RealClimate logo


Unforced variations 3

Filed under: — group @ 19 March 2010

Another open thread. OT comments from the Amazon drying thread have been moved over. As usual, substantive comments only please and no abuse.

844 Responses to “Unforced variations 3”

  1. 451
    John Peter says:

    John E. Pearson@444

    I agree, Ram described it as a zero dimensional global model.

    What I wonder is could anyone discover a zero dimensional regional model? If such a regional model could be made not to depend on any global model but instead depended only on data and elementary physics directly, regional models might not be so dependent on ensembles of global models. We have a lot of global models, maybe we could get along with a smaller, more easially comprehended, set of elementary physics laws. Such ideas may be pretty far “off the wall” and my poor description of my quest has been non-productive.

    I apologize to all whose time and effort I may have wasted.

  2. 452
    Hank Roberts says:

    John Peter, read it again, that interview is talking about changes comparing hemispheres of the planet — not a general broad statement that all (or all but two?) models are wrong about radiation physics. It doesn’t say what you seem to think.

    Have you read Weart’s book? He invites questions on the radiation physics section, which he says is the most challenging.

  3. 453
    Hank Roberts says:

    SM, plenty of comments out there on that from a while back.
    Google will help.

    Here’s one: http://rabett.blogspot.com/2009/05/krammed-to-our-misfortune-gerhard-kramm.html

  4. 454
    John Peter says:

    t_p_hamilton @422

    Thank you very much.

    Actually the interview was from a Science Magazine podcast 11/27/09. http://www.sciencemag.org/cgi/data/326/5957/1287-b/DC1/1

    There were three interviews, the second was of Mike for his Science magazine paper making sense of the Medieval Climate Anomaly and Little Ice Age

    The abstract at

    was:
    “Origins of the Little Ice Age and Medieval Climate Anomaly
    Michael E. Mann,1* Zhihua Zhang,1 Scott Rutherford,2 Raymond S. Bradley,3
    Malcolm K. Hughes,4 Drew Shindell,5 Caspar Ammann,6 Greg Faluvegi,5 Fenbiao Ni4
    Global temperatures are known to have varied over the past 1500 years, but the spatial patterns have remained poorly defined. We used a global climate proxy network to reconstruct surface temperature patterns over this interval. The Medieval period is found to display warmth that matches or exceeds that of the past decade in some regions, but which falls well below recent levels globally. This period is marked by a tendency for La Niña–like conditions in the tropical Pacific. The coldest temperatures of the Little Ice Age are observed over the interval 1400 to 1700 C.E., with greatest cooling over the extra tropical Northern Hemisphere continents. The patterns of temperature change imply dynamical responses of climate to natural radiative forcing changes involving El Niño and the North Atlantic Oscillation–Arctic Oscillation

    Buried in the paper were a few paragraphs about models that led to my back casting query.

    We examined results for two different coupled model simulations of the past millennium, driven with those factors (solar irradiance changes and stratospheric aerosols from explosive volcanic eruptions) that can most plausibly explain the climate changes of the past millennium (17)…The La Niña–like nature of the MCA-LIA pattern is not reproduced in either of the two different coupled model simulations analyzed. On the other hand, such a pattern is reproduced in simulations (19) using the low-order Cane-Zebiak (24) model of the tropical Pacific coupled ocean-atmosphere system. The discrepancy in the model responses may arise because the tropical Pacific “thermostat” mechanism (25) is not active in either the NCAR or GISS simulations…(i) the high- and low-pressure regions in the NorthAtlantic sector are somewhat asymmetric and geographically shifted relative to the conventional pattern—hence, for example, the relative absence of warming in western Europe; and (ii) there is a positive SLP anomaly over Northern Greenland and part of the Eurasian Arctic Ocean that is absent in the conventional pattern]. Comparisons over the Pacific sector and neighboring regions, by contrast, are of limited utility, given the inability of the GISS-ER model to reproduce the aforementioned LaNiña–like feature of MCALIA pattern, which strongly affects the Pacific basin. There is no evidence of a positive NAOAO response in the NCAR simulation (Fig. 4)…”

    I’ve probably “cherry-picked the areas of disagreement and elided the areas of agreement to get closer to the sense of the interview. Of course I am disappointed that Mike didn’t seem to agree to mainstreaming the next IPCC with versions of the GISS and NCAR and GISS-ER that reproduce the “thermostat” behavior (negative forcing is it?).

    So my question is what do you make of all this? Should John Q Public, a financial analyst, believe our coupled global models back cast pretty well?

    TIA

  5. 455
    Andreas Bjurström says:

    419 Richard Ordway,

    You are pre-occupied by combat climate skepticism (AB)

    come out and just say it. You think we should just be allowed to burn every last drop of oil, coal and gas that we have. We should just adapt to global warming effects. (RO)

    The irony is that your response verify that preoccupation of yours …

    My ethically based viewpoint on climate politics is that the western world needs huge mitigation (especially the US) and that we should more or less stop using oil, coal and gas rather soon. Regarding adaptation, I think that should be directed to the most vulnerable regions in the south.

  6. 456
    Completely Fed Up says:

    “That may not be true. IR radiation is proportional to T^4, so small variations in T from region to region, day to night, and across seasons make it quite a challenge to compute a single aggregate (average or total accumulation), as shown in the paper that I cited in 440.”

    Uhm, no it isn’t.

    You take each pixel and work out its temperature by taking the fourth root of the energy.

    You then have a simple linear series to average.

    This is not rocket science for most of the educated world…

  7. 457
    Completely Fed Up says:

    Rod B talking rectally : “CFU (395), I’m not sure to which post you’re referring: if the navy comment, I simply asked what Richard meant”

    No you didn’t you simply smeared him with this statement:

    “Richard Ordway (353), if you are implying the US Navy is a strong protagonist AGWer, I would suggest that such misleading exaggeration is not helpful to you all.”

    WHERE does this say in ANY FORM WHATSOEVER “what do you mean, Richard?”.

    NOWHERE, that’s where.

    I can’t believe you said that. Did you really say “I simply asked what Richard meant”?

  8. 458
    Andreas Bjurström says:

    412 Ray Ladbury,
    We should not demand that gender studies equals, or even involves, hands on rectification of gender bias. Perhaps the researcher in question are ONLY interested to understand some mechanism involved in the reproduction of gender bias in the laboratory? Or the mindset regarding gender of the laboratory researchers? Gender studies are very often accused of being mere politics (also by you). We can´t blame them both for not being objective and for not being enough political and action oriented, can we?
    And we can´t equate the field to the worst possible studies we can find. that is kind of the climate denialism strategy: Find a bad study and refute a whole field. Well, it is very easy to be a gender denialist since there indeed are easy to find bad studies.

    “I start with the premise that science works–which is pretty difficult to deny in a reality-based paradigm.”

    Work in what aspect and context and for what purpose??? natural science works well in the laboratory. Can the same approach be effectively applied in a policy context? I would answer NO! But this is exactly what the IPCC are doing. They, as you, think that policy follows in a linear fashion from science and that we first must reduce scientitic uncertainty. that is not how the world works outside the laboratory. that is not the prioririties of the world. that is just natural science priorities that can be uphold just as long as the natural sciences are very powerful inside climate change. We already have a strong concensus. its time to move one. We are dead-locked, the natural sciences and the scéptics are deadlocking us. natural sciences are not very relevant in solving climate change, yet they have almost all the research money. The budget for climate modelling is huge, and also tied to military and space interests of the US. In a perfect world, we would take all this money and do something important with it, invest it to solve the problem instead of doing very expensive “pure” “objective science that values and politics are tainting science.

  9. 459
    Completely Fed Up says:

    “You are so eager to score cheap points that you have forgotten that I want coal gone. Coal has no up-side.”

    You appear to think that means nuclear has to be safe.

    The lack of coal doesn’t make nuclear power safe.

  10. 460
    CM says:

    Andreas (#388): Sure, communication is a two-way street. And it’s not your responsibility that e.g. CFU and Richard Ordway insist, wrongly, on labeling you a coal-burning denialist. But if you haven’t given the rest of us your best shot, complaints about power assymetries and the like are a bit moot. (Of course, you could give us your best shot and people might still disagree with you simply because they think you’re wrong.)

    You might catch some undeserved flak here just by coming from the academic angle you do, by asking searching questions of the consensus and the IPCC, and by not slotting easily into a pro or anti position. That is perhaps part of the culture that has developed around this blog, which is after all a frontline defense of science and scientists against some very nasty attacks.

    But cultural obstacles to communication are just a professional challenge, something for the researcher-critic to understand, anticipate, and patiently work around. This is where a political scientist could pick up useful clues from colleagues in the social anthropology department.

  11. 461

    Did (423): In stark contrast, your own actions and rhetoric seem designed to force the UK and other countries into a corner where they can’t generate enough renewables, and they can’t use nuclear, and they are stuck with CCS nonsense.

    BPL: Crap. I think renewables can do it all and I don’t think CCS will work. It’s YOUR view that we can only do it with nuclear, not MY view.

    Did: You said that nuclear is a lesser evil than coal, but everything else you say is militantly anti-nuclear.

    BPL: For good reason. I think nuclear is a lousy way to generate municipal power. It’s expensive, dangerous, and takes far too long to deploy. Plus it provides material for nuclear weapons to any country that has it, plus whatever terrorists they’d like to give it to.

    Did: I’m not asking you to go out and campaign for nuclear power, I’m just asking you to stop spreading misinformation.

    BPL: Specifically what misinformation have I spread, Did?

  12. 462

    JP (432): AGW forcings are much too small to have any measurable effect on earth/sun black-body T^4 radiation balance.

    BPL: No, they are not. AGW has already reduced outgoing longwave radiation 0.85 W m^-2.
    But the biggest change with AGW, of course, is at the surface, not at TOA.

  13. 463

    Ray L. (433),

    Humans now appropriate about 40% of global net primary productivity, not 25%–i.e., it’s even worse than you think, and the margin is even smaller (maximum theoretical safety factor of 2.5 rather than 4).

  14. 464

    JP (434),

    I don’t understand what you’re asking. Do you want to know how to calculate the additive factors, or how to define an average, or both?

  15. 465

    SM (440),

    In brief, Kramm doesn’t know what he’s talking about. Check Rabett Run for several extensive, commented posts about this. Kramm still believes Gerlich and Tscheuschner who, on climate issues, are crackpots of the first water.

  16. 466
    Ray Ladbury says:

    SM@440
    OK, so we are not content now to merely dispute physics that is older than Special Relativity. Now we have to go back and dispute physics that is older than thermodynamics, electromagnetism and the Theory of Evolution. As nearly as I can tell, they are saying that a first-order refutation of an absolute bullshit paper has problems at second order. Duh! And they only take 26 pages to do it as opposed to the original G&T, which went on for f*cking ever.
    Reply: Global Circulation Models. Next!!!

    This looks like an example of stupidity sent to grad school.

  17. 467
    Septic Matthew says:

    445, Richard Ordway.

    Yes, tobacco is dangerous and promoters lied about it. Alar, aspartame, acrilonitrile, power lines (as leukemia risk), thimerasol, and fluoridated water supplies are safe, and opponents lied or were self-deluded about them.

    Now we have AGW to evaluate, independently of alar and tobacco: are you really unaware of or indifferent to the amount of money that is invested in advertising the risks of AGW? I respect Al Gore’s work, his Noble Prize, and his Oscar, but it does promote his substantial busniness interest: at the Academy Award ceremony his company was giving away free CO2 offsets as introductory offers. Then there’s ADM, Sharp, Siemens, GE, and on and on who will gain $billions in subsidies and protected sales.

    446 Sou, 452 Hank Roberts, Thank you.

    465, Ray Ladbury: This looks like an example of stupidity sent to grad school.

    So itemize the stupidities. If it’s rebutted, I’ll read the rebuttal.

  18. 468
    Hank Roberts says:

    John Peter, you’re utterly confused because you’re trying to find a “negative forcing” and a “radiation balance” problem — but you’re referring to a paper about how the energy is _rearranged_ on the planet.

    Google would like to be your friend. Even if you just take the bit you quoted, look for the acronyms, and paste them into the search (not usually the best way to look things up) — Google will help you with this one:

    http://www.google.com/search?q=MCA+LIA
    http://www.meteo.psu.edu/~mann/shared/articles/MannetalScience09.pdf

    Please spend a little more time reading the basics.

    The paper and the discussion you’re stuck on is about how energy _moves_around_on_the_planet_. It’s a big complicated heat engine spinning around with currents and mountains and phase changes and changing forcings.

    This paper isn’t about “energy in/energy out” — it’s about how energy moves within the Earth system.

    Of course it’s complicated. It’s enormously complicated _inside_ the atmosphere, and that’s what this paper and discussion are about — the inside patterns and changes.

  19. 469
    Rod B says:

    Richard, Mentioning the phrase on eight pages out of 126 doesn’t strike me as “slapped all over it.” And of course there is a section: it is a serious strategic military assessment of a potential major problem. But have a go at describing it how you wish. I was just offering a suggestion, but it’s your ballgame.

  20. 470
    Rod B says:

    CFU, My statement to Richard was a conditional, starting with If you are implying. If this English syntax is too difficult for you, there’s probably help at a library or night school.

  21. 471
    t_p_hamilton says:

    “So my question is what do you make of all this? Should John Q Public, a financial analyst, believe our coupled global models back cast pretty well?”

    Globally back casting, yes. Regionally back casting, no (just as models are thought to perform poorly for future regional projections).

    Keep in mind that there are multiple models. They all agree (back to Arrhenius) on the overall global effect of the known forcings. The chances of this happening by coincidence are infinitesimal. The primary purpose of scientific modeling is to elicit understanding of what the important effects are. The secondary result was the realization that increasing CO2 is going to heat us up. The models can and are being refined through incorporation of more known effects (carbon cycle, etc) and comparisons with more data (modern, historic and prehistoric). To expect radically different results, when each improvement has given the same answer as before, is not rational.

    La Nina and El Nino currently swap back and forth periodically, with known effects. If El Nino continues, 2010 is bound to be a global record, because we understand how global temperatures are tied to El Nino (when it is occurring – not long term) and CO2 increase warms the planet, and volcanoes (if one goes off, then 2010 won’t be a maximum). None of these are particularly difficult ideas.

    However, if the La Nina El Nino pattern changes (say La Nina for a couple hundred years), expect large changes in climate. According to the paper you found, there is a connection between changes in that pattern, and in the pattern of the rest of the globe (Little Ice Age, Medieval Warm Period). Most models don’t get the exact distribution, but that is assuming the climate reconstruction from proxies is good enough to say precisely where cooling and warming were.

  22. 472

    Extraordinary recent observations of extreme steady warming of the entire Arctic ocean area requires more attention. Thinner first year ice is playing an important role with greater heat flux warming the air immediately above.

    My own Observations in Resolute, Nunavut Canada are nothing short but extraordinary, sunsets are rounder, horizon sun disk positions are severely displaced, water skies never seen before over the Western part of the Northwest passage also have added a newly observed boundary layer heat injection causing a never seen before refraction effects.

    I believe that the key failure for Ice GCM at Hadley to predict greater ice melts is the radiative flux effect from thinner ice and or greater numbers of leads, so far I read scant bits of info from some journals proclaiming something like 6 w/m2 extra heat coming from first year compared to multi year ice. This number is quite close to CO2 doubling 4 w/m2 calculation. Yet the temperatures over the last winter were +5 to 8 C warmer than average for the Arctic Ocean during March 2010:

    http://www.esrl.noaa.gov/psd/map/images/rnl/sfctmpmer_30b.rnl.html

    followed by equally warm dec-feb

    http://data.giss.nasa.gov/cgi-bin/gistemp/do_nmap.py?year_last=2010&month_last=2&sat=4&sst=0&type=anoms&mean_gen=1203&year1=2009&year2=2010&base1=1951&base2=1980&radius=1200&pol=reg

    I rather we deal with analyzing current climate results as they tend to show amazing warming in the Arctic.

  23. 473
    J says:

    >>>Ray Ladbury #433: “cause a collapse of civilization.”

    This is not part of the “consensus on the basic science” It’s at least two levels away from it. No, this is not established.

    It reminds me of Paul Ehrlich’s “Great Die Off” [edit. continued ad hominem attacks will get you banned]

  24. 474
    John Peter says:

    BPL@461

    I misspoke. “any measurable” should have been “much”
    (0.85/390 = 0.22% might be measurable under proper conditions)

    BPL@463

    Thanks for listening.

    I had the idea to try to partition a region as some sort of isolated radiator and come up with physics that avoided complexities of other forms of heat transfer (except at boundaries?).

    It’s probably a dumb idea.

  25. 475
    John Peter says:

    Hank Roberts@451

    Great idea!!!

    I like Weart’s stuff, agree with him that it’s challenging, and will follow your always good idea to read his book and try some questions.

    Thanks Hank

  26. 476
    Ray Ladbury says:

    Andreas B. says “natural science works well in the laboratory.”

    It also works extremely well in the field, in the school, in the workplace…in fact anywhere you might want to have reliable information on the natural world.

    As to policy, I am not saying that science determines policy. I am saying that the most reliable science must form the basis for policy that affects or is affected by the natural world. What is more, there is a record of success for science-based policy–from air and water quality to soil conservation–even to some extent wrt endangered species.

    Now, as to the IPCC–I don’t know where you get the idea that they feel tightening uncertainties on parameters will push policy forward. The science has been at a state to justify action for at least a couple of decades now. The fact that politicians and the public still think there is controversy is simply absurd.

    There is value, though, in reducing uncertainties, as this tightens upper bounds on risks that need to be mitigated.

    Look, Andreas, we know how to do this. The discipline of probabilistic risk assessment is well developed and science-based. The problem is that it is not being allowed to proceed–and that has nothing to do with the scientists or the IPCC.

  27. 477

    Contrarian’s anti-science history in the peer review:

    If anyone wants a thorough documented history of the deceipt, tactics and history used by the contarians in climate science, you might want to look up this solid peer reviewed source:

    It’s been reasonably well cited (129 times), and was cited by CICERO. The writing journal’s Eigenfactor AI was pretty high: 91.

    http://stephenschneider.stanford.edu/Publications/PDF_Papers/McCrightDunlap2000.pdf
    McRright, Dunlap, 2000, Social Problems, cited 129 times/ ISI ranking for Social Problems placed it among the leading journals in sociology, with an impact factor of 2.059- Eigenfactor AI 91 Cited by, CICERO Policy Note, 2005

  28. 478
    Andreas Bjurström says:

    The problem I am trying to address, very often, is that uncertainty in the physical sub-systems are rather low compared to biological and social systems. Politics are dealing with uncertainties that are of a different magnitute than the physcial sciences and they are used to that. To invest billions of dollars to reduce physical uncertainty a little bit more will not do us very much good. If politics was rational (it is not) and the funding of science was rational (it is not) I think we would see different kind of research by now, less research on adressing the physical mechanism, and much more research on adaptation and mitigation. However, we dont see such a shift, the physical sciences tend to control the agenda of climate change. If one wants to be conspirational (I think that is not that good) one could claim that denialism are the best friend of the physical sciences, as long as we have strong denialism we will probably see huge investments of research money in the scientific basis. But sooner or later we must also do something and understand what we should do …

  29. 479
    J says:

    To those who responded to my previous post – in the off-chance that this post makes it – I seem to have been frozen out of replying to you. So now it is a one-way argument for your benefit.

    Enjoy. [see warning in your last comment. -moderator]

  30. 480

    467Septic Matthew says:
    26 March 2010 at 9:21 AM
    445, Richard Ordway.

    Yes, tobacco is dangerous and promoters lied about it. Alar, aspartame, acrilonitrile, power lines (as leukemia risk), thimerasol, and fluoridated water supplies are safe, and opponents lied or were self-deluded about them.

    Now we have AGW to evaluate, independently of alar and tobacco: are you really unaware of or indifferent to the amount of money that is invested in advertising the risks of AGW? I respect Al Gore’s work, his Noble Prize, and his Oscar, but it does promote his substantial busniness interest: at the Academy Award ceremony his company was giving away free CO2 offsets as introductory offers. Then there’s ADM, Sharp, Siemens, GE, and on and on who will gain $billions in subsidies and protected sales.
    ______________________________________________________________________________________________________________________________________________________
    I think you missed something. Yes the American left and right are battling each other with lies and exaggerations… and I agree they are both probably bad for science.

    The left’s rabid/fanatical anti-nuke policies are probably so entrenched, that the USA has stopped work on much safer 4th generation nuke power plants which are partial-nuke-problem-solving (it eats up existing nuclear bomb making radioactive material stocks) and does not produce active bomb making materials…except for dirty bombs(Clinton canceled the 4th generation research as it was about to be tested if I understand correctly).

    But it’s science (and scientists being slandered-Saunter, Wigley, Mann) who are caught in the middle. Science, studies (were) and scientists are being repressed and harassed (I hope not with future catastrophic consequences for the United States…We have to act 30-50 years ahead of individual effects of human caused global warming showing up(and perhaps hundreds of years ahead if feedbacks come into play) on human caused global warming because that it about how long the delay is due to the oceans’ thermal inertia). Peer reviewed science and scientists should be left alone by both sides.

    Screwing with science has lead to safety concerns for the US public to the point of whole papers/studies/science never being published or released to relevant authorities (or being whited-out- before being released but not for the papers/information at the place I was that I heard about) and the public being put at risk…like for chemical effects on pregnant women, childhood lead poisoning, toxic chemicals, polluted drinking water supplies,potential chemical hazards in communities, diseases and of course human-caused climate change.

    It has been recorded in peer review as well.
    Rest and Halpern American Journal of Public Health | November 2007, Vol 97, No. 11

    http://ajph.aphapublications.org/cgi/content/abstract/AJPH.2007.118455v1

    McRright, Dunlap, 2000, Social Problems
    http://stephenschneider.stanford.edu/Publications/PDF_Papers/McCrightDunlap2000.pdf

  31. 481
    John E. Pearson says:

    450: JOhn Peter asked: “could anyone discover a zero dimensional regional model? ”

    For what use? I’d like to see some simple models myself but you have to be realistic in what you hope to learn from them. I don’t think you can expect an overly simplified model to have sufficient precision to determine whether the climate sensitivity is 1C or 3C or 6C.

  32. 482
    CM says:

    BPL,

    > Humans now appropriate about 40% of global net primary productivity,
    > not 25%

    Isn’t that mainly a question of definition? The headline figure from Haberl et al. 2006 was 23.8% (28.8% if limited to above-ground NPP. They got to 37% when recalculating for a “high” estimate as defined in the original Vitousek et al. (1986) study. It’s staggering in any case.

  33. 483
    Patrick 027 says:

    Re 437 John Peter
    “The energy flux, 396W/m2, is 200 times the forcings to which you want to refer. AGW forcings are much too small to have any measurable effect on earth/sun black-body T^4 radiation balance. ”

    (If the only way we knew such forcings was to measure the totals and subtract, then that could be true. But we know that CO2 has an effect and we know to a good approximation how to quantify it. We can do this even if errors, whether in approximation of theory or in measurement, are larger in total than the change we are considering. Because these types of errors don’t tend to jump back and forth a lot; if the total greenhouse effect of ~ 33 K has been overestimated by 1 K, for example, it isn’t likely that a small change in greenhouse effect will switch that error a lot, because of the nature of what gives rise to the error. Consider for example a person who’s height is known to be between 5 feet and 6 feet. If this person stands on their toes, is there an uncertainty of 1 foot in the change of the height of their head?)

    and Re

    441 Sou
    442 Septic Matthew
    450 zero dimensional models

    Re 448
    “So notions as “climate sensitivity” understood as a single derivative along the forcing has no real physical ground. It may be approximately justified by models, but isn’t a consequence of first principles”

    (A constant single climate sensitivity for all types of forcings is not justified (though for forcings not too idiosyncratic and for some range of climate, it may be a reasonable first approximation), but the idea that for a given initial state, some forcing results in some amount of change, is justified, and that is what defines climate sensitivity).

    Re 455

    OKAY,

    For constant emissivity (greybody), greater spatiotemporal (latitude, region, day-night, transient, seasonal, low-frequency variability) temperature variations (over a horizontal surface) result in greater emitted flux for the same average temperature over that surface, because the flux is proportional to the fourth power.

    But that effect is not unquantifiable. My own attempt for the surface temperature, assuming perfect LW emissivity, came up with an effective difference of under 1 K (it was a rough estimate so I won’t bother specifying further – I’d be interested to see a more accurate calculation). That is, for the spatiotemporal variations in surface temperature as they are, in the annual average, a global average surface temperature of 288 K, if a perfect blackbody, would emit to space over the whole globe with the flux of an isothermal 289 K surface, roughly. These temperature variations at the surface are generally larger than through most of the mass of the atmosphere, for any given vertical level (at least in geometric or pressure coordinates), so the difference for emission from the atmosphere and for surface temperature with a greenhouse effect could be less (although the effect on equilibrium average temperature would be counteracted by decreasing temperature with height within the troposphere). Further complications (perhaps tending to decrease the difference between average and ‘effective average’ temperatures) will arise as atmospheric optical properties may have some correlation with surface and atmospheric temperatures. But that can be quantified by calculations that take that all into account.

    The effect of imperfect LW emissivity – Yes, this increases the equilibrium temperature. And because of the correflection of LW, depending on angular and spectral variations in the nonzero LW albedo, this effect on temperature decreases with increasing greenhouse effect, generally with more of that occuring with the first bits of added greenhouse effect. If the emissivity of the surface were 0.96 (I’m not quite sure of the value, this is for illustrative purposes), that would increase the equilibrium temperature for the surface, absent any greenhouse effect, by about 1 %, or 3 K. This effect should diminish as a greenhouse effect is added (at least for one based on emission and absorption), because the reduction in emission from the surface is partially replaced by reflected radiation from the atmosphere (depends on the spectral and angular distribution of optical properties, though). Thus, relative to a blackbody surface, increasing the the greenhouse effect from zero results in a smaller than otherwise warming, but the effect for more and more greenhouse effect increases should tend to be less and less. So it may not matter as much to the warming from a further 8 or 10 W/m2 or ___ greenhouse effect (forcing plus non-planck feedbacks) as it does, in relative proportion, to the total warming from the total greenhouse effect.

    Of course, variations in surface emissivity do occur, and that, along with atmospheric temperatures and surface temperatures and atmopspheric optical properties, and how they correlate over space and time, could have some further effect. Again, though, this can actually be quantified by doing the calculations.

    For that matter, there could be some small effects from index of refraction of the air, the curvature of the Earth and the increasing area per unit surface area with increasing height (which will have a combined effect with tropospheric expansion and increasing height of sources of emission to space with increasing greenhouse effect), though the vertical compactness of most of the mass of the air relative to the dimensions of the globe tend to minimize the last two, and the index of refraction of the air is only just slightly different than 1.

    And gravitational lensing and redshift, and doppler shift of sunlight depending on time of day and latitude and season, etc, but I’m guessing those effects are even smaller.

    Anyway, for any time of day, any weather condition, any time of year, any time of Milankovitch cycles, etc, there is some upward and downward radiative and convective heat fluxes at any given vertical position, and how they change over vertical position corresponds to some accumulation or depletion of heat. This may be balanced by storage and horizontal convergences or divergences of heat fluxes, and by conversion to or from kinetic energy at some locations (to a first approximation kinetic energy budgets don’t affect the overall heat budget (except via moving heat around) because 1. small rates of conversion compared to overall energy budget 2. I think most kinetic energy produced in the troposphere/surface is then converted back to heat in the tropospher/surface; certainly very little energy radiates to space as kinetic energy (perhaps radio waves produced by wind in the ionosphere?)). In the net production and consumption of kinetic energy, this effectively acts as a transport of heat from where kinetic energy is produced to where kinetic energy is consumed.

    (Enthalpy is lost from rising air that is decreasing in pressure, and gained by sinking air increasing in pressure, by an amount proportional to temperature; so there is a net loss in enthalpy when warmer air rises and colder air sinks past the same pressure level. This is equal to kinetic energy production (as in a heat engine). Kinetic energy is consumed by the reverse process (like a heat pump or refrigerator). It is also converted back to heat by friction and mixing across momentum variations, and by mixing against stable stratification. There is some more complexity in considering the effects of compositional variations, though those are more important in the ocean, and ultimately the energy they may impart must be supplied from heat (and organized via differential heating and cooling) (aside from gravitational tides, which are a much smaller energy source than geothermal heating, which itself is quite small globally).

    For global averages and totals, the horizontal surfaces that define vertical levels are closed surfaces, so there is no net horizontal loss or gain.

    There is some (I think) small amount of non-radiative energy flux from the troposphere into the stratosphere and above, from a small amount of kinetic energy that drives ‘thermally indirect’ (hot sinking, cold rising, kinetic energy converted to enthalpy) motions in the upper atmosphere, and from actual mass transport across the tropopause. Regionally, parts of the stratosphere and mesosphere can be very far out of radiative equilibrium, but in the global average, so far as I know, they are near radiative equilibrium, with the net vertical heat flux being mostly radiation. The troposphere is more fundamentally not in radiative equilibrium, because pure radiative equilibrium would require a lapse rate unstable to convection. Regionally this is not always true; a permanent night or polar winter condition would certainly allow convectively-stable radiative equilibrium, but it would also tend towards absolute zero K. The troposphere exists over the globe because, besides lack of permanent night (heat capacity prevents equilibrium from being reached over a few hours, or even longer, especially over water), of horizontal convective coupling (in the ocean and in the atmosphere).

    Not every location and time is in radiative-convective equilibrium; the lapse rate can be locally stable to convection, and even if unstable to moist convection, moist convection is not automatically triggered by such instability. However, local vertical overturning is just one way to transport heat vertically by convection; another way is large-horizontal scale overturning. This larger scale overturning, as occurs with the Hadley cell, the Walker circulation, monsoons, and extratropical storms / baroclinic waves, can transport heat vertically on a global or regional basis even when all locations are themselves stable to convection (although in the examples given, some more localized convection often or generally occurs, generally within regions of general ascent); these motions also transport heat horizontally from warmer to cooler regions. If the larger-scale overturning were reduced, with no other changes, heat would initially build up at and near the surface, reducing vertical static stability, tending to increase localized convection. Of course, these two forms of overturning are not always completely distinct (**) and they can occur with each other; localized moist convective updrafts tend to produce descent over a larger region (effects of vertical displacement communicated via gravity waves; like throwing a stone in a pond, the water level doesn’t rise everywhere instantaneously but a change ripples outward.)

    Greater thicknesses of the troposphere tends to gain heat convectively from the surface in those places and times where the surface is warmer (though not a perfect correlation); In some locations and times, there is a net radiative flux up from the tropopause, and heat is being brought in from other locations by the air within some portion of the troposphere, keeping the surface from getting colder faster.

    As the surface cools, at least some layer of air may become warmer than the surface via storage from another time or horizontal transport, and heat is lost from this layer and part of that goes to the surface, slowing the rate of surface cooling or keeping it warmer than otherwise..

    In the diurnal cycle in particular, over land, in particular when humidity is low and clouds are absent and especially if the elevation is high (when the greenhouse effect is locally small), the surface and near-surface air temperature drops much faster than in most of the atmosphere’s mass. The rapid cycling of solar heating limits how far temperature fluctuations can penetrate into the ground, so there is a larger solar heating per unit heat capacity of the surface than of the air; the solar heating cycle goes from high to zero, but the heat capacity limits the temperature cycle amplitude, and thus limits the cycling of LW radiation emitted; thus surface radiation can’t drive a large diurnal temperature cycle in the atmosphere as a whole; the more constant temperature of the atmosphere keeps the LW emission from the air more steady (for given optical properties), and this also reduces the temperature cycle that can be achieved at the surface. A wet surface can also cool by evaporation, which limits the temperature cycling at the surface.

    The greenhouse effect depends on the variation of temperature with height as well as optical properties; the surface can at some times and places be colder than some of the air above; however, increasing the greenhouse effect globally doesn’t miss such locations; aside from regional variations in surface albedo feedback, etc, changes in temperature in one location are communicated to other places. With ongoing localized convection, a change in temperature at one level tends to increase or decrease convective heat fluxes so as to bring a thicker vertical layer along to a new convective lapse rate, but absent localized convection, any forced change in temperature at any vertical level will locally tend to drive changes in the same sign at different vertical levels at the same location via changes in LW fluxes, modulate by LW optical properties. If the regions of the surface underneath general ascent (with or without localized convection) get warmer, this tends to warm the troposphere above convectively. Even with no change in atmospheric circulation, this warming then propagates within some layer of the air to a descending region, ultimately making some layer of air warmer above where the surface may be cold, warming the surface there. If a cold surface area beneath descending and spreading air gets warmer, then the low-level air arriving at warmer locations will be warmer initially and cool the warmer areas less. So to some extent the troposphere and surface do tend to warm up and cool off together in response to changes in heat supplie or removed, such as from the subsurface ocean (ENSO, for example) or from radiative forcing and feedbacks in the global average at the tropopause level – not the same everywhere and with possible exceptions depending on optical and circulation feedbacks.

    PS to illustrate why radiation at the tropopause level is key, consider what happens if the troposphere has zero thickness, as might occur if there is no greenhouse effect. In this case, define the tropopause as resting at the surface. The atmosphere might be warmer than the surface if absorbs any solar radiation. In that case, initially increasing the greenhouse effect (an absorbing/emitting greenhouse, not a scattering greenhouse) will increase the outgoing LW radiation to space, and increase the downward LW radiation to the surface tropopause. After stratospheric cooling, the outgoing LW radiation to space may have increased or decreased relative to before the greenhouse effect was changed, depending… But the downward LW radiation at the surface will still be nonzero, whereas it was zero before. Thus the net upward LW flux at the surface has decreased, and the surface warms, until the net fluxes (with whatever feedbacks occur) are balanced again. At some point a troposphere may form, raising the tropopause off the surface. Then, changes in the greenhouse effect can force changes in both downward and upward LW fluxes across the surface, both before and after stratospheric adjustment. Etc.

  34. 484
    Patrick 027 says:

    Correction: last sentence refers to tropopause, not surface.

  35. 485

    Here is a non-peer just-released paper on the history of climate change scientific supression with historical dates (hard to screw that up) from greenpeace.

    It probably has some bias in it but deals a bit with documenting the recent attacks on science and scientists…and probably has some useful information in it. Many things such as dates and events are easily verified.

    http://www.greenpeace.org/raw/content/international/press/reports/dealing-in-doubt.pdf

  36. 486

    WMO releases 2009 report on human-caused global warming:

    The previous decade was the warmest on record in spite of the pseudo-sceptics multiple claims to the contrary.

    http://www.wmo.int/pages/mediacentre/press_releases/pr_869_en.html

  37. 487
    Didactylos says:

    BPL said “Specifically what misinformation have I spread?”

    Let me see…. you have conflated military and civilian nuclear accidents, you have compared US nuclear costs with California wind costs, and applied your “result” to the entire world, you have cherry picked prototype reactors when discussing build costs….

    …and those are just off the top of my head. I’m sure a search through the comments would find dozens more, but I don’t want to waste my time. I have made my point. If you won’t accept it, then you are less reasonable than I had supposed.

    BPL said “Crap. I think renewables can do it all and I don’t think CCS will work. It’s YOUR view that we can only do it with nuclear, not MY view.”

    My view, yes – backed up by hard data for the UK. If you plan on refuting that, go ahead. Otherwise, I will give “your view” the attention it deserves. Or do you think that the UK should demolish a few cities to make space for wind farms?

    Do you know the biggest obstacle to building new UK wind farms? Yes, you guessed it – environmentalists.

    I think it’s time everyone concerned with the future of the planet corrected their cranio-rectal inversion, and started working pragmatically, working together, and forgetting old and irrelevant battles.

  38. 488
    Sou says:

    @ 478 Andreas Bjurström says: (26 March 2010 at 3:14 PM)

    (snip)…To invest billions of dollars to reduce physical uncertainty a little bit more will not do us very much good. If politics was rational (it is not) and the funding of science was rational (it is not) I think we would see different kind of research by now, less research on adressing the physical mechanism, and much more research on adaptation and mitigation. However, we dont see such a shift, the physical sciences tend to control the agenda of climate change.

    In order to adapt and mitigate, we need to know more about what we need to adapt to and where – at the regional and local level. The science is able to provide more information as time goes by, but we are not there yet.

    National politicians are still making decisions at the global level (eg through Copenhagen) to reduce overall CO2 emissions. That part is clear.

    It will largely be the local politicians at the state/province and regional level who will need to make decisions about local adaptation – and the pathway is not clear enough at the local level. There are many issues on which more information is sought. Such as do we need to build more water storage facilities and of what kind – ie is it better to invest in stormwater capture or desalination plants. If we build a desalination plant where should it be built? Will it be submerged in 30 years time? Will we need to build irrigation infrastructure or storm water channels or both?

    These questions need more precise answers before the political decisions can be made. Even then, the questions move from the scientific to the engineering, social, economic and financial. The restructure and rationalisation of agricultural sectors in most nations will be huge and costly, as an example. The infrastructure involved in adapting major cities will likewise be huge and costly. Mitigation will be even more costly and mistakes could easily bankrupt states and even nations.

    At the national level there remain questions about immigration policies, capacity of nations to absorb refugees – these will require examination by physical scientists, biologists, economists, agricultural scientists as well as by engineers, social scientists and economists. The answers are not readily apparent, and in any case will involve intergovernmental cooperation and agreements.

    But sooner or later we must also do something and understand what we should do …

    Many governments, organisations and individuals are doing something, but it is still very haphazard and insufficient to deal with the problem so far. The continued investment in science is essential if governments are to properly work out ‘what we should do’.

    The devil is in the detail!

  39. 489
    Icarus says:

    Could anyone please comment on this:

    Total net anthropogenic forcing is calculated at ~1.6W/m². At any one time half the planet is in darkness and for the half that is illuminated, the sun strikes at different angles, so the average forcing over the whole of the Earth’s surface is one quarter of that, i.e. 0.4W/m² (one quarter being the ratio of the cross-section of the Earth, πR², to its surface area, 4πR²).

    At 0.4W/m², each 2,500km² of the Earth’s surface on average receives 1GW of additional energy from the sun. Surface area of the Earth is 510,072,000km². Hence the Earth should be receiving the additional energy of 510,072,000/2,500 = 204,000GW continously pouring into the climate system, due to anthropogenic forcing.

    Skeptical Science has a figure of 6 x 10^21 Joules per year for the rate of heat accumulation in the climate system since 1970 (from measurements), which is 190,000GW.

    204,000GW and 190,000GW match pretty well. Is this meaningful? Is this calculation correct? Am I right in thinking that the anthropogenic forcing calculated from what we know about greenhouse gases, aerosols etc. is close to the measured increase in the Earth’s heat content in the last few decades?

  40. 490
    Ray Ladbury says:

    Andreas, The entire US government investment for all aspects of climate research is less than 3 billion dollars. That is certainly not an unreasonable funding level. For comparison, high-energy and nuclear physics get 1.35 billion, NASA about 18 billion (half to manned spaceflight). I would say that if anything climate science is slightly underfunded. The Europeans spend considerably less on climate science than the Americans–I think it was $13 million for the Brits.

    As to shifting funding toward mitigation and adaptation, that is a problem. How much funding? Certainly, the funding should be commensurate with the risk, don’t you agree? Unfortunately, several of the risks due to climate change remain unbounded.

    And what mitigation techniques will be effective? One of the leading candidates at this point is injection of sulfate aerosols into the stratosphere. Unfortunately, there are many unanswered questions. Would this really be effective? How long would the sulfate aerosols work? How often would they need to be replaced? Would they exacerbate ocean acidification as they rained out? Would decreasing visible light to compensate for greenhouse warming have unintended consequences. And yet, the portion of climate forcing we need to answer these questions has some of the biggest uncertainties in it.

    In fact, the only mitigation we know would work is drastic reduction in fossil fuel consumption? But how much would we have to decrease consumption? Over how long before we face the prospect of severe risk? Would Hansen’s proposed program of concentrating initially on secondary ghgs be effective? Again, we don’t know completely.

    Sorry, Andreas, but in part, this is a science project. We need to target our resources and efforts efficiently. How do you propose to do that if you don’t base policy on science?

  41. 491
    Ray Ladbury says:

    SM@467,
    I suffered through G&T once. I think that is enough. G&T are idiots. I think it is safe to assume that anyone who takes them seriously must be at least as stupid. The little bit that I looked at this morning was mainly crap. Smith’s rebuttal never set out to give an exhaustive treatment–merely to show G&T was utter crap. It succeeded. For the authors to then take him to task because he is not detailing a full GCM is disingenuous. Beyond that, I don’t care to read bullshit.

  42. 492
    Septic Matthew says:

    480 Richard Ordway: I think you missed something. Yes the American left and right are battling each other with lies and exaggerations… and I agree they are both probably bad for science.

    You may have missed my point about both sides having strong financial interests.

    The left’s rabid/fanatical anti-nuke policies are probably so entrenched, that the USA has stopped work on much safer 4th generation nuke power plants which are partial-nuke-problem-solving (it eats up existing nuclear bomb making radioactive material stocks) and does not produce active bomb making materials…except for dirty bombs(Clinton canceled the 4th generation research as it was about to be tested if I understand correctly).

    On that we agree, but I think that Obama, Chu and others have shown that the left has changed. At least it seems that they may have changed enough.

  43. 493
    David Miller says:

    Naindj asks in #404:

    Also, David Miller, 378, I don’t understand your point. If you burn locally 75% of you coal (or gas, or oil), the question is: are the 25% remaining, that you can export, still enough to cover all costs? And coal is so highly energetic that it might be the case. Of course, environmentaly, this is not the best… Did I miss something?

    Yes, I think you missed the reference to tar sands and coal-to-liquid.

    The way tar sands are currently being processed is to have gigantic machines mine the tar sands for processing. The raw material is heated, usually with natural gas, and the bitumen is washed off the sand. The sand and wash water is stored in vast tailing ponds that are an environmental disaster waiting to happen. The bitumen is mixed with naptha and piped off to be further processed/upgraded.

    That’s what’s happening now.

    What they’re talking about is a very different process. If you drill vertical shafts into the tar sands, then a horizontal shaft across the bottom you can force air down one side and vent the exhaust at the other. By lighting a fire in the horizontal shaft you can burn some of the bitumen without ever having to extract it from the ground. That’s the “in-situ” combustion.

    By burning some portion of it in place you heat it enough to extract some without also having to extract all the sand. Neither do you have to heat with natural gas, wash with water, and provide tailing ponds for the tailings. Nor do you have to pretend you’re going to push all the tailings back where they came from when you’ve stripped all the economically feasible bitumen from the deposit.

    So with the in-situ processing you have far lower setup and processing costs, you don’t have to burn a lot of natural gas, and – this is a big one – you can extract deposits that aren’t economical with surface mining because they’re too far down or under rock.

    Naindj, do you see the problem here? If you acquired mining rights to, say, a billion barrels of oil equivalent and the most practical way to extract it is through in-situ combustion because they’re 400 feet down do you worry that you’re burning 3 barrels of raw material to get one to sell? Businessmen will look at it as an investment and on a cash-flow basis. If a maximum rate of return on your investment comes from burning 3/4 of the stock to get the other quarter how many will not do this? If you extract 250 million barrels and sell at $100/bbl you’ve got 25 billion in revenue, and in-situ processing means you can get it quicker and with less investment.

    It’s financially very possible. It’s an environmental disaster.

    And note that while I talked specifically of tar sands, the picture is not very different for shale or coal.

  44. 494
    Septic Matthew says:

    483, Patrick027,

    Good enough as far as it goes. The paper I cited that Ray Ladbury didn’t like tries to quantify a lot of the effects that you wrote of semiquantitatively.

    Consider for example a person who’s height is known to be between 5 feet and 6 feet. If this person stands on their toes, is there an uncertainty of 1 foot in the change of the height of their head?)

    I think that weight is a better analogy: if your weight fluctuates +/- 10% across seasons, regions (visits to relatives), epochs (repeated partially successful exercise regimens while raising children or commuting 50+ miles to work sometimes), then it is very difficult to create and maintain and document a permanent decrease of about 1% in the mean. It is even harder to tell what caused it (giving up milk in the coffee?) For 230 lb men, repeated weight losses and gains of 10% are not that uncommon. It’s an even worse problem if the scale itself is changing and requires frequent recalibrations.

    This is where tamino and BPL, among others, start using more complex time series analyses (autocorrelation, partial autocorrelation, cross-correlation, vector autoregressive models [the result of a VAR analysis was recently put up by a friend of tamino, but I don’t remember the name]), and others start to write that “the CO2 mechanism is sufficiently well known and nothing else exists” or other things of that nature.

    Proponents of the solar theories are up against the same problems, probably worse.

  45. 495
    John Peter says:

    t_p_hamilton @471

    Hmmm. I thought Mike Mann said (many times) that he “knew” where the LIT and MA were, the proxy data was good enough.

    In this paper – as I read it, and as he told the interviewer – NCAR and GISS, both models, reversed the proxy data and responded cold where the proxy data indicated hot and hot where the proxy data showed cold, the models were out of phase.

    A tyro like me would see that as a back-casting failure in NCAR and in GISS. That’s the way the interviewer saw it and Mike did not try to correct him. Mike just wouldn’t commit to fixing this problem in AR-V.

    To me it’s clear in the interview, confused in the paper, and not mentioned in the abstract.

    What do you think?

  46. 496
    Patrick 027 says:

    … in other words:

    For a forcing that directly causes warming or cooling at one position, there is a tendency for the response to be less strong at that location but extend outward (the outward extensions of forcings at other positions add up at any given position, though).

    This happens via LW radiation vertically (this reduces the difference between tropospheric/surface and stratospheric/above temperature changes generally caused by increased greenhouse effect; the direct tropopause level forcing is reduced somewhat by stratospheric cooling, and when the troposphere and surface warm, the stratosphere warms back up a bit (relative to adjustment with troposphere and surface conditions held constant) in response (with corresponding tropopause-level feedback).

    This happens via horizontal motion.

    And, at least and especially within the troposphere, this happens by responses of vertical convective heat fluxes.

    ——

  47. 497
    Patrick 027 says:

    Re 489 Icarus –

    You have the right idea but some corrections need to be made.

    Climate forcings are generally expressed as per unit area over the whole climate system, which means the whole surface area of the globe. Thus 1.6 W/m2 is what you wanted, not that divided by 4. Solar TSI variations need to be divided by 4 to be converted to climate forcings (And then, for tropopause-level forcing, there’s an issue of how much is absorbed in the stratosphere, etc.).

    As the climate responds, it tends to approach equilibrium by changes the fluxes so as to balance the forcing. It is the remaining disequilibrium that drives the heat accumulation (or depletion in the other direction). The amount of warming required to restore climatic equilibrium depends on feedbacks. The Planck response (if that is the best name for it) is a negative feedback whereby LW emission increases as a function of temperature. Other feedbacks may reduce or increase the net upward LW flux and change net incoming SW flux (equal to solar heating below the level for which the flux is described) in response to temperature changes. These other feedbacks, combined, are most likely positive, meaning they reduce the increase in upward LW emission relative to what it would be with the Planck response alone (these are the feedbacks that are generally described as ‘the feedbacks’, because the Planck response is default – this can cause confusion, as the total feedback including the Planck response is actually negative (for present Earthly conditions) so that the climate is stable (in the sense that it can reach a new equilibrium in response to a forcing, given time), but this doesn’t limit the climate sensitivity to be less than 1 K per doubling CO2, rather it (as so-far described in this paragraph) merely limits climate sensitivity to be a finite value).

    The time it takes to approach equilibrium is proportional to climate sensitivity and to heat capacity.

    At present the disequilibrium is roughly half of the forcing; that is the rate heat is accumulating now (averaged over shorter-term variability).

    For 1 W/m2 of radiative disequilibrium, and approx. 510 trillion m2, the global heat accumulation would be 510 TW (I’m using American trillion, etc.). With 31.5576 Ms per year (based on 365.25 days/year), that’s approximately 16.1 billion trillion J / year, or 1.61 e22 J / year.

    The disequilibrium has been growing because of continually increasing anthropogenic forcing. So an average heat accumulation of 6 e21 J/year, which is a little less than 0.5 W/m2, sounds about right.

  48. 498
    Patrick 027 says:

    Re 494 Septic Matthew

    Your weight analogy: Maybe okay for regional climate variations over short time periods (??) – or maybe not…

    But the error introduced by setting aside relativistic effects, approximating the atmosphere as having no curvature and area not varying with height, ignoring macroscopic index of refraction variations,

    and setting aside LW atmospheric scattering

    and even approximating the surface as a blackbody for the LW portion of the spectrum

    and even using a 1 dimensional, global annual representative radiative-convective model for the purposes of estimating vertical energy fluxes and global average temperatures,

    these errors are not the sort of errors that flip back and forth as the global average temperature is increased over several K; rather they grow or decay, generally slowly. Which means the errors they make to changes of a few K is small. In other words, these are not the types of errors that introduce a noise that can hide a sufficiently weak signal; rather they may introduce an error that is some small fraction of the signal.

  49. 499
    Patrick 027 says:

    Re 494 Septic Matthew

    Your weight analogy – maybe okay for issues of detecting a signal mixed with noise for short time periods.

    But the types of errors introduced by such approximations as

    setting relativistic effects aside

    assuming the macroscopic index of refraction is exactly 1 within the atmosphere

    assuming the atmosphere is horizontally flat and area doens’t change with height

    and even setting aside atmospheric LW scattering

    and even approximating the surface as a blackbody for LW radiation

    and even using a 1-dimensional global annaul representative model for relating vertical heat fluxes to temperature

    and using some approximation for optical properties of gases and maybe even clouds

    these types of errors are not the types of errors that fluctuate and flip back and forth over changes in global average temperature of several K; rather, they may change by small amounts. So they don’t produce any noise that would hide a sufficiently weak signal; rather, they may introduce a small fractional error in the signal.

  50. 500
    Patrick 027 says:

    Re my Re 489 Icarus
    “Solar TSI variations need to be divided by 4 “…

    And then scaled by the fraction absorbed (1-albedo), etc.