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Comments 100451 to 100500:

  1. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Original Post The general point that skeptics must offer alternative models and research is bogus. Pointing out inconsistencies and weaknesses in AGW science - does not oblige the critic to offer a whole new theory. It does oblige the purveyors of the AGW theory to explain the inconsistencies if they are to be taken seriously. Here are a few 'inconsistencies' to consider: Deep mixing of the ocean layers is inconsistent with suface layer acidification. Flat or slight increase in OHC content from Argo is inconsistent with a steady or increasing TOA forcing imbalance. The mix of SLR (steric and mass) is inconsistent with the energy balance. Three more important 'inconsistencies' I cannot contemplate.
  2. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    I have to disagree with the base assertion that all things are considered unsafe until proven safe. Nothing is 'safe'. Getting out of bed in the morning is (so we are told) the most risky thing you can do. Everything we do has some kind of risk attached to it and thus nothing is 'safe' Risk assessment is just that - making an objective assessment of the risk and then deciding whether the benefits derived are sufficient to warrant taking the risk. Thalidomide was considered 'safe'. Cars are definitely 'not safe' in many ways. Potholing/sailing/sex/alcohol are full of risk. ( I don't do any of them...well, maybe one) Life is about risk management, not risk avoidance regardless of the cost - the Nanny State Syndrome. Is it safe to double CO2 concentrations over a 200yr period is an unanswerable question - we simply do not have the means to accurately predict the effect on climate, but we can predict the effect of reducing FF . Modern society, like it or not, relies heavily on cheap electricity generation so maybe the question ought to be - what are the risks if we restrict FF usage without first having economically viable alternatives ??
  3. A Merchant of Doubt attacks Merchants of Doubt
    Oops, I should have placed the previous link between anchor tags. UCSD (University of California at San Diego) Professor of History and Science Studies "Naomi Oreskes" presented this 58 minute lecture on the History of Global Warming Science. http://www.youtube.com/watch?v=2T4UF_Rmlio Many viewers will be surprised to learn that the science as been settled (more or less) for five decades.
  4. Miriam O'Brien (Sou) at 00:31 AM on 25 December 2010
    Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    I don't understand why anyone is still denying climate change and global warming. Where I live there are an increasing number of extreme weather events signifying global warming. Record long hot drought with record bushfires, followed by record rain events with widespread flooding. From what I read, record (ie extreme) weather events are happening more and more frequently around the world with serious consequences for food production, housing and travel. And this is just the start of the global warming. If people can't recognise it's happening now, what on earth will it take? Will they be still denying it when the extreme events get worse as they will as the earth warms, if we don't do enough soon enough to curb emissions?
  5. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    fingerprinter: "So people should ask the skeptics their own set of questions... Why have they never developed their own climate models, and performed their own model experiments?" ABSOLUTELY! Where is the science, fullstop. Most of them seem to depend more on myth, rumour and political intrigue than any rational thought.
  6. Lindzen and Choi find low climate sensitivity
    RW1 at 15:36 PM on 24 December 2010
    "...but being so diametrically opposed to what is empirically measured...
    But we've already seen that contemporary (20th century) warming is entirely consistent with a climate sensitivity in the range 2-4.5 oC. Since we've already had virtually the warming expected from a climate sensitivity of 2 oC, even without factoring in the inertia in the climate system and the counteracting effects of man made aerosols as described here, and here, and here. The empirical data are simply incompatible with your model and it surprises me that this doesn't concern you.
    "However, the amount of positive feedback needed for 3 C rise is NOT derived from first principle physics or empirical observation of the system's response to changes in radiative forcing - but from model estimates that involve numerous assumptions and fudge factors."
    That's simply not true. It's worth familiarising yourself with the large body of data that informs us about likely ranges of climate sensitivity, ranging from empirical analyses to modelling. A good place to start is here. As for the analysis of seasonal temperature variations, which seems to play a large part in your argumentation, I think it might help if you were to consider more carefully why the Earth is overall warmer at aphelion (July) and cooler at perihelion (January).
  7. Comparing all the temperature records
    GrADS software is available at http://www.iges.org/grads/ . It is an open source software. On MS Windows, it requires CygWin. If you have latitude-longitude grid data of temperature and if you can read it with a variable name "TMPsfc" (for example), you can compute its global average as aave(TMPsfc, global) .
  8. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    kdfv that's a real risk, the typical situation of a tragedy of the commons. Avoiding the unpleasant outcomes of a warmer planet stands on the ability of our societies to look beyond their backyard and further away; which, by itself, I'd dare to call a cultural revolution.
  9. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    I think the problem you have is that you are trying to get people to change their whole way of life, and companies to worry about other things than their profitability. The governments of countries to carry out unpopular things. I don't think you have much chance until it is too late and the world is burning up or drowning. Here in the UK we are having a very unusally cold winter which will undermine your attempts to convince ordinary people that there is a problem. Hot dry summers here are longed for.
  10. Arkadiusz Semczyszak at 21:21 PM on 24 December 2010
    Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    @MattJ „we must” - very good - all right - but on the proper methods of risk prediction ...
  11. Arkadiusz Semczyszak at 21:17 PM on 24 December 2010
    Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Sorry - I give the current link: May 4, 2010.
  12. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    The author of this article is using "null hypothesis" in a surprising sense. I am much more used to seeing it used in a somewhat different sense, as in http://en.wikipedia.org/wiki/Null_hypothesis. So is the author's sense an acceptable one, or is he misusing the term?
  13. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Arkadiusz is misusing "peer-reviewed" as if it conferred some sort of infallibility on the authors's conclusions. Far from it. On the contrary: every "peer-reviewed" paper he cites is proof of how flawed the peer review system has become. For despite the skeptic's regular rants, there really is no logical denial of the conclusion: AGW is a serious problem, we must cut greenhouse gases immediately to avoid catastrophe.
  14. Arkadiusz Semczyszak at 21:08 PM on 24 December 2010
    Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    “Faulty Forecasting Procedures” - incorrect assessment of the risks of global warming - is a fundamental objection - skeptics - to the theory of AGW proponents. About this - not the climate - for example, often says economics professor Vaclav Klaus. You may not like: J. Scott Armstrong, Kesten C. Green and Willie Soon ..., but they have excellent academic achievements - an important peer-reviewed publications. So why did they write in their report (May 4, 2010.)?: - “Most of our findings have been published in the peer-reviewed literature and all have been presented at scientific meetings.” - „The alarming forecasts of dangerous manmade global warming are not the product of proper scientific evidence-based forecasting methods.” - “As with many conclusions from scientific research on forecasting, this conclusion derives from a finding that is not intuitive: in complex situations with high uncertainty, one should use methods that are conservative and simple (Armstrong 1985; Armstrong 2001).” - “The forecasting procedures described in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report violated 81% of the 89 principles relevant to climate forecasting.” Atte Korhola, author important peer-reviewed paper about past climate: “Decision-makers should make sensible choices regarding the overall benefits in the environment of uncertainty. We shouldn't expect anything magical from the climate change panel that it is incapable of producing.”
  15. Arkadiusz Semczyszak at 20:17 PM on 24 December 2010
    Do high levels of CO2 in the past contradict the warming effect of CO2?
    ... CO2 is a key factor in controlling the climate ... - how the results from the current post, since the Ordovician glaciation in the Sun may be responsible (it could be as high as 30% weaker than it is now)? Most researchers favor a decisive influence CO2 on the current warming, but when it comes to paleo-warming, opinions are much more diverse. Let's not forget about the possible impact (Ordovician) of galactic: Figure 4., and Fig. 5.
  16. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    For the record. I was not stating that we historically or currently test everything we do. I am simply stating that when we do seek to apply a scientific risk assessment, there is an established methodology for doing that. We rely on this standard methodology more than people immediately imagine. Happy holidays.
  17. The Physical Chemistry of Carbon Dioxide Absorption
    I have seen this Modtrans graph on WUWT a few times, and I was hoping someone could explain its relevance. http://wattsupwiththat.com/2010/03/08/the-logarithmic-effect-of-carbon-dioxide/ Obviously this David Archibald guy is too big for his britches (I don't need help dissecting his rubbish). However, is this Modtrans graph showing actual forcing effect CO2 has on our planet (besides feed backs), or is there something missing? To me it looks like it is showing the 3.7 watts per square metre that the IPCC suggests in AR4 section 2.3.1. Thanks in advance.
  18. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Is it safe to double atmospheric Carbon Dioxide over a 200 year period?" A resounding "No!". Why are we humans so myopic? The events occurring right now (well for several years now) on the planet are evidence that tinkering with the the planet's energy budget and oceans (i.e., ocean acidification) is just not a good idea. There are warning signs everywhere, why do some insist on continuing to ignore them?
  19. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    The first part of cloa513's assertion is correct. There are other facets of our lives where we seem to shoot first and ask questions later: food, banking, wars - all spring to mind. So, sadly, dumping crap in the environment without nary a concern for the effects is by no means unique. The second half, however, is incorrect. Now that we have done the deed, the studies have been done, the data has been collected and the evidence is overwhelming.
  20. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Not true- Food is not proven to be safe yet we eat it (where are the studies) No food for scientists. Are we going to stop everything going into atmosphere because no studies have proven that its safe. With dynamic systems you can't stop everything and wait for the studies the beginning position is so difficult to pick. You have no scientific credibility. You will have to be covered in a hermetic sealed container until the studies are done.
  21. Do high levels of CO2 in the past contradict the warming effect of CO2?
    Eric @8, the mechanism postulated by Young et al. is that increased glaciation reduced exposed rock, thus reducing the removal of CO2 from the atmosphere by weathering. With a large background vulcanism, this resulted in elevated CO2 levels.
  22. Do high levels of CO2 in the past contradict the warming effect of CO2?
    "Glenn, I'm not sure that explains how we got out of the glacial conditions 400m years ago. How does warming temperature feed back to create 1000 more ppm of CO2 (i.e. where does the CO2 come from?)" If everything's in equilibrium, the oceans ...
  23. Lindzen and Choi find low climate sensitivity
    KR (RE: Post 214), I know the 3 degrees C requires positive feedback amplification. The net effect of all the individual feedbacks in the system is already accounted for in the gain, because it's an aggregate empirically measured response of the total power entering vs. the power at the surface. This is not the same as the net feedback operating on the system as a whole, which is what the 3 C rise comes from. However, the amount of positive feedback needed for 3 C rise is NOT derived from first principle physics or empirical observation of the system's response to changes in radiative forcing - but from model estimates that involve numerous assumptions and fudge factors. That in and of itself doesn't mean the models are wrong, but being so diametrically opposed to what is empirically measured, suggests they likely are.
  24. Do high levels of CO2 in the past contradict the warming effect of CO2?
    Going back as far as 450 mya requires that you take plate tectonics into account. Look at this map; the entire land mass was in the Southern Hemisphere and the area affected by Ordovician glaciation was the South Pole at the time. The last ice left in our world, if we ever get that far down the drain, will probably be at the South Pole. The other aspect of the distant past that some people ignore is evolutionary. There weren't any land plants. So it is the most extreme apples and oranges (except there weren't any oranges!) comparison to look at today's CO2 concentration and compare numbers with 'way back when'.
  25. Do high levels of CO2 in the past contradict the warming effect of CO2?
    Glenn, I'm not sure that explains how we got out of the glacial conditions 400m years ago. How does warming temperature feed back to create 1000 more ppm of CO2 (i.e. where does the CO2 come from?)
  26. Lindzen and Choi find low climate sensitivity
    RW1, you are right, Pe has nothing to do with "gain" in the paper in #150. It is mostly a tangent. Pe is 10 W/m^2 but the power flux from 3 x 10^22 J of seasonal OHC storage (#117) is only about 2 W/m^2 Robust-warming-of-the-global-upper-ocean.html. I suspect that Pe is overestimated in that paper due to problems with Pout (#208).
  27. Conspiracy theories
    Again, NETDR, everything comes down to the science, which is either largely wrong or largely right. Whether "challenges" to the conservative, consensus-based findings of the IPCC are compelling or not hinges on that point. Maybe we can discuss that, instead? As for the value of Dr. Curry's speculations on "tribalism" (which you might well reject as armchair psychologizing if she'd applied them to you, instead of the IPCC), I'm sure we can agree that even if the consensus view turned out to be wrong, it wouldn't necessarily follow that Dr. Curry was right. Other explanations are possible, so why would I want to jump to her conclusions before it's even been demonstrated that she has a legitimate grievance? What she's offering, IMO, is basically a feed-good narrative that puts a slapdash intellectual gloss on the preconceived notion that the consensus view can't be right (much like the recourse to Kuhn, elsewhere). Is there an element of truth to what she says? Sure, on all sides of the issue, including hers. Can noting this substitute for the hard work of studying the actual science, without getting sidetracked by politically charged meta-theories? I don't think so.
  28. Do high levels of CO2 in the past contradict the warming effect of CO2?
    Eric #3 The ratio of forcing between 4000 and 3000 is roughly comparable to the ratio we see between glacials and interglacials in the far more recent Ice Core records - 100's of 1000's of years rather than 100's of millions. So the size of the forcing change is comparable. The reason it occurs at several doublings of CO2 higher in the deep past is that the Sun was several percent weaker 400 million years ago and so the CO2 threshold at which you can slide into glacial conditions is several doublings higher.
  29. Lindzen and Choi find low climate sensitivity
    RW1 - the 3 degrees C is the result of feedback amplification, which you have not acknowledged at all (as far as I can see - I would welcome being corrected). Doubling CO2 results in about 1.2°C direct warming - the 3°C results from climate sensitivity. And the same warming (depending on what you accept as climate sensitivity) results from volcanic aerosols, solar insolation, or any change in energy. Again, your 1.6 is a result, not an input. It's a nonsense number in terms of inputs. You would be much better served to look at the temperature required to radiate a power equal to insolation. Enjoy your (solstice related) holidays.
  30. Conspiracy theories
    NETDR: She seems to think there would be some negative fall out from challenging the IPCC ! Is she wrong ? Yeah, I think she is, to a large extent. I think plenty of people have challenged the IPCC, and far from being punished or ostracized, they've enjoyed attention and respect — especially from the media — to an extent that's not necessarily commensurate with their actual expertise and accomplishments. In fact, I might even go so far as to argue that Dr. Curry herself is one of those people. Also, when we talk about "challenging" the IPCC, we need to consider the quality and coherence of that challenge. Some people make poor counterarguments, and then scream "oppression!" when those counterarguments are debunked. Unfortunately, Dr. Curry has not always observed this distinction when defending her pet "skeptics" against AGW "tribalism." By the way...it's been said here before, but the "AGW is a religion" line is one of the oldest and silliest "skeptical" tropes. Reiterating it is a good way to be mistaken for someone who's not capable of arguing rationally or fairly.
  31. Do high levels of CO2 in the past contradict the warming effect of CO2?
    #5: "maybe not the higher temperature -> more CO2 part of the feedback" That part is cryptic; presumably you mean CO2 released from warming oceans? Every time I hear that assumption, I have to ask 'if there is a net increase of CO2 coming from the oceans, why are the oceans acidifying?'. We have an excellent thread on that topic.
  32. Lindzen and Choi find low climate sensitivity
    Eric and KR, Despite my efforts, I still don't think either of you understand what the gain is representing. The gain is the net result at the surface from the greenhouse effect in the atmosphere, which makes the surface warmer that it would be without it. KR, I know the gain isn't a constant, but an average. It fluctuates somewhat, but the range of fluctuation doesn't go anywhere near 8 (or 4) that is necessary to amplify 2xCO2 to 3 degrees C. Eric (RE: Post 211), That the gain is increasing as solar power is decreasing and vice versa has nothing to do with excess energy being stored. The ocean heat content is included in Pe, which is the power coming in and out of the Earth's thermal mass. If more power is arriving than leaving, Pe is a positive number; if more power is leaving than is arriving, Pe is a negative number. The averages are virtually zero, with power out being slightly more (0.1 W/m^2 higher on average). Also, the gain decreasing as radiative forcing is increasing - both hemispherically and globally, demonstrates negative feedback to increases in radiative forcing; meaning any small rise in surface power would be opposed rather than reinforced. This contradicts the AGW theory of large positive feedbacks greatly amplifying the small instrinic increase in radiative forcing from 2xCO2.
  33. Do high levels of CO2 in the past contradict the warming effect of CO2?
    So the more CO2 -> higher temperature part would work, but maybe not the higher temperature -> more CO2 part of the feedback cycle?
  34. The Physical Chemistry of Carbon Dioxide Absorption
    Realizing that I did not give my rationale for the proceding, it is: I assume that when averaged over a year and over the whole surface the flux into the eath's surface will equal that exiting from the surface. The rationale for this assumption is that if there is an imbalance the earth, if it is at a higher temperature than this steady-state temperature, will have a higher out-going than in-coming flux and the opposite is true if it is at a lower temperature. Imbalances will occur at various places over the surface and at different times but the average over a year and the earth's surface will yield the balance energy in = energy out. Actually there is a slight imbalance due to the increasing greenhouse gas effect, but that can be calculated with even greater precision than has been achieved in GWPPT6. The fact that the increase in the earth's temperature is essentially what is calculated for the increasing GHG effect of CO2 means that the mentioned energy balance is a reality for the earth in the absence of astronomical effects such as the Milankovich cycles (which result from perturbations of the earth's orbital eccentricity and the angle of its axis to the orbital plane and are very well understood to occur on time scales very much greater than those concerning us in the current increase in the GHG effectI.
  35. Conspiracy theories
    #47: "She seems to think ... " You won't get any mileage quoting J. Curry around here; this isn't 'climate-skeptic'. You haven't responded to questions here, here and here, among others. Your rhetoric is escalating again; words like 'CAGW' (whatever that means), 'glaciers in on the conspiracy', 'blinders', 'dogma', 'religious importance', etc. are the usual clues to an impoverished argument. I suggest a radical change in tactics; learn something about what the science has to say and you might be able to mount a credible argument. Now that would be an interesting change!
  36. Lindzen and Choi find low climate sensitivity
    RW1 - "Can you give me the power in = power out relationship between the numbers in your post #196": For the surface, I did. In post #196. Keep in mind that Trenberth's numbers split the Earth system into three layers - surface, atmosphere, and space. If you add up the numbers for any one of the three layers (interacting with the other two) the sums match up to zero. He explains the derivations and evaluations of these numbers in Trenberth 2009. As I said before, if you have issues with any of the Trenberth numbers, say so, and specify which, with some justification as to why. You have not done so to date.
  37. Conspiracy theories
    Many people, including some regulars to this very site, make the claim that the world isn't warming. The #4 skeptic argument is currently "It's cooling." Yes, Judith Curry is wrong. Dismissing independently validated empirical observation and scientific theory as a religion is a good indicator of ideological "blinders". What would you think about that quote if the subject were evolution through natural selection rather than anthropogenic global warming?
  38. Do high levels of CO2 in the past contradict the warming effect of CO2?
    #3: Eric, a doubling is a doubling; ln 2 is still 0.693 regardless of the level. The difference is that there are more ppm between 2000 and 4000 than between 280 and 560, so it may take longer for subsequent doublings to occur (depending, of course, on how fast CO2 is being put into the environment). The sensitivity, ie the constant of proportion between delta T in degrees and delta F in W/m^2, remains the same. If you are familiar with music, an A = 110 hz & A = 220 hz & A = 440 hz & A = 880 hz & A = 1760 hz etc.
  39. Conspiracy theories
    NETDR - Consider where fame, reputation, and status in science comes from: producing correct results. Nature is a harsh critic, and bad science (Lindzen and Choi? Gerlich and Tscheuschner?) gets found out fairly quickly. Perhaps there is some negative fall out from challenging the IPCC (not surprising, you would be making an extraordinary claim, and hence require extraordinary evidence [Sagan]). But there is a much higher cost to promoting incorrect results. Consistent results work, and make a reputation. Making stuff up out of whole cloth (as conspiracy theories require) is a really foolish tactic - you quickly get caught by nature, the world, and reputation hungry grad students! :)
  40. The Physical Chemistry of Carbon Dioxide Absorption
    #21: "the earth’s temperature is currently rising by 0.014 degrees per year" Please refer to Are surface temperature records reliable in which you will find details of the measurements that provide independent verification of hfranzen's detailed PChem calculations. You will note in Figure 8 on that page that the ocean temperatures are, on average, rising at 0.14-0.15 degC/decade. Land-based temperatures are rising at a faster rate, 0.2-0.3 degC/decade. This article reconciles 30 years of satellite data and 130 years of surface measurements to a high level of consistency. If you look in detail at other data collections, you may find even higher rates in the last 30-40 years. These data are overwhelming evidence of global warming, which no objective scientist should fail to recognize.
  41. The Physical Chemistry of Carbon Dioxide Absorption
    response to # 21. The eath's temperature, as I understand it. is the average temperature over a year and over the whole surface of the earth. For me the best way to view it is: the temperature given by the Stefan-Boltzmann Law for thermal equilibrium from the earth when the flux to the earth is given by the GHG effect (all GHG's e.g. CO2, H2O, O3, CH4, etc.) and the albedo corrected radiatio from the sun
  42. Do high levels of CO2 in the past contradict the warming effect of CO2?
    Given the logarithmic response of CO2 wouldn't the difference in forcing between 3000 and 4000 be quite small? That would then suggest that the "sensitivity" to CO2 warming shown in the figure above is much larger than what has been calculated in detailed-look-at-climate-sensitivity.html. But it also would suggest that paleo sensitivity analysis has lots of confounding factors that are not being considered. If there are such factors above (extremely likely) then they exist in more recent paleo history as well.
  43. Conspiracy theories
    46 The natural world is warming, that is a given. Despite some people spending huge amounts of time saying things like glaciers aren't in on the conspiracy that is just a straw-man. No one said it wasn't warming. Presenting CAGW as plausible is the wisest course for a non tenured individual as recent e-mails proved. PhD climatologist Judith Curry has had the "blinders" removed ! She wrote: "When I refer to the IPCC dogma, it is the religious importance that the IPCC holds for this cadre of scientists; they will tolerate no dissent, and seek to trample and discredit anyone who challenges the IPCC. Who are these priests of the IPCC? Some are mid to late career middle ranking scientists who have done ok in terms of the academic meritocracy. Others were still graduate students when they were appointed as lead authors for the IPCC. These scientists have used to IPCC to gain a seat at the “big tables” where they can play power politics with the collective expertise of the IPCC, to obtain personal publicity, and to advance their careers. This advancement of their careers is done with the complicity of the professional societies and the institutions that fund science. Eager for the publicity, high impact journals such as Nature, Science, and PNAS frequently publish sensational but dubious papers that support the climate alarm narrative." She seems to think there would be some negative fall out from challenging the IPCC ! Is she wrong ?
  44. Lindzen and Choi find low climate sensitivity
    Also note that the "global monthly gain" chart in the paper from #150 shows it to be almost exactly inverse to the solar input. That suggests that "gain" is actually representative of the excess power not being stored as OHC. IOW, despite the fact that solar power wanes in NH summer, the earth temperature rises more than in summer as a ratio of that power (ie the "gain" is higher) due to NH land mass (much less OHC storage). The author does point out the hemispherical differences earlier in the paper, but does not carry any of those conclusions to the gain section (again it may be because they are not quantitative). The whole paper seems like a genuinely interesting experiment in data analysis, but ultimately discards the interesting part (seasonal variation in "gain") which seems to preclude its use with long run CO2 forcing.
  45. Lindzen and Choi find low climate sensitivity
    RW1 - Thank you for the explanation; that clarifies things quite a bit. Unfortunately, that leaves you with a non-constant 'gain', which I do not feel is a meaningful number. In the absence of greenhouse gases (first approximation, mind you, a Gedankenexperiment) the incoming solar energy at dynamic equilibrium will still be ~240, and the outgoing IR will be 240 to match (zero imbalance). Your 'gain' is then 1.0. As the greenhouse effect changes value (more CO2 in the atmosphere, for example), the incoming visible light still be ~240, and the outgoing IR close to that as well - with a higher surface temperature, and a 'gain' > 1.6. What matters is the surface temperature required (with the current emissivity of the Earth) to radiate ~240 W/m^2 out to space. As the emissivity 'e' decreases with GHG's, an imbalance occurs between sunlight in and IR out - resulting in a changing temperature 'T'. Not a 'gain' factor, but basic thermodynamics and math. Your factor of 1.6 is not a constant, but a result. You can't use that as an input - that's confusing cause and effect.
  46. Lindzen and Choi find low climate sensitivity
    e (RE: Post 204), Put another way, regardless of who is right or wrong about the energy flows, the gain is still going to be roughly 1.6
  47. Lindzen and Choi find low climate sensitivity
    e, the 1.6 comes from the paper linked in #150 (RW1: I think it would have been better to post that paper at the beginning to show where you are coming from). After reading the paper, the data comes from ISCCP, the variables are described here http://isccp.giss.nasa.gov/products/variables.html I started with graph 1, albedo looks reasonable compared to some papers online. Next, input power is derived from Psun and albedo, also reasonable. That's the denominator in the "gain". The next section is where I have issues, both from lack of understanding of the data sources and from what looks like errors in a formula. As described in that document "The output power is calculated as Po = (1-ρ)*Ps + ρ*Pc + Pw, where ρ is the fraction of clouds, Ps and Pc are the power fluxes originating from the surface and clouds" First I do not know where Ps and Pc come from (in my link above). The Ps might be calculated from emissivity and temperature (but I have no idea really). The Pc may come from cloud top temperature but I think that lacks some parameter (clouds are not black body) Then my biggest issue comes from using the fraction of clouds (the corresponding variable is cloud amount). Then there may be a problem with "power consumed by weather" albeit small. The next step is subtracting the input from the output power, then comparing that to the change in temperature to conclude that "As expected, the net flux in and out of the Earth's thermal mass, Pe, closely follows the solar input variability." IMO that should have been followed with an analysis of thermal storage, namely something like #117 in this thread and the others muoncounter mentioned. After that fairly obvious and non-quantitative conclusion, the author gets to the "gain" formula which he conflates with sensitivity (I also have a problem with how sensitivity is defined, but I don't think the solution is this formula for gain). The numerator in gain is the power flux calculated from surface temperature using S-B. IMO the previous discussion came from an analysis that was supposed to yield a quantity but did not. The choice of surface power flux is quite limiting IMO due to issues I discussed in #144.
  48. Lindzen and Choi find low climate sensitivity
    e (RE: Post 204), e: "Can you explain the physical relevance of the gain factor you keep citing (not the numbers you divided to get 1.6, but what does this number physically represent)? Nobody here understands why you think this number is meaningful." Using Trenberth's numbers, the gain is still about 1.6 (396/239 = 1.65). The gain is the simplest representation of how the system responds to each 1 W/m^2 of power entering, because it makes the fewest assumptions - like what all the energy flows may or may not be (cloudy vs. clear sky, how much absorbed power is re-directed toward the surface or space, how much passes through unabsorbed, etc.) The gain of 1.6 is the net measured result of all these things, independent of whatever specifically they may all be. Does that help clarify it?
  49. Lindzen and Choi find low climate sensitivity
    e (RE: Post 204), e: "Can you explain the physical relevance of the gain factor you keep citing (not the numbers you divided to get 1.6, but what does this number physically represent)? Nobody here understands why you think this number is meaningful." I'll try again. The gain is simply a representation of the amount of post albedo power entering the system from the sun that is "gained" at the surface due to the presence of GHGs and clouds in the atmosphere, which delay the release of infrared heat energy by redirecting some of it back toward the surface, which makes the surface warmer than it would be otherwise. A gain of about 1.6 simply means it takes a 1.6 W/m^2 power flux at the surface for each 1 W/m^2 of power to leave the system, offsetting each 1 W/m^2 entering the system from the Sun. that 1 W/m^2 of post albedo power entering the system from the Sun, you get 1.6 W/m^2 of power at the surface,
  50. Lindzen and Choi find low climate sensitivity
    RW1 @ 203, The numbers are right there in the diagram, you can add them up however you prefer. Precisely which numbers do you find confusing?

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