern climate change is not natural” can be found here. http://www.skepticalscience.com/its-not-us.htm. We have found the enemy and it is us.

  7. So according to Muenchow CO2 is not a GHG. Waiting for the ground-breaking publication in Nature.

    [Response: He didn't say that.]

  8. An excellent, clear and simple summary of how we know our planet is warming.

    Of course the problem is that those in denial, to a man, now all retort, “yes, everyone accepts the world is warming, but it has natural causes” (for ‘natural’ read ‘the sun’, ‘cosmic rays’, etc.). Of course, this apparent acceptance of warming doesn’t prevent them pointing out with glee every inevitable, brief, downward turn of any rising graph whenever it occurs: a contradiction which suggests they don’t really want to believe the world is warming but that they know it’s difficult to refute the well-documented evidence. Much easier to man the barricades behind, “humans aren’t causing it”: and often, again in contradiction, just for good measure, “the human contribution to the observed warming is insignificant”.

  9. Seeing is (not?) believing . . .

    We know the figures, we see the facts but as humans we are evidently to small and live to short to feel the concequences of our behaviour. It all ends up with the question: to beleive or not to believe . . .

  10. Tamino, I think it would be worth to present the “vast array of data and analysis” that quantify the amount of anthropogenic change, if you really want to convince those who need to be convinced (of course those already convinced don’t need anything else, but I assume your blog is not (only) directed to them. ). The best I’ve seen so far is “comparison with models”, but I don’t think it is a very strong evidence.

  11. The current rate of change in ocean chemistry, specifically the carbonate ion concentration, is falling at a rate 214 times the average rate of decline for the entire Holocene. Decidedly not natural indeed.

    Andreas, it’s probably time for scientists and communicators to stop beating about the bush – the negative consequences of global warming are already upon us. We need to be accurate, but there is plenty of literature to support Tamino’s claim – this paper for instance:

    Testing for the possible influence of unknown climate forcings upon global temperature increases from 1950-2000 – Anderson (2012)

    The important bit:

    ” Results indicate that the radiative forcing needed to produce the observed long-term trends in sea-surface temperatures—and global-mean near-surface temperatures—is provided predominantly by known changes in greenhouse gases and aerosols. Further, results indicate that less than 10% of the long-term historical increase in global-mean near-surface temperatures over the last half of the 20th century could have been the result of internal climate variability. In addition they indicate that less than 25% of the total radiative forcing needed to produce the observed long-term trend in global-mean near-surface temperatures could have been provided by changes in net radiative forcing from unknown sources (either positive or negative). These results, which are derived from simple energy balance requirements, emphasize the important role humans have played in modifying the global climate over the last half of the 20th Century.”

  12. Muenchow-san,

    Temperature anomalies are closely correlated to the level of carbon dioxide in the atmosphere (r = 0.87 from 1850 to 2010). The increase in CO2 is almost all artificial, as we can tell from the radioisotope analysis. The new CO2 is deficient in 13C and appears to have no 14C. Plants preferentially take up 12C rather than 13C, and very old material has no 14C left since its half-life is only 5570 years. Thus the source of the new CO2 is primarily fossil fuels. Carbon from the biosphere would have the same mix as recent air overall.

    • Agreed. And yet, there is more to climate change than the human-made increase of CO2, its tentative relation to air temperatures. In a strongly non-linear and dynamic system as the ice-ocean-atmosphere-land-biosphere, a linear correlation is not always a good way to probe cause and effect relations. I am not denying that we humans are probably causing some, perhaps even most of the currently observed changes, but unless we understand and correctly model the physics and non-linear interactions at the many physical boundaries between ice-ocean, ocean-atmosphere, atmosphere-biosphere, etc., we cannot claim that the observed changes have the cause we like to attribute to it. Linear correlations do not explain cause-effect, they merely indicate that two variables co-vary, perhaps because both relate to third forcing variable. The “why” is always more tricky that the “what.”

      [Response: Indeed "correlation is not causation." But attribution is based on a great deal more than correlation.]

      • Andreas Muenchow,
        You are on record as effectively stating that global climate has been warming at an average of some 0.02 deg C per annum, of which you say here “I am not denying that we humans are probably causing some, perhaps even most of the currently observed changes.”
        This suggests that you consider there could well be non-anthropogenic causes for most of this continuing 0.02 deg C annual rise. Do you have any views on what those causes might be?

      • @ Al Rogers: I stand by what I wrote on the topic at http://icyseas.org/2012/06/27/greenlands-warming-melting-and-sliding-to-sea/ with regard to the “record.” I had not seen the quote at the site you reference and would first need to read it in its entirety before further commenting on it.

        As for other than human-made global temperature and associated climate changes, I believe that any casual inspection of any ice core record from Greenland or Antarctica would suggest a range of time scales that all can contribute to the signals we currently observe as well. What causes the “weak” spectral peak in the melt signatures atop greenland in the 150-200 year range that NASA reported recently and that I commented on at http://icyseas.org/2012/07/24/record-warming-and-melting-of-greenland/ The tricky part in the attribution question, that Tamino did NOT address in this excellent summary post here, is to clearly demonstrate how much of the currently observed warming is actually caused by what how.

        I apologize for the links, but I do feel challenged which is what good scientists do and should be prepared to be done to them as well ;-)

      • Non-linear results can be caused by lots of things. Including pre-existing factors.For example, there are carbon sinks that damp the amount of CO2 in the atmosphere. Once those sinks are exhausted as dumping grounds, the relationship between co2 and additional rises in the temperature will become more linear.

  13. toto@club-med.so

    Hi,

    sorry for the boring technical question but, how do you smooth at the end-points of the timeseries?

    [Response: With a lowess smooth.]

  14. A bit OT, but could someone please explain (or direct me to a source) the concept of polar amplification? What are its causes? I understand it’s something even Arrhenius knew, so it must be something pretty basic that does not depend on sophisticated climate modelling. Why is it less pronounced in Antarctica? Is it just the ozone depletion or are there other causes?

    • Hi, Alexandre. Polar Amplification is discussed in this RC post. It is currently less pronounced in Antarctica vs the Arctic because Antarctica is essentially a 2-mile high monolithic ice cube sitting at the South Pole. As a result, it creates its own weather systems (polar vortex, circumpolar current, etc) which help deter the current effects of warming.

      The Antarctic Peninsula and the Arctic are much more affected by maritime delivery systems that more effectively transfer heat energy poleward. Antarctica is affected, but it will take longer for the magnitude of the effects of polar warming to ramp up there.

      • That RC post is due for a rewrite/update. Conditions in the Arctic have changed rapidly since then due to positive feedbacks not as well understood then.

      • Any suggestions for a good source (maybe maps) on recent Arctic warming? If the last 6 years of the Arctic are especially warm as Daneil Bailey says, I’d be interested in seeing some data.

      • Neil, Neven’s Arctic Sea Ice blog is the go-to resource in the blogosphere for the best understandings of the workings of the Arctic. Neven should be posting a new summary article on Monday which will address your questions, at least in part.

        The expert participants there are glad to answer any questions, as well.

        For maps, you can make your own custom ones if you like at the NASA GISS Surface Temperature Analysis website, here. Be sure to select the polar projection option before outputting.

      • Thanks Daniel, I did not realize the geographic differences had this big a role, too.

        On that RC article, it looks like the amplification is something figured out only with climate models around the mid 80’s…

        Yet it appears already on Arrhenius 1896 (Table VII). I don’t believe he could figure out ocean circulation or albedo behaviour then, so I guess there must be a conceptual basic reason for that.

        [Response: Another reason is that in colder regions the atmosphere has less water vapor. Therefore CO2 has a greater share of the total greenhouse-gas load.]

      • Daniel. I agree Neven’s blog is a brilliant site for information and links about the Arctic, but …
        “The expert participants there” are more like children in a sweetshop at the moment.

      • Alexandre: “Yet it appears already on Arrhenius 1896 (Table VII). I don’t believe he could figure out ocean circulation or albedo behaviour then”

        I’m quite sure that he could figure out albedo changes just fine–though I don’t recall the mechanics enough to know if that’s what he did.

    • @Neil – They’re not specific to the Arctic, but these might do, and they output a temp/latitude chart too.

      http://data.giss.nasa.gov/gistemp/maps/

    • Svante Arrhenius calculated the amplification (http://www.rsc.org/images/Arrhenius1896_tcm18-173546.pdf – section IV, Tables VI and VII) directly from water vapor and CO2 – with colder air having less water vapor, CO2 changes do indeed have a higher influence in higher latitudes.

      “The influence has a minimum near the equator, and increases from this to a flat maximum that lies the further from the equator the higher the quantity of carbonic acid in the air. For K=0.67 the maximum effect lies about the 40th parallel, for K=1.5 on the 50th, for K=2 on the 60th, and for higher K-values above the 70th parallel”

      Add in higher land percentages in the north, albedo changes due to warming, and you have polar amplification, primarily in the Arctic.

  15. “What causes the “weak” spectral peak in the melt signatures atop greenland in the 150-200 year range that NASA reported recently ”

    I’m not a scientist, but it is obvious that the Arctic ice in general, including sea ice, did not melt 150 years ago, like now.
    Or 300 years or 450 years ago………..

  16. Andreas Muenchow,

    Perhaps it would help to identify more precisely how our opinions disagree.

    According to your first comment, you do not dispute that it’s possible that “modern climate change in not natural,” but you do not consider it established. Is that correct?

    You also seem to agree that the laws of physics support the idea that an increase in greenhouse gases will lead to an increase in global temperature. Is that correct?

    If I have read you correctly, then you would attribute some of modern warming to non-natural (i.e., man-made) causes. You would even admit the possibility that enough of the observed warming is man-made that my statement is essentially correct. (I’m guessing that you’re aware that I don’t claim man-made warming has put an end to natural climate change.)

    I’m curious to know, what is your best estimate of the amount of warming (either in deg.C or deg.C/yr or as a fraction of observed warming) which is man-made? What is your best guess of the uncertainty in that estimate? You needn’t have a quantitative analysis to support your estimates, I just want to know your opinion. If you want to point to quantitative analysis also, that’s fine.

    If you were firmly convinced that 99% of warming was man-made and only 1% natural then I suspect you would not object to my statement. Likewise, if I were firmly convinced that 99% was natural and only 1% man-made, I would not have made my statement. What is the threshold above which you would agree that “modern climate change is not natural”? You may if you wish wax philosophic about what combination of estimated human fraction together with uncertainty in that estimate would be required. In fact I’m very curious whether your skepticism is rooted in a lower estimate of human influence, or higher estimate of uncertainty, or both. (Just to satisfy the “rigor police,” it’s possible that the human contribution is more than 100% while the natural component is negative.)

    What physical mechanisms do you propose for natural climate change? I’m really interested in global trend rather than local or temporary fluctuation, so phenomena like the el Nino southern oscillation don’t seem to me to be relevant here (you may argue otherwise). Similarly, volcanic eruptions cause fluctuation but not trend unless you want to suggest some trend in their frequency or intensity. I’m also interested in modern times, the late Holocene at most (which doesn’t mean you can’t include orbital variations even though on this time scale they’re slow and weak).

    On another topic entirely, I’m always skeptical of the reality of a “weak spectral peak” even when the claim appears in the peer-reviewed literature. Do you have a link to the actual data on which that analysis is based? I’m just curious, since Fourier analysis is my thing.

    • Tamino: There is no disagreement between the two of us regarding data, statistics, and interpretation of both. The attribution of the globally observed climate change is not as exact a science as our data collection and statistical analyses. It is tricky to do with so many unknown or poorly understood physical processes that provide, at least potentially, non-linear feedback in a system with both hysteresis and multiple equilibria. It is hard to know what is causing what we observe with ease almost everywhere we look.

      So if you want a guess, and this is really just a gut feeling that could also be called “wishful” or “contrarian” or “happy” or “obnoxious” thinking, I’d say that 2/3 of the observed warming trend is human induced while the other 1/3 is not. The uncertainty on this “feeling” should be 100% at a 75% confidence, but, and this is for the “rigor police,” I am not sure if the underlying processes are stationary … and if they are not, then much of our statistics, feelings, and uncertainty estimates go out the window.

      If there is a 10% chance that 10% of the current global warming is human-made, which I consider a strong possibility, then it makes economic sense to minimize our dependence on carbon-based energies and develop more efficient ways to use carbon-based energies where we must. I really view the global climate change and our response to it as a multi-dimensional nonlinear optimization problem with multiple solutions and equilibria. I am not smart enough to solve it … I am sorry to say. [I think in Fourier space also, to the detriment of my mental health, but I am prepared to consider variance to flow from one time scale (frequency) to the next which most people do not, do you?]

      • I think you are exaggerating uncertainty is the level of understanding the physical processes. For this to be a rational argument, then surely there must be some evidence of change for which current understanding cannot explain.

        To attribute 1/3 to an unknown process seems bizarre. What in our knowledge of physics could that process be? Do you think there is past natural climate change for which we have no physical understanding? As you go further back, into the realm of uncertain climate with uncertain forcings, then the problem does become unconstrained, but only in the sense of the difficulty of distinguishing between multiple possible causes and the relative importance of various factors.

      • Andreas,

        Certainly the climate system is complex and nonlinear. But it is also subject to conservation laws, particularly conservation of energy. That’s one of the reasons I don’t regard its evolution to be as uncertain as you seem to.

        I suppose it’s only fair that I should answer my own questions. I consider a figure of 2/3 man-made to be implausible but not unreasonable. I believe that 100% uncertainty at 75% confidence is an overestimate. Both basic physics and paleoclimate (on multiple time scales) confirm that increasing greenhouse gases increases temperature, so I regard 0% (or less) man-made as outside reasonable confidence limits. I would say my 100% man-made figure would have 30% uncertainty at 95% confidence.

        I understand the flow of variance between time scales, but I’m not convinced that it’s relevant to the issue, which is not the long-term but the short-term (the rest of this century in particular).

        In my opinion, the pure Stefan-Boltzmann response to climate forcing (warming of about 1.2K per doubling of CO2) represents a lower limit of believable values for climate sensitivity. In fact I don’t even consider that lower limit realistic. There are many feedback mechanisms, most of which are likely positive and some of which (snow/ice albedo, increased water vapor) are known to be so.

        The climate forcing since pre-industrial times is nearly 2 W/m^2. The Stefan-Boltzmann response alone would result in warming of about 0.6K, but we’ve observed about 0.8K. Considering the thermal inertia of the oceans, the odds are overwhelming that global temperature has not yet equilibrated to the anthropogenic forcing, so there’s yet more warming “in the pipeline.” Hence we should expect considerably more warming than just the Stefan-Boltzmann response, which is evidence not only of positive feedbacks, but that they are strong.

        Millenial-scale temperature reconstructions indicate that the natural variations of temperature on centennial time scales are not nearly enough to constitute the majority of the observed warming. Also, long-timescale (Plio-Pleistocene glaciation) variations indicate climate sensitivity in accord with theoretical and model-estimated results.

        I have yet to hear of any plausible physical mechanism which could account for a substantial fraction of recent global warming.

        Finally, there is the fact that the warming we have observed over the last three decades was predicted before it was observed. Hansen et al. 1981 (Climate Impact of Increasing Atmospheric Carbon Dioxide, Science, 213, 957) is one particularly impressive example.

        In all, I think the statement that “modern climate change is not natural” is supported by a large body of evidence. I doubt I will have persuaded you to regard it as established rather than possible — but that’s OK. I might call your opinion “wishful” or “happy,” but I wouldn’t say that it’s either “obnoxious” or “contrarian.”

        The plain fact is, I hope you’re right and I’m wrong. But I doubt it.

      • Tamino: We are on the same page with regard to conservation laws. They are universal, simple to state, easy to understand in principle, but generally very hard to solve for except in idealized linear cases or as discretized approximations with boundary and initial conditions.

        Where we part, I believe, is that while you single out one or two such laws that allow simple, linear, and perhaps static explanation and estimates, I am trying hard to wrap my head around ALL relevant conservation laws including those of mass, momentum, heat, and partial mass on a rotating planet with multiple fluids who all have boundaries via which energy, mass, and momentum is exchanged. I avoid large scale integration (averaging) that get rid of the pesky details and noise that actually make a system work and respond the way they do. And what I usually get is a massive headache, as this s all a little over my head. I know observations and can tell good from bad analyses, but I become very skittish when told that one or two parameters (CO2 and/or air temperature) are the global and general indicator of all. The dynamics of climate change are an ongoing and a complex puzzle that is NOT solved. This is why we have projections, that are different from predictions, which are different from solutions. If we had good enough solutions to the conservation laws, then we could all go home and focus on making energy out of splitting hydrogen atoms as a more fruitful activity than trying to understand why our planet does what it does, presently warming …

        I agree that there is more warming to come, but I also note, that while our current CO2 levels are outside the norm with regard to glacial time scales, our temperature levels are not (yet). I do not know, if we can make a prediction on how much temperature increase we will get in the next 50 or even 20 years. There is no guarantee, I feel, that the largely linear increase of temperature of the last 150 years will stay linear. The conservations laws are nonlinear after all, and variance from one scale can move to a larger or smaller scale. Not all turbulence or noise is being damped out by “integration.” Preponderance of the evidence for human-induced warming, I give you, but conviction of the guilty party beyond a reasonable doubt, I do not.

        [Response: When it comes to feeling overwhelmed by very complex problems, you're in good company -- I recall reading that Newton complained the 3-body problem gave him a headache.

        I think for the moment we'll have to agree to disagree. It is refreshing, however, to meet a skeptic of the genuine kind.]

      • But… temperature increase hasn’t been linear over the last 150 years. Nor is projected temperature rise linear, except when approximated over a very short period.

        Also, nobody claims CO2 is the only relevant parameter, only the *dominant* factor.

        If you want to argue that GCM uncertainty estimates are wrong, then you will have to come up with some concrete reason, otherwise you will sound like Judith Curry.

        Thousands of scientists are working on climate change, studying all the aspects individually and in combination. If you are going to wait until you understand every aspect yourself, then you will never, ever be able to come to a conclusion. Meanwhile, even conservative estimates of attribution indicate that action is overdue.

      • Dr. Muenchow, I sympathize in multiple dimensions–pitch class set theory used to make my head ache, back when I was trying to get sufficiently far ahead of the development of the field to get a paper actually published! (Never happened–eventually, I decided I’d rather just write music.) And much of what you say seems to me to fall under the heading of ‘proper scientific reticence.’

        The trouble is, it’s not just academic. The “preponderance of evidence”, to borrow once again the fine old legal phrase you used, suggests that 1) we have a real problem on our hands, one potentially endangering human health, wealth and well-being on a huge scale, and 2) that the timescale for forestalling the worst of these potentially disastrous effects is short, relative to those for complete solution of the scientific problems you mention.

        So we are faced with a situation where we can’t wait for complete information, if we hope to retain some efficacy for our actions. That shouldn’t change your scientific stance. But we need to be clear collectively that this isn’t just a scientific problem, central though the best scientific insight should be to our assessment of the situation. It is, as our friend Snarkrates has often pointed out, an issue of risk management–and one which we as a society seem unwilling to face honestly.

      • Andreas,
        I have to say that I tend to become a bit skeptical when scientists use “nonlinear” as a synonym for “incomprehensible”. Scientists must deal with nonlinear systems all the time, and there are certainly techniques whereby we can make definitive statements.

        I am particularly surprised that you dismiss anthropogenic greenhouse gasses (which are well established as a forcing and well understood) so readily in favor of some unknown mechanism. This seems unscientific to my physicist’s eye. Should we not construct a model with known forcings and see how much it explains, what it predicts, etc. before invoking “the unknown”?

        Finally, if climate is really so nonlinear that we can make no definitive statements about it, does that not argue even more strongly for taking a conservative approach to fiddling with its energy balance? Uncertainty cuts both ways, and the blade on the high-risk side of anthropogenic causation is much sharper.

      • Having read Andreas Muenchow’s (August 23, 2012 at 4:32 am) reply, I am very strongly inclined to agree with Phil Scadden – uncertainty is being exagerated.
        The climate system is complex but it is “disorganised” and thus can be analysed without all its interations being well modelled. Uncertainty is managable. If it was weather we were forecasting, that would be different. Climate is not weather.

        I am not that happy with such exageration of uncertainty. The upshot of Andreas Muenchow’s position is “we cannot presently know” which really doesn’t sound much different to the position of many within the climate debate who we would be described as wantonly or willfuly ignorant. That the position of ignorance (or if you prefer ‘professed inescapable uncertainty’): that this position is based on the philisopical grounds (that the system is too non-linear to be predictable) may be understandable in a responsive role. But this position has been given as a proactive argument. It must be remembered the argument was began thus:- “(Attribution of climate change to human cause) …is a polemical and, I feel, unnecessary value judgement that does little to advance what we know, do not know, or perhaps need to know.” In the quartet of comments since, Andreas Muenchow has, it appears, effectively argued that in his opinion all avenues of advance are impossible. Is this a happy outcome of the interchange?

        [Response I think that a more fair characterization is that he agrees that the "balance of evidence" supports AGW, but doesn't yet consider the case proved beyond a reasonable doubt. That seems to me to be very different from those who are wantonly or willfully ignorant.]

      • Isn’t there an element of throwing the baby out with the bathwater here?

        Something is only right until a better explanation comes along. But that doesn’t meant that current understanding is worthless.

        We could probably have a long conversation about whether it’s right to think of, say, climate sensitivity as an easy to remember 2.5C or 3C per doubling of CO2. It’s probably very crude and in decades to come we might be much better at knowing how sensitivity changes with place and circumstance. But I think we’d probably have a much shorter conversation about whether, for the time being, thinking in terms of 2.5C per x2 of CO2 is good enough to be getting on with.

      • “Modern theories of dynamical systems have very clearly demonstrated the unexpected fact that systems governed by the equations of Newtonian dynamics do not necessarily exhibit the ‘predictability’ property. Indeed, very recent researches have shown that in wide classes of very simple systems satisfying those equations predictability is impossible beyond a certain definite time horizon.” Sir James Lighthill, F.R.S. wrote this in 1986 in the Proc. R. Soc. Lond. A 407, pages 35-50.

        If as simple a system as a forced spherical pendulum gives rise to aperiodic motions with multiple equilibria, I personally like to move with caution before I attribute all of the currently observed warming to man-made CO2 emissions. If this argument is considered hand-waving, I can live with that.

        Is it really that important if our global civilization causes 20% or 50% or 80% of the current warming trends? The fact that our energy use contributes at all should be reason to pause, think, and consider a lesser impact, albeit not at all costs. These are ethical and political discussions and decisions that should involve citizen not a group of scientists and experts. I usually act according to the preponderance of the evidence and always consider the possibility that I am wrong especially when I am absolute certain to be right, as I do here.

      • Is it really that important if our global civilization causes 20% or 50% or 80% of the current warming trends? The fact that our energy use contributes at all should be reason to pause, think, and consider a lesser impact, albeit not at all costs.

        Yes, it is really (and I would say obviously) that important. If our global civilisation is causing 80% of the current warming trends by increasing greenhouse gas concentrations, a very different set of policy responses and a very differently focused program of scientific research will be needed than if we’re only causing 20% of the observed warming and the rest is caused by some unknown factor. Also, the benefits of any action to lessen our contribution to the warming would be different by a factor of 4 between the 80% and the 20% contribution scenarios. Somehow, I think that might make a difference to any cost/benefit analysis of the actions intended to lessen our impact.

      • And Lokenath Debnath wrote in 2008 in the preface to “Sir James Lighthill & Modern Fluid Mechanics”:-
        In his memorable lecture at the discussion meeting held jointly by the Royal Society and the British Academy in 1986 on Predictability in Science and Society, Sir James Lighthill vigorously criticized the view that dynamical systems governed by Newton’s laws of motion do not necessarily exhibit the predictability property. At the same time, he provided the first systematic and persuasive arguments in support of the complete predictability of systems governed by the equations of Newtonian dynamics.
        I have a feeling the quote I present here is in context, although I have to confess I am no expert on Sir James Lighthill.

      • While I agree that dynamical systems make predictability difficult, I would also point out that they are predictable over short time spans and that at all times, chaotic systems operate within physical laws. If temperatures are going up, this is energy change and must have a reason. We lack any evidence for other causes for this temperature rise. On the other hand, it is easily accounted for by greenhouse theory so why postulate 30% to mystery?

      • I’ve always looked at the Ice core records as evidence that the climate is a very dynamic system – never in equilibrium for long. Certainly once it starts shifting from one regime to another, the internal dynamics can move it quickly. But how can it be that humans are NOT giving a giant kick to this fragile not-to-stable system when we double the CO2 in the air and transform the ground cover and poison the oceans.

    • The “weak” spectral peak at 150-250 years is shown as a time series at http://www.gisp2.sr.unh.edu/DATA/alley1.html which also provides the peer-reviewed reference to work by Richard Alley. The data originates from the Greenland Ice Sheet Project at http://www.gisp2.sr.unh.edu/ … I am sure the data are available to the public as well.

      • Glenn Tamblyn

        Andreas

        Tamino’s post presented a number of indicators of warming in what we refer to as ‘the climate’ – meaning conditions here on the Earth’s surface. There are other measures that, while still only correlations (ultimately isn’t all data that), nonetheless rule out most possible causal explanations. The principle one of these is heat build up in the oceans.

        Since 1970 approximately 2.5 10^23 Joules have accumulated in the oceans. 30 times more than the heat buidl up in the atmosphere.

        This is a very large number, hard for us to grasp emotionally. It is the equivalent of detonating 3 Hiroshima bombs a second, every second, since 1970. Some people have even started using a new term for power, the Hiro – 60 TeraWatts or 1 Hiroshima Bomb per second.

        What is more interesting however is when we start asking the question of where this energy could have come from. Simple conservation of Energy says that this heat must have come from somewhere. And the basic fact is that there is no heat source anywhere else on the Earth that is large enough to have supplied this heat. The closest contender, the next largest heat source here on Earth is Geothermal heat. But this is too small by a factor of 4. Geothermal heat from all sources is around 45 TerraWatts or 0.75 Hiro’s. All human energy consumption is less than a 3rd of this.

        There is no available source of heat here on Earth capable of supplying the amount of heat that has been observed.

        So the only possible conclusion is that the source must be extra-terrestrial. The Earth is not in thermal balance with Space.

        Could it be the Sun? Certainly the Sun is a large enough energy source that a modest increase in it heat output could easily cause the observed warming. But the Sun isn’t warming. Observations over the last 1/2 century are showing a Sun that is cooling ever so slightly. And another piece of evidence: if it were the Sun, we would expect to see more surface warming during the day and in Summer. Actually we have observed the opposite. Just as much or more warming at night and during Winter. So the Sun can’t possibly be the cause of the warming.

        Similarly clouds reflect sunlight. If there were fewer clouds for some reason then more sunlight would reach the surface and have a warming effect. But such a decrease in cloud cover should also have a daytime/Summer heating pattern since it simply modulating the amount of sunlight we receive. And again the nighttime/Winter warming pattern argues against this.

        Which leaves only something effecting the radiation of heat to space as a possible explanation.

        There is no other natural process that could supply that heat.

        So the warming may be only correlated to CO2 levels. But that warming isn’t correlated at all to anything else.

      • Mark Harrigan

        Glenn, I agree completely with your conclusions but would point out a slight error in your logic (forgive me). The Geothermal Contribution would actually have to have INCREASED by 3 Hiro’s (180TW) to account for the observed increase heat content. It is, after all, a constant (relatively) source of heat and cannot explain even a tiny fraction of the observed increase.

        That would mean, in the last 100 years or so, Geothermal flux has increassed to 5 times the level it was. Such a phenomenon would clearly be observable.

      • @Dr. Muenchow

        Preponderance of the evidence for human-induced warming, I give you, but conviction of the guilty party beyond a reasonable doubt, I do not.

        Given that we’re trying to get humans to refrain from inducing warming sufficient to significantly degrade the biosphere’s ability to sustain us rather than trying to get major polluters imprisoned or executed as punishment for their actions, I think civil standards of evidence, i.e. a preponderance of the evidence, are the ones that should apply, not criminal ones. Which you apparently agree with since you have stipulated that it probably “makes economic sense to minimize our dependence on carbon-based energies and develop more efficient ways to use carbon-based energies where we must.” based on our current knowledge.

        I’m curious as to your response to the obvious followup to Tamino’s question about your estimate of how much of the observed warming is anthropogenic – what evidence would be required to make you agree with Tamino’s statement that you originally took issue with? You’ve been asked directly in this thread, twice, to say what other causes might be responsible for some portion of the observed warming and as far as I can tell you haven’t got any other suspects than anthropogenic greenhouse gases, just a lot of, forgive me, handwaving about how the climate system is too complex to fully understand. I suspect that twenty years from now the climate system will be just as complex and we still won’t have computers capable of simulating it at the level of individual atoms or parts thereof and producing weather and climate forecasts that are as accurate as could possibly be desired indefinitely into the future. Will you still be saying we can’t be certain most of the warming is anthropogenic if twenty years from now warming has continued unabated and neither you nor anyone else has come up with an explanation anywhere near as well supported by evidence as is attributing most of the warming observed to date to anthropogenic greenhouse gases?

      • Preponderance of the evidence for human-induced warming, I give you, but conviction of the guilty party beyond a reasonable doubt, I do not.

        Note that this is a civil, not criminal, “case” … preponderance of evidence is sufficient to rule for the “plaintiffs” and for the “court” to specify action, such as to demand efforts be made to cut CO2 emissions.

        Proponderance of evidence is the norm in all environmental litigation, why should this case be any different? The fact that the negative consequences of the science being right is far greater than that which follows from typical environmental legislation means we should *raise* the bar ???

      • Pete Dunkelberg

        The vast forgetting: after considering all the known climate forcings, the human contribution to the observed warming is:
        80 to 120 percent

        Any unaccounted natural forcing could as easily cause cooling as warming.
        # 244 http://www.realclimate.org/?comments_popup=1853

      • Glenn Tamblyn

        Mark Harrigan

        Agree Mark, I was just using the slightly simpler version of the argument. In fact Geologists are measuring a slight warming of the ground and down to some depth in mines. Top down warming so definitely not an increase from geothermal rising from below.

      • Mark Harrigan

        Thanks Glenn. I had not heard before that Geologists were measuring a slight downward warming. Interesting corroboration. Do you have a reference for that? useful to have on file :)

    • If your policy or political position on how to best respond to global warming and climate change depends so strongly on the human contribution being 20% or 50% or 80% with absolute certainty, then your policy analysis is going to be screwed and should not be implemented given limited economic resources and a variety of equally pressing political and social problems besides climate change. I admit that this is a political, not a scientific statement reflecting personal bias, values, experience, as well as religious and philosophical beliefs.

      In my oceanographic measurements I am often happy, if my estimates have error bars less than 50% at 95% confidence, and even then I often wonder, if my statistics are really valid on account of possible non-stationarity of the regional ice-ocean-atmosphere systems that I study.

      If there is a severely under-sampled and misunderstood component in the earth system, it is the oceans. And, as has been pointed out by others, the ocean’s heat capacity is rather large, dynamic, and it has the ability to redistribute heat rather efficiently on a range of dynamic time and space scales that are rarely resolved appropriately in the climatologies towards which many global climate models are tuned and nudged.

      [Response: One thing the oceans do not do, is create energy from nothing. Nor is it reasonable to suppose that after thousands of years of relatively stable climate, they would suddenly unleash vast stores of heat sufficient to rapidly warm both the atmosphere and the ocean to a depth of several thousand meters. That this would happen just when humans are causing a massive increase in the greenhouse-gas loading of the atmosphere is a coincidence that defies belief. Rather than call that idea "reasonable doubt," I'd say you have stretched the limits of credibility beyond the breaking point.

      As for global climate models being "tuned and nudged," I'd say that opinion reveals insufficient understanding of global climate models.]

      • Presumably the issue here is, not that the oceans will suddenly start returning some long-lost heat to the atmosphere, rather that we are uncertain about how much excess heat it will continue to absorb, as well as the fate of that excess heat (ie how much of it will be distributed to the deep ocean where it could be sequestered for hundreds of years vs how much is being returned to the atmosphere pretty much immediately).

      • Mark Harrigan

        Readers may find it instructive to read what Lenny Smith has to say about climate models. I certainly recommend the following two papers.

        “Adaptation to Global Warming: Do Climate Models Tell Us What we Need to Know?”
        (Orestes, Stainforth & Smith)

        http://www2.lse.ac.uk/CATS/publications/papersPDFs/80_AdaptationtoGlobalWarming_2010.pdf

        and “Uncertainty in science and its role in climate policy”
        (Smith & Stern)

        Although Smith points out the models cannot say much with certainty at anything less than a continental scale he points out

        “Scientific understanding of the mechanisms of the climate system and their likely responses reinforces the view that the risks are signficant and that a delay in action can be very costly” (P16) and

        “The case against action has to sucessfully argue that the risks are small not merely that the outcomes are uncertain” (p18)

        The real lunacy is the failure to understand that mitigation/emissions reduction is a process, not an event. And a lengthy one at that.

        By the time we wait to discover whether or not climate sensivity is low or high, or what, exactly is the “proportion” of climate change due to human influence – it will be too late to do anything about it if sensitivity is high and it established “beyond reasonable doubt” (whatever THAT means in this context) that humans are the cause. We are not talking about protection of someone from wrongful conviction by the state (where the reasonable doubt standard of proof is judged the benchmark). We are talking about the weight of the evidence AND the risks of taking action based on a false positive versus the risks of not taking action because of a false negative.

        Waiting till “certainty” is reached not only means the costs of mitigation will be enormous but there will be unavoidable consequences that we many not even have the capacity to adapt to.

        On the other hand if our migiation steps have been more than necessary it is relatively easy to slow them down.

        I offer the following analogy I used on another site.

        We are in a car. We know there is a potential hazard up ahead but we don’t know exactly how hazardous – only that it could quite possibly result in a serious smash if we hit it too fast and that this is a realistic scenario – although we might get lucky and find it’s a hazard that just causes a few bumps.

        What would you do? Slow down? or step on the gas?

      • Andreas,
        Do you really have evidence that models are “tuned and nudged”? If so, I would agree that would be unscientific. However, it is my understanding that most parameters, such as they are, are fairly tightly bound by empirical evidence, and that those parameters where there is wiggle room are very imprecise. Tuning to acheive agreement in, say, temperature will blow other results out of the water.

        I think, perhaps, you need to be more careful with your rhetoric–especially for those areas outside your immediate expertise.

        Yes, the oceans are a source of significant uncertainty, but what we do not know does not invalidate what we do know.

      • The term “nudging” in the context of modeling is a technical term that modelers use themselves in their technical literature. It is meant to dampen out or minimize the effects of numerical problems that develop when coarse models are run over long periods of time. A casual google-scholar search “nudging+modeling+climate” will reveal that this is not something as “dirty” or as “suspect” as some make it out to be.

        The term “tuning” refers to comparison of models against observations at critical or well sampled locations by varying some of the many unknown or free parameters within some acceptable range. These semi-free parameters usually parameterize processes that are not resolved by the grid size of models.

        While it is entirely possible that I misunderstand the current state of climate modeling, it is equally possible, that many of those who are so certain on matters of active research do so also.

      • Andreas, with all due respect, I think you are trying to have it both ways. It is one thing to nudge a model to smooth out numerical issues, and quite another to try to “nudge” it into a particular climatology. I also contend that the “free parameters” you are positing are not nearly as free as you suggest, and that there are probably too many observables for effective “tuning” to any one or small subset.
        Yes, there are uncertainties, but they don’t invalidate what we know–which is considerable.

      • If your policy or political position on how to best respond to global warming and climate change depends so strongly on the human contribution being 20% or 50% or 80% with absolute certainty, then your policy analysis is going to be screwed and should not be implemented given limited economic resources and a variety of equally pressing political and social problems besides climate change. I admit that this is a political, not a scientific statement reflecting personal bias, values, experience, as well as religious and philosophical beliefs.

        Who said anything about needing absolute certainty? Do you have absolute certainty as to the causes of the “political and social problems” you claim are “equally pressing”? Also, absolute certainty as to which proposed solutions would work and how well and at precisely what cost? We have no choice but to formulate policy despite uncertainty, in addressing climate change as in all other areas, based on, as you put it earlier, the preponderance of the evidence. The alternative is never doing anything about any problem ever.

        In the course of this discussion, you’ve been asked if you have any possible non-anthropogenic causes in mind that might be behind a significant part of the observed warming and it seems you don’t. You’ve also been asked what evidence it would take to convince you Tamino is right in saying most of the observed warming is anthropogenic and have failed to give any answer. Tamino may or, going by his latest response to you, may not still consider you a real skeptic rather than a fake one. For my part, based on what you have said to date it isn’t clear to me that any evidence or analysis would convince you short of, given that you mention religious beliefs in your latest contribution to the discussion, the deity of your choice personally contacting you and telling you Tamino is right. If that’s the case, then I’d have to say you’re a fake skeptic. If there is some evidence that might reasonably be expected to be available in the next couple of decades that would convince you, please do tell us what it might be.

        [Response: Clearly I disagree with Andreas. But I still regard him as a real skeptic.]

      • The term “tuning” refers to comparison of models against observations at critical or well sampled locations by varying some of the many unknown or free parameters within some acceptable range. These semi-free parameters usually parameterize processes that are not resolved by the grid size of models.

        The problem is that the term “tuning” is often used in the denialsphere to accuse modelers of fudging model parameters so the model output is consistent with some pre-determined assumption, such as climate sensitivity to a doubling of CO2 being roughly 3C.

        Obviously this isn’t what you meant, but it’s understandable that others might suspect that you did.

        Perhaps “parameterization” is a more neutral term to describe, well, parameterization. You’re right that processes that can’t be resolved by the grid size are parameterized, but from what I’ve read they’re pretty tightly constrained by observational data.

      • @ Jon, Snarkrates, tamino, dhogaza, et al.:
        You are correct: I do not have all the answers to all questions asked of me. Perhaps I am indeed too close to some trees to see the forest, but people are complex beasts, too: My answers as a scientist are often different from my answers as a citizen. As a scientist I must quantify uncertainty, I must doubt my results, statistics, and conclusions. As a citizen I make value judgments, ethical decision, vote for or against policies, and feel perfectly comfortable to do all those things in the face of uncertainty without taking myself too seriously most of the time.

        As for the interface between science and policy, the lack of scientific certainty should never be taken as an excuse for inaction. Some of the same issues that I, perhaps in vain, tried to argue here are also on the record at
        http://energy.nationaljournal.com/2010/08/is-climate-change-causing-wild.php#1628477 … and if you read that essay closely, you will find that I indeed entertain possibilities regarding climate change that can cut both ways. If that makes me fake or real, warmist or alarmist, republican or democrat, fox or chicken, or whatever label people like use these days, that’s none of my concern at the moment. Groucho Marx comes to my mind … [I have to stop discussing this here for now, not for lack of personal enjoyment and enlightment, but for the trees and seedlings that need tending. Thank you all for the responses, arguments, and new learning. Let me stew and chew for a while on this.]

        [Response: Thanks for sharing your opinions with honesty and candor.]

      • Pete Dunkelberg

        Dr Muenchow,

        “If your policy or political position on how to best respond to global warming and climate change depends so strongly on the human contribution being 20% or 50% or 80%…

        Why isn’t 100% +/- 20% suitable? Is there a reason to think that natural variation has produced more warming than cooling in recent decades? (Compare the well known paper Foster & Rahmstorf 2011).

        “…then your policy analysis is going to be screwed and should not be implemented given limited economic resources and a variety of equally pressing political and social problems besides climate change.”

        What are the equably pressing problems, of such character that they cannot be dealt with if we improve our energy infrastructure?
        > limited economic resources
        Well, there’s plenty of money. It’s just maldistributed. What could be better for the economy than to re-direct cash flows into a great jobs program to update our energy infrastructure?

        “I admit that this is a political, not a scientific statement reflecting personal bias, values, experience, as well as religious and philosophical beliefs.”

        We all know about politic$. What is the religious objection to non-carbon energy? Or to whatever precautionary measures give rise to the problem as you see it?

      • Andreas,
        I don’t think anyone here questions your bona fides. I apologize if anything I said gave that impression.

        I wonder whether you see any value in the approach Tamino has taken in his next thread. From the point of view of risk management, once science has established a threat to be credible–that is having a reasonable probability of being realized and of causing a significant loss if realized–then science has contributed about as much as it can to policy, other than refining probability and loss estimates.

        Certainly, you would agree that climate change poses a credible threat, would you not? And I think the Risk post establishes the possibility of substantial loss.

        The thing about risk management is that you cannot ignore a credible threat. The risk must be bounded. I think that our current state of our knowledge doesn’t permit a realistic bound. And an unbounded risk simply cannot be ignored while waiting for the crystal ball to clear.

      • @ snarkrates et al.:

        No worries, no offences taken. Climate change is a very credible thread to me and the burning of fossil fuels since the industrial revolution is a substantial contributor and forcing agent to many (though not all) of the observed changes. Quantifying the exact human contribution, I feel, is both tricky and perhaps outside our present capabilities on account of limited computational power (grid scales) and not well understood physics. Does anyone know how to land-fast ice real well in coupled ice-ocean numerical models? Back to the trees …

  17. Bill Ruddiman

    How can a rational society possibly ignore or deny so overwhelming a case demonstrating worrisome global warming? Key assumtion: rational?

  18. Horatio Algeranon

    The climes they are a changin’. Especially for ocean- dwelling creatures and plants

    And we humans are responsible. Little to no doubt.

  19. Clues to solving the source of the extra carbon dioxide, a long wave absorber in the atmophere, can be found @ http://www.skepticalscience.com/anthrocarbon-brief.html

  20. I am curious as to the source of the global drought graph presented in this post.

    http://journals.ametsoc.org/doi/abs/10.1175/2008JCLI2722.1

    The link to J Sheffield paper on global droughts has graphs of global droughts and different graphs show no increase in global droughts.

  21. “Storms — especially damaging storms — have become both more frequent and more severe. According to the giant re-insurance company Munich Re (who sell insurance to insurance companies), weather-related disasters have more than doubled since 1980:”

    How can one conclude that storms have become more frequent and severe based upon the fact that weather related-disasters have more than doubled since 1980.?

    Global population has increased by 1.57 times from 1980 to 2010.
    http://en.wikipedia.org/wiki/World_population

    Disasters are based upon human death and property damage. Property values have also increased during this time frame.

    http://www.ncdc.noaa.gov/billions/

    Links on this page lead to information that most damage in the US is done by hurricanes (over 50%).

    This link shows that people are moving to the coasts in the US and very possibly it is a global activity. Not only has population grown (so more people are in harms way) since 1980, it is possible that people are concentrating in areas that are more prone to weather-related hazards.

    I still wish science sites would not use the Munich Re graph as some sort of proof that weather is getting more severe or concluding based upon this that storms are getting worse.

    Science teaches that before making conclusions one needs to control variables to find which ones are effected. In disaster charts you have uncontrolled variables like poplulation growth, property values, movement of population. More disasters indicates more people are being killed and more property is being damaged, but you also have more people and property to damage so even if the number of severe storms remained the same disasters would go up.

    [Response: The Munich Re analysis also compared the growth in disasters from meteorological causes, to that from non-meteorological causes. The extreme disparity shows clearly that the increase of weather-related catastrophes cannot be ascribed to population growth or development. You can hear their own analyst say so in this video. And by the way, their analysis is global, not just U.S.

    Perhaps there's another reason you wish science sites wouldn't use the Munich Re graph.]

    • Horatio Algeranon

      Munich Re decided some time ago that climate change is real and poses a real risk.

      They undoubtedly came to this conclusion based on careful analysis because they “personally” have a lot to lose (their company, for example) if they simply ignore the issue as so many others have done.

      Horatio suspects that if some others were faced with significant personal losses, they might sing a different tune.

      Ideally, people should get a discount on their homeowner’s weather related insurance if they acknowledge climate change and can show that they are actively doing something about it. Kinda like a discount for having taken Driver’s ed or for having a good driving record.

      But sadly, it’s far more likely that Munich re and the insurance companies they serve simply jack up the rates because they can see that countries like the US are not serious about doing anything and know that (unless they are proactive) the insurance companies will be among those left holding the empty money bag in the long run.

    • You really really don’t like the Munich Re data, do you Norman? (Considering your numerous posts on SkepticalScience disputing its relevance; see http://www.skepticalscience.com/news.php?n=1296)

      Non-meteorological disasters provide a scaling factor for population, location, and exposure – and to anticipate a comment you’ve made before, improved building codes mitigate hurricane and other weather disasters much as they do non-meteorological causes.

      Non-meteorological disasters have not increased anywhere near as fast as weather related ones – the climate is changing, and risks and disasters from the climate are increasing as well.

  22. A pet peeve of mine. News reports and quite a few climate scientists refer to future temperatures rising 2 or 3C. In reality, since very few people live on the ocean and more live in the northern hemisphere than the southern, and most of those are north of the tropics; the temperature increase experienced by most of the world’s population will be more like 4 or 5C. Scientists cite the global average, but when discussing future impacts on humans, they should revert to a figure more representative of where most people live. There’s got to be some way to do this that is neither mislieading or confusing to the general public.

  23. Wendy Crowelll

    A pet peeve of mine is the use of the word “natural” to mean “non-anthropogenic”. Since humans are demonstrably part of the natural world, it is an extremely imprecise word to use in a scientific discussion. The scientific description of human impacts on atmospheric concentrations of certain gasses and their subsequent effects on global climate systems should be seen in the context in which they belong, which is the study of animal populations and their impacts on the ecosystems in which they occur. We have a lot to learn about our species by looking at our impacts on climate world wide. Despite the fact that we can describe with brutal clarity our species’ negative impacts on the very ecological systems that our populations depend, we seem to have a lot of trouble changing those behaviors that lead to negative impacts. My hope is that our species will persist and will develop or evolve the ablity to maintain the ecosytems upon which we depend, without the need for predation, famine, or disease to reduce our numbers.

    • A pet peeve of mine is the use of the word “natural” to mean “non-anthropogenic”. Since humans are demonstrably part of the natural world, it is an extremely imprecise word to use in a scientific discussion.

      It’s been used this way for centuries and is standard usage in common english and in science, as well (“natural history”, “natural philosopher”, etc).

      If it’s extremely imprecise, how can you say that its use of an adjective is equivalent to “non-anthropogenic”? It’s clear that you know precisely what is meant by “natural” in that context …

      • Wendy Crowell

        Yes, yes, I understood from context what he meant by “natural”. My point is that we would be better served to think of the influence of our species the way we might look at the effects of algae in the sea or rabbit populations. Non one thinks, “if only rabbits wouldn’t eat everything in sight” they look at them for what they are. Humans are part of the natural system just as much as algae and rabbits. I am an ecologist by trade, not a climate scientist, and this is how I think of things.

  24. Rob Honeycutt

    I’m reminded of Stephen Schneider’s words, “You just can’t add 4W/m2 to the entire surface of the planet and think things are not going to warm up.”

    While there may be some possibility that we are still within an envelope of natural variability (which is what I believe Dr Muenchow is stating), it seems to me that we have certainly placed ourselves on a track that catapults us dangerously outside of that envelope.

  25. What approach did you use in generating Figure 4 in the way of smoothing?

    [Response: If you're referring to Arctic sea ice volume, I applied no smoothing. Those are the data from PIOMAS.]

  26. I discover that Andreas Muenchow’s quoting up-thread of Sir James Lighthill is actually the abstract to the referred 1986 Lighthill paper. So it is quite strange that it is effectively contradicted by my own quoting up-thread from Lighthill’s biographer’s account of Lighthill’s 1986 “memorable lecture” as the paper and lecture are actually one and the same!!

    An explanation for this bizarre situation can be gleaned from a 1996 Memorial Tribute by this same biographer. Lighthill’s 1986 paper/lecture is quoted at some length (foot of p19 of PDF onward).

    I feel fully justified, therefore, in repeating that systems subject to the laws of Newtonian dynamics include a substantial proportion of systems that are chaotic; and that, for these latter systems, there is no predictability beyond a finite predictability horizon.
    This message is what Andreas Muenchew bases his argument for caution when attributing causes of global warming. After all, Lighthill’s systems are a lot simpler than climate.

    This message, however, is not Lighthill’s finding. Others had already shown that this chaotic behaviour existed, in the process disproving a long-held belief in full predictability. Lightfoot’s point was to put the recent ideas of chaos in context. “The behaviour of such systems had long been thought to be completely predictable but is now known, for a certain proportion of such systems, to be ‘chaotic’ in a well defined sense” (Lighthill’s emphasis)

    So Lighthill’s paper is saying that not all the systems he is referring to are chaotic Further where chaos is present it is a well-defined chaos. Weather is chaotic in a well-defined sense. This ‘well-definedness’ allows climate to be analysed and for predictions-projections-forecasts (or whatever you wish to call them) to be made of future climate. There are indeed issues of complexity, accuracy, feedbacks, tipping points, hysteresis, external input forecasting, etc, but importantly – at a climatical level there is no chaos.

    I thus contend that Andreas Meunchow’s ‘personal preference’ for ‘caution’ is wrong.

  27. Concerning the anthropogenic influence on climate change I prefer to start from the historically valid order.

    In line of the early observations of Tyndall, Arrhenius and others atmospheric scientists had reached in 1970’s the level of knowledge that allowed for rather reliable estimation of something that could be called no-feedback sensitivity. Based on that and the observed rate of increase of the CO2 concentration they realized that significant warming is to be expected and that it should follow the increase in CO2 concentration with some delay. Due to problems in estimating the feedbacks the actual strength of this effect turned out difficult to determine. Even so we had the prediction of raising temperatures roughly proportional to the increase of the CO2 concentration until the logarithmic nature of the forcing and other nonlinearities start to be important.

    What we have seen agrees well with that. In the spirit of Bayesian inference that’s rather strong evidence for the correctness of the theory and supports taking the total strength of the increase as the first guess on the climate sensitivity. For that we don’t need any proof that no other explanations are possible, but quantitative estimates of the uncertainties in the conclusion require a thorough study of the set of all possible explanations and a set of justified priors for the quantitative Bayesian calculations. (We are still short of having that study ready).

    One phenomenon that seems to be important in that approach is the apparent (quasi)periodic variability of temperatures with a period of about 60 years. The time series seems to have had a maximum around 1940 and it’s easy to imagine that another maximum of some quasiperiodic effect was around year 2000. If that’s true then we might think that the CO2-related warming is best estimated comparing temperatures around these two years. There are other known effects like those related to aerosols, which may change the conclusion, but I try to argue here on a level that does not depend on complex models.

    From my approach we should not be particularly interested in the relative shares of anthropogenic and natural contributions to warming, but should ask directly: What can we say about the absolute strength of the influence of CO2, i.e. the only relevant question is the value of climate sensitivity over various time spans and for various levels of CO2 concentration (all these details are of interest due to delays and non-linearities). IPCC has adopted a similar approach, while many “skeptics” and some “warmists” like to discuss the relative shares which are of less interest in my view.

    The estimation of climate sensitivity is also influenced strongly by the choice of the prior when looked from the Bayesian perspective (which is the only justified one for me). This has been discussed by Annan and Hargreaves in papers that make a very important point in my view. Basically the issue here is related to whether it’s appropriate to use a flat prior over some range for the climate sensitivity or perhaps rather a flat prior for the feedback coefficient. This choice has a really major effect on the fatness of the high sensitivity tail. My personal favorite is flat in feedback which makes the tail much less fat.

    [Response: In my opinion, the evidence for a “(quasi)periodic variability of temperatures with a period of about 60 years” doesn’t even rise to the level of “weak.” Not only does it fail truly rigorous statistical testing, once one removes the very real impact of the very real increase in anthropogenic aerosols there’s not even much “apparent” left.}

    • It offers, however, a nice “excuse” for the certainly temporary flattening in the rise of the temperatures.

      Taking into account the whole temperature history until 2012 it does not make much difference, whether such quasiperiodic effect is accepted as true or not. Ten years ago it would have affected the estimates more but not any more.

  28. Andreas Muenchow, Just curious – do you harbor serious doubts about the competence of climate scientists? If, with the information and skills at your disposal you reach widely different conclusions (such as that there remains too much uncertainty to draw any conclusions about the contribution of human activities to climate change) will that lead to a conclusion that it is they – rather than you – that lack competence?

    Whilst I can’t speak for you, I think that more generally, being unwilling to accept or agree with climate scientists is not a consequence of a genuine lack of rigor in climate science – rather that it is (as I believe to be the case ) a consequence of wide ranging and organised efforts to undermine public trust in climate science and it’s practitioners. I believe our scientists have earned a high degree of trust and respect; certainly the peak science bodies that have used independent experts to repeatedly scrutinise the methodology and conclusions of mainstream climate science haven’t found incompetence. Or that it’s conclusions lack substantiation.

  29. “But unlike the changes which have happened in the past, modern climate change is not natural.”

    Seems perfectly natural that a clever hominid species would seek out large hydrogen-carbon pools of energy to increase their organizational complexity to the point of upsetting an established environmental equilibrium – indeed, the 2nd Law of Thermodynamics does arguably demand it. Rabbits do it, foxes (eating the rabbits) do it, even microbes in a petri dish do it – I don’t see why our self-professed intelligence would stop us from doing it.

    Any solution to the problem will need to address why we’re different than every other self-organizing entity that increases entropy in its surrounding environment. I don’t think we are different – thus, we know the problem but we can do little about it… because it *is* perfectly natural.

    • Actually, the comparison of human use of hydrocarbons with other species’ use of resources is very largely spurious.

      Humanity’s use of fossil energy is not simply fractally proportionate in cause-effect compared to most other species. Humanity is profoundly altering the climate of a whole planet, and with it the planet’s biosphere (quite separate to other impacts that humans cause). No other species has manifested such a monumentally fundamental alteration of the entire planet in such a geologically short period of time, and in the process placed itself and a large swathe of other living species in the face of extinction.

      Quite the opposite, in fact. Most heterotrophs, and indeed many autotrophs competing amongst themselves for resources, exist in a dynamic equilibrium with their ecosystem partner-species that shows resilience over cycling scales of time. Yes, even in ‘natural’ boom-and-bust circumstances. This is reflected in the fact that biodiversity has been increasing over time, prior to the advent of human technology: now it is decreasing precipitously. To put this into a modern context, pre-technological evolution progressed so that it maximised the life-complexity bang for the entropy buck, whilst humans are massively devaluing the life-complexity return on any entropic investment.

      What humans are inflicting on the planet involves a whole lot of non-equilibrium effects, a great train-load of one-way impacts that won’t be reversing in any context relevant to the life-time of most species, and certainly not in the context of the number of generations required to recover from the damage to populations that we’re currently enacting.

      Human cultural/technological impact on the planet is only “natural” in the sense that when a complex system is FUBARed it fails or otherwise becomes much simplified and unbalanced, and much information is permanently lost. Human impact on the planet is only “natural” in the same way that a computer crash is a natural part of typing your autobiography on a computer without any recourse to backing up.

      Humanity’s experiment with technology is the blue screen of death for biodiversity.

      • Wendy Crowell

        Bernard, I don’t understand why you think the comparison of human use of hydrocarbons with other species’ use of resources is “very largely spurious”. The only thing that is different in our case is the scale of the impact. The process is entirely the same. Animal populations modify their habitats for the worse all the time, on time scales that we can observe. Very high levels of herbivorous insects decimate the plants on which they depend. The populations of insects then crash, the plant populations build up again, and then the insect populations build up again. It looks like it is a stable relationship, but from the point of view of the generation of insects born when almost all the plants are dead, it looks like the worst catastrophe in the world. Ecological systems do come into new equilibrium, and I am sure new ecosystems and even humans will persist. What is different about our situation is that it is happening to us. We are modifying our habitat in ways that are detrimental to us. Our children and our grandchildren will have to cope, as best they can, with the situation.

      • Bernard, I don’t understand why you think the comparison of human use of hydrocarbons with other species’ use of resources is “very largely spurious”.

        Then you probably need to re-read my post.

        The only thing that is different in our case is the scale of the impact. The process is entirely the same.

        My point is that our impact does not scale fractally. Our use every year of about a millions years’-worth of fossilised energy is incomparable in the living world.

        Yes, the process of ending up dead is entirely the same. It’s the way that we allow ourselves and our biospheric companions to die that is going to different, and it’s the way-of-living bit before the dying bit that’s going to be different, to what they would otherwise have been had we not been quite so clever at using a resource never exploited in the past as it is now..

        Our children and our grandchildren will have to cope, as best they can, with the situation.

        How very amorally nihilistic. Basically you’re saying that we can enjoy our laissez faire inclinations, and bugger the intergenerational, interspecies ethics of it all, because life is red in tooth and claw. The whole point of being (supposedly) human is that we’re supposedly more than the sum of our teeth and our claws.

      • Wendy Crowell

        Bernard, how could you say this?
        “Basically you’re saying that we can enjoy our laissez faire inclinations, and bugger the intergenerational, interspecies ethics of it all, because life is red in tooth and claw.”

        Enjoy!?? how could have possibly read enjoyment into my post? It is a catastrophe of epic proportions that will be visited upon my children and and everyone else’s children and all our grandchildren, and many, many of earth’s species. But to me, it fits a pattern of things that occur in nature. I try not to let my wishful thinking get in the way of my understanding of what is happening. And I do think it is similar to other patterns in animal populations, in so far as the habitat destruction (carbon dioxide increases and resultant climate change) is pretty closely correlated to human population levels. I am doing everything I can to stop this train wreck from occurring, but smart as we are in some ways, we appear to be stupid in this way. I also hope that in identifying patterns of behavior that are leading to this mess we can figure out some way out of it.

      • But to me, it fits a pattern of things that occur in nature.

        Wendy, the point of contention here is essentially the manner in which human impact on the planet “fits a pattern of things that occur in nature”.

        Yes, organisms impact on the species and in the environment around them. Yes, humans do so too. But what humans are doing is out of all proportion to how non-human species affect their ecosystems. It’s a qualitative versus quantitative difference, and focusing on the qualitative similarities results in an abrogation of effective acknowledgement of the quantitative seriousness of what is occurring.

        Most species alive today are alive because they have achieved an equilibrium within their ecosystems, whether or not their populations exhibit notable fluctuations. Most species alive today are not engaged in a trajectory impacting the rest of the species within their ecosystems that would see wholesale extinctions resulting.

        Human impacts (most especially the rates of change resulting from those impacts) are far and away beyond what any other single species inflicts on those around it, both proportionately and absolutely. Human impacts are far and away beyond what day-to-day, season-to-season, year-to-year, and millennium-to-millennium non-biotic ecosystem events inflict on the biosphere. In this regard the action of humanity is a novel situation, and it is one perpetrated by what is supposed to be the most intelligent of species to ever exist.

        We are an enormous stochastic assault on the biosphere, comparable to the magnitude of the major volcanic periods, to asteroids, and to orbital extremes. And our impact may grow to beyond the magnitude of some of these rare stochasticities. Ecological systems stagger and recover from such profound stochastic events, but these events are not a runaday part of the biosphere’s function.

        To reiterate, human use of resources is fundamentally different in quantity, if not in quality, to how any other species uses its resources. It is for this reason that I say that the comparison with other species is “very largely spurious”. If the distinction is not made, then it becomes so much harder that “we can figure out some way out of it”.

      • Bernard, how could you say this?
        “Basically you’re saying that we can enjoy our laissez faire inclinations, and bugger the intergenerational, interspecies ethics of it all, because life is red in tooth and claw.”

        Enjoy!?? how could have possibly read enjoyment into my post? It is a catastrophe of epic proportions that will be visited upon my children and and everyone else’s children and all our grandchildren, and many, many of earth’s species. But to me, it fits a pattern of things that occur in nature. I try not to let my wishful thinking get in the way of my understanding of what is happening.

        I read no enjoyment from you, Wendy, but your approach seems to be that human impact on the biosphere is “natural”, that “it fits a pattern of things that occur in nature”. You said that “[o]ur children and our grandchildren will have to cope, as best they can, with the situation”. One can similarly argue that organochlorides and halocarbons and hydrogen bomb explosions are natural, and that we should let them occur as they will with no control, because species will adapt, will “cope as best they can”. If one is truly of this inclination one would effectively endorse a laissez faire approach to the issue of fossil carbon emissions also, with the accompanying nihilism that is implied.

        Our very use of pointy rocks tied to sticks, of fire and of textiles and of agriculture, of fossil energy and of nuclear energy, implies that we have at least some mastery over our environment. Why then should we not accept that such a profound degree of mastery separates us in some way from the impacts that other species have on their environment, that we have a choice in whether and how much we damage our world, and that we can either enrich or decimate the planet’s biodiversity for many millennia, and perhaps æons, to come?

        We have the choice if we apply our wits to the problem. Why should our descendants cope “as best they can” when we have it within our capacity to mitigate as best we can, now, before we screw it up for the future?

      • Wendy Crowell

        Bernard,
        My ultimate goal in thinking about these things is to figure out how to stop humans from continuing on our merry way, accepting the possibility, even the significant probability, of long-term loss, even extreme loss, in exchange for short term gain. I share your desire to impress upon people how short-sighted, and selfish this continued laissez-faire attitude towards human – caused environmental destruction is.
        The question I am trying to answer is the question you pose . “Why then should we not accept that such a profound degree of mastery separates us in some way from the impacts that other species have on their environment, that we have a choice in whether and how much we damage our world, and that we can either enrich or decimate the planet’s biodiversity for many millennia, and perhaps æons, to come?”

        Except I am trying to answer the question “Why don’t we accept our degree of mastery and impact on the world, and why do we act like we don’t have a choice?”. The data on human behavior in the face of global warming is as clear as the data on global warming itself, we are not as a group changing our behavior, we are continuing with business as usual. Most organized societies on earth are not planning ways to sacrifice in the present in order to preserve a viable future for our descendents and the planetary ecosystem. But our behavior in small groups and as individuals is different. I actually believe that humans have it in us to change our behavior, to put long term goals ahead of short term gain, even when the future risks are hard to see and the present loss is all too real, because individuals and small groups do this. So why do small groups of people and individuals behave so differently than large groups of people? And what does that mean about how we go about thinking about this problem and fixing it?

      • Wendy, we’re very much on the same page now.

        You ask questions about which I have been long mulling over, and I have a few thoughts about it all. I’m pressed for time now, but perhaps I will return soon.

        Note though, this is the stuff of whole blog and books…

      • I doubt anyone is still following this thread but for what it’s worth…

        I don’t disagree with the difference in scale of our environmental impact. But my comparison is not really intended to be in terms of impact – it is more about how we view ourselves. Almost all discussion of climate change involves the notion that we’re in control of our behavior – when we’re clearly not. We don’t discuss coyotes outstripping the carrying capacity of their environment by preying on a burgeoning deer population as if they should do anything other than what they’re doing – doing “what nature intended” them to do.

        Human impacts are off-the-scale – but it’s temporary. It was most likely only possible due to an exceptional period of climatic stability that allowed for large scale agriculture – that equilibrium was exploited for what it was worth, carrying-capacity was exceeded and the Holocene era is rapidly drawing to a close. Human carrying-capacity will likely return to pre-Holocene levels (perhaps something slightly above or below) – and over a lot of time the overall organizational complexity of the biosphere will increase again. It will self-repair as it has done in the past.

        For what it’s worth, I don’t actually think our off-the-scale impacts are attributable so much to our technological prowess or our facility for burning fossil fuels as much as to the happenstance of discovering how to fix nitrogen in the beginning of the last century… but that’s another discussion…

        There’s a Zen saying that the source of the problem is also the source of the solution. Or as Einstein put it, you can’t solve a problem with the same thinking that created it… or something like that. At any rate, I think a large part of the puzzle that confronts us is the concept that we’ve created the mess we’re in and therefore we’re responsible for it. Every objective observation would seem to suggest we have absolutely no control over the mess we find ourselves in – and I think that’s the thing we need to accept as unpalatable as it may be to our sense of self. Without accepting the humility of that reality I don’t think we’ll find ourselves with anything more than a rapidly diminishing illusion of control which never existed in the first place.

        [Response: There's much to consider in your statement, but I don't think it's the whole truth. Remember the words of Margaret Mead:

        "Never doubt that a small group of thoughtful, committed citizens can change the world; indeed, it's the only thing that ever has."

        While I'm on the soapbox I'll recall another quote from her, not related but very important:

        "Every time we liberate a woman, we liberate a man."]

      • Aaron.

        Almost all discussion of climate change involves the notion that we’re in control of our behavior – when we’re clearly not. We don’t discuss coyotes outstripping the carrying capacity of their environment by preying on a burgeoning deer population as if they should do anything other than what they’re doing – doing “what nature intended” them to do.

        The facts that we have laws, and regulations, and international treaties, that we’ve effectively solved perceived problems such as death by disease and holes in the ozone layer, tend to contradict your thought on whether we can control our behaviour. More important is whether we can elect to control our behaviour, and whether we have the wisdom (inappropriately attributed to us by our binomial epithet sapiens) to understand when it is necessary to do so.

        Also, it’s dangerous to use the anthropomorphisation “what nature intended”, because I doubt that “nature intended” for a single species to wipe out a significant percentage of the others, even if “nature” does have a mechanism for recovery.

        Human carrying-capacity will likely return to pre-Holocene levels (perhaps something slightly above or below) – and over a lot of time the overall organizational complexity of the biosphere will increase again. It will self-repair as it has done in the past.

        Oh, no one’s disputing that the biosphere will repair in some way or another. Thr trouble is that it doesn’t happen on the same timescale in which it was disrupted: as I said in another post, we’re a stochastic event on the order of magnitude of an asteroid or major vulcanism, and any recovery, such as it is, will occur on the scale of millions of years – far longer than the likely species life-time of a primate.

        For us, and for our decendant species, that means that our impacts are effectively permanent. And if we go back to the anthropomorphising of nature, I’m sure that the other species affected wouldn’t be so nihilistically sanguine about their extinctions if they had the choice to comment on what humanity is doing.

        For what it’s worth, I don’t actually think our off-the-scale impacts are attributable so much to our technological prowess or our facility for burning fossil fuels as much as to the happenstance of discovering how to fix nitrogen in the beginning of the last century… but that’s another discussion…

        The Haber–Bosch process is very much a product of both our “technological prowess” and “our facility for burning fossil fuels”. It’s certainly a boon to efficiency in food production, but it is somewhat naïve to imagine that without it we would not have scaled up nitrogen sourcing with which to increase food production, whether through microbial fixation or through more effective nitrogen recycling. Indeed, those last two processes are becoming more important for future farming practices as Peak Oil looms.

        Every objective observation would seem to suggest we have absolutely no control over the mess we find ourselves in – and I think that’s the thing we need to accept as unpalatable as it may be to our sense of self.

        Aside from the fact that there is plenty of evidence to the contrary with regard to having control, predicated in your statement is the implicit assumption that humans have absolutely no free will. Putting aside the philosophical Gordian knot of the nature of free will, the fact remains that humans chose not to ‘burn’ away the ozone layer, or (so far) to nuke the planet to a crisp. We do have quite a big say in how, and whether, we shit in our nest – it’s a consequence of the phenomena of being self-aware, and of being aware of ‘the future’ and our own mortality.

        Without accepting the humility of that reality I don’t think we’ll find ourselves with anything more than a rapidly diminishing illusion of control which never existed in the first place.

        I think that you’re making a fundamental mistake in confabulating the capacity to control, with the inclination to do so. As a species we can all participate in the former, but most are stymied by the latter. We have ‘free will’, but many simply ‘lack will’ – and no, the two are not contradictory.

        It’s really no different to dieting – some people can reduce their weight, but many are not inclined to go the hard yards to do so. The trouble is that not going on a carbon diet will affect those around us (and those in the future) far more than not going on a food diet does (and would).

        I agree in a way with your very last statement though. Without urgent response to our emissions to date of carbon dioxide, we will rapidly lose any control of the situation, whether or not that control is an illusion as you think, or was previously real as I and many others would suggest.

      • “Homo procrastinatiens”
        — by Horatio Algeranon

        We’re self-named “Homo sapiens”
        But there is little proof.
        “Homo procrastinatiens”
        Is closer to the truth.

      • Tamino, this paragraph from the previous post of mine above should have been blockquoted.

        For what it’s worth, I don’t actually think our off-the-scale impacts are attributable so much to our technological prowess or our facility for burning fossil fuels as much as to the happenstance of discovering how to fix nitrogen in the beginning of the last century… but that’s another discussion…
        <Blockquote

        If you can fix it I'd be obliged, but if not at least this should serve to alert others!

      • (I am not having a good day…)

        Tamino, this paragraph from the previous post of mine above should have been blockquoted.

        For what it’s worth, I don’t actually think our off-the-scale impacts are attributable so much to our technological prowess or our facility for burning fossil fuels as much as to the happenstance of discovering how to fix nitrogen in the beginning of the last century… but that’s another discussion…

        If you can fix it I’d be obliged, but if not at least this should serve to alert others! Sorry for the mess.

      • Arghhh!

  30. Aaron, if you mean it’s perfectly natural for an otherwise intelligent species to behave like idiots to the point of self-extermination, then I agree with you.

  31. Tamino says: “Another reason is that in colder regions the atmosphere has less water vapor. Therefore CO2 has a greater share of the total greenhouse-gas load.” And thus larger temperature changes.
    Thanks Tamino. Figured this out on my own but never see it mentioned anywhere.
    Although the question still remains as to why this mechanism is not so apparent in the Antarctic. Is it because energy transport and ice feedback mechanisms are substantially more important?