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chris at 00:18 AM on 2 March 2012The Certainty Monster vs. The Uncertainty Ewok
Yes Curry rather misrepresents the work of Swanson and Tsonis by cherry-picking their broad hypothesis about climate shifts without actually considering what Swanson and Tsonis determine via quantitative analysis of temperature series. For example in their 2009 paper on the attribution of 20th century temperature variation Swanson and Tsonis state:"Removal of that hidden variability from the actual observed global mean surface temperature record delineates the externally forced climate signal, which is monotonic, accelerating warming during the 20th century."
and determine that internal variability (their shifting of climate regimes) has made essentially zero contribution to 20th century warming. I don't have a problem with Swanson and Tsonis' hypothesis about climate shifts, and it seems entirely reasonable that changes in ocean current behaviour (as measured for example by changes in the NAO index), might give rise to small effects on surface temperatures variability on decadal time scales. But you can't hijack Tsonis' and Swanson's hypothesis without also making clear Swanson and Tsonis' own conclusions that the effects average out to around zero on multi-decadal timescales and anyway have contributions to surface temperature variability of only around 0.1 oC above and below the mean temperature (see Fig 2 of paper linked to just above). -
CBDunkerson at 23:56 PM on 1 March 2012The Certainty Monster vs. The Uncertainty Ewok
Curry: "Is it “cherry picking” to start a trend analysis at 1998? No, not if you are looking for a long period of time where there is little or no warming, in efforts to refute Hypothesis I." It isn't cherry picking if you select a time period specifically to fit a preconceived notion? Ummmm... what!?! That's the bloody definition of cherry picking. -
CBDunkerson at 23:42 PM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
I've used a more detailed version of the 'pool balls analogy' for global warming previously. Specifically; Imagine balls (photons) moving in a completely frictionless environment on a pool table (the Earth's atmosphere). Since there is no friction they will continue bouncing around until they hit one of the pockets (escape to space). Now assume that additional pool balls (incoming photons from sunlight) are rolled onto the table at a fixed rate. Let's also say that the size of the table and the momentum of the pool balls is such that on average balls leave the table at the same rate that they enter it. Now, if we block off one of the pockets (increase greenhouse gas levels) the balls will initially not be able to escape at the same rate and thus the incoming balls will result in an increasing number of balls on the table (more energy in the atmosphere) which results in more collisions and greater total momentum until eventually the rate of balls exiting the table again equals the rate at which they are entering... just with more balls on the table (higher atmospheric temperatures) at any given time. Thus, no it isn't really the ricochets per se... in this simplified example warming is caused by a change in the rate at which energy escapes the system. That does result in more ricochets, but it is the temporary imbalance between incoming and outgoing rate which is the real issue. -
Tom Curtis at 23:27 PM on 1 March 2012The Certainty Monster vs. The Uncertainty Ewok
Mike @5, because we can predict climate to some extent, but not weather, predictions for temperatures at the end of this century are couched as predictions for mean global temperatures in a given one or two decade period. To then further express uncertainty in temporal terms on top of that would create confusion. -
Tom Curtis at 23:22 PM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
skept.fr @38, within the troposphere, and to a first approximation, and ignoring feedbacks, all altitudes will heat equally. Of course, with that many qualifications the answer is probably not very satisfying. The two most important of the caveats are the spatial (within the troposphere) and the feedbacks. The consequence of increased greenhouse gases at the boundary of the troposphere (the tropopause) will be to warm the lower reaches, thereby lifting that boundary. Above that, in the stratosphere it definitely cools but the reason for the cooling is not certain, and extensively discussed elsewhere on SkS. (Hint: of topic for this thread, but you are welcome to follow the link read the comments and wade in.) Feedback wise, the most important feature is the Lapse Rate Feedback. In the lapse rate feedback, the Lapse rate becomes smaller (smaller decrease in temperature with altitude) due to increased water vapour in the atmosphere, resulting in a warmer upper troposphere relative to the lower troposphere in areas of high humidity, ie, the tropics. Again, extensively discussed elsewhere. All this is arm waving, so it would be better to look at the model predictions:
This however also takes us of topic. I would appreciate it if we restrict discussion of the enhanced greenhouse effect, ie, how the greenhouse effect changes with increased GHG to some other thread, or wait till I actually discuss it later in this series.
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chriskoz at 23:11 PM on 1 March 2012German translation of The Debunking Handbook
Indeed, my guess that "a press attention in Germany triggered that translation" was a silly one. Thanks for your hard work of letting German speaking people know this useful work. -
chriskoz at 22:57 PM on 1 March 2012The Certainty Monster vs. The Uncertainty Ewok
Mike @5, Given the range of uncertainty (predicted dT 2-6K) and the fact that dT is proportional to ln(dCO2), if you want to express your uncertainty as a around a=2100, with dT=4, then you would end up with Piosson distribution. Therefore, the confidence interval would be from say 2060 to 2260 (only roughly, I'm too lazy to calculate it for you), so not a symetric normal distribution as you would think (with your guess of sigma-a of 20). Is there a point in framing temp predictions that way? I don't think so. It can only fuel "skeptic" (==ignorant) thoughts, that "it's not that bad, because it may not happen until 2260 so we have more time". What matters, is how much warming we are commiting to the pipeline (not just immediate but equilibrium warming) and thats dT. It does not matter if a given dT happens in a=2100 or 2260, it's irrellevant (just instant) on the geological timescale. A question of dT itself is far more important, and scientists correctly present AGW problem from that perspective. -
skept.fr at 22:53 PM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
#33 Chris : "However, changes have been in the vertical distribution of how that energy escapes. Specifically, the height of the so-called TAU=1 (an optical depth coordinate) level increases, such that the "mean" level of emission to space decreases in pressure (or increases in height)." #36 Tom : "The most fundamental fact about the greenhouse effect is that if the energy escaping to space exceeds the energy entering the system, then the temperature will rise until they balance again." These two comments bring me to ask a question: the system will warm, but where should it warm? By where I mean at which height? The same point than #19 Bart. It has been answered to Bart that the higher layers of atmosphere will cool rather than warm because of IR trapping near surface (so these higher layers would emit less at T^4 toward outer space). But that is unclear for me, because if we speak of a thermodynamical equilibrium, there are also non-radiative mechanisms on Earth, precisely between surface and troposphere (for example latent heat and wet convection if there is a water vapour feedback). -
Volker Doormann at 22:46 PM on 1 March 2012Scafetta's Widget Problems
Riccardo at 07:13 AM on 1 March, 2012 says: “The sea level data are detrended and retain the seasonal cycle which is what the solar tide function apparently matches. “ Let’s check your theory. There is a science of algebra. From this we can count the number of sea level oscillations in 3 calendar years { http://www.volker-doormann.org/images/sealevel_vs_xyzo.gif } as 19. From astronomy books we can take the frequency of Mercury with 4.15207 [y-1] and the frequency of Earth with 0.9998 [y-1]. The synodic frequency of this couple is f_syn [y-1] = 4.15207 -0.99998 = 3.15209 [y-1]. And because a (solar) tide function is twice the synodic function, because springtides occur as well on conjunctions and also on oppositions, the solar tide frequency of Mercury/Earth is f_sol_tid = 2 x 3.15209 = 6.30418 [y-1]. This means from the logic of algebra that the number of solar springtides from this couple in 3 years counts 3 x 6.30418 = 18.9125 oscillations, mostly equal to the number of terrestrial sea level oscillations in 3 calendar years. In contrast to the (terrestrial) seasonal cycle, which is locked to the frequency of the Earth (http://sealevel.colorado.edu/content/2012rel1-global-mean-sea-level-time-series-seasonal-signals-retained ) , there are only 3 oscillations in 3 calendar years. Conclusion: Your theory is wrong. Personal remark: I read that on this blog science from peer reviewed work is standard. But it seems to me that lacks in simple algebra do not match with that claim. V. -
DrTsk at 22:39 PM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
Also, mass transfer of CO2 to minerals (geologic time), oceans, and biosphere, is first order in CO2 concentration. Therefore, a spike of CO2 will be an exponential decay, a long as the mass transfer coefficient does not change. The adjustment time is the half-life of CO2 in the atmosphere after a spike. The important half-life is the one relating to the ocean sequestration until saturation which is in the order of hundreds of years, assuming emissions of CO2 ended today. -
DrTsk at 22:28 PM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
Why are we keep talking about residence time???? Residence time, only matters when a chemical reaction that changes the identity of a molecule happens. CO2 remains CO2, so residence time has no meaning at all . It does for CH4 since it oxidizes to CO2. Please ignore whoever argues about the importance of residence time and CO2. Dikran, good work!!! It is however, akin showing that the earth is spherical to flat-earthers.... -
Glenn Tamblyn at 22:00 PM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
owl905 The ricochet is a characteristic of the GH Effect But it isn't what defines the GH Effect. If the ricochet is what defines how long it takes a pool ball to leave the table, what is far more important is how many balls are on the table because of that. If one pool ball ricochet's off per second, so what. How many balls does it need on the table to generate that one ricochet per second. -
Dikran Marsupial at 21:06 PM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
owl905 Yes, the C14 issue is quite subtle. The residence time is the average amount of time a molecule of CO2 stays in the atmosphere, and is about 4-16 years regardless of which isotope you look at. However the reason that the residence time is short is because about 20% of the CO2 in the atmosphere is exchanged with CO2 from the oceans and terrestrial biosphere each year. However this is just an exchange of carbon and doesn't change atmospheric CO2 levels at all. The rate at which CO2 levels rise and fall, known as the adjustment time, depends on the difference between natural uptake and natural emissions. This is small compared to the magnitude of the exchange fluxes, which is why the adjustment time is much longer than the residence time, and it is the adjustment time that matters, not the residence time (hence the title of the post). The C14 in the atmosphere is created in the upper atmosphere by the action of cosmic rays on nitrogen. This means that the exchange fluxes replace C14 in the atmosphere with lighter isotopes of carbon, rather than with more C14. This means that C14 analysis only tells you about the residence time, but not the adjustment time. I think that the confusion arises from not appreciating the difference between residence time and adjustment time, and the effects of the vast exchange of carbon between the atmosphere and oceans/terrestrial biosphere. It took me some time to fully appreciate when I first came across this argument. -
Dikran Marsupial at 20:54 PM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
Michael Hauber In the scenario you suggest, where the hypothetical sink were controlling atmospheric CO2 levels, the level would remain near the equilibrium level, rather than rising rather rapidly. However, the main point is that the natural environment is known with high certainty to be a net carbon sink, and hence is opposing, rather than causing, the observed post-industrial increases. Anthropogenic CO2 levels are currently controlled by anthropogenic emissions, the net environmental sink is demonstrably unable to cope with our current level of emissions, so if we carry on at the current rate or higher, atmospheric CO2 levels will continue to rise. If we cut emissions sharply enough that the net environmental sink outstrips anthropogenic emissions, then atmospheric levels will fall. The choice is in our hands. The equilibrium concentration of the ocean is also determined by the difference in partial pressure between the surface waters and the atmosphere, not just temperature. Our emissions have increased the CO2 content of the atmosphere and that has changed the fluxes into and out of the oceans so that the ocean is now a net carbon sink. If someone wants to argue that the rise in temperature is causing the rise in CO2 (e.g. due to ocean degassing) they need to be able to explain why the oceans are so much more temperature sensitive now than they were at the end of the last major glaciation. At that time there was a similar rise in CO2 levels (although much slower) but the change in temperature was about ten times that we have observed since the end of the industrial revolution. "Some more understanding of what Co2 is doing in the ocean is required to rule out natural sources of the Co2 increase." While more understanding is always a good thing, this statement is simply false. If the observed rise were due to natural sources, the annual rise would be greater than anthropogenic emissions, instead of less. This is a simple matter of accounting, and is valid assuming conservation of mass, which seems a pretty reasonable assumption. -
Tom Curtis at 20:21 PM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
owl905 @34, I'm sorry, but you have been had. The "ricochet on the pool table" is irrelevant to the greenhouse effect. The most fundamental fact about the greenhouse effect is that if the energy escaping to spaceexceedsis less than the energy entering the system, then the temperature will rise until they balance again. If the energy escapingis less thanexceeds the energy entering system, temperatures will fall until they balance again. Now, if you imagine a series of pipes, with a tap which will be used to force water flowing through the pipe to take a longer or a shorter route. If you switch from the shorter to the longer route, but maintain a constant flow, there will be no build up of pressure, and the reservoir you are draining will not drain any slower. Analogously, if you introduced GHG to the atmosphere so that energy took longer to reach space, but maintained the same temperature at all altitudes so that the amount of energy being emitted to space was not reduce, you would not warm the surface of the planet. Note: Edited to correct an error pointed out by ribwoods @ 6:50 am of March 3rd below. My thanks to him for picking up on my mistype, and my apology for any confusion caused by it. -
Mike at 20:17 PM on 1 March 2012The Certainty Monster vs. The Uncertainty Ewok
I've always disagreed with the way uncertainty of future temps is framed. Instead of staying if current emission trends continue "there is a 95% chance we will between 2-6 C of warming by 2100" we should say "there is a 95% change we will have 4C of warming sometime between 2080 and 2120" (or whatever the correct time span should be). And I'd guess there is a 95% of 6C between 2120 and 2160. -
Tom Curtis at 20:08 PM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
Coal Geologist @32 and Chris Colose @32, I apologize for my lack of clarity. The full quote in context (which Coal Geologist truncated) is:"That means that the red area itself, which is the upwards radiation from the surface minus the upward radiation to space, is the reduction in energy radiated to space because of the presence of Infra-Red absorbing molecules in the atmosphere. That is, it is the greenhouse effect."
As is evident from the initial part of the first sentence, if discusses modtran diagram above, and refers to the difference between the Infrared radiation from the surface, and the Infrared radiation to space. On Trenberth's diagram, it is the difference between the Surface Radiation (396 W/m^2) and the Outgoing Longwave Radiation (239 W/m^2). Without that difference, there would be a approximately 150 W/m^2 energy imbalance between incoming and outgoing energy which would very rapidly cool the surface to about 255 degrees K (-18 degrees C). Except for the interpretation of what I said, there is little to disagree with in Coal Geologists explanation, and nothing in Chris Colose's. The little I disagree with is saying "...that the greenhouse effect was due to a slowing of the escape of outgoing heat by its absorption and re-emission (so-called radiative heat transfer) by GHGs." Although green house gases do increase the time it takes for energy to go from the surface to space, on average, that of itself will not cause a greenhouse effect. -
owl905 at 20:06 PM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
Coal Geologist 32 - Great post. Whenever I 'get it', the very next article challenges me in a way the could turn 'gets it' into 'been had'. The balance is absolutely right. The missing explanation is the time that 238.5 W/m2 takes before it escapes. Think ricochet on a pool table. That ricochet time defines the Greenhouse Effect. -
skept.fr at 19:17 PM on 1 March 2012The Certainty Monster vs. The Uncertainty Ewok
I think the interesting point is the status of internal climate variability (which is called in the literature "intrinsic", "chaotic" or "unforced" variability) and what it means for surface temperature in transient sensitivity (but not the heat content of the whole Earth system and not for equilibrium sensitivity after a more or less long relaxation time). If we look at a precise prediction, like the regional and global surface temperature in 2100, it is important to cope correctly with such variability. The main point for human affairs seems to be the ocean-ocean and ocean-atmosphere heat transfers, because only oceans can slow or accelerate the surface signal on decadal-to-century scale. -
Riccardo at 18:29 PM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
galopingcamel "they assume that CO2 is responsible for most of the recent warming" I'm sure you know this isn't true. -
Bernard J. at 18:26 PM on 1 March 2012The Certainty Monster vs. The Uncertainty Ewok
I could imagine Curry's entry into my discipline - biology. Given her current form in climatology, she'd come in with three hypotheses for human reproduction:I. Sexual reproduction hypothesis: Humans have two sexes, each of which produce a specific type of gamete, which come together in the female reproductive tract after intercourse, and which then fuse and go on to develop into a new individual. II. Spontaneous generation hypothesis: offspring develop at random, and with no external influence, within a female's uterus. III: Stork hypothesis: as is widely known by sceptical old wives, biologists are all alarmist about having a bit of fun - babies are brought, bundled in bunny rugs, to fortunate parents via the agency of avian couriers belonging to the family Ciconiidæ.
Each of these three hypotheses provides a different interpretation of the natality attribution and has different implications for 21st century contraception and population management...Response:[dana1981] 'Stork hypothesis' literally made me LOL!
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owl905 at 18:26 PM on 1 March 2012The Certainty Monster vs. The Uncertainty Ewok
Curry's too busy preaching what sells to study the truth. The ugly factor missed in these analyses is the run-down of the latent cold storage in the system. The Greenland ice sheet has shown huge losses; 95% of the globe's glaciers are in retreat; and PIG in the Antarctic has passed the tipping point. Ask Curry to factor the ice-block melt into her pablum presentations. PIG Adds a New Wrinkle "expected to create an iceberg of about 900 square kilometres." -
Chris Colose at 18:21 PM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
CoalGeologist- Your understanding is quite good. The statement you quote above is not wrong either, though it could be modified to be made more clear that it refers to the instantaneous effect of adding GHG's and not the final effect. The apparent contradiction can be resolved if you interrogate more closely the steps going from perturbation to equilibrium: 1) Suppose first we introduce some extra CO2 into the atmosphere while holding temperature fixed. This is the step where the outgoing radiation to space is reduced. The consequence of this is that if we leave the incoming solar radiation unchanged, more energy is coming into the planet than is exiting. This is the "slowing of outgoing heat by its absorption and re-emission" that you referred to. 2) Because of this the planet warms, and the emission increases to space in order to let that imbalance decay to zero. This is the step that you are talking about. 3) When measured from space, the net result is actually that the outgoing radiation has not changed at all from the initial value once you go back to equilibrium, since it must match the unchanged solar radiation. However, changes have been in the vertical distribution of how that energy escapes. Specifically, the height of the so-called TAU=1 (an optical depth coordinate) level increases, such that the "mean" level of emission to space decreases in pressure (or increases in height). Of course, the height of this surface is really a strong function of wavelength. Note that in my plots in the feedbacks and runaway post, I plotted OLR as a function of temperature. Thus, if you pick any specific temperature (say, 300 K) the OLR is reduced by adding CO2. Look at figure 2 for example in that post. That will always be true because of the absorption by the excess CO2. However, for thermodynamic reasons, this disequilibrium cannot be maintained forever, since it must be accompanied by an increase in temperature. So instead of thinking about the instantaneous effect of adding CO2 as decreasing the OLR for fixed T, you can think of it as increasing the temperature for a fixed equilibrium point (i.e., where the OLR intersects the incoming solar curve). -
gallopingcamel at 17:54 PM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
KR @74, 75 & 76, As acknowledged in my #68, Scafetta's model is open to the charge of curve fitting as are all the IPCC models. Scafetta understands that the "hard part" is to develop a theory to explain why his model is more than just curve fitting. See my #73. The IPCC models suffer from confirmation bias because they assume that CO2 is responsible for most of the recent warming while ignoring the evidence that 50-80% is attributable to natural causes.Response:[DB] "The IPCC models suffer from confirmation bias because they assume that CO2 is responsible for most of the recent warming while ignoring the evidence that 50-80% is attributable to natural causes."
Unsupported assertion. It is incumbent upon you to now provide links to peer-reviewed articles published in reputable journals that document that the evidence you mentions both exists and that the IPCC has ignored it.
You will be held accountable for the above statement.
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Sceptical Wombat at 17:50 PM on 1 March 2012The Certainty Monster vs. The Uncertainty Ewok
The thing that really convinces me about the last 15 years is Foster & Rahmstorf's work. By doing a fairly straight forward multivariate regression and removing the effects of solar variation, El Nino and areosols they get a pretty steadily increasing trend for each of the major temperature data sets though there is still some residual noise. Even the noise is surprisingly consistent across the data sets -
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gallopingcamel at 17:38 PM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
Jose_X @70, Your calculation based on CO2 doublings greatly underestimates the effect of multiplying Earth's ~400 ppm of CO2 by a factor of one million. Adding that much mass to our atmosphere would raise the surface temperature to at least 900 Kelvin. Once the surface temperature gets high enough the oceans would vaporize causing an additional 300 bars of surface pressure and a further increase in temperature. Venus with its 90 bar atmosphere would look chilly by comparison. Chris Colose would (posthumously) call this a "Runaway" greenhouse effect. You can find an excellent discussion of this here with plenty of side references that are worth reading: http://scienceofdoom.com/2010/06/12/venusian-mysteries/ -
owl905 at 17:37 PM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
From here it's a mixture of sympathy and pity for Essenhigh's paper. It's understandable why he wouldn't budge from his position - his framework is false. His claim that CO2 levels spiked 1000% and declined in 16 years only measured the rare C14 values, not the CO2 well-mixed global levels. Those levels showed no spike at all to nuclear testing. He connects CO2 levels as a consequence of warming while skipping two basic tests. First, there's no record of a similar CO2 rise of 25%/century anywhere in the geological or historical record. Second, if .7dC warming can push CO2 levels up 40% (his claim), there would be a GHG record that looked like a seismograph output showing extremely unstable values for atmospheric CO2. Basically, he's failed to review the data, and he's missed the cacophony claiming CO2 is rising WITHOUT temperature rising. Then he constructs a one-way model that has no relevance to the carbon cycle - he missed the basic difference between residence time in one regime (atmosphere, land, ocean) that averages about 8 years; and the residence time of the system load in the biosphere as a unit - which is in the 50 to 200 year range the IPCC outlines. Feel sorry for a man when the need to invent a paradigm, that embarrasses academic degrees and a professional status, that fails to listen and learn before it talks and teaches. The '1000%' spike source -
CoalGeologist at 17:31 PM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
OK... I can no longer restrain my reluctance to bare my ignorance in public. I just don't 'get it' that:"the reduction in energy radiated to space because of the presence of Infra-Red absorbing molecules in the atmosphere. That is, it is the greenhouse effect.
What reduction of energy radiated to space? I also didn't 'get' the same thing in another recent discussion on SkS about "Radiative Balance, Feedback, and Runaway Warming" According to diagrams such as this one from Kiehl & Trenberth (1997):
incoming solar radiation is ~341.3 W/m2, of which ~101.9 is immediately reflected back out into space. 0.9 W/m2 is estimated to be absorbed by the oceans. The outgoing LWR is 238.5 W/m2.
I'm not too good at math, but 238.5 + 101.9 + 0.9 = 341.3, which basically tells me that, at least to the first decimal place, the energy balances... which is pretty much what I expected, based upon certain principles of thermodynamics.
It was my impression that the greenhouse effect was due to a slowing of the escape of outgoing heat by its absorption and re-emission (so-called radiative heat transfer) by GHGs. The increased heat is manifested as a higher temperature, owing to a certain other principle of thermodynamics. It has been my understanding that the outgoing long-wave radiation is suppressed in the absorption bands for GHGs--a telltale sign that GHG warming is occurring--but that owing to the increase in temperature (due to greenhouse warming), the emission in the parts of the spectrum transparent to outgoing longwave radiation is increased.
Either my understanding is wrong, or the excerpted statement is wrong. Someone please correct me. (I can take it.)
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KR at 17:27 PM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
My apologies, the Loehle/Scafetta reconstruction in the illustration has a cyclic+linear component. The most recent Scafetta paper, on the other hand, has a cyclic+quadratic basis up until ~2000, when (for reasons not clearly justified, or understood here, as it leads to a worse fit) he changes to cyclic+linear again. Either way, his model fails in backprojection, includes no physics, but is simply correlation without causation, and hence has no predictive power. Physics: Good predictions Good stats: Reasonable predictions if nothing changes Bad stats: Better off repeatedly flipping a coin Since CO2 forcings are constantly changing, ENSO, solar, and volcanic forcings are not correlated, Scafetta's work is simply bad statistics. -
KR at 17:19 PM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
gallopingcamel - Scafetta's work is simply curve-fitting to a limited period. When taken outside the 'training period' for his cyclic+quadratic fit, it fails horribly:
This is simply a rather limited Fourier decomposition (over-attributed to larger frequencies within the timeframe that happen to somewhat match selected astronomical periods) of the period under analysis, with no predictive power whatsoever - correlation without causation, unable to make any predictions as it is not based upon any physics related to the system. That's fine as long as the inputs/forcings do not change, but cannot predict future (or past, as shown above) behavior if they do, for example as CO2 levels change.
I'll note that the quadratic term in Scafetta's most recent work (oddly without emphasis in his papers) does roughly correspond to CO2 forcing. With no conclusions drawn, or analysis applied...
Where is your skepticism?
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KR at 17:07 PM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
Jose_X - I will (putting my 2 cents in, if that) note that it is a bit difficult to follow a stream of consciousness post. It would be easier to follow if you were to note your assertion(s), followed by the backing. Otherwise it's a bit difficult to identify any issues you might raise. That said - Huffman appears to think that plate tectonics is nonsense (not the best recommendation), N&Z have apparently used basic curve fitting to re-derive the S-B relationship without acknowledging it, PV=nRT requires a separate temperature driven by convection and radiative physics to set the pressures, etc. Even WUWT has pointed out N&Z issues with significant justification. Which aspect(s) of those postings do you consider significant issues with basic radiative physics? -
gallopingcamel at 17:03 PM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
scaddenp @71, Scafetta has shown that planetary motions correlate with global temperature. At first blush this sounds like astrology rather than science. You should be skeptical as I am but maybe we should suspend judgment. Suppose that the gyrations of the major planets somehow modulate the reactions taking place in the sun's core. If this was happening, how long would it take for the effects to reach the sun's radiating surface? If you rely on Radiative Transfer the answer is tens of thousands of years. So is there any process that could explain the very short time constant that matches observations? If such a mechanism exists it may take decades to understand it just as in Wegener's case. -
Composer99 at 15:58 PM on 1 March 2012DenialGate - Highlighting Bob Carter's Selective Science
The CASS-CFI report I linked to indicates Patterson was for some time the teacher of the course; the year they audited the course's videos it was taught by a Tom Harris. -
Bob Loblaw at 13:54 PM on 1 March 2012DenialGate - Highlighting Bob Carter's Selective Science
Carleton University is the home of Tim Patterson - a well-known climate change denier. That's probably where the guest lecture was done. The geography department used to have people who actually knew about climatology, but I'm not sure who they have there now. Tim Patterson is in geology, and would probably consider Tim Ball to be a peer (which is not a strong recommendation). -
KR at 13:45 PM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
Michael Hauber - Your post is contradictory, I would assume not intentionally. Your hypothetic source/sink will emit/absorb CO2 above a specific level? This is not comprehensible. The oceans have (as per the ice core record) absorbed or release ~90ppm of CO2 over a 5-6C temperature swing, with a time delay of 500-800 years. Not due to atmospheric CO2 concentration changes, mind you, but due to solubility changes with temperature. The oceans therefore do not fit your hypothetical, as atmospheric concentrations have changed in sync with our emissions for the last 150 years or so, with natural sinks (primarily the oceans) absorbing only half of our emissions. In regards to the oceans, I would suggest reading the OA Is Not OK series, Why ocean heat can’t drive climate change, and What is causing the increase in atmospheric CO2 to review the mass balance issues. We certainly understand enough of what CO2 is doing in the oceans to determine that the oceans are not the source of CO2 increases over the last 150 years. -
Composer99 at 13:44 PM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
Michael: Fortunately, we are already very well aware that the oceans are taking up CO2 at a very high rate, leading to an ocean acidification which is effectively unprecedented in geological history. There is a long series here on Skeptical Science going through the chemistry which demonstrates this is the case. This is despite the rise in temperatures, which would normally result in the oceans outgassing CO2. -
Michael Hauber at 13:26 PM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
The logic of this argument is flawed. Hypothetically imagine a natural carbon sink that emits Co2 if current concentrations are above a specific equilibrium level, and absorbs Co2 if it is above this level. And assume that this equilibrium level increases as temperatures increase, and that the carbon sink acts quickly enough to maintain Co2 concentrations close to the equilibrium level. Then it would be possible for man to emmit Co2, this hypothetical sink to be a net absorber of Co2, and the overall increase in Co2 be determined not by man's emissions but by the hypothetical sink. The ocean does act a little like this, and has a preferred equilibrium for Co2 concentration that depends on temperature, and will tend to absorb or emit Co2 as required to maintain this equilibrium. Some more understanding of what Co2 is doing in the ocean is required to rule out natural sources of the Co2 increase. -
Jose_X at 12:26 PM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
Moderator JH from #69, I thought I asked a reasonable question about radiative balance. If I kept quiet about the resolution, the question stays on the comment thread unanswered. Was that the preferable option? Is it my fault I didn't know the answer when I asked it and later realized it? Is there no use to detailing an answer? Is it not useful to present the sort of honest thought process that goes through people's minds? I thought this thought process (the form of #69) is useful to a website trying to understand its audience so as to better communicate the website's message. I'm not the best writer. Was that the problem?Moderator Response: [JH] Suggest that you do your calculations off-line and keep your comments focused. People are just not inclined to read lengthy rambling posts. -
Sceptical Wombat at 11:56 AM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
The thing I don't understand is what Essenhigh et al think the CO2 content of the atmosphere would be if the industrial revolution had never happened. Do they really think it would be the same as it is today - or do they think it would be higher? If I take the plug out of the handbasin in my bathroom I can turn on the cold water tap to a point where the basin remains half full - ie the water runs in from the tap at the same speed that it escapes through the plug hole. If I then turn on the hot tap a little the water will rise in the basin and eventually overflow. The residence time in the basin is very short, the percentage of hot water in the basin at any time will be very low but I defy anyone to argue that the overflow was not caused by my turning on the hot tap. -
PluviAL at 11:04 AM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
Boba10960, Strong second on the critical value of this explanation. I have been studying ths subject for some time, and most discussion gloss over this as if everybody knows it. But we don't we just assume someone did thier work and so we can just wave our arms as the article sais to communicate. I am mostly an avid arm-waver; who knows it might help to cool the planet. Like so many ither posts here, this is really valuable instruction. A hardy thanks to all who work so hard to provide such good stuff. -
owl905 at 10:37 AM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
@jimb 29 and DMCarey 28 - DM's fear is warranted. It's sanctified by the National Post, upheld by most of the other 'national' newspapers. And a decade of national governance that's power-base is built on the tar pits has taken the old phrase 'blue-eyed Arabs' to a whole new level. Here's the latest (c/o CCTNG): Heartland Does Carlton University Any claim that the Greenhouse Effect is 'generally accepted' is a pitch in the dirt daring everyone to argue from square one - waiting for a chance to butwhatabout. -
scaddenp at 10:20 AM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
"Remember that Alfred Wegener had been dead for many years when the scientific world stopped laughing at his theory of "Continental Drift"." So who stopped laughing? The idea that continents could move over the seafloor was and still is ridiculous. His observational evidence that eventually helped lead to modern tectonics was not ridiculous and not laughed at. However, where are the unexplained puzzles in climate theory comparable to Wegener? -
Jose_X at 09:56 AM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
I think I resolved my Venus/Earth conflict http://www.skepticalscience.com/news.php?p=2&t=53&&n=1310#75971 . Believe it or not, that particular planet comparison had been nagging me for at least a few weeks. None of my few replies addressing it (on a different forum) had simply calculated the 10^6-fold increase scenario to make it apparent that there was no inconsistency between that data and GHE. -
Jose_X at 09:40 AM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
The majority of this comment (middle on down) serves to illustrate a misunderstanding that perhaps a number of people might be having. >> please, stop quoting from bad science sites Riccardo, I brought up a point that presumably is based on data and which is a reasonable question to ask of the GHE since on the surface appears to suggest the amount of ghg does not matter. I linked the webpage for reference to reduce the number of replies asking for more detail. >> If you have a transparent atmosphere you end up with a isothermal atmosphere at the same temperature as the surface My second scenario is not 100% N2 (which is this simple case you answered). Essentially, I have not verified that there is an appreciable difference between having a small amount of CO2 vs having almost the entire atmosphere be CO2. In Venus, we have a number of similarities to the Earth but the opposite extreme as here in terms of relative proportion of ghg. Has no one published a paper applying GHE equations to Venus? [See conclusion below, as it suggests a classroom exercise might be more appropriate.] >> In the real case, use the adiabatic lapse rate, the emission altitude from the effective radiation temperature and extrapolate back to the surface. This approach was exactly what gave me a little concern. I think it's also what Joel Shore describes in part (c) of his reply here http://wattsupwiththat.com/2011/12/29/unified-theory-of-climate/#comment-849734 Let me take this slowly. If we initially only concern ourselves with a rough approximation, then the webpage I linked takes you through the data to suggest that we would get exactly the same answer regardless of the amount of CO2. The slope of that lapse rate appears to be about the same for Venus as for Earth.. again, to first approximation. Now, I would not have expected this result.. even to first approximation. Now, on to more precise estimate considerations. One of my next thoughts was that the lapse rate is basically linear over a narrow pressure range (or more linear nearer to TOA?) but then bends on the way down in very high pressures. This would perhaps solve the problem. As we go deeper into Venus, the curve would bend towards higher temperatures.. in comparison to the path it would take if Venus has the % makeup as the Earth has. [Update to self: the graph here http://en.wikipedia.org/wiki/Atmosphere_of_Venus#Troposphere appears to show a slight bend towards higher temperatures in the low part of the line] This is why I ask about a precise calculation. Now, let's look at a few potential curves more closely. First, I have the question of what to expect, so let's consider some possibly hypotheses. H1: I know that 100% CO2 perhaps might not make much of a difference vs 10% CO2 + N2. I don't know but some degree of saturation certainly could be in play. H2: In fact, the actual physics could potentially make the 100% CO2 case do worse. These are all possibilities a priori. H3: A different form of reasoning might hypothesize that more CO2 should *always* lead to greater GHE within the limits imposed that a doubling of concentration leads to linear temperature increases. This is the standard model, I think, so I will look at it first. I now look towards the Earth predictions. We have a few degrees.. or let's say 1 K for 2xCO2. Extending this, 1 million xCO2 (approx 20 doublings) would lead to 20 K increase. 20K increase!! OK, maybe the model is being driven out of range by my example of 1 million fold increase. This would lead to about 390 atmospheres of pressure at the surface of the Earth and near 99.99% CO2. Or maybe the model would hold. Very interesting result. I did not expect that. I'll stop here since it appears I might have my answer from standard theory. My conclusion is that the climate models would appear to be consistent with the Venus example since a small change in slope is enough to change the temperature at the surface of Venus by about 20 K (or vicinity) rather easily. My concerns have been dispelled for the most part (pending a recheck of the logic and math). After thought: On earth we can have a very modest change in pressure of 40% via 1000 fold increase in CO2 yet get a full 10K. This 10K would be more than half of the 18K or so ballpark figure representing the super hot and high pressure Venus. This result is certainly a bit counter-intuitive (thanks to the log relationship).Moderator Response: [JH] Please refrain from using this comment thread as your personal scratch pad. -
Dikran Marsupial at 09:36 AM on 1 March 2012Scafetta's Widget Problems
Volker Doorman I don't believe in repetition either, especially if the cycle in question has no statistical significance nor a plausible physical mechanism that can explain the strength of the effect. Sorry, the irony of your response was just too tempting! ;o) -
Volker Doormann at 09:18 AM on 1 March 2012Scafetta's Widget Problems
@Dikran Marsupial I do not belief in repipition. I'm off.Response:[DB] If you did not wish to participate in science-based dialogue, of which experimental repeatability is an integral part, than why are you here?
As an FYI, this forum has witnessed curve-fitting exercises based on the CET before. And is therefore dubious.
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gallopingcamel at 09:12 AM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
Jose_X at 16:41 PM on 29 February, 2012, You have identified the main weakness in the references I cited. They lack a physical mechanism to underpin them and that leaves them open to the charge of "curve fitting". Remember that Alfred Wegener had been dead for many years when the scientific world stopped laughing at his theory of "Continental Drift". Nicola Scafetta is all too well aware that even if his prediction of global temperatures to 2040 proves to be more accurate than that of the IPCC's AR4, it proves nothing unless he can explain the underlying processes. He is making progress and I find his ideas quite plausible. When he "goes public" we will be able to take this discussion to the next level. In my opinion, N&K are in the same boat but I have not had the opportunity to meet them. (-snip-) Early drafts of the AR5 Working Group 1 have been leaked and I have a team working on them. You are clearly a deep thinker so would you be interested in participating? http://www.gallopingcamel.info/IPCC.htmResponse:[DB] Imputations of impropriety and fraud snipped. Please pay more than a passing nod to the Comments Policy of this site.
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jimb at 08:23 AM on 1 March 2012Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
@28- This is not being helped by the latest news re this year's proposed budget in Canada. From our local newspaper;"The federal Conservatives are planning significant spending cuts for the upcoming 2012-13 budget years in areas such as environmental monitoring, fisheries and oceans, Via Rail, national defence, the Canadian Space agency and green energy initiatives." The budget, according to the report, will cut funding to the Canadian Environmental Agency by 43%. (Edmonton Journal February 29th) And, of course, Canada pulled out of Kyoto earlier this year. -
Pete Dunkelberg at 07:56 AM on 1 March 2012The Independence of Global Warming on Residence Time of CO2
Dikran is right that denial of the cause of the increase in atmospheric CO2 is worth treating in print. He might offer to educate Heartland's chosen educator David Wojick. From a comment at Eli'sI made the mistake of visiting the House of Curry, and followed some links from Curry's laudatory description of Lindzen's talk (and having _been_ to one of Lindzen's talks in person, I find it hard to think that there is anything of laudatory content in there). Some interesting quotes from delving into the rabett-hole... First, David Wojick, Climate Educator: "I am not convinced that the CO2 increase has caused any warming, nor that the CO2 increase is due to human emissions. So I certainly do not agree with AGW, in any form." While this was in 2010, this one quote pretty much demolishes his (already non-existent) credentials as someone who should receive money for creating a climate curriculum: if you can't accept that the CO2 increase is due to human emissions, you are pretty much in Moon-landing-denial territory. (comment from http://judithcurry.com/2010/12/14/co2-no-feedback-sensitivity-part-ii/) Quote 2 is of note because Curry tries so hard to never let herself get pinned down on anything, and is so hard on anyone who doesn't acknowledge uncertainty in their conclusions: she states as "almost certain" something that I consider "likely wrong". "This is how I would do the analysis to determine the CO2 no feedback sensitivity. The number would almost certainly be less than 1C." from http://judithcurry.com/2010/12/11/co2-no-feedback-sensitivity/ -MMM
Thanks Dikran for doing this. -
Riccardo at 07:34 AM on 1 March 2012Radiative Balance, Feedback, and Runaway Warming
Jose_X you have three possibilities, look at what other scientists published on the topic or read a textbook on radiative transfer and do proper calculations yourself or satisfy your curiosity with a crude semi-quantitative model. The latter is straightforward. If you have a transparent atmosphere you end up with a isothermal atmosphere at the same temperature as the surface; the latter is determined by simply balancing the fluxes. In the real case, use the adiabatic lapse rate, the emission altitude from the effective radiation temperature and extrapolate back to the surface. But please, stop quoting from bad science sites ...
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