RealClimate logo

Unforced variations: June 2014

Filed under: — group @ 1 June 2014

June is the month when the Arctic Sea Ice outlook gets going, when the EPA releases its rules on power plant CO2 emissions, and when, hopefully, commenters can get back to actually having constructive and respectful conversations about climate science (and not nuclear energy, impending apocalypsi (pl) or how terrible everyone else is). Thanks.

488 Responses to “Unforced variations: June 2014”

  1. 51
    patrick says:

    #42 chris colose > other news

    Other news, for sure.

    That’s a great article you point to, by Michael Mann, and the entire section looks like a good learning tool and a useful resource.

    Thank you very much; and thank you, Michael E. Mann.

    [Response: Thanks Patrick. And thanks Chris for posting the link :-) -mike]

  2. 52
    Chuck Hughes says:

    “This recession will either be voluntary, government-imposed, or climate-imposed. My guess is the final option — as CO2 rises, climate havoc will increasingly disrupt economic growth, forming a negative feedback that provides an ultimate, upper-bound on warming.”

    Comment by Joel

    I’ll take “Climate-Imposed” for $500 Alex…

    I do not envision a scenario where either the government or the populace voluntarily cause a recession.

  3. 53
    Killian/ccpo says:

    Re #9 Edward Griesch:

    Lovely numbers, sir! Out-standing! Tell me, good sir, has green power (I shall not call it renewable until it actualy is) been installed in Australia with comprehensive local planning of the environment, built and otherwise? Or with local planning? Then bio-regional? Then island-wide/continental?


    Well, then, we shan’t be surprised when weaknesses appear, no? Planningless planning is, well, less than intelligent.

  4. 54
  5. 55
    Edward Greisch says:

    18 SecularAnimist: See: New article at 
“Critique of the proposal for 100% renewable energy electricity supply in Australia” Which I listed above and you didn’t read. The author, Dr Ted Trainer, reviewed and critiqued a paper by Elliston, Diesendorf and MacGill on how eastern Australia might be run off 100% renewable energy. The summary of the summary: It can’t be done unless Australians loose their lifestyle and move back a century or so. Elliston, Diesendorf and MacGill make assumptions that are nonsense.

    WHO is insulting? WHO is a troll?

    My complaint is that people WILL NOT do the math. I mean literally THE MATH. Nor will they look at the results of other attempts to go renewable. Berliners are paying FOUR times what I am paying for electricity. Many Germans cannot afford electricity at all now. I have repeatedly given you good references. Nobody reads them. A good example out of many:
    I bet SecularAnimist never even looked at the URL.

    There are so many of them:

    Again: Batteries are not included with renewables
    Be sure to read the linked papers.
    “Renewable Energy – Cannot Sustain an Energy-Intensive Society.”

    “100% renewable electricity for Australia – the cost”

    So, SecularAnimist, if you again make no attempt to do the scientific thing, as in read the references I have given you and find mistakes in the math, and do experiments and calculations on your own and show us the math you did, what am I supposed to think of your effort? I predict that you will do the same as before: Wave your arms vigorously and generate words, words, words. So sorry, words don’t cut it here.

    SecularAnimist: Go invent the SuperBattery or the Room Temperature Superconductor. Get rich. We will all cheer when you come back with a patent. But bla bla bla is not music to our ears.

    25 owl905: I am paying 7 and 1/2 cents per kilowatt hour. Californians are paying twice as much at 15 cents per kilowatt hour. Berliners are paying 28 cents per kilowatt hour. The difference is that California and Germany are forcing renewable energy into their grids. My electricity is from coal and nuclear. Higher prices for electricity are exactly due to the forced introduction of wind & sun.

    owl905: Wind delivers 20% of nameplate power on average, very intermittently.
    Solar delivers 15% of nameplate power very intermittently.
    That adds up to 30% of the time since wind and solar overlap. What is your power source the rest of the time? I know: A fossil fueled power plant. You have done nothing more than decorate a fossil fueled power plant.

    29 Thomas: Keep reporting what happens in Austin, please. Remember that $.05 per KWhour is wholesale, not retail. Confusing wholesale with retail is a typical trick of the renewables salesmen.

    Thank you 32 Joris van Dorp

  6. 56
    DIOGENES says:

    Hank Roberts #40,

    “having constructive and respectful conversations about climate science”

    Well, there’s climate science and there’s CLIMATE SCIENCE. I would like to see some real CLIMATE SCIENCE of central interest to climate change amelioration addressed on the premier climate science blog. What we are being fed are articles like those of Brigitte Knopf, which tell us “many of these issues cannot be answered solely by science, such as the question of a temperature level that avoids dangerous anthropogenic interference with the climate system”. What we need to see specifically are articles that address “the question of a temperature level that avoids dangerous anthropogenic interference with the climate system”. Why are they not being posted?

    McPherson, in his Update and Summary, lists 30+ positive feedbacks that drive the temperature upwards. What are the consequences of these feedbacks acting in concert? What are the metrics that will inform me of how serious the combined action of these feedbacks is? How do I judge the validity of McPherson’s, or any other commentator’s, conclusions about these feedbacks without such metrics? How can any of us on this blog state McPherson’s conclusions about extinction are incorrect without such metrics?

    So, the above initiating statement only addresses part of the larger picture, and not the most critical part. Yes, on a climate science blog, we should be having constructive conversations about climate science, but under the present critical conditions, these constructive conversations need to focus on those climate science issues of highest importance to climate change amelioration. For the most part, this is not happening now. [edit – just stop]

  7. 57
    DIOGENES says:

    Pete Best #43,

    “Maybe it’s a 3C or 4C world but it won’t be a 6C one.”

    We don’t know that! I suspect that when we reach 3 C, we may be on autopilot, and we’ll get to 6 C or more whether we want to or not. Why do you think Hansen, Anderson, et al call even 2 C Dangerous or Extremely Dangerous? My interpretation is that’s where the danger of self-sustaining positive feedback mechanisms increases substantially.

    But, at this point, it’s only a suspicion. I have no metrics that can act as Early Warning Indicators or precursors of runaway feedback. And, for whatever reasons, RC continues not to address some of the critical climate SCIENCE issues like identifying these metrics.

  8. 58
    Chris Dudley says:

    The science of one:

    One of the things scientist really like to have is an ensemble. This allows the mathematics of statistics to be used to learn something about the whole thing by studying some of the parts.

    Here at realclimate, we’ve even heard reality called just one realization in the context on an ensemble of model runs. I don’t think I agree with that, but you can see the attraction of ensembles.

    In cosmology, we can eliminate certain fine tuning issues by supposing that THE Big Bang occurs in a context of chaotic inflation. The laws of physics don’t have to be the same in different non-causally connected parts so our particular laws of physics are just one set of many and we don’t have to be surprised that the Hoyle resonance of carbon has just the right energy: in other parts of the Universe it doesn’t.

    So, in chaotic inflation, beginnings are happening all the time. But, how many endings are there? By construction, since these different universes are not causally connected, they each get their own fate.

    On Earth, we’ve had a number of mass extinction processes. But these apocalypsi only have meaning if there has been time for new species to evolve in between. Since the event is defined by the destruction, if there is nothing left to destroy, a second event just gets rolled into the first. So, a zombi apocalypse followed by peak oil collapse followed by a climate runaway, while mutually contradictory and quite different in nature, just make one apocalypse because there is only one civilization to destroy. There really isn’t an ensemble to consider in this case.

  9. 59
    michael sweet says:

    I read here a lot although I rarely post. Diogenes and Edward Greisch are getting beyond bearable. Citing nuclear salesmen to show solar salesmen are incorrect is illogical and a waste of time. Diogenes has been given his own thread and he still has made 20% of the posts on this thread, all off topic according to the rules we were given. None of them add anything to the discussion. If you add the people complaining about these two it is almost half the thread.

    I second the motion to send their posts to the bore hole if they cannot stay on the thread they have been given.

  10. 60
    Walter Pearce says:

    Michael Sweet @ 59: Agreed.

  11. 61


    “…it only seems ‘bizarre’ to you and the other members of the ‘tag team’ because you refuse to look at the numbers involved.”

    – See more at:

    You are not listening. (Quelle surprise.) I am well aware of ‘the numbers.’ But issue at the moment is not whether this or that ‘challenging’ renewables plan will avoid ‘Climate Apocalypse.’

    At issue is the question of whether or not supply side contributions to mitigation are ‘minor’. The Diogenes Apocalypse Avoidance Plan (™) has so far, as far as I know, never actually offered quantitative targets, despite multiple requests for same. (Talk about ‘refusing to look at the numbers’!) So I will assume for the sake of argument that the DAAP asks us to reduce per capita energy use by 75%, which I think most would find quite aggressive.

    By 2050, projects, we’ll have 9.6 billion people on Earth. That’s up from the current 7.2 by a third. Combining that population figure with the assumed energy reduction factor, we have E(2050)= E(2014) x 0.25 x 1.33, or 0.33.

    So, for this version of the DAAP to actually avoid Apocalypse–due to climate effects a la Diogenes, if we keep burning FF at the lower level, or due to economic collapse on an unimaginable scale if we ‘just say no’–we need to have essentially one third the current total energy consumption supplied by carbon-free sources.

    If you choose to call that ‘minor’, I would still find the categorization bizarre, but would carry on in silence, satisfied that we had achieved quantitative understanding at least.

    The consequence that I draw from this line of reasoning is that it is of vital importance to do everything possible to speed the adoption of low-carbon energy sources. (In the real world, this is going to mean renewables first, with increased nuclear as well, in places where this is politically feasible.) This is particularly important since there is clearly a long learning curve in doing so–luckily, for some technologies (notably wind, and to a lesser extent solar PV) we are already a long way along that curve. (And if we are talking about cost, I should probably say “down” that curve.)

    But in terms of scaling up generation, of grid management, of integration into the economic system, and (as Chris Dudley points out) of avoiding perverse outcomes in emissions terms, there is a lot of work to do, and we need to be getting on with it–not denigrating those who point out this reality, and not arguing that it is unimportant.

    Philosophers have been accustomed to speak of the ‘necessity’ and ‘sufficiency’ of particular conditions with regard to particular outcomes. Diogenes, you make a decent argument that energy substitution measures are unlikely to be ‘sufficient’ to avoid ‘CA.’. But I think that the argument that such measures are ‘necessary’ is far more compelling.

  12. 62
    Chris Dudley says:

    Edward (#55),

    People have done the math. That is why they don’t believe you and realize you suffer from an emotional attachment to nuclear energy. Just look at the anecdotal evidence you present. You claim to have cheap electricity. And yet new wind and solar are cheaper now than old nuclear power, so is new natural gas. New nuclear power is vastly more expensive than old nuclear power owing to a negative learning curve. So, the math is very clearly against you, yet your strange love propels you on. Read this and you could get clear:

  13. 63
    Radge Havers says:

    Scientists can provide options. The choices people make collectively and systemically are based on diverse hopes, desires, values; on the vagaries of all sorts of emotions, ethics, world views; on hard science; on delusions; on dogma and many other things too numerous to mention–including the inability of people to get past their Dunning-Kruger impairments and their unreasonable sense of self-importance and have meaningful exchanges of ideas.

    Anybody who confuses science on the one hand and policy/politics on the other is very naive and understands neither at a very fundamental level.

  14. 64

    #55–Ed, why are you stuck on the idea that it “must be” either renewables or nuclear?

    I have skimmed the Trainer piece you link. It’s a bit ironic, because Trainer’s whole thing is demand reduction, and he thus supports Diogene’s POV, not yours. See, for example:

    The piece already is in disagreement with your statements, which have been adamant that renewables can’t possibly replace fossil fuels. Front and center is Trainer’s summary, which says, inter alia:

    “My general view is that it would be technically possible to meet total Australian electricity demand from renewables but this would be very costly and probably unaffordable, mainly due to the amount of redundant plant needed to cope with intermittency.”

    But leaving that aside for the moment, I’d invert the comment–can’t find it now, for some reason–to the effect that there is no evidence that nuclear generation *can’t* scale sufficiently to avoid CA™. (Actually, I think there is such evidence, in the form of a 60-year track record during which nuclear power has consistently failed to scale well, or to fulfill its own (admittedly extravagant) promises about cost.)

    I’d contend that there is absolutely no evidence suggesting that we *can* train a sufficiently large nuclear work force and find the massive financing necessary in order to build hundreds of new reactors within the next couple of decades. Admittedly, hard data is not easy to find–no-one seems to want to look at this question, least of all nuclear advocates. (That reality is suggestive in itself, I’m afraid.)

    Renewables are presently scaling up to a useful degree:

    “In the power sector, global capacity reached 1,560 gigawatts (GW) in 2013 – an increase of about 8.3 per cent over 2012 – and renewables accounted for more than 56 per cent of net additions to global power capacity.

    “Renewable energy provided around 19 per cent of global final energy consumption in 2012.”

    Note that last: 19% of consumption. That’s downstream from ‘capacity factor.’

    I’d suggest that the binary renwables/nuclear concept is pointless because it’s unrealistic: we are going to have a lot more renewables in the future, and we are going to have nuclear in the future, too. A more rational outlook would consider what a realistic energy mix might look like, and what we should be aiming at. An intriguing thinker in this regard is Dr. Charles Forsberg, who points out that nuclear and renewable energy have complementary strengths and that there could also be some novel and potentially very helpful synergies between them:

  15. 65
    SecularAnimist says:

    By my count, the scientists who maintain this site, or their guests, have posted 21 articles so far this year, a little less than one per week. I continue to find those articles informative and worthwhile, and I continue to be grateful to the scientists who take time from their important and demanding work to offer that material to the public. Much of it is quite unique in giving an inside look at climate science.

    Having said that, I think the limitation of this site is precisely that it is a project run by scientists in their “spare time”, rather than by professional journalists or bloggers who could make it a full-time effort.

    For frequent, current updates on developments in climate science, I find Skeptical Science especially, and Climate Central and Climate Progress as well, to be more useful. Articles are published more frequently, and information is presented in a way that in my opinion communicates more effectively to lay readers. The comment pages are better moderated. All of which takes more time, and perhaps more training in journalism and blogging, than the hosts of this site can bring to it.

    As for the comment pages, and discussions of mitigation — the comment pages have basically become a playground for a couple of boorish, belligerent, hostile trolls who seem primarily concerned with heaping abusive, personal attacks on anyone who presents any positive views or accurate information about solar or wind energy technologies. I have now been called a paid liar and a shill DOZENS of times, simply because I have occasionally posted links to informative articles about what’s happening in the real world today with solar and wind energy and efficiency, or corrected misstatements of fact.

    As far as I’m concerned they have succeeded in turning the comment pages — especially the monthly “unforced variations” threads — into an utter waste of time to read, and probably an even greater waste of far more valuable time for the hosts to moderate.

  16. 66
    Edward Greisch says:

    West Antarctic Ice Sheet WAIS: Could we have a RealClimate article on this please?

  17. 67
    Hank Roberts says:

    > thread they have been given

    The UV Mar 2014 thread dedicated for more Diogenetic conversation isn’t writeable (and hasn’t been for a while).

    Maybe adding a new “Recent Comments” category to the right sidebar — listing only Recent Comments by Dio in his own topic — would get him the attention he requires?

  18. 68
    Radge Havers says:

    Kevin @~60

    Thank you, Kevin. That was clear and refreshingly well modulated.

    I’d like to challenge anyone who can’t resist the temptation to drop the ‘A’ and/or ‘C’ words to first define them both rigorously and scientifically to a level that’s fit for publication in a respectable peer review science journal

    Well make that the ‘C’ word. The ‘A’ word has pretentious, if not downright superstitious, biblical overtones that will always tend to make it sound stupid on a science thread. Best to just drop it altogether.

  19. 69
    David Miller says:

    Michael Sweet, I completely agree. I’ll third the notion for the bore-hole for those who can’t respect the mods direct requests and keep specific topics out of their posts.

    Mods, if you choose not to bore-hole the comments, perhaps you could dedicate a thread to nuclear discussions as a means of localizing the noise? It kept some of the Diogenes apocalyptic noise out of last months open threads…

  20. 70

    For Wally, from last month–as far as I know, the closest thing to an actual CCS plant is the Boundary Dam project in Saskatchewan. It’s supposed to come online in October.

    The CCS portion was supposed to run $600 million CDN.

  21. 71
    Chris Dudley says:

    Kevin (#60),

    Perversity is the rudder of invention.

  22. 72
    Gordon Kenney says:

    Hope springs eternal, and much could occur with an enlightened populace and a carbon tax.

  23. 73
    Steven Sullivan says:

    re: 3 Jun 2014 @ 5:09 PM Yeah, I realized, soon after posting, that that nasty ‘news’ service ‘aggregates’ articles without citing the original venue…and almost certainly without informing the authors either. I’ve notified Judith Curry of it, after a fashion, on her own site (where the article originated).

  24. 74
    owl905 says:

    @michal sweet #59 – Second your second to have the nukers relocated to some other paradise. Griesche’s science source is the whole blog, and nothing but the blog. His statement that the diff in price is all renewable is absurd … so he repeats it. Even tho examples of existing variable-demand backup were provided, he reverts to the refuted canard that a standby coal-plant is the only alternative. Isn’t there some way to encourage them to interact elsewhere?

  25. 75
    Dave says:

    Dear All

    Questions/musings from a non-scientist.

    Depending upon which data set one looks at, there has been “x” amount global warming since, say, 1950. Based upon the accepted maths of the greenhouse effect of CO2, and the levels that man has introduced, we (but not me because I ain’t clever enough) should be able to quantify what warming man has, and is, contributing to the total figures.

    Once we know that, then we should be able to subtract those numbers from the “observed” to establish the underlying, natural trends. Has anybody done that work?

    Secondly, has anybody done any work that concludes what the “ideal” global temperature should be? I guess that depends on who’s “ideal” we are looking at i.e. what would the Inuit, or the Bedouins, “ideally” want to make their lives better, more sustainable, less arduous, more plentiful, comfortable, etc. But has anybody suggested the “ideal” global temperature that represents the best fit overall?
    Is it that we would want it where it is now, or 1,2,3,4, degrees warmer or colder?

  26. 76
    DIOGENES says:

    Kevin McKinney #60,

    “At issue is the question of whether or not supply side contributions to mitigation are ‘minor’. The Diogenes Apocalypse Avoidance Plan (™) has so far, as far as I know, never actually offered quantitative targets, despite multiple requests for same. (Talk about ‘refusing to look at the numbers’!) So I will assume for the sake of argument that the DAAP asks us to reduce per capita energy use by 75%, which I think most would find quite aggressive…..So, for this version of the DAAP to actually avoid Apocalypse–due to climate effects a la Diogenes, if we keep burning FF at the lower level, or due to economic collapse on an unimaginable scale if we ‘just say no’–we need to have essentially one third the current total energy consumption supplied by carbon-free sources.”

    I don’t know which is worse: responses on my posts containing nothing but vitriol (SA) or responses based on lies (#60). How can you say with a straight face that I’ve never offered quantitative targets. I’m one of the only ones, if not the only one, who offers quantitative targets. Go back and re-read my posts!!!

    I have told you repeatedly I believe the 1 C limit (OR LESS) is the appropriate target, and at a minimum, we might be willing to take a gamble with very high probability of staying within 2 C (not my preferred choice). I have told you repeatedly that to achieve the latter target, according to Raupach, we are out of carbon budget TODAY, and to achieve the former target, we are not only out of carbon budget TODAY, but we are heavily in carbon debt TODAY. Now, ‘out of carbon budget’ TODAY means ZERO; is that quantitative enough for you; if not, it should be.

    Now, let’s look at the numbers you provide, picked as they are out of the air. You project a reduction of total energy use by 2/3 (if I understand your convoluted wording) by 2050, with all the energy at that time supplied by low-carbon sources. If my interpretation is correct, and we assume a linear reduction in fossil fuel use over that period, then we will have burned the equivalent of eighteen years FTE of fossil fuel over that period. That’s slightly more than half of what I calculated for the Ceres Clean Trillion plan, since your rate of low carbon source introduction is approximately twice theirs.

    We can’t afford eighteen more years of fossil fuel combustion at today’s rates; the remaining budget TODAY is ZERO!! Plain and simple!! Are your numbers better than if we had no low carbon introduction; of course? Will they do the job required to avoid disaster; of course not!! And, by the way, if you go back and read my plan, rapid introduction of low carbon sources is a part, but not the major part. It can’t be, as Anderson has pointed out repeatedly.

    What is the role of low carbon sources in my plan? Think of the analogy with a patient who has an extremely serious condition. For survival, high-dose Keemo and high-dose radiation are necessary. To make the process bearable (but not pleasant), high amounts of asspiirin are allowed as well. The latter is the main role that low carbon sources play in my plan. They do not reduce demand sufficiently to have more than a minor impact on what is required, but they will make life somewhat bearable for many people.

  27. 77
    Walter Pearce says:

    Dave @ 69, here’s a 2010 link from Skeptical Science:

    Given a choice, wouldn’t you ideally want to continue with the relatively stable climate we’ve had during which agriculture and civilization flourished?

  28. 78
  29. 79
    Walter Pearce says:

    Lastly, Dave, the discussion of the “ideal” climate appears to be moot:

  30. 80
    Hank Roberts says:

    Dave —
    > natural trends?
    That’s been done — click the “Start Here” link at the top of the page, or the “Categories” list in the right sidebar. Natural trends are very slow compared to what we’re causing.

    > “ideal” temperature
    None. The issue is how fast conditions change. Many plants and animals can’t move far enough fast enough or have enough offspring fast enough for natural selection to find any offspring that can survive the new conditions, as conditions keep changing.

  31. 81
    Steve Fish says:

    Re- Comment by Dave — 5 Jun 2014 @ 4:12 AM, ~#69

    The answer to your first question (anthropogenic component) can be found on this site repeatedly, but for a concise explanation, I recommend the Skeptical Science site. Their articles are written by, or vetted by, scientists. Switch between the basic and intermediate explanations as seems appropriate for you. For human cause-

    The ideal temperature question is a climate denialist straw man. What small groups of people who live in extreme environments might prefer would surprise you. The real question involves the climate during the current interglacial period which made it possible to develop human society and support currently 7 billion and soon to be 10 billion, people. We are currently at the top of the temperature range that allows feeding everyone, and this is on top of a whole bunch of other developing ecological problems.


  32. 82

    #69–Dave, this is a bigger task than you appreciate.

    The most authoritative source is the recently released Fifth Assessment Report (Working Group I.) Chapter 2 deals with observations of the Earth system, including temperature changes. It says, in part, that:

    The globally averaged combined land and ocean surface temperature data as calculated by a linear trend, show a warming of 0.85 [0.65 to 1.06] °C, over the period 1880–2012, when multiple independently produced datasets exist, and about 0.72°C [0.49°C to 0.89°C] over the period 1951–2012.

    However, the ‘accepted maths of the greenhouse effect’ part remains a real problem. The basic physics isn’t bad, but the response of the Earth system to radiative forcing is extremely complicated. That’s the problems of ‘detection and attribution,’ which are the subjects of Chapter 10:

    Detection and Attribution results can be used to constrain predictions of future climate change (see Chapters 11 and 12) and key climate system properties. These properties include: the Equilibrium Climate Sensitivity (ECS), which determines the long-term equilibrium warming response to stable atmospheric composition, but not accounting for vegetation or ice sheet changes; the transient climate response (TCR), which is a measure of the magnitude of transient warming while the climate system, particularly the deep ocean, is not in equilibrium; and the transient climate response to cumulative CO2 emissions (TCRE), which is a measure of the transient warming response to a given mass of CO2 injected into the atmosphere, and combines information on both the carbon cycle and climate response.

    TCR, in other words, is short-term–in this context, that means a characteristic time frame of ~70 years–and ECS more long-term. Neither one can be usefully calculated from first principles:

    Because neither ECS nor TCR is directly observed, any inference about them requires some form of climate model, ranging in complexity from a simple zero-dimensional energy balance box model to OAGCMs (Hegerl and Zwiers, 2011).

    There’s a lengthy discussion of particular studies of TCR, but the bottom line given is this:

    TCR is likely to lie in the range 1°C to 2.5°C and extremely unlikely to be greater than 3°C. This range for TCR is smaller than given at the time of AR4, due to the stronger observational constraints and the wider range of studies now available. Our greater confidence in excluding high values of TCR arises primarily from higher and more confident estimates of past forcing: estimates of TCR are not strongly dependent on observations of ocean heat uptake.

    So if CO2 doubled over 70 years or so, you would expect to see 1-2.5 degrees C of warming. Just for fun, according to GISS estimates, CO2 in 1944 was ~310; currently it’s at 401, for an increase of 29% or so. The equation given for TCR in a case like this is:

    TCR = F2xCO2 dT/dF

    So, you’d naively expect 0.29-0.72 C warming since 1944. Using the Woodfortrees site to calculate warming since 1944 by the least squares method of trend estimation, you get ~0.49 C.

    Returning to work that actually is ‘primetime’, the AR5 ‘bottom line’ statement about ECS is this:

    …there is high confidence that ECS is extremely unlikely less than 1°C and medium confidence that the ECS is likely between 1.5°C and 4.5°C and very unlikely greater than 6°C.

    (This follows voluminous discussion of the various methods used to estimate ECS.)

    As to considering the overall ‘compromise ideal’ temperature you discuss, no, no-one has ever tried to calculate such a thing, because there is no objectively agreed standard for ‘ideal.’ The closest thing to an answer to your question is consideration of the effects of warming to various degrees. The short version of that research is that warming which exceeds 2 C is apt to prove very dangerous and have increasingly fewer ‘winners’ and increasingly more ‘losers’ the more extreme it is allowed to become.

    There’s a lot on the effects of specific levels of warming in Mark Lynas’s book, “Six Degrees”, which I discussed and summarized here:

    Each chapter also has a separate table of effects, as best as I could summarize them in a tabular format. The final one is here (and also includes some updated information):

    On the ‘cooler’ side, Annan and Hargreaves (2012) estimated global mean surface temperature during the last Glacial Maximum–in other words, the very depth of the last ‘Ice Age’–to be just 4 C cooler than present. I doubt we’d want to cool things more than a degree or so.

  33. 83
    Gene says:

    Answer to Dave:
    It could be that more than 100% of warming is attributable to human activity. How? Look at the Milankovitch theory, and we should be seeing a cooling trend since 1950. Ah, if only it were that simple. However “skillful” the models are, they may not include as yet unidentified factors in what we measure. Weather remains a chaotic phenomenon, and climate data will, to some extent, reflect uncertainties because of this.
    “Ideal” temperature? I think this would entail too many assumptions to be meaningful. What we need to be most concerned about isn’t the absolute “ideal” temperature, it is the rapidity with which change in climate is occuring, and the impacts of this on the biosphere. Given time, organisms adapt. But lacking enough time, many organisms will be going extinct. There is plenty of reason to be concerned about how this affects the entire food chain, including apex consumers like humans.

  34. 84
    MARodger says:

    Dave @69.
    Your second question “Is it that we would want it where it is now, or 1,2,3,4, degrees warmer or colder?” probably should be couched in terms of tenths of degrees rather than degrees (or fifths of degrees if you’re talking fahrenheit). Human civilisation was established during the Holocene (the last 11,000 years) and the climate has been remarkably constant over that period. The global temperatures over that period as reconstructed by Marcott et al (2013) and recent global temperatuers are graphed here. Note the graph’s Y-axis.

  35. 85
    MAXMARE says:


    There are people that dislike daylight saving time or vaccines. How do you imagine a consensus can be reach about an ideal temperature?
    It is amazing the gigantic amount of hubris that can fit a human brain.
    Stop burning fossil fuels is the answer. All the rest is talk and crossing of the fingers.

  36. 86
    Eric Rowland says:

    Thomas @ 1 – I will be quite surprised if renewables plateau any time soon. I’ve worked in the renewable energy business for over 10 years and during that time I’ve designed and sold a little over 50MW of installed solar energy in California, Arizona and Hawaii. I’ve no doubt that solar energy works reliably and as designed because my customers have often had to sign performance contracts which guarantee output over a 20-25 year period. Of the over 100 of these contracts, not one of the systems is under performing. Solar energy is just simple. It’s output is based on a known amount of insolation per square meter in a given location and a well regulated output capacity for a given standard poly silicon panel, (+/- 6% per year). Is it the only solution? Of course not but it will be an important part of our overall solution to electrical energy generation.

  37. 87
    patrick says:

    How to Criticize with Kindness: Philosopher Daniel Dennett on the Four Steps to Arguing Intelligently:

    “Just how charitable are you supposed to be when criticizing the views of an opponent?”

    Good luck.

  38. 88
    sidd says:

    Schon et al. -76+/-15Gtonne/yr for WAIS and periphery over 2003-2009

    might be low, but it is 2014 now


  39. 89
    patrick says:

    Dave > [Would we] want it where it is now, or 1,2,3,4, degrees warmer or colder?

    Not to distract from any of the responses to the question so far, but if you ask the same question about your own body temperature–and answer it–you have made a good start. You are in good company, too. More than one leading climate physicist has said as much. The comparison is valid.

  40. 90
    Chuck Hughes says:

    Ezra Klein highlights the hurdles of tackling Climate Change:

    “If you were going to weaponize an issue to take advantage of the weak points in the American political system — to highlight all the blind spots, dysfunctions, and irrationalities — you would create climate change. And then you would stand back and watch the world burn.” – Ezra Klein

  41. 91
    Rafael Molina Navas, Madrid says:

    #30 Edward Greisch says:
    “Ocean water has penetrated under the West Antarctic Ice Sheet. Is “penetrated under” more accurate than saying “the WAIS is afloat”?”
    It´s not just that … Warmer (or less cold …) is penetrating, and melting ice beyond the end of what could be considered previously floating … The video illustrates it pretty well.

  42. 92

    @ 59. I agree. Given the recent flood of published findings related to climate science (West Antarctica, EPA rules, rumours on Chinese emissions cap, upcoming Club of Rome report), it seems a waste of RealClimate’s potential to be rehashing last month’s debates instead of getting views on these and related points. As much as I dislike nuclear power, there are other matters to be understood, which is why I read RealClimate.

  43. 93
    Chris Dudley says:

    Paul Krugman, who won a Nobel Prize for understanding world trade, has come out for climate damage tariffs.

    Here is the note the note I left with him:

    It is very good to read a world expert in the economics of trade propose this move. Article XX of GATT does indeed allow us to unilaterally impose tariffs on China. I’d suggest that there should be a ramped approach. First, we should acknowledge that dangerous climate change has come early and we are already suffering damages. The growth in Federal crop and flood insurance payouts is owing to the effects of climate change. Instead of increasing premiums, we should use climate damage tariffs to cover this increase. That amounts to a pretty small tariff, but it firmly establishes the liability connection. Non-Annex I countries (as listed in the Kyoto Protocol) are becoming the main contributors to cumulative emissions just as climate change has turned dangerous, that makes their emissions the cause of dangerous climate change. An accident of timing? Yes. But deliberately increasing emissions, as China is doing, eliminates safe harbor as well.

    This small tariff could be used as a stepping stone to larger tariffs imposed cooperatively with other Annex I countries if China does not turn around. The larger tariffs could be used to assist with adaptation costs in countries with low per capita emissions where vulnerability to dangerous climate change is high. Lack of a clear funding mechanism for this sort of thing has been a sticking point at climate negotiations. This would essentially det funds from those who are causing the damage.

  44. 94
    Hank Roberts says:

    > Dennett
    Dennett cites Anatol Rapoport as his source for these ideas.
    Op. cit. (quoted excerpt): 20 May 2013 at 10:51 AM

  45. 95

    There’s a big new report from IRENA out today, which I’ll link below. But first, some context.

    Looking at the ClimateCodeRed site, devoted to the ideas of Kevin Anderson and Alice Bows-Larkin, one can see quite clearly the roots of the Diogenes Apocalypse Avoidance Plan™. See, for instance:

    (Dio has, of course, cited Dr. Anderson (though, curiously, not Dr. Bows-Larkin) quite frequently.)

    There’s the same insistence on demand reduction, driven by the same (and far from unreasonable) pointing out that, really, adopting strategies giving 50-50 chances of avoiding enormous catastrophes is not what one would call ‘good risk management.’ Again, Dio has been quite clear on the intellectual attribution.

    The principle difference–and it’s a curious one, to my mind–comes clear late on this page, where the blog author summarizes:

    …a radical plan looks something like this:
    –Low carbon energy supply is pivotal in the long term but can’t be built fast enough in order to solely be relied upon for 2°C, so;

    –Radical reductions in energy demand from now to ~2030. Radical reductions in energy demand over one decade are possible if carefully planned. This extends the window to get the low carbon energy supply in place.

    –A Marshall plan to build 100% low carbon energy supply by 2030–2040.

    So, for Anderson and Bows-Larkin, building a low-carbon energy supply is “pivotal,” but can no longer serve as the sole option because we have quite simply frittered away too much of our lead time. By contrast, for Dio, anything on the supply side is “minor”.

    Needless to say for those who read what I wrote above, I’d come down on the side of Anderson and Bows-Larkin: failing to build a much more substantial low-carbon energy supply would be, far from Apocalypse Avoidant™, actually Apocalypse Invitational. (Still a public domain term, if anyone cares.)

    By the way, one other difference–I’m not certain if it’s real or apparent–is that Anderson/Bows-Larkin (or perhaps the CodeRed author?) are clear that the 10% demand reduction Dio cited is for developed nations, not the whole globe:

    So let’s assume non-Annex 1 nations (developing nations) collectively peak their emissions by 2025 (which a a big ask) and reduce emissions thereafter by 6 to 8% per year. Then what emissions budget is left for the rich, developed Annex 1 nations? The answer is that Annex 1 nations require at least a 10% reduction in emissions year on year (this is based on analysis a few years old so 10% is a bit low now).

    But leaving that last point aside, and with reference to renewables alone, what is the prospect today? Perhaps the best answer so far is the report I mentioned at the top of this post, IRENA’s REmap 2013:

    The headline point is that it’s the first comprehensive global bottom-up analysis of the potential of renewables to contribute to what IRENA analysts term “Total Final Energy Consumption” (TFEC). The reference case is business as usual, in which renewables would grow from 10% (in 2010) to about 18% of TFEC by 2030–quite a bit of which would still be burning traditional biofuels such as wood and dung. But with existing technologies and clear policy choices at the global level, we could see that double renewable TFEC to 36% by 2030.

    That’s not the best case, though. There’s also an RE+ case, which envisages renewable TFEC hitting ~50% by 2030, if there were both substantial early retirement of FF sources and technological breakthroughs in RE technology. (The report notes that there are currently some limited instances of both already, so these possibilities are at least a bit better than pure pie-in-the-sky.)

    RE+ would cut emissions to ~22 GT CO2. When you compare to today’s level, that seems a bit disappointing: we’re currently around 30 GT, so that would only be a one-third reduction. But we figuratively need to run faster just to stay in the same place: the reference case would yield 2030 emissions of over 41 GT!

    You can directly view the relevant figure from the report here:

    Some of the best news, though, is the net cost: though required investments are very substantial, when you factor in the savings, the net cost of change is small. In fact, if external costs are accounted for, “switching to renewable energy results in savings of up to USD 740 billion per year by 2030.”

    The bad news–before other commenters point it out–is that this still doesn’t put us on a path that would meet the more stringent Anderson/Bows-Larkin risk management targets. IRENA considers that it would put us on a path to achieve 450 ppm and a reasonable chance to stay under 2 C, but is that safe enough, given the magnitude of the risk?

    Dio would certainly say no, Anderson and Bows-Larkin would say no, and I would, too, for what that’s worth.

    In addition to the home page linked above, here are a couple of REmap 2030 links for those interested:

    Fact Sheet #1:

    Summary of Findings:

    A couple of additional points:

    1) Although this report is focussed exclusively on renewables, that does not imply that I (or the IRENA analysts, for that matter) think that RE is the sole ‘silver bullet’ solution to the problems we face. The future energy mix will also include nuclear energy to some degree. And energy efficiency (as IRENA points out, too) is tremendously important.

    2) It’s worth noting that the IRENA approach differs from Anderson/Bows-Larkin in that the adoption of renewables considered is global in scope, which rather renders the emphasis on the Annex 1/non-Annex 1 divide somewhat moot. This is particularly the case since renewables need not entail high net costs, and can be helpful in increasing energy access in the developing world. As has been pointed out more than once, non-Annex 1 nations don’t really *need* to make all the energy/sustainability mistakes we have…

    3) And of course, Anderson/Bows-Larkin emphasize the necessity of demand reduction IN ADDITION TO supply side transformation. I haven’t determined how compelling their case is; they seem to be outliers in the climate policy scene. But the conclusion of the blog page quoted above is, I think, very well worth considering seriously:

    Anderson concluded by quoting Robert Unger that“at every level the greatest obstacle to transforming the world is that we lack the clarity and imagination to conceive that it could be different.” He said the paradigm he had outlined will be dismissed as not being practical, but 4, 5 or 6°C is impractical and certainly not equitable.

  46. 96
    Meow says:


    Non-Annex I countries (as listed in the Kyoto Protocol) are becoming the main contributors to cumulative emissions just as climate change has turned dangerous, that makes their emissions _the_ cause of dangerous climate change.

    (emphasis added)
    Thus it’s always the last straw that breaks the camel’s back, not the many other straws that went before, even though the straws are “cumulative”? Ha! All of us are responsible for preventing dangerous climate change.

  47. 97
    Hank Roberts says:

    New at Robert Grumbine’s:

    Wednesday, March 26, 2014

    AABW in the news!

    It only took 25 years, but my thesis topic is now becoming newsworthy!  Gluttons for punishment can see at least the abstract at A model of the formation of high-salinity shelf water on polar continental shelves.  Which is aimed at one of the important ingredients for AABW (Antarctic Bottom Water).

  48. 98
    David B. Benson says:

    Henk A. Dijkstra
    Nonlinear Climate Dynamics
    Cambridge University Press, 2013
    concentrates on climate variability.

  49. 99
    Joseph O'Sullivan says:

    It seems that the arguments and name calling about different forms energy are not adding anything useful to the discussion. Mitigation is not the most useful discussion on RC.

    I think RC is being generous when they open with the topic of the new EPA proposed regulations on CO2 from powerplants. It is a mitigation strategy, but the commenters on RC aren’t interested. In the 85+ comments on this post only two or three comments address this issue. There are some informative articles at the Center for Progress Reform about the recent proposed regulations. The CPR is a think tank that advocates better regulations to protect human health and welfare as well as the environment as a whole.

  50. 100
    Thomas says:

    Eric @79. I follow renewables especially PV, but as an outsider. I think the people inside the industry expect exponential growth of 30-50% per annum to continue. But the energy agencies routinely forecast that growth will stop or even reverse. I suspect this is largely due to institutional blind spots, including, but not limited to the fact that future project pipelines will always empty out as you go forward in time (PV farms to be built ten yeras from now are not yet in the planning pipeline). Supposedly IEA now has new leadership, we will see how their predictions change the next few years.
    But, if I look at Europe, the three big PV countries were Germany, Spain, and Italy. All three have decreased their rate of adoption by severalfold. So we have an example of formerly enthusiastic adopters practically falling off the map -and at a time when the cost of new systems has plummented. So the issue is, are these European examples outliers, or are they an indication that the exponential phase can rapidly end -and at not particularly high penetration rates.