by Judith Curry
Six months after the thread Slaying a Greenhouse Dragon, discussion still continues with well over 2000 comments.
Since comments are becoming unwieldy on the other thread, here is a new thread for technical discussion only.
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To start things off, I have recently posted a description of the atmospheric greenhouse effect at http://blog.timesunion.com/weather/understanding-global-warming-how-to-build-a-greenhouse-effect/1196/
It is not very technical, so I think it can serve as a good starting point for where people disagree..
You don’t mention Ozone which absorbs UV (which has high energy per photon).
Is the amount of Ozone in the atmosphere constant? If not, would that not change the amount of energy absorbed by the atmosphere?
I can take questions on the comments there as well*
Ozone matters of course, but it is pretty small for the energy balance of the planet. Humans care more about for skin problems…
How small?
There is two effects…UV absorption in the atmosphere and the greenhouse effect. In the modern day, the decline of ozone actually had a slight cooling effect owing the longwave effect.
On the greenhouse side, Schmidt et al 2010 calculated that all other gases aside from CO2, water vapor (and clouds) contribute only ~5% to the greenhouse effect. Further, only ~1% of the suns energy is emitted at UV wavelength between 200-300 nm. It is very small for the energy budget but there have been some indirect Uv-climate links proposed, like strat-trop dynamics, etc which can impact climate (see Gray et al 2010 for a review). The UV flux is also much higher in the distant past.
O2 forms O3 in order to conserve energy, in the presence of high electrostatic fields, or UV light it is just much more efficient for O2 to form Ozone as the magnetic reluctance of O3 is three orders of magnitude lower than for O2 at most temperatures. Response time for the effective change is in micro seconds when associated with lightning strikes, then the return to O2 is determined by residual levels of electromagnetic energy, with the decay rate slightly enhanced by the presence of N2O and possibly CFC’s. There is also a shift in response and so resultant concentrations for temperatures below -60C, [don’t have my Physics handbook to look up the numbers here with me at the moment].
With regard to the presentation of the Ozone hole over the Southern pole it will be found that size correlates to strength of UV component of sunlight, time of year due to solar angle, strength of the Earths geomagnetic field in the area, and the circulation patterns in the SH oceans and atmosphere.
Movements in the shape of the hole can be shown to be affected by auroral displays due to shifts in solar activity resulting in solar wind speed and density, and the lunar declinational tides in both the ocean and atmosphere [cite needed here sorry].
The occurrence of the hole and size should be predictable due to the monitoring of the above, as it is the “climate change” effects that drive what you do not understand yet about the importance of the interactions of geomagnetic fields, solar wind and the ionosphere, processes of modulating energy into the weather, not just the radiative balance changes that are the result of these unstudied (by you any way) drivers.
HINT: this is an area of next potential breakthrough in understanding weather and climate enough to be able to predict it.
Just in case you want your name remembered in a good light.
Are you saying Gavin says water vapour only contributes to “only ~5% to the greenhouse effect”? you better cite that one!!
No, I said everything else except CO2, water vapor, or clouds. That would include ozone, methane, N2O, etc
That maybe what you meant, but you said “water vapor (and clouds)”.
Be more careful. I don’t know if you are consciously or sub-consciously always downplaying the role of water vapour.
I just blogged on this, actually:
http://theidiottracker.blogspot.com/2011/08/ozone-recovering-will-accelerate-global.html
Money quote from the paper: The global and annual mean enhancement of surface warming is about 0.16 K for 2001–2050, with maximum enhancement in the winter Arctic.
If there is more Ozone, there will be more OH. And OH is the primary oxidant of NOx and CH4 and CO.
If that results in less NOx and CH4 (which are way more powerful GHG’s) shouldn’t warming go down?
Without specific numbers, stratospheric ozone shouldn’t affect tropospheric methane except over the very long term due to the slow rate of stratosphere/troposphere mixing. Or so I’ve heard….
NOx – not a hugely important GHG. N2O – much more so. Ozone will oxidize N2O. In fact in the absence of CFCs there was a study suggesting anthro N2O will become a leading ozone depleter. Damn, can’t win.
Gotta make a comment somewhere on here – we need to get some numbers going on this thread.
http://earthobservatory.nasa.gov/Features/ChemistrySunlight/chemistry_sunlight3a.php
And here is how Methane helps form Ozone … described as simple compared to other VOC’s …
http://earthobservatory.nasa.gov/Features/ChemistrySunlight/chemistry_sunlight3a.php
Oops. this should be the first URL”
http://earthobservatory.nasa.gov/Features/ChemistrySunlight/chemistry_sunlight3a.php
Since >70 percent of the surface is liquid water, please explain how the green house effect works there since DWLWR cannot heat water?
Judith Lean (2008) commented that ‘ongoing studies are beginning to decipher the empirical Sun-climate connections as a combination of responses to direct solar heating of the surface and lower atmosphere, and indirect heating via solar UV irradiance impacts on the ozone layer and middle atmospheric, with subsequent communication to the surface and climate. The associated physical pathways appear to involve the modulation of existing dynamical and circulation atmosphere-ocean couplings, including the ENSO and the Quasi-Biennial Oscillation. Comparisons of the empirical results with model simulations suggest that models are deficient in accounting for these pathways.’
There is this form Lockwood et al 2010 – http://iopscience.iop.org/1748-9326/5/3/034008/fulltext
My theory is that higher SLP (negative Soutrhern Annular Mode) in the polar region results in storm tracks pushing further into lower latitudes. More cold Southern Ocean surface water accumulates off the South American coast. Here it dilutes the warm surface layer allowing more upwelling of turbulent subsurface currents. The cold water upwelling in the Humboldt Current drifts westward across the Pacific. As the cool water moves westward, ocean and atmosphere coupling reinforce Walker circulation strengthening tradewinds and the evolving La Niña pattern.
ENSO is a complex and dynamic sub-system of the Earth’s climate system. Our ‘examples lead to an inevitable conclusion: since the climate system is complex, occasionally chaotic, dominated by abrupt changes an driven by competing feedbacks with largely unknown thresholds, climate prediction is difficult, if not impracticable.’ (Rial et al 2004)
It is fairly obvious that most recent warming occurred in the 1976/77 and 1997/98 ENSO ‘dragon-kings’ – defined as extreme events ‘associated with a neighborhood of what can be called equivalently a phase transition, a bifurcation, (or) a catastrophe (in the sense of Rene Thom)’. (Sornette 2005). Most of the rest seems to involve Pacific Decadal Variation (PDV) SST changes and associated cloud feedbacks (eg Clements et al 2009, Burgmann et al 2008, Zhu et al 2007, Palle et al 2007, Trenberth et al 2010, Dessler 2010 and Spencer and Braswell 20121, McLean et al 2010). Most of the rest occurred as a result of SST changes and cloud feedbacks in the Pacific Decadal Variation.
Most Arctic temperature and ice changes were the result of multi-decadal variability (80 year odd variability) in the Northern Annular Mode – which seems to follow solar UV/stratospheric ozone interactions. There appears to be very little change in the Arctic
‘To obtain knowledge on Arctic sea ice extent in a longer time perspective, Polyakov et al. (2003) analysed the Russian historical records of Arctic sea ice extent and thickness extend back to the beginning of the twentieth century. Occasional ship observations of summer ice edge started in the first decade of the 1900s when the first Russian hydrographic surveys and commercial shipping routes along the Siberian coast began. Starting in 1929, when the Soviet Polar Aircraft Fleet was created, aircraft-based observations began, which improved the quality of the data substantially. However, systematic aircraft and ship observations of sea ice from the Kara Sea to the Chukchi Sea only began in 1932, when the Northern Sea Route was opened by the ship Sibiryakov. There were information gaps 1942-1945 because of World War II. The missing data were reconstructed using statistical (regressionlike) models relating atmospheric processes to ice extent. Aircraft ice-edge observations continued until 1979, when the satellite era began, but until recently a combination of satellite and aircraft summer ice-edge observations was used. Since 1990 all ice-extent observations have been satellite based.
Based on these observational data, Polyakov et al. (2003) concluded that the “examination of records of fast ice thickness and ice extent from four Arctic marginal seas (Kara, Laptev, East Siberian, and Chukchi) indicates that long-term trends are small and generally statistically insignificant, while trends for shorter records are not indicative of the long-term tendencies due to strong low-frequency variability in these time series, which places a strong limitation on our ability to resolve long-term trends”. “Correlation analysis shows that dynamical forcing (wind or surface currents) is at least of the same order of importance as thermodynamical forcing for the ice extent variability in the Laptev, East Siberian, and Chukchi Seas”.’ Prof Ole Humlum – http://www.climate4you.com/
Indeed the variability of Arctic temperature – with negligible 20th century increase – suggests that sulphates are a minor factor in decadal variability (Chylek 2009).
Mochizuki et al (2010) use SST initialised models to suggest that there will be a halt in temperature increase for a decade. Swanson et al (2009) suggest that the new trajectory for surface temperature since the climate shift in 1998 – may persist for decades.
Many scientists reject the simple narrative of a stable climate forced by carbon dioxide. The real problem is that carbon dioxide is one of those pesky threshold things.
‘Recent scientific evidence shows that major and widespread climate changes have occurred with startling speed. For example, roughly half the north Atlantic warming since the last ice age was achieved in only a decade, and it was accompanied by significant climatic changes across most of the globe. Similar events, including local warmings as large as 16°C, occurred repeatedly during the slide into and climb out of the last ice age. Human civilizations arose after those extreme, global ice-age climate jumps. Severe droughts and other regional climate events during the current warm period have shown similar tendencies of abrupt onset and great persistence, often with adverse effects on societies.
Abrupt climate changes were especially common when the climate system was being forced to change most rapidly. Thus, greenhouse warming and other human alterations of the earth system may increase the possibility of large, abrupt, and unwelcome regional or global climatic events. The abrupt changes of the past are not fully explained yet, and climate models typically underestimate the size, speed, and extent of those changes. Hence, future abrupt changes cannot be predicted with confidence, and climate surprises are to be expected.
The new paradigm of an abruptly changing climatic system has been well established by research over the last decade, but this new thinking is little known and scarcely appreciated in the wider community of natural and social scientists and policy-makers.’ Judith Lean (2008) commented that ‘ongoing studies are beginning to decipher the empirical Sun-climate connections as a combination of responses to direct solar heating of the surface and lower atmosphere, and indirect heating via solar UV irradiance impacts on the ozone layer and middle atmospheric, with subsequent communication to the surface and climate. The associated physical pathways appear to involve the modulation of existing dynamical and circulation atmosphere-ocean couplings, including the ENSO and the Quasi-Biennial Oscillation. Comparisons of the empirical results with model simulations suggest that models are deficient in accounting for these pathways.’
There is this form Lockwood et al 2010 – http://iopscience.iop.org/1748-9326/5/3/034008/fulltext
My theory is that higher SLP (negative Soutrhern Annular Mode) in the polar region results in storm tracks pushing further into lower latitudes. More cold Southern Ocean surface water accumulates off the South American coast. Here it dilutes the warm surface layer allowing more upwelling of turbulent subsurface currents. The cold water upwelling in the Humboldt Current drifts westward across the Pacific. As the cool water moves westward, ocean and atmosphere coupling reinforce Walker circulation strengthening tradewinds and the evolving La Niña pattern.
ENSO is a complex and dynamic sub-system of the Earth’s climate system. Our ‘examples lead to an inevitable conclusion: since the climate system is complex, occasionally chaotic, dominated by abrupt changes an driven by competing feedbacks with largely unknown thresholds, climate prediction is difficult, if not impracticable.’ (Rial et al 2004)
It is fairly obvious that most recent warming occurred in the 1976/77 and 1997/98 ENSO ‘dragon-kings’ – defined as extreme events ‘associated with a neighborhood of what can be called equivalently a phase transition, a bifurcation, (or) a catastrophe (in the sense of Rene Thom)’. (Sornette 2005). Most of the rest seems to involve Pacific Decadal Variation (PDV) SST changes and associated cloud feedbacks (eg Clements et al 2009, Burgmann et al 2008, Zhu et al 2007, Palle et al 2007, Trenberth et al 2010, Dessler 2010 and Spencer and Braswell 20121, McLean et al 2010). Most of the rest occurred as a result of SST changes and cloud feedbacks in the Pacific Decadal Variation.
Most Arctic temperature and ice changes were the result of multi-decadal variability (80 year odd variability) in the Northern Annular Mode – which seems to follow solar UV/stratospheric ozone interactions. There appears to be very little change in the Arctic
‘To obtain knowledge on Arctic sea ice extent in a longer time perspective, Polyakov et al. (2003) analysed the Russian historical records of Arctic sea ice extent and thickness extend back to the beginning of the twentieth century. Occasional ship observations of summer ice edge started in the first decade of the 1900s when the first Russian hydrographic surveys and commercial shipping routes along the Siberian coast began. Starting in 1929, when the Soviet Polar Aircraft Fleet was created, aircraft-based observations began, which improved the quality of the data substantially. However, systematic aircraft and ship observations of sea ice from the Kara Sea to the Chukchi Sea only began in 1932, when the Northern Sea Route was opened by the ship Sibiryakov. There were information gaps 1942-1945 because of World War II. The missing data were reconstructed using statistical (regressionlike) models relating atmospheric processes to ice extent. Aircraft ice-edge observations continued until 1979, when the satellite era began, but until recently a combination of satellite and aircraft summer ice-edge observations was used. Since 1990 all ice-extent observations have been satellite based.
Based on these observational data, Polyakov et al. (2003) concluded that the “examination of records of fast ice thickness and ice extent from four Arctic marginal seas (Kara, Laptev, East Siberian, and Chukchi) indicates that long-term trends are small and generally statistically insignificant, while trends for shorter records are not indicative of the long-term tendencies due to strong low-frequency variability in these time series, which places a strong limitation on our ability to resolve long-term trends”. “Correlation analysis shows that dynamical forcing (wind or surface currents) is at least of the same order of importance as thermodynamical forcing for the ice extent variability in the Laptev, East Siberian, and Chukchi Seas”.’ Prof Ole Humlum – http://www.climate4you.com/
Indeed the variability of Arctic temperature – with negligible 20th century increase – suggests that sulphates are a minor factor in decadal variability (Chylek 2009).
Mochizuki et al (2010) use SST initialised models to suggest that there will be a halt in temperature increase for a decade. Swanson et al (2009) suggest that the new trajectory for surface temperature since the climate shift in 1998 – may persist for decades.
Many scientists reject the simple narrative of a stable climate forced by anthropogenic greenhouse gases.
‘Recent scientific evidence shows that major and widespread climate changes have occurred with startling speed. For example, roughly half the north Atlantic warming since the last ice age was achieved in only a decade, and it was accompanied by significant climatic changes across most of the globe. Similar events, including local warmings as large as 16°C, occurred repeatedly during the slide into and climb out of the last ice age. Human civilizations arose after those extreme, global ice-age climate jumps. Severe droughts and other regional climate events during the current warm period have shown similar tendencies of abrupt onset and great persistence, often with adverse effects on societies.
Abrupt climate changes were especially common when the climate system was being forced to change most rapidly. Thus, greenhouse warming and other human alterations of the earth system may increase the possibility of large, abrupt, and unwelcome regional or global climatic events. The abrupt changes of the past are not fully explained yet, and climate models typically underestimate the size, speed, and extent of those changes. Hence, future abrupt changes cannot be predicted with confidence, and climate surprises are to be expected.
The new paradigm of an abruptly changing climatic system has been well established by research over the last decade, but this new thinking is little known and scarcely appreciated in the wider community of natural and social scientists and policy-makers.’ http://www.nap.edu/openbook.php?record_id=10136&page=1
Apologies for another long post – but Chris is a particularly clueless individual.
Chief
“Apologies for another long post – but Chris is a particularly clueless individual.”
I have lot of time for your ideas and comments but that was uncalled for. Personally, I want to read Chris Colose’s comments even if I don’t agree with all his views on CAGW. Your remarks give the appearence of someone trying to discourage him from contributing. Not in the spirit of Judith’s blog.
I did email Judith to remove the double paste – and moderated that comment. The sentiment remains largely intact however – unless he is willing to look more broadly at what these other areas of science are actually saying it is a pointless exercise to engage in a discourse with those who have little capacity for incorporating conflicting information into their worldview. .
To call it a consensus is a nonsense of monumental proportions. It is utterly incomprehensible as the world cools into the depths of the current decadal variation – that is so widely recognised that to ignore it or to argue against it seems the depth of folly.
There are simple things that fail to register for some incomprehensible reason – the ENSO warming in 1976/77 and 1997/98 for instance. cloud feedbacks from the Pacific decadal variability, no trend in Arctic temperature or sea ice over a hundred years, negligible hydrological variability over a hundred years. Records of at least a hundred years are needed for meaningful analysis.
They have huge gaps in their world views – and think they’re clever, the heirs of scientific enlightenment, an intelligentsia leading the ignorant masses to new world order.
So unless you have something substantive to add to or to dispute the many peer reviewed studies or the report from the National Academy of Sciences discussed above – I suggest you take a hike.
Chief, I have no problem with the length or content of your post only your final remarks about Colose.
I’m here to try and learn so if you don’t mind I’ll stick around and continue to read – even your posts despite your rudeness. I agree that it would be interesting if the consensus addressed your ideas. Good day to you, Sir.
Chief
Thanks for a very informative post (despite double cut/paste).
I have no problem with your comment about Chris. My observation (here and elsewhere) is that he is one of the experts described by Nassim Taleb, who knows very well what he knows, but does not know what he does not know.
Max
Readers can judge for themselves what others do and do not know…my posts are freely available on the web, such as when you click on my name. The comments there are always open too. Of course, writing a thesis paper that doesn’t address a single word I’ve said won’t really impress me. It will only impress the same conspiracy theorists judging me…
Chris
If you have the time, please could you provide some detailed comment on the Chief’s ideas in his long post upthread? I would be interested to read your views on his thoughts about ENSO, PDV and chaotic climate bifurcation events. They seem quite compelling to me. Thanks.
Thanks, Chris, but I think a better place to start would be with the 1967 Bilderberg decision that Earth’s heat source is homogeneous and in hydrostatic equilibrium [1].
http://adsabs.harvard.edu/full/1968SoPh….3….5G
It is not homogeneous or in hydrostatic equilibrium [2].
http://dl.dropbox.com/u/10640850/20110722_Climategate_Roots.pdf
Those false assumptions are at the base of the climate controversy and the illusion that hydrogen-fusion will meet our future energy needs.
With kind regards,
Oliver K. Manuel
Former NASA Principal
Investigator for Apollo
Dear Chris:
This is a new explanation of the greenhouse gas effect theory, totally different than what we learned all these years, based on which computer models are built. We learned that greenhouse gases trap heat. Do they still trap heat in your theory? Do the same mathematics apply to your new theory or do you have new mathematics? If so where is your mathematics?
It isn’t a new theory. Read Houghton’s Physics of Atmospheres, Pierrehumbert’s Planetary Climate book, or many more…
Dear Chris:
There are no heat trapping gases, and the related science is incorrect; people are not buying this science. It is time for a change, and I was hoping that you are bringing something new and different.
Thanks for your opinion
Thank you for the exchange.
Gases cannot trap heat!
Indeed. It is unbelievable that Chris is still trying to propagate the myth that Co2 ‘traps’ heat, and using false analogies of river dams and house insulation.
The SI unit for heat is joules.
The amount of energy in one photon of infared radiation can also be measured in joules, as Planck’s constant is often expressed as 6.6 * 10 -34 joules*seconds
A molecule of carbon dioxide can absorb certain photons of infared radiation.
Now, what do you mean by the myth that CO2 traps heat?
And how many years is the energy from the IR “trapped” in that CO2 molecule bob? OK, how many days. Alright, exactly what point is there in talking about trapping when the energy is lost in less than one cycle? In fact, in an infinitesimal part of that diurnal cycle??
By the way, does that “trap” have iron jaws or is it like my trap that keeps flapping? (you know, trap as in shut your trap)
If you have a desert region with little or no water vapor at say 100F and a jungle region at 100F that is very humid, when the sun goes down deserts can bleed off a huge amount of that heat while jungles rarely change temperature.
“A single daily variation of -0.5°C to 37.5°C has been recorded.” … in the Sahara.
Why is it CO2 rarely traps heat without the presence of water vapor?
look at the transmission windows.
Not an answer.
I don’t think they like to give detailed answers anymore since the physics have been discussed to death. The transmission WINDOWS are THE first important step to understanding what CO2 can and cannot do. It is funny that something so simple is made so complicated by people who’s job is to simplify the complicated.
One of the most confusing “simplifications” is the concept of “back radiation” or “downwelling long wave radiation”. Other than a trivial mathterbation exercise on an atomic level, colder gas does not warm warmer gas, liquid or solids. The temperature of the sky in the longwave radiation spectrum regulates the rate of heat loss from the surface, period. Most of the regulation is due to water vapor because its absorption spectrum is broader that the other non-diatomic gases. With an increase in altitude, or in a dryer environment, where water vapor concentration reduces, the role of the other non-diatomic gases become more significant. That is where things start getting interesting.
With dryer air, the transmission window becomes much larger. CO2 has a rather small absorption/transmission window for purely radiative heat transfer. With fewer molecules in lower air pressures at altitude, there are fewer collisions so the radiative heat transfer of non-diatomic molecules becomes more significant. In a desert area CO2 transfers most of its energy by collisions with diatomic gases. Those gases transfer heat the old fashion way, so more of the heat they pick up from collisions is released as longwave outside of the wavelength of CO2.
It is in the tropopause area that things really get interesting. At the Tropopause there is a transmission “picture window”. Non-diatomic molecules can release longwave radiation in any direction to space other than down. Down, CO2, CH4 and traces of water vapor that actually release packets of longwave in their respective spectrum, transfer heat to other molecules that can release more of their heat energy to space up than they can down thanks to the picture window. Only the non-diatomic molecules between that point and space can reduce the rate of heat flow to space. This is where the enhanced “greenhouse effect” begins. So it is simple to calculate how much warming should take place due to the increase in non-diatomic molecules caused by man, not! The Tropopause varies in altitude and temperature. Planetary waves penetrate the tropopause, Convective storm tops penetrate the tropopause. It is a lava lamp of thermodynamic turmoil. So when Mosher tells you to look at the transmission windows, ask him where?
Is this where the CO2 signature warming in the troposphere can’t be found?
If you are talking about the so-called “hot spot” in the tropical troposphere, it is not a signature of warming due to CO2 specifically. It is in fact expected for warming due to any cause. It arise simply because the temperature profile in the tropics is expected to approximately follow what is called the “moist adiabatic lapse rate” ( http://en.wikipedia.org/wiki/Lapse_rate ).
In fact, this “tropical tropospheric amplification” (a more technical name for the “hotspot”) is seen very clearly for fluctuations of temperature on the timescales of a few months to a few years, such as those that occur due to ENSO (El Nino and La Nina). Whether or not it occurs for the long-term warming trend is more controversial because both the satellite and radiosonde (weather balloon) data used to investigate that are easily contaminated by artifacts that can affect these long-term trends.
But again, this does not provide evidence one way or the other in regards to the mechanism causing the warming. The fundamental reason this is so, by the way, is because the troposphere is mixed well by convection and so the temperature profile is determined more by that than by where any additional radiative forcing is absorbed.
What is true, however, is that different warming mechanisms make different predictions for the stratosphere. For example, an increase in solar forcing is predicted to cause the stratospheric temps to increase along with the tropospheric temps, whereas an increase in greenhouse gases is predicted to cause the stratospheric temps to decrease while the troposphere warms. The data shows the stratospheric temps have decreased as the troposphere warms and, although part of that can be accounted for by the reduction in stratospheric ozone, the analyses are generally that the increase in greenhouse gases is needed to explain some of it too.
Joel Shore,
“If you are talking about the so-called “hot spot” in the tropical troposphere, it is not a signature of warming due to CO2 specifically. It is in fact expected for warming due to any cause.”
This is a revisionist version of history. If you go to Figure 9.1 of AR4 WG1, you will see that the “hotspot” is described as a “fingerprint” of AGW and that its evolution is shown as distinctly different for solar heating and AGW heating.
The argument that you are presenting only appeared (first in an RC article IIRC) AFTER it was shown that observational data did not support the differential heating ratios expected by AGW theory.
I have always thought in any event that this defence leads to a very weak position for those supporting a high climate sensitivity.
First postulate: the tropical hotspot is a unique fingerprint of AGW
Observation: no evident tropical hotspot
Second postulate: the tropical hotspot is a feature of any warming, since it is driven by temperature-dependent feedbacks, leading to…
Conclusion: …therefore the absence of a tropical hotspot does not disprove AGW.
Whoops, even if the revisionist version is accepted, a big problem is that this suggests a significant overestimate in the models of WV postive feedback, or underestimate of tropical cloud negative feedback. Hence…
Third postulate: there really is a tropical hotspot; we just can’t find it in the data.
Stretch the error margins on the observations and the model predictions until an overlap becomes evident at the margins. There, fixed it.
Paul_k,
Sorry, not even close, and certainly no cigar. The physics of the moist adiabat has been well known before people starting getting up and arms about the “missing hotspot” and certainly well before RealClimate or AR4 existed. The hotspot emerges due to the non-linearity of the Clausius-Clapeyron equation, and the effect of moist convection which tends to adjust the static stability of the atmosphere toward the moist adiabatic lapse rate…this can be derived by hand, so I see no reason people dispute this.
If the people who made up that only GHG’s could do this could show even one shread of evidence or explain why all attribution studies to date think otherwise, they would have, but it has been a repeated fallacy on the blogosphere only to score points among the untrained. In fact, the NASA GISS model run can be forced with 1.02x solar irradiance which shows this response
http://data.giss.nasa.gov/efficacy/Rc_pj.3.06.html
Figure 9.1 in the AR4 has also been misinterpreted in the process. The reason a predominant solar signal does not show up here is not because it can’t potentially amplify the upper tropical atmosphere, but because the sun has not changed much over the last few decades! The simulations here are forced with observed solar changes…simply read the descriptions and references!
Paul K
Fourth postulate: Thermometers cannot find the missing hot spot. Let’s try wind shear…
Joel,
“it is not a signature of warming due to CO2 specifically. It is in fact expected for warming due to any cause.”
So, not even the sun has been warming us?? Figures.
LOL, you can see the other answers. If I remember correctly, warming due to CO2 should be most noticeable at the polar regions and the upper troposphere. Since CO2 is a well mixed gas, if CO2 has a signature it would be detectable warming in these areas that is uniform after filtering out the weather noise. There is the rub. If you compare the warming in these areas, CO2 appears to not be performing as advertised.
To perform as advertised, CO2 needs significant water vapor feedback to enhance its enhanced effect. Since the impact of CO2 is most significant in regions with little water vapor, things get complicated. I have to go fishing, but I will ponder the state of the climate change the whole time I am sure, so maybe I will have more tantalizing theories why this afternoon.
Chris Colose,
I am genuinely puzzled by your response. Specifically, I am unsure of your intent.
You imply in your first paragraph that somehow there is a dispute about how to calculate a MALR or abstract SVP from Clausius-Capeyron. I know of no such dispute. Having set up the strawman, you then conflate this with the expression “the hotspot emerges due to…”, and “I see no reason why people dispute this”.
The dispute arises because the hotspot, er, doesn’t emerge in observations, and this, in turn, suggests that there are some basic errors in the GCMs and/or in the inputs. Calculation of moisture content above the boundary layer seems to be an obvious candidate, but there are other possibilities, including dynamic or conceptual errors in modeling sensible heat movement (grid truncation errors and/or instability suppression), erroneous calculation of latent heat transfer and/or errors in the assumed forcings. Your ability to calculate a MALR for a given suite of assumptions by no means alters the fact that there is a divergence in GCM prediction against observed heating ratios with altitude.
In terms of history, in light of your comment, I went back and re-read Ch 9 of WG1 AR4 to see if my memory was playing tricks on me, but no, there it is (still) written (Section 9.2.2.1):
“The ability to distinguish between climate responses to
different external forcing factors in observations depends
on the extent to which those responses are distinct (see, e.g.,
Section 9.4.1.4 and Appendix 9.A). Figure 9.1 illustrates the
zonal average temperature response in the PCM model (see
Table 8.1 for model details) to several different forcing agents
over the last 100 years, while Figure 9.2 illustrates the zonal
average temperature response in the Commonwealth Scientifi c
and Industrial Research Organisation (CSIRO) atmospheric
model (when coupled to a simple mixed layer ocean model) to
fossil fuel black carbon and organic matter, and to the combined
effect of these forcings together with biomass burning aerosols
(Penner et al., 2007). These figures indicate that the modelled
vertical and zonal average signature of the temperature response
should depend on the forcings. The major features shown in
Figure 9.1 are robust to using different climate models. “
AND
“The simulated responses to natural forcing are distinct from
those due to the anthropogenic forcings described above. Solar
forcing results in a general warming of the atmosphere (Figure
9.1a) with a pattern of surface warming that is similar to that
expected from greenhouse gas warming, but in contrast to the
response to greenhouse warming, the simulated solar-forced
warming extends throughout the atmosphere (see, e.g., Cubasch
et al., 1997).”
You wrote: “If the people who made up that only GHG’s could do this…”. You can argue all you like that the AR4 authors should not have written what they wrote, but it is revisionist to suggest that they never wrote it.
It surprises me not at all that the GCMs can be forced to yield a tropical hotspot by increasing TSI by 2%. However, as I indicated in my first post, this does not make the problem go away or even ameliorate it. The true science problem, if we can get away from rewriting history, is that for the actual forcings used in the attribution studies, the models all produce a tropical hotspot which is not supported by observations .
Dallas and Paul_k are still confused. I see no reason this is difficult to comprehend. My post above never implied there was disagreement about how to derive a moist adiabatic lapse rate. But the moist adiabatic adjustment lies at the heart of why we worry about a hotspot at all, and why it clearly is not a unique signature of GHGs. So there was no strawman. If people studied the topic instead of simply parroting the “models are wrong!!!” line they pick up from WUWT and similar sources they would see this.
The IPCC AR4 authors did not make a mistake. Paul is simply misunderstanding them. The reason there is not a strong solar signal in obs is because the sun has not really changed. In contrast, we see evidence of stratospheric cooling, which we do expect exclusively from GHGs. The “hotspot” is a more diffuclt issue to separate models and obs, and it is probably going to take several more years of data to convince most experts there is in fact a substantial disagreement. The disagreement also depends strongly on the timescale. See Steve Sherwood’s article about this, as well as the implications
http://theconversation.edu.au/satellite-stories-what-do-new-findings-on-tropospheric-warming-mean-for-climate-change-2277
The reason skeptics like this topic so much is because there is apparently a lot of wiggle room for them to make stuff up. In fact, the implications of a missing hot spot may be large for some communities like hurricane science, but it not obvious that it would have much to do with climate sensitivity or certainly attribution.
Paul_K says:
Wrong. It is in fact seen very clearly in the data for fluctuations in temperature on the scale of months to a few years, which are over time periods where artifacts in the data that can affect long term trends are not an issue. So, the fact is that where there is debate about its appearance is for the multidecadal trends where the data is least reliable, there are known problems with the data, and different analyses of the same data get very different results.
Fine…But, good luck coming up with explanations that tell us why the GCMs get it right for timescales of months to a few years and only fail for the multidecadal trend! I am not saying it is impossible to make such a case, but I certainly have not heard one made yet.
As for your quote from AR4:
(1) You are reading a heck of a lot into what they wrote to get from what they say to what you claim they are saying. As Chris says, those of us who have read enough to understand basic atmospheric dynamics know that your insinuation about re-writing history is nonsense. Heck, even Richard Lindzen explains the hot spot as arising from the MALR and that it basically has to be there by some very basic principles. [Of course, what he then tries to argue is that it is the surface data in the tropics that is overstating warming.]
(2) A lot of the issue from AR4 Fig. 9.1 comes from the fact that most people don’t know how to read a contour plot like that. They look at the dramatic “hot spot” there for CO2 and then they look at solar and it looks like there is hardly anything! But, then try looking at the contour intervals: You will find that because of the contour spacing, the amplification ratio between the surface and higher altitudes for the CO2 can be narrowed down to something like 2-3 (I forget the exact numbers) but the one for solar is compatible with anything between 1 and infinity! Needless to say, that doesn’t tell you much, which is why it is good to have a plot like Chris supplied where the solar forcing was raised up enough to see the actual structure of the warming.
Dallas and Paul – The “hotspot” issue was the topic of an entire thread a few months ago, which you might want to review to avoid repeating the material here. Chris is correct in what he says on this point. AR4 and the models don’t distinguish between solar and GHG forcings in estimating changes in the mid to upper troposphere as a function of surface warming, and so “tropospheric amplification” (misnamed a “hotspot” although it refers to the coldest parts of the troposphere) is not a signature of CO2-mediated warming. The figures and text in AR4, if interpreted correctly, support this principle.
The amplification signal has been found in short term trends but not in longer ones, and the causes are still unclear – probably they reflect both technological and modeling inaccuracies. However, the basic principles are intact, and so the discrepancy, which has diminished as measurements have improved, relates to quantitation.
Some of this may reflect overestimates of upper tropospheric moisture addition, but that problem is limited by reasonably good observational data indicating that upper troposphere humidity is increasing, and so perhaps the issue relates to the extent to which RH has kept pace with warming, which is a matter of some uncertainty.
On the other hand, the amplification signal comes primarily from latent heat release as water vapor condenses at higher altitudes. This phenomenon is the so-called “lapse rate feedback” and its salient feature is that it is a negative feedback rather than a positive one. To the extent the signal is missing, this implies a smaller negative feedback than estimated by the models. Whether this conclusion is accurate is speculative, but is supported by recent comparisons of two versions of the same model (described in the previous thread). One version (the older one if I recall) estimated a greater amplification than the other version. That version was characterized by a lower climate sensitivity than the version with diminished amplification, which exhibited a higher climate sensitivity value.
From the previous thread on this topic, the two models I referred to are CCSM4 and CCSM3.
Without GHGs the surface cooling rate would be about 10 degrees per hour, so your number shows some effect even over a desert.
I think the figure in Chris Colose’s article hints at the lapse rate explanation for the GHE. I also noticed a form of this explanation from Lubos Motl here:
http://motls.blogspot.com/2008/01/why-is-greenhouse-effect-logarithmic.html
And also in F.W. Taylor’s textbook on Climate Physics (7.6.2, page 112 in my copy). The very simple model of the tropospheric temperature curve being lifted rigidly upwards by increased C02 leads to an estimate for the 2xC02 temperature rise of 18K from both Taylor and Motl, with about 6K of that rise expected to date. Taylor explains the discrepancy from observation by a combination of aerosols, ocean storage and stratospheric cooling. I don’t really understand Motl’s explanation. I’m no expert in these issues, but I’d guess that the assumption of the rigid lifting is probably unjustified as well.
In any case, the calculation is so transparent that greenhouse skeptics should be able to convincingly demolish the assumptions behind it, and thereby explain how it comes to be wrong by a factor of 6 or more. I don’t understand enough of the details to see how to do this myself, but can anyone else here offer up the explanation?
Chris, Sorry but that is the same old song and dance and painfully wrong.
Describing the Average Temp of the Earth’s Surface without an atmosphere is nonsensical. Daytime temps would reach into the hundreds and nighttime temps into the negative hundreds. Okay so the average is below zero. That does not explain a GreenHouse Effect (GHE) within an atmosphere that’s volume is not fixed and has a constant supply of gravity at one end of it.
Without an Atmosphere there would be no Ocean so ice would not be a consideration. In addition N2 and O2 do not have to interact with IR the Earth emits. N2 and O2 are not without temperature. In fact at the surface a cubic meter of dry air at 15C contains about 362,000 Joules, of that cubic meter of air about .77 grams (of ~1300 g) is CO2 and the energy contained within the CO2 is about 187 Joules. This poses all sorts of exceptions to the Laws of Nature for the misnomer GHE and requires exotic explanations for the additions and subtractions of energy within the various thermo-systems within the Earth’s overall thermo-system.
You can think of a thermo-system as a homogeneous volume of space that is similar in both Energy Pressure (aka Temp) and Energy Capacity (aka Specific Heat). There are trillions of trillions of them within the Earth’s Thermo-system.
You DO NOT get a GreenHouse Effect without a GreenHouse Cause. A GreenHouse Cause comes from two phenomena. 1st the volume of a GreenHouse is Fixed (not extremely elastic as our atmosphere is). This prevents the air inside from Expanding and therefore reducing pressure as Temperature Increases and the added volume reduces the Temp.
2nd, Even without a physical barrier to prevent cooler more dense air from being dragged beneath what would have ben air that expanded (save having a GREENHOUSE to prevent it), if the density does not decrease then gravity will have no more effect on a cooler gas than the warmer and the Ideal Gas Laws fail. Convection fails and the only means to cool becomes Radiation. This simply is not the case in reality.
Convection requires two things; Gravity and varying densities of liquids. Since our atmosphere heats the surface and then the surface the air just above it, Convective Currents develop for a continuous cycle. Else the Convection would cease as the air at the surface quit expanding for lack of temperature increase.
The GreenHouse Effect is the ‘Effect of Preventing Convection’ which requires a GreenHouse Cause which is fixing the GreenHouse’s Volume and preventing cooler air from being dragged under the now Higher Temp and Higher Pressure (same density) air within the GreenHouse.
What you are describing is an Emissivity Effect which in no way prevents or inhibits air masses from expanding or the effects of gravity on varying densities of air aka Convection. In fact any increase in Surface temp will result in an increase in the Radiation Cooling Rate and the Convective Cooling Rate. http://wp.me/pB8xR-9Q
Reality with regards to Climate and the Misnomer Atmospheric GHE cannot be done with brevity so I’ll continue in a separate thread which acknowledges another property of the Earth’s atmosphere and varying surface (Oceans, Soil, Rock, and Varying Vegetation) called Enthalpy which not only shows but demands that Energy is not easily “backed up” and combined with an elastic atmosphere of thousands of trillions of tons of matter to absorb any energy that is slightly slowed from its journey back to space prevents this Emissitivity Effect from being observable as Temp Changes save in GCM’s that do not reflect reality.
In the meantime consider the varying altitudes of the Tropopause over latitude, why they vary, and how fixed or elastic the volume of the Earth’s atmosphere is to give you a measure of what a sorry GreenHouse it makes.
It’s a pity you start off by informing us you don’t know the difference between energy and power. Do you know that they are different?
If the atmosphere was 280ppm CO2, and visible light hit the earth and turned into IR and the IR was travelling upwards, how far off the ground would the IR get before it was all absorbed by the CO2 and water vapour?
How far would the IR get if the CO2 was at 380ppm?
Start by reading this:
http://geosci.uchicago.edu/~rtp1/papers/PhysTodayRT2011.pdf
http://www.newport.com/Introduction-to-Solar-Radiation/411919/1033/content.aspx
http://www.pvts.net/pdfs/ndvi/2_2_radspec.PDF
or go read scienceofdoom
Do any of those answer my question?
And what was the answer?
knowing steve mosher, even without following the links, I’m pretty sure it does.
Have you and SOD figured out why 390w/m2 emitted at the surface compared to 240w/m2 received at TOA does NOT show GHE yet?? (snicker)
First, the visible light that hits the earth’s surface doesn’t get turned into IR, the earth’s surface is emitting IR whether or not the sun is shining on it.
Secondly, I know you are hinting at the saturation argument, but that’s wrong, but the answer to the question how far off the ground would the IR get before it was all absorbed by the CO2 and water vapor is that some of it would make it all the way to space, not much, but you did specify all. Absorption being a probability type function.
If the earth is emitting IR all the time, which makes sense, is there a difference between 290ppm and 380ppm?
More IR will be absorbed with 380.
Lets say the first meter of atmosphere with 280ppm absorbs 95% of all the IR. And then the next meter absorbs all the rest.
Would it matter if 380ppm caused all the IR to be absorbed in .7m and then another .7m?
I mean, there are many more meters of atmosphere available in the 280ppm, so why would it make any difference?
Some wavelengths, in particular at the center of the 15 um absorption line will be absorbed within meters. With 380 ppm the distance is reduced by 280/380. At the same time some other wavelengths can penetrate with little loss through the whole atmosphere even with 380 ppm.
The answer cannot be stated in simple terms.
Ok. Now we are getting somewhere. Most IR will be absorbed within a meter or so so that there is no difference between 280 or 380 since it really doesn’t matter if you warm the CO2 at 15 inches or 16 inches.
But you say some of the IR will never be stopped at all.
So … where does that leave us?
No difference between 280 and 380?
Not most IR, only most of a the small part of IR that happens to have that wavelength. That may be a few percent of all IR.
What about the air above 1.4 meters, that air is also emitting longwave infared radiation.
And the air that contains the CO2 that absorbed the IR, which either re-emits radiation or transfers the energy to other atoms and molecules, which then can emit IR.
Sounds like a perpetual motion machine.
Perpetual motion machine?? Only for the grants for more research!!
I believe Pekka has explained to us how when the CO2 and other GHG’s absorb IR they typically lose it through collision. I believe he never made clear whether there was a transfer of energy to the colder particle. For now my assumption is that in the lower atmosphere, at least in the morning through peak temp of the day, the GHG’s transfer a significant amount of the energy to the local parcel which drives convection. This energy then is NOT available for emission until higher up. The rest of the energy gets emitted in all directions with less than half going down.
Gee, it seems the more we learn the less IR is available to be emitted toward the ground. (ready for a learning moment here)
“It is not very technical, so I think it can serve as a good starting point for where people disagree..”
I disagree. It’s so naive that it’s just plain wrong.
Chris, I know that your audience is the ‘average Joe’ on the street, but you do need to explain that; the ‘radiative’ properties of ‘any’ individual gas is unique, ‘all gasses radiate’ at different wavelengths, and ‘GHE’ (greenhouse effect) expires at ~12 kilometres altitude.
What should this tell you? The ‘parameters’ fit H2O for Earth’s GHE and Earth’s surface is cooled by the process of ‘evaporative cooling’ by way of ‘H2O’ (water phase) evaporation.
Otherwise, that was as average a description that I’ve read elsewhere (it’s ‘the norm’).
Best regards, Ray Dart.
huh?
Dear Chris:
The mathematics of the greenhouse gas theory accounts only for the heat trapping effects of trace gases such as methane, ozone, and carbon dioxide and neglects the atmosphere. Does this make sense to you?
In a greenhouse sunlight heats the ground which heats the air inside which is then trapped inside by the glass. In the atmosphere sunlight heats the ground which heats the air which is trapped by gravity. It’s a perfectly analagous situation.
The key is to remember that the fact that glass and CO2 absorb infrared radiation is not really important. Glass absorbing IR plays no role in a greenhouse. CO2 absorbing IR is simply how the ground heats it in the atmosphere (in a greenhouse convection and conduction dominate the heating).
Ryan,
Radiation dominates the heating to more than 100% of the final total. Convection and latent heat transfer control the cooling part that brings the net heating to 100% or what it is.
Radiation dominates the heating to more than 100% of the final total.
Pekka,
What does that mean? Heating to more than 100% of the final total?
Convection and latent heat transfer control the cooling part that brings the net heating to 100% or what it is.
What Convection? Within the GreenHouse?
Doesn’t Radiation and Conduction control the cooling part since Convection is prevented?
The balance of radiative heat transfer, i.e. the sum of solar SW absorbed at the surface and net IR is strongly positive, i.e, would lead to rapidly rising surface temperature unless there would be other mechanisms that transfer heat from surface to the upper atmosphere from where it radiates to space. The other mechanisms are convection and latent heat transfer (evaporation at the surface and condensation in the atmosphere).
The references to more than 100% and the negative contribution that brings the total to 100% were a reaction to the last sentence (in parenthesis) of Ryan’s comment.
This is a MAJOR problem with describing the Emissitivity Increase of the Atmosphere, which includes an Increase in Absorption with an increase in IR absorbing Gases (like CO2) as a GreenHouse Effect.
We don’t describe Gravity as the Magnetic Effect. We don’t describe a GreenHouse (a REAL one) as having a Conduction or Radiation Effect.
Is what is being terribly misnamed the GHE not in fact an Emissitivity and/or Absorption Effect?
You may have a problem, I don’t.
;) And there lies your failure. You have failed time and time again to answer the question “Is the misnomer ‘Greenhouse Effect’ in fact describing an Absorption and/or Emissitivity Effect?” (an increase in Absorption = an equal increase in Emissitivity)
I’m quite confident you refusal to answer lies in that you recognize more and more exotic explanations will be required to keep up this charade if you answer correctly. If you answer incorrectly, the flaws you defend be found out even quicker.
Perhaps it is that you cannot determine the Cause and therefor have a need to falsely describe the Effect? Not a rhetorical question.
If so you will dread and excuse yourself even more vehemently from answering questions about the declining Enthalpy as altitude increases and the Effects that has on the efficient flow of energy away from the Surface which averages thousands of times as much energy per unit volume as the atmosphere.
Radiative “Backups” don’t amount to much when reality is observed.
It also has serious ramifications for Back Radiation and Back Back Radiation and Back Back Back Radiation and so on.
Perhaps you can share the usefulness of a similar False Cause/Effect? Serious. How about Magnetism and Gravity. When is it useful to describe one as the other when you have an understanding of both?
There are some commenters here, whose comments I don’t understand practically at all. When I can’t understand, what they are asking, I can’t answer either. Your comments in this thread belong to those that don’t make any sense to me. Thus I don’t even try to answer.
We are likely to have very different opinions on, where the errors are.
For a given wavelength the absorptivity=emissivity=1-transmissivity (via Kirchoff´s law). And if you don´t like the name greenhouse effect, then run a Find+Replace on every article you come across, and replace ¨greenhouse¨ with ¨fruit loops¨ and follow the same mathematical and physical arguments.
P.S- Please try to be less tedious. The conspiracy tone is old now…
In E&M, we do use the term “electromotive force” to describe something that is not a force…but in fact has units of potential. (Some textbooks have such a strong objection to this that they use the abbreviation EMF exclusively and say that it used to stand for “electromotive force” but doesn’t stand for anything now! However, others just go ahead and use “electromotive force” after noting that it is not a force.)
I think the term “greenhouse effect” is less an abuse of terminology than that. The fact is that in some ways the atmospheric greenhouse effect is analogous to a greenhouse in that both warm by blocking the escape of heat. They are not analogous, however, in the main form of heat transfer that they block. As has been pointed out, arguing about whether the accepted terminology is the best possible terminology is usually not a particularly interesting thing to argue about.
I’ve never seen the term used to describe anything but voltage, or (electrical) potential difference – so much so that EMF and Voltage are synonymous.
For instance, the ‘E’ in Ohm’s Law: I=E/R is the shorthand form of ‘EMF’
Who says convection is prevented by the Greenhouse effect?
A GreenHouse prevents Convection, Correct?
Interesting how the ignorance of how science works is compounded by the ignorance of how language works. I say ignorance, but the total inability to see beyond his own first association verges on concrete thinking — very creepy.
Pekka,
I have a lot of respect for you and your “know-how” of the CO2GW. That’s the reason I have a question for you. What’s the dominant heat transfer mechanism between the surface (water and land) and TOA? Can you give an “official” estimate for the ratio (Rad:Conv:Evap = x:y:z)) in average? The system is the atmosphere between the surface and TOA.
Thanks in advance.
This is a question, where I would say that the answer of Trenberth, Fasullo and Kiehl (2009) should be accepter even by those, who don’t accept the main stream estimate for climate sensitivity or the small net balance of 0.9 W/m^2. The other larger numbers can be accepted even if the net value is not.
Their paper tells the answers at the surface and as the radiative fluxes at the top of atmosphere, but not at the other levels of the atmosphere. There are uncertainties of a few W/m^2 in the following numbers.
The surface is heated by solar SW (161 W/m^2) and downwelling IR radiation (333 W/m^2) and loses energy by IR emission (396 W/m^2 gross or 63 W/m^2 net), by evaporation (80 W/m^2) and convection (17 W/m^2). At the top of the atmosphere the outgoing IR is 239 W/m^2, mostly radiated from various levels of the atmosphere, but including 40 W/m^2 that comes unabsorbed from the surface.
Going up in the troposphere the fluxes change as 78 W/m^2 of solar SW is absorbed at various levels, largely by clouds and aerosols. The large flux of latent heat stops when moisture condensates. IR gets absorbed and re-emitted but its net flux gets gradually larger. The net flux remains at all levels between that at the surface and that at TOA.
Convection fills automatically the imbalance left by latent energy transfer and radiative processes, but I cannot tell, how large it is at various altitudes. What is, however, certain is that it diminishes when the tropopause is approached and the altitude, where it goes to zero is the altitude of tropopause. As the only other form of energy transfer at those altitudes is radiative, this means that IR can carry the whole upwards flux at tropopause and above.
Pekka,
“Convection fills automatically the imbalance left by latent energy transfer and radiative processes…”
So, if there is imbalance left by radiative processes, caused by anthropogenic CO2 emissions (assuming they can cause atmospheric CO2 increase), convection will automatically fill it. Why do we worry then?
Except warm air rises.
I am not sure this is a technical point but is anyone claiming there is no scientific debate here? It seems clear to me that there is.
“Many confused bloggers” debate doesn’t equal scientific debate
ah but is it a “technical” debate?
no comment…
Yeah this is the science debate that uses the tobacco industry, who you know, and trash talker as its proof.
Way to represent!
Chris et al: Confusions come in many forms (this is my field). What is the specific nature of the confusion, or confusions, in this case? In particular, are people using words differently, or incorrectly? This is a common form of talking past. However, in science, as in life, the meaning of words is partially determined by what one believes. So what appears to be a semantic difference may in fact be a scientific difference.
I find it hard to believe that there are no scientific differences in such a protracted and technical debate. If there are such differences it would be useful to isolate them.
For instance, someone could post a link to modeled and measured lapse rate profiles for 280 ppm CO2 and 380 ppm CO2 and maybe 480 PPM CO2. Or whatever. Then we could get toward answering Bruce’s question, and those wishing to dispute would have pictures to criticize.
We need more pictures on this blog, but not oversimplified ones.
I meant to say, lapse rate profiles at various locations (tropics, poles, ocean, land).
Calling Chris Colose….
David,
For lukewarmers (like myself) there is no scientific debate about radiative heat transfer theory, the physics is what it is. For greenhouse dragon slayers, there is a debate. Personally, I don’t see this as being the scientific area of debate for AGW. Many will disagree.
Can you answer this question?
http://judithcurry.com/2011/08/10/greenhouse-dragon-technical-discussion-thread/#comment-97096
See the first link provided by Steven Mosher, it gives the best explanation of the three he provides, particularly the inset paragraph on page 37 called ‘saturation fallacies’. I don’t think I can answer your direct question about how far off the surface it would all absorb (statistically it won’t all absorb). The Beer-Lambert law could be used to figure this.
John, if there is a debate for one side isn’t that sufficient to make it a debate? The fact that you are convinced does not nullify the fact that others are not. On the contrary that is the essence of debate.
But perhaps you are invoking some unspoken threshold of credibility? One the GDS have not attained, or something, so there is no “real” debate or some such. That is, this sounds like a backdoor consensus argument. Are you saying there is only a debate if the right people do it? There is a certain merit to this argument, but the argument has to be spelled out. To me the GDS folks have sufficient knowledge to make a case, if not to win it.
In short, claiming there is no scientific debate when there is so much technical argument seems a very strong claim, requiring very strong evidence. The mere fact that you disagree with the other side is not evidence at all that there is no debate, quite the contrary.
David,
I don’t mean to invoke that all who argue against the greenhouse theory have no credibility as scientists, this is not a good way to debate. However, for this part of the AGW debate, the education I received and the physics and QM I learned, are all consistent with what I understand of the science about the GHE. I am convinced enough that I would not challange it. If others want to duke it out, that’s ok with me, I’m just saying those who accept the current GHE theory, the physics of radiative heat transfer, will be hard swayed to change and so for them there is no debate about it.
I understand where you come from wrt to the debate and I empathize with those who want to challange the GHE thoery as I share common ground with them on other areas of the overall AGW debate.
Finally, I find myself in a bit of an ironic situation (not unusual for science). I will argue all day long that the science of AGW thoery is far from settled. I am not convinced that GW is largely A or even a lot A. For me it is some A to a little A, maybe even neglible A, this is the debate for me and other lukewarmers. So I am convinced the GHE theory is accurate and will accept it on one hand (not much to debate) and on the other I will debate how much of an effect it really has wrt to CO2 being the big driver vs natural variations. The irony is… one of the debating arguments I would use against those convinced GW is largely A, you just used on me about about how GDS’s want to debate the physics of the GHE.
“The mere fact that you disagree with the other side is not evidence at all that there is no debate, quite the contrary.”
:)
Chris Colose says
“These gases helps us breathe, but on their own, they would not change the temperature much.”
Please explain this.
If the atmosphere were all N2 and O2 we could breathe but it would be a lot colder…maybe a different story for plants, though then again we probably wouldn’t last long w/o the plants…hypotheticals are fun
Chris, what would be the situation with a 100% N2/O2 atmosphere? Seems to me that it would be completely optically thin wrt longwave radiation and so the surface temp would be 33K lower than present. Would the atmosphere be essentially isothermic, as the stratosphere is currently? Or would there still be a lapse rate arising from simple physics (i.e., ideal gas law, 1st law of thermo, gravity)?
I give my answer.
There would be some atmospheric circulation due to the temperature differences at the surface, but those would heat the whole atmosphere to a high enough almost isothermal state that would limit those circulations soon to low altitude winds. One reason for this development is in the fact that warm surface would induce convective energy transfer that would be quite effective, but there would be no strong mechanisms for the atmosphere to lose energy. Temperature inversion would make the opposite heat transfer weak over the colder surface. Thus the warming would continue until the atmosphere would be warm enough to stay at a constant temperature not far below the warmest areas of the surface.
When there are no strong mechanisms for energy loss the stationary state is nearly isothermal.
FiveString
With no absorbers or emitters, all energy flows would decay and I would expect that the atmosphere settles into an isothermal state…that is, the tropopause approaches the surface.
Without CO2, life ceases. But surface temperature would be about the same. As long as nitrogen and oxygen have density and molecular weight, they absorb solar radiations following the Beer-Lambert law equation, just like other gases. It is the atmosphere and water evaporation that dictates surface temperature, not CO2.
Nabil, with respect your ideas are simply not right. Please read an introductory textbook on the subject; I can recommend many if you have the interest.
Thanks Chris and Pekka. The basic physics should be second-nature to me but, alas, I went corporate enough years ago that that’s no longer true.
I’m struggling with the intransigent mental picture I have of this situation.
From a radiative transfer pov I see why it’s isothermal, but that would seem to conflict with the canonical derivation of the lapse rate, which has no explicit dependence on the IR optical thickness. I keep assuming that atmospheric pressure and temperature must be coupled and have a hard time picturing an isothermal atmosphere with a steep pressure gradient. On the other hand a tank of compressed air can happily sit at room temperature…
FiveString, the adiabatic lapse rate is a stability limit. I.e., what it says is that a parcel of air is in hydrostatic equilibrium if the lapse rate is equal to the adiabatic lapse rate. If the lapse rate is greater than this, then the parcel of air that’s starts to rise will experience an upward force and you get convection, which then works to restore the lapse rate. However, if the lapse rate is less than this, things are stable, convection is suppressed, and there is no reason why the atmosphere will go toward the adiabatic lapse rate.
Actually, the sentence about “hydrostatic equilibrium in my post is erroneous. I should have said “neutrally stable” or whatever the term is to describe the boundary between stability and instability.
FiveString – Whether a radiatively inert atmosphere coupled to a planetary surface will establish an isothermal or adiabatic profile is not a settled issue in my view, although it’s largely irrelevant to our own atmosphere with its complement of greenhouse gases.
The issue has been around since the 19th century, when Willard Gibbs deduced that an isolated atmosphere would exhibit an isothermal profile as the maximum entropy equilibrium state. Various analyses since then have differed in their conclusions depending on which aspects of atmospheric behavior they believe dominate the picture. The coupling to the surface is important, because without that coupling, there would be no tendency of the surface to modify an isothermal profile, nor would the entropy of the entire planet enter into the analysis. Some of the papers have simply considered the isolated atmosphere case.
Pekka and I have discussed this in this blog and his own blog. He is convinced of the isothermal solution. I’m not. If you visit his site, you can see some of the issues that have been raised.
The discussion that Fred mentions starts here
http://pirila.fi/energy/random-topics/#comment-52
That comment has also links to earlier discussion on Climate Etc.
The main points, as I see them, are:
– Convection dominates and determines the temperature profile as long as something keeps it going, which means that there is a continuous upwards flow of energy through the atmosphere. That requires heating from below and getting rid of the energy at the top of the convective region.
– When convection is not maintained (i.e., when there isn’t any way to get rid of energy at the top of the atmospheric layers considered) and radiation is excluded, only conduction is left. That leads very slowly towards isothermal atmosphere.
“That requires heating from below and getting rid of the energy at the top of the convective region.”
Convection requires a temperature difference able to cause density differences that drive fluid circulation. Everybody concentrates so much on the warm air rising, they forget that it has to descend somewhere else as well – pushed around the cycle by air pressure from the hot/cold ends, descending even without being cooled.
In a perfectly transparent atmosphere with differential heating of the surface, warm air will rise at the equator or on the daylight side, circulate adiabatically and descend slowly to the poles or night side, where the heat will transfer to the cold surface and be radiated away. The cold dense air will then flow across the surface back towards the equator. Most of the atmosphere will be at (adiabatically adjusted) tropical temperatures, with a thin cold layer near the surface over the poles.
If a temperature differential between two surfaces drives convection, it will drive it to transfer heat between those two surfaces.
Also, it doesn’t have to be heated from the bottom. The circulation of the oceans is driven from the top. Tropical waters close to the surface warm and rise, drive currents polewards, where it cools and descends to great depth. It then flows adiabatically through the deep ocean back to the equator. The ocean circulation is an example of convection with no heating from below, and the energy being got rid of at the same level it is absorbed at.
You are perfectly right that the discussion has largely neglected large scale circulation, which is, indeed, an essential part of the atmosphere, as it’s also of oceans.
You are also right that the requirement of heating from below does not apply to oceans.
Nothing in that changes the fact that many basic features of the atmosphere are due to the fact that the atmosphere is as a whole heated from below and loses energy from the top. The idealized descriptions apply directly to idealized conditions, and one should always be careful in generalizing such results to more complex real world situations.
The simplistic arguments survive better, when they give the correct answers for the real world as well, but here one should remember one of the points mentioned in Judith’s new post on meta-expertize:
This could be modified as follows:
I could continue giving explanations to support the particular simplifications I have used, but that’s gets too complicated for now.
I only notice that the perfectly transparent atmosphere would have a very thin troposphere, so thin that it would not really exists at all as a easily identifiable layer. The stratosphere would extend almost all the way to the surface and the large scale atmospheric circulation would not be large scale at all in the present meaning of the word.
“I only notice that the perfectly transparent atmosphere would have a very thin troposphere”
Why?
Because the altitude of the tropopause is determined by the balance of radiative heat loss from that layer to heat transfer to the layer. When the radiative heat loss is essentially zero the altitude goes to zero, i.e. the whole atmosphere becomes stratosphere.
Thanks Fred and Joel. I’m glad to hear that it’s not a completely dumb question and will do more reading, as per your suggestions, to satisfy my curiousity.
Sunlight converts O2 to O3 and absorbs UV.
Perhaps not.
Such an atmosphere would (very) gradually warm from the bottom, but, lacking the ability to radiate from the top, how would it lose heat?
The surface radiates heat energy upwards. If the atmosphere can’t absorb any of that radiation, as would nearly be the case with an all-N2/O2 composition, the heat escapes into space without interacting with the atmosphere.
There would be a small amount of heat transfer to the atmosphere via conduction. Admittedly, this would take a very long time, but we’re assuming a very long time.
Except that Chris doesn’t want you to know that H2O vapour is by far the dominant greenhouse gas
Yup I am keeping it top secret. Like in my next post
http://blog.timesunion.com/weather/understanding-global-warming-feedbacks-and-how-carbon-dioxide-helps-control-earths-temperature/1220/
Dear Chris:
I extracted the following from your link: ” This question can be answered using complex computer models where various greenhouse gases are artificially added and removed from the atmosphere. The question is not straightforward because the effects of various gases overlap to a large degree”
Nothing new! Based on this quote, we all have to accept the output of your complex computer models and there will be no room for logic or reason. That is why the world is not buying your science.
How would you go about the problem of breaking up the greenhouse effect by contribution?
Dear Chris:
Whatever method is used, science has to be transparent and accepted by all science disciplines. It is inconceivable that the creator has placed on a planet whose climate can only be deciphered by supercomputers. In my opinion, we just have not tried correctly or hard enough to figure out the climate science.
Completely OT, but I have to say Chris, I have to commend you for your efforts in changing your tone in your conversations ;).
oh and please don’t take my comment as patronizing. Having re-read it I am afraid that’s how it sounds like, but that’s not what I want to communicate at all.
Oh my… no statistically relevant warming since 1979, corruption of the surface data by UHI effect, “corruption within the climate science community,” and the knowing fraud and misrepresentation by, “a small coterie of scientists [that] can be counted upon to modify the data” to fit the models.
“For warming since 1979, there is a further problem. The dominant role of cumulus convection in the tropics requires that temperature approximately follow what is called a moist adiabatic profile. This requires that warming in the tropical upper troposphere be 2-3 times greater than at the surface. Indeed, all models do show this, but the data doesn’t and this means that something is wrong with the data. It is well known that above about 2 km altitude, the tropical temperatures are pretty homogeneous in the horizontal so that sampling is not a problem. Below two km (roughly the height of what is referred to as the trade wind inversion), there is much more horizontal variability, and, therefore, there is a profound sampling problem. Under the circumstances, it is reasonable to conclude that the problem resides in the surface data, and that the actual trend at the surface is about 60% too large. Even the claimed trend is larger than what models would have projected but for the inclusion of an arbitrary fudge factor due to aerosol cooling. The discrepancy was reported by Lindzen (2007) and by Douglass et al (2007). Inevitably in climate science, when data conflicts with models, a small coterie of scientists can be counted upon to modify the data. Thus, Santer, et al (2008), argue that stretching uncertainties in observations and models might marginally eliminate the inconsistency. That the data should always need correcting to agree with models is totally implausible and indicative of a certain corruption within the climate science community.” Richard Lindzen, 15-Jan-2011
what a joke. So on one hand you claim the surface data has been corrupted by UHI warming, but on the other-hand you claim there’s no warming in the surface record since 1979 (so how do you figure there’s UHI warming?).
Then you claim there IS warming in the surface record afterall but it’s 60% too large.
Too funny.
As cities grow and add more A/C units belching hot humid air into the city … UHI gets worse.
NASA thinks 7 – 9C in the summer for UHI in northeast US cities.
http://www.nasa.gov/topics/earth/features/heat-island-sprawl.html
Japan suggest 2-3C and more at night.
“In the twentieth century, the mean temperature in six large cities in Japan, including Tokyo and
Nagoya, risen 2 – 3 ℃, while the globally averaged temperature risen 0.6 ℃. The trend of urban
heat island phenomena in those large cities in Japan is significant even compared with the trend of
the global climate change.”
http://www.env.go.jp/en/air/heat/heatisland.pdf
“UHI in Paris is estimated at 8 deg C at night and up to 10 deg C in some suburbs in the afternoon.”
http://www.nasa.gov/pdf/505253main_dousset.pdf
via
http://climateaudit.org/2010/12/15/new-light-on-uhi/
Bruce, yes, the UHI and other LGW effects are under the radar.
No, what is funny, is that he makes the claim that starts “all models”
How many models are there and has he examined the runs of all of them?
If he could look at one a second it would be a good days work.
Disparities in the near (6′) surface temperature profile changes with the topographical patterns, and surface features that change the soil type or water content locally, there were natural sheltered areas before people entered the scene. Most of the recently (18th-20th C) settled areas, were selected because of their naturally sheltered effects for settlement, and as the areas population grew it moved on into the more exposed areas.
Over time centers of cities were thus naturally all located in areas most susceptible to UHI in cooler climate areas, get over it!
So the problem we have is most of the urban thermometers are located in the most sheltered spots, the problem is “do we the people” care about how cold it gets out in the woods?
To get some fictitious “global average temp” is a waste of time, from the ground alone, due to the sparse and resultant non random sampling spread, and large changes in density of weather stations, across most of the globe.
By choice of measurement platforms, and selected data modeling processes you can come up with a lot of different things, and to say which one is “right” depends on your POV, model, and method of station selection.
A better metric would be dew point with maybe only a correction for elevation changes, because it would better reflect specific heat content, due to H2O GHG effects, as a more viable metric reflective of the total Joules involved in the interactions over time. A more usable and standardized approach to energy budgeting than just temperatures.
Richard Holle.
“Disparities in the near (6′) surface temperature profile changes…..”
I concur with your post Richard.
Best regards, Ray Dart.
What greenhouse effect. So why is mars not hot, mostly C02? Why is Venus hot when no sun reaches the surface? Ah pressure.
Mars only has slightly more CO2 than Earth and it has no water vapor.
Sunlight does reach the surface of Venus
by “slightly” I mean about 12 times as much by mass, not the 1000 times as much as some people claim
No, the complete answer would include pressure broadening!
Facts are facts: Lindzen says there has been no statistically relevant warming of the atmosphere since 1979; and, all people of reason recognize that the surface record has been corrupted by UHI, not to mention purposefuly manipulation of the record by AGW ideologues.
Moreover, the most accurate temperature we have ever had available to us shows that the oceans of the Earth are in a cooling trend. Spencer tells us that there is no end to the cooling in sight. And, in a period when the oceans are cooling there is no global warming.
Wagathon’s cunning plan is to triumph over the pro-science folks by killing us with laughter. There’s really no other explanation for why he humiliates himself like this.
Satellites did not exist prior to 1979. “And since 1979 there’s been an increasing divergence between the thermometers on the ground and those in the satellites. Those on the ground show more warming, and since it’s documented that they’re near air conditioning exhaust vents, concrete slabs, heated buildings and at airports, it seems likely that they’re in the wrong.”
What satellites show is that surface records are exaggerated—i.e., corrupted by the UHI effect. AGW ideologues can no longer hide the decline. In France, for example, there has been no global warming since 1850. In France, “all of the thermometers were located at airports where the energy-reflecting snow–which has an even greater effect on the albedo than do clouds–is continually removed from the tarmac, creating erroneously warm winter temperatures compared to the adjoining countryside where the UHI-effects of snow removal, jet airplane thrusts and black tarmac do not exist.”
Has anyone noticed that global temperature seems to follow Mathane much better than CO2?
http://www.csiro.au/greenhouse-gases/
Or is it that Methane follows temperature?
I would have to guess that with a short life time, and even lower levels for Methane, generated by Mann compared to CO2 in Nature, the soil temperature that regulates the microbial release of Methane is in control of the release rates, and is just slightly modified by agriculture. You will see the Methane levels following the growing seasons shifts in temperature, with some effects caused by land use changes by man, modulated onto the natural temperature changes signal.
But why did Methane growth pause for 10 years after the 1998 El Nino in the same way temperature paused?
One naive question regarding a phenomenon observed by me, a layman:
On a cold winter day in my hometown we had the meteorological situation inversion – the temperature at ground level was about -15C, but the temperatures above my rooftop increased rapidly to something like 0C only a few hundred feet above my rooftop, according to what was reported in the local newspaper (sorry I don’t remember the numbers exactly).
This weather situation persisted for days without any notable change. It remained perfectly windless, the weather report just showed a circle for the wind symbol, day after day. And it stayed cold.
Now why didn’t the warmer air above us radiate downwards to increase the colder air temperatures at ground level? It would certainly not have broken the famous second law, nor any other laws of physics that I know of. And radiation is supposed to happen pretty fast, isn’t it? But it just didn’t happen – we remained cold.
Isn’t the obvious conclusion that convection is the king, and that the radiation at these low levels (just above sea level) where I live is insignificant?
I should add that we last November had a similar situation with no wind and extremely cold temperatures – but without inversion. The result was exactly the same and the temperatures were very similar – no notable effect from the back-radiation from colder air, either.
Now Bruce above asks about the temperatures in dry places like the deserts, if the greenhouse effect shouldn’t be detectable there, but no one seems to be much interested. My question is related to his in the sense that I am (we are?) thinking in a sort of practical way – if there is a notable or even dangerous greenhouse effect then it should be observable some place locally, like in the desert were water vapour is ruled out, or in places were convection pauses. If it is unable to produce any such detectable effect locally, the claim that it should worry us on a global level, really makes me scratch my head.
…..or maybe I should just ask: Where can I observe the greenhouse effect?
Bebben,
The greenhouse effect is always “present” albeit to different degrees depending primarily on variations in moisture and vertical temperature profile. I would note that the strength of the greenhouse effect is not just determined by the absorber amount, but by the temperature structure. You cannot really have a strong greenhouse effect in an inverted temperature structure state, and you have to remember that to determine the surface temperature requires consideration of not just the downward IR fluxes but the other surface and advective processes. If a cold air mas is coming in from the Arctic, it will probably bring in cool weather!! I addressed the fallacy of thinking about the GHE as only being about the downward IR flux in my Times Union blog post linked in comment 1, and am going to bring it up again in my post on the Postma paper that I will put up on SkepticalScience (soon!)
why didn’t the warmer air above us radiate downwards to increase the colder air temperatures at ground level?
There is no reason to think it didn’t, Bebben. However, if the surface had lost heat rapidly (several degrees or more over a few days or less), that downward radiation would not keep up.
If you Google “temperature inversion”, you’ll find a variety of types and a variety of mechanisms. In many cases, a surface cooled by nighttime radiative loss and/or inadequate daytime solar heating, will cause air immediately above it to cool below that of higher air, which has not had time to cool, or which can’t mix downward because of insufficient wind. These inversions tend to be transient, at least in non-polar latitudes, and will eventually return to a more normal temperature profile in which temperature declines with altitude up to the tropopause.
When the cold air is dry the absolute humidity is very low. Therefore the air above the surface radiates effectively only at some wavelengths. It radiates more strongly than the surface at 15 um, where the CO2 emission is strongest, but at most other wavelengths the surface radiates more than the warmer air. The total radiation from the surface can therefore exceed that coming to the surface and the surface may remain colder.
Another way of expressing the same phenomenon is to say that the surface sees different layers of the atmosphere at different wavelengths. The atmosphere may be warmer all the way up to 1000 m or so. Thus the radiative balance acts to heat the surface at those wavelengths where the opacity of those 1000 m is low, but at other wavelengths the lowest 1000 m have little influence and the balance is formed by the surface and the higher and colder altitudes. In your case this latter cooling influence is stronger than the first warming influence.
Bebben, you are perfectly correct. Your simple observation confirms that convection dominates over radiation as a mechanism for heat transfer.
Actually it’s a good example of the fact that convection enters only, when radiation alone would lead to a stronger negative temperature gradient with altitude than the adiabatic lapse rate allows.
Convection is indeed a limit on one side, but totally powerless on the other side. It helps in keeping the Earth surface as cool as it is.
I recommend this new paper by Joseph Postma.
He analyses the possibility of an atmospheric greenhouse effect.
He has spent much time developing a more realistic model of our planets climate.
This model pays more attention to day/night effects and thermal energy retention which in turn smooths out temperature variations.
http://www.tech-know.eu/uploads/The_Model_Atmosphere.pdf
Basic greenhouse effect mechanisms have been well addressed here by Chris Colose, Pekka Pirila, Paul S, and Bob Droege, with additional contributions on individual points from others, and at this point I have nothing further to contribute on most of those items. Rather, let me throw in two additional relevant items.
(1) For an excellent overview of greenhouse effect mechanisms, the Physics Today review by Raymond Pierrehumbert is very much worth revisiting. It also answers some of the specific questions raised in this thread.
(
2) Questions are frequently raised as to sources of warming observed in some regions in comparison with global warming. This is particularly the case for temperature change in regions encompassing large population centers, where an urban heat island (UHI) effect is observable and could add to a warming trend if the UHI effect is itself growing. The magnitude of such a phenomenon (increasing UHI, not UHI itself) as a contributor to global trends is generally thought to be very small even if more significant in selected areas. This has been disputed, but rather than address that issue in detail, I thought it would be worth making a few separate points.
First, about 70 percent of the Earth’s surface is ocean, and “global warming” trends are in fact dominated by ocean warming trends (see recent threads on SST for more on this topic). Second, it has been known for many centuries that when the climate warms, land warms faster than oceans. This is due at least in part to the enormous heat capacity of the oceans, as well as the evaporative cooling associated with a water-covered surface. By itself, the observation that land warming trends have exceeding ocean trends is expected for this reason alone, and any effects of human civilization must only be those that go beyond the natural land/ocean difference.
There is another intriguing observation, however, that adds to this perspective. The recent BAMS report on State of the Climate in 2010 looked at temperature changes in an element of the system that is internal to land, namely lakes. Data are presented in the section starting on S39, with an emphasis on satellite data obtained since 1985. The global trends averaged about 0.04 C/ year (0.045 C unweighted or 0.037 C when Northern and Southern Hemisphere data are weighted equally). This translates into 0.4 C/decade (4 C per century), which is on the high side even for land data generally during the same interval, although not outside the upper limits of observed trends.
The lake data and overall land data are not strictly comparable for two reasons. Lakes experience an evaporative cooling effect that would tend to create a cool bias and underestimate warming. On the other hand, the lake data were obtained at night, where evaporative cooling would be reduced, and where a blunting in overall anthropogenic trends from a relatively unchanging solar contribution is eliminated – this would tend to create a warm bias. Overall, however, even with these qualifications, the lake data support the conclusion that the Earth has warmed substantially on land on a global basis independent of very localized effects that have influenced the trend in specific regions.
“it has been known for many centuries that when the climate warms, land warms faster than oceans. This is due at least in part to the enormous heat capacity of the oceans, as well as the evaporative cooling associated with a water-covered surface.”
This leads to a huge flaw in the Trenberth energy balance calculations, which assume the entire Earth surface is supposedly heated by ‘backradiation.’ The fact is LWIR can only penetrate the surface of the ocean about 10 microns, with all energy used up in the phase change of evaporation, causing skin surface cooling and no warming of the oceans. Ergo, greenhouse gases cannot heat the oceans, 71% of the planetary surface area.
Furthermore, as you mention, the enormous heat capacity of the oceans precludes GHGs from any significant heating of the oceans. The IPCC effectively claims that GHGs are preventing 0.85 Peta Watts/year in LWIR from leaving the atmosphere to space. Meanwhile, the Sun pumps in 105 times more energy in the short wavelengths that can penetrate and heat the oceans to a depth of several meters. Even if one falsely assumed LWIR could penetrate and heat the oceans, and also that the oceans release NONE of this heat, the effect of GHGs would be ocean heating of a mere 0.005C/yr.
The IPCC and climate models conveniently ignore the fact that LWIR cannot heat the oceans, that even if it could it would not cause any significant change in ocean temperatures due to huge differences in heat capacity, and that the “solar constant” is definitely not constant in the UV (recently found to vary up to 10% within solar cycles) which can actually penetrate and heat the oceans.
This point has been discussed very many times on this site.
The whole point of GHE (greenhouse effect) is always that we need sun to do the actual heating, while the GHE provides insulation. This is totally analogous to insulating the house. Well insulated house can be kept warm by a small fraction of the energy that an non-insulated would need. We can save much more than 50% of the energy. In that sense the insulation heats the house more than the space heater, but without the space heater the well insulated house would be as cold as the non-insulated.
Similarly the GHE would have no meaning without the heating by solar SW, but quantitatively the share of GHE could exceed 50% (on the average the real value is very close to 50%). That’s equally true for continental and ocean areas. The only difference is that on the ocean areas the solar heating penetrates the surface. Thus the insulating effect starts already in the water. The sea surface is just one surface within the insulating layers. It’s analogous to the surface between the inner lining and the main insulation of the wall of the well insulated house. There is a net flow of energy up through the sea surface and that net flow is reduced very much by the GHE. Again the analogy is valid: The outer surface of the inner lining is kept warm by the main insulation. It’s slightly cooler than the inner surface of the lining, but only slightly.
I prefer this analogy. Let say you have a gun shooting bullets into water and you are swimming underneath. Lets say that no matter how many you bullets you fire into the water, all the energy would be dissipated within 1 meter. Does it matter how deep the pool is? No.
If all the IR is absorbed by Co2 within 1 meter of the surface at 280ppm does it matter if there is 380ppm? No.
If and if, but if not?
And it’s really not.
You try to play with words creating purposefully false impressions.
The amount of CO2 affects how fast the ocean cools.
Since the ocean is heated by short wave radiation and cools by evaporation, convection, conduction and long wave radiation; if you reduce the amount of cooling by increasing the CO2 above the ocean, then you increase the heating due to conservation of energy.
Agree with Bob Droedge, is there anyone saying CO2 warms the ocean in any significant way other than by limiting convective cooling via a warmer atmosphere?
The immediate influence is reduced cooling by IR, as the net IR flux is reduced, but remains still well on the cooling side. When the atmosphere warms also convective cooling is affected.
It is worth noting too that the downward IR to the surface increases primarily because the air temperature increases, not because of the direct addition of CO2.
This whole reasoning is nonsense though because IR can heat the ocean. Go put a bucket of water under an infrared heating lamp for a while…
I would simply add the point that there is a diurnal variation in the net transfer of absorbed energy. During the day, the combination of direct solar radiation and back radiated IR warms the ocean (with the IR contributing more than the solar component) – i.e., the temperature rises. At night, the ocean cools, but the back radiated IR reduces the net cooling so as to maintain the ocean warmer than without that downward IR component. Note also that during both day and night, the back radiated IR is actually contributing to the kinetic energy of the water molecules that remain in the ocean, with only a smaller fraction contributing to evaporation – in other words, at the molecular level, it is causing a heating effect even though the net IR effect is one of cooling because more IR is emitted than absorbed.
Chris,
By immediate influence I referred to that kind of reasoning that is used in defining the radiative forcing. I.e. making a hypothetical addition of CO2 to the atmosphere and looking, what happens before the balance has been restored through changes in temperatures.
Yes Chris. This debate is becoming confused at this stage of events.
The ‘thin skin’ of ~10 microns that ‘Hockey Schtick’ relates to is the ‘ocean/atmosphere contact conduction region’! The ocean temperature is the ‘psychrometric’ ‘wet bulb’ side of the equation and the atmospheric temperature is the ‘dry bulb’ side. Needless to say that an increase to atmospheric temperature both lowers atmospheric RH and increases the ‘ocean/atmosphere contact conduction region’ temperature to boost water evaporation.
Best regards, Ray Dart.
chriscolose says “This whole reasoning is nonsense though because IR can heat the ocean. Go put a bucket of water under an infrared heating lamp for a while…”
I encourage you to do that very experiment and report back on your results. Here’s some background reading from Nature for your science fair experiment:
http://www.nature.com/nature/journal/v358/n6389/abs/358738a0.html
Additional background reading for chris colose on why LWIR does not heat the oceans
http://omlc.ogi.edu/spectra/water/abs/
http://hockeyschtick.blogspot.com/2010/08/energy-environment-full-special-issue.html [see paper by Ray Clark]
http://climaterealists.com/index.php?id=4245
Pekka Pirila.
A timely response here is impossible (due to ‘nesting’), however, I’ve discovered that a ‘right mouse click’ on a ‘post’s time-stamp’ gives a menu from which the ‘properties’ of the time-stamp can be seen. These ‘properties’ disclose a unique post identity as “# comment-!!!!!!” (! = a numerical identifier). With the interest of clarity in mind, I think it best that I include the ‘unique post identity’ when I respond to a message here. :)
My last response within this ‘nest’ (#100161) was in reply to your response #98003. However, to bring our dialogue up to date:
In your response #100425 you say that “It’s not an analogy. It’s the demonstration of a specific point. It demonstrates that heating the surface by IR may influence also lower layers.”
I disagree with your suggested context. The ’10 micron layer’ (warmed by back radiation) can ‘mix’ with lower regions by way of ‘wave-let mixing’, and perhaps ‘wave mixing’ as a further process. However, this process is shared with the ‘evaporation process’ (we have two energy ‘atractors’ [drains, sinks]) and the ‘mixing attractror’ seems ‘weak’ in a ‘natural’ scenario. I don’t understand how your described scenario could apply.
Best regards, Ray.
The Trenberth energy budget effectively says 333 W/m2 of LWIR ‘backradiation’ is heating the oceans. It is not. Show me where Trenberth acknowledges in his paper that the effects of LWIR on land and on water are vastly different. You cannot both claim Trenberth is correct that GHGs are heating the oceans to the tune of 333 W/m2, while simultaneously claiming on this blog that they are only passive insulators.
I see no one commented on the second part of my comment about the huge differences in heat capacity precluding GHGs from any significant heating of the oceans. How come?
Technically, back radiation dosnt heat anything(well on average, if the ground is colder than the atmosphere, the net flow could be from atmosphere to land…), it slows radiative loses. Water is extremely opaque to LW, it is an excellent absorber and emitter, but because the path length is so long in liquid water, it only loses energy via radiation from the skin layer, but to calculate the energy moved via radiation is still εσT1^4-εσT2^4… so the atmospheric T directly effects the movement of energy from the skin layer into the atmosphere via radiation.
HS – Your recent comments may have been addressed to Pekka and/or Chris, who are both well qualified to answer them if they return to this thread. If not, and if you are the only one confused about these issues, I’ll invite you to email me – I’ll be glad to answer your questions. If others are similarly confused (despite these topics having been addressed previously on multiple occasions), then we can probably continue here.
Just briefly, though – ocean heat capacity determines the rate at which the ocean warms, but for a persistent forcing, won’t change the final result. LWIR contributes more to ocean temperature than direct solar radiation (although of course all the energy originally came from the sun). A net effect described as “reduced cooling” simply signifies that despite the large quantity of backradiated IR that is absorbed, the net direction is upward, in that outgoing IR exceeds absorbed IR – it does not mean that very little IR is absorbed to increase the kinetic energy of water molecules. Finally, we know from global evaporation/precipitation rates that the amount of absorbed energy that goes to evaporation is a fairly small fraction of the total absorbed IR, so that even if all the evaporation came from IR (it doesn’t), most of the IR incident on the ocean must be accounted for as absorbed into the ocean and contributing to its temperature.
Again though, feel free to email me for more details if Pekka or Chris don’t return to answer your questions.
We meet time after time the situation where one specific factor, like the back radiation is heating in the sense that changes in its strength influence the temperature. Increasing back radiation keeping everything else fixed leads to higher temperature, but looking at the back radiation alone is not reasonable.
We have never back radiation without emission of IR and in great majority of cases emission of IR is stronger than back radiation. Thus IR taken in total is cooling, not heating, but the strength of the back radiation determines, how strongly it’s cooling. Trenberth’s average numbers are 396 emission and 333 back radiation leading to 66 W/m^2 cooling by IR. For the ocean areas the net cooling is 57 W/m^2.
The heating component for the oceans is solar SW, which penetrates strongly a coupe of meters and weakly hundreds of meters to the ocean. All the other components are cooling, when IR is considered as a whole. IR can, however, be divided also to emission and to back radiation. This is equally correct and this is the way estimating the net IR is usually done, because the strength of emission is so easy to calculate from Stefan-Boltzmann law and because some parts of the net IR are difficult to calculate directly as net effect.
All the discussion that increased back radiation cannot cause warming is either semantic snobbery or false. It causes warming by compensating cooling energy flows, most importantly the IR emission. Saying that it’s not possible to heat from above are meaningless, when the role of the heating is to reduce net heat loss true the surface rather than to make the surface warmer than the bulk.
It’s indeed true that heating water by an IR lamp from above is not effective, but changing the setup so that there is heating both from below and from above and another way of cooling from above, we reach a situation closer to that of the ocean. That could be done as follows:
We have a container of water. It’s heated from below at constant power and cooled with constant cooling power from the top by a grid of thin tubes that leaves most of the surface open. The above gas space is closed by an IR transparent cover to prevent evaporative heat loss. Now add IR from above at a power less than the cooling power, which is kept constant. That will now lead to warming of the whole volume of water by reducing the net heat loss from the top.
Fred Moolten:
Reference please supporting your statement “LWIR contributes more to ocean temperature than direct solar radiation ”
Reference please supporting your statements “most of the IR incident on the ocean must be accounted for as absorbed into the ocean and contributing to its temperature.”
Well, apparently you and Pekka (and others below) disagree on this
Pekka: “It’s indeed true that heating water by an IR lamp from above is not effective” “The heating component for the oceans is solar SW” “Saying that it’s not possible to heat from above are meaningless, when the role of the heating is to reduce net heat loss true the surface rather than to make the surface warmer than the bulk.”
HS – The references have been given many times in the past, but for one good source, review the TK energy budget diagram for the oceans. Pekka and I don’t disagree. If you want to know why, email me.
For an opposing argument to both 1) Fred Moolten’s claim that LWIR directly heats the ocean by being “absorbed into the ocean and contributing to its temperature.”
and 2) Pekka Pirila’s (and others) claim that LWIR instead only slows radiative losses
see Stephen Wilde’s essay here:
http://climaterealists.com/index.php?id=4245
Fred Moolten: Thanks for the offers for a private email exchange since I’m “confused” and keep asking annoying questions, but I would like continue the discussion here. In that regard, your latest post says “HS – The references have been given many times in the past, but for one good source, review the TK energy budget diagram for the oceans.” Ok fine, TK’s diagram says 161 W/m2 solar radiation is absorbed by the ocean surface and 333 W/m2 in LWIR is absorbed by the ocean surface. Apparently upon this basis you made the claim “LWIR contributes more to ocean temperature than direct solar radiation.” This again reiterates the point made in my first post above that TK fail to consider the all-important difference of wavelength. 333 W/m2 of LWIR does not heat the oceans more than 161 W/m2 of solar SW, due to the 10 micron penetration depth. Table 2b in TK’s 2009 paper also directly contradicts your claim.
HS – My invitation for you to email me is based on the presumption that you might want to understand these phenomena better. If your main purpose is to argue – either here or by email – I’m not interested. There is no point my wasting either my time or yours if you have no intention of changing your mind. If you believe you already understand enough so that you don’t need to be further informed, that’s fine with me, because I have other things to do.
That is an interesting technique for argumenation I have noticed lately from you believers Fred. You don’t want to waste any time on those who you have less chnace convincing. You only want to discuss things with people you can convince.
Obviously y’all are not here to try and advance knowledge, if you ever were, only to proselytize!! Of course, your response is that you already know it all so this is only for our good and if we refuse to learn you are wasting your time!!
HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA
Fred Moolten: Would you kindly address the scientific issue I posited instead of continuing to throw ad homs at me? Sorry, but ad homs and posts that refuse to answer questions on this forum, saying I have to email you for an answer, are not helpful to a technical discussion forum. It is helpful for others to see the dialog and perhaps contribute with differing opinions.
Do you contend that 333 W/m2 of LWIR heats the oceans more than 161 W/m2 of solar SW?
Hockey Schtick,
I certainly don’t disagree with Fred on that point.
The issue we have had some argumentation here concerns the ways the physics can be expressed in words. Fred has strongly favored on correct way of doing that, while I have argued that another formulation might be in some ways better, This concerns only formulation in words, not the real physics.
Back radiation is most certainly a very important factor in determining the ocean skin temperature and changes in back radiation lead to changes in ocean temperature. I have written several comments to explain specifically, why it’s so and the comment you quote is just one of those.
How is your understanding of what you read? I’m sure that my comment was not impossible to understand.
Why did you pick from there one sentence giving it a meaning that’s opposite to the content of my message as whole? Do you consider that honest argumentation?
Hockey Schtick,
The 333 W/m2 does indeed heat more than twice as much as 161 W/m2. Both are needed to counteract the strong cooling influences of IR emission, evaporation and convection. Both are equally effective per unit of energy in that and 333 is more than 161.
There are other ways of describing the processes but that doesn’t invalidate the above.
The solar SW has an important extra role: it’s heating a thicker layer, but when it’s doing that the back radiation is efficient addition at the full power of 333 W/m2.
Pekka Pirila.
“The above gas space is closed by an IR transparent cover to prevent evaporative heat loss.”
Invalid analogy/scenario! Earth’s oceans aren’t covered with “Cling-film”. :)
Best regards, Ray.
It’s not an analogy. It’s the demonstration of a specific point. It demonstrates that heating the surface by IR may influence also lower layers.
Pekka
I understand the concept of the GHE providing insulation – less heat can escape form the oceans into space. It would follow from this that over time the oceans would accumulate heat. It seems though that the oceans go through cycles during which they accumulate heat and then release it. PDO and AMO come to mind. Do we know what the mechanism is for the release of heat from the oceans? and in particular is it not possible that if the oceans accumulate heat more quickly due to GHE they will reach the point at which they release the heat more quickly? Is there any evidence for this? Thanks in advance and kind regards
Gary
My approach is to look, what happens assuming that only that much changes as must change. The Earth system is complex and in some cases it gets disturbed so that the final changes end up to be quite different. It’s good to keep that in mind, but it’s not wise to allow that to prevent making more straightforward conclusions.
The simpler argumentation gives in most cases results that are not totally false, while they can certainly be inaccurate.
Gary Mirada.
“I understand the concept of the GHE providing insulation – less heat can escape form the oceans into space.”
If you’ve taken Pekka’s POV I’m not so sure that you do “understand the concept of GHE”!
Ocean temps are lower than atmospheric temps. Why? Because ‘wet bulb’ temps are always colder than ‘dry bulb’ temps (psychrometricly speaking). Earth’s oceans are definitely ‘wet’ and Earth’s ‘atmosphere’, by direct comparison, is decidedly ‘dry’. Thus, any ‘radiative’ energy transport flux must flow from atmosphere to ocean in the IR spectrum. However, because the ocean surface temp is below the near surface atmospheric temp, radiative calculation is rendered obsolete!
The ‘net flux’ of energy transmission from our oceans is into the atmosphere by way of ‘latent transmission’.
Can you add to this?
Best regards, Ray.
Your comment about the dry bulb and wet bulb temperatures apply only to the very lowest layer of atmosphere in contact with the water. The relative moisture of that thin layer is close to 100% under normal conditions allowing the temperatures to be almost the same.
The difference in the emitted and absorbed IR comes from wavelengths that penetrate far in the atmosphere or even through the whole atmosphere. That part of the spectrum makes the net IR to be up.
Is that 10 micron sea surface layer static, or does it mix with the ocean due to wave action?
The 10 micron penetration of long wave radiation is a seriously flawed argument due to wave action and spray formation.
At any given time, what percentage of the ocean surface has whitecaps?
It’s most significantly flawed, because the net flux is from the ocean below to the atmosphere. When that flux is reduced by the change in IR, the cooling of the ocean is slowed down and brought back to balance with solar SW warming only through increased temperature of the ocean, both the skin and layers below.
The argument that heat cannot be transferred from the skin to lower layers is moot, because the flux goes in the other direction and there is no problem in influencing the rate of this flux by the warming of the skin.
Here Here Pekka – I admire your stamina.
I think the temperature of the ‘skin’ is a clue. The net IR is up from the surface – and there is of course mixing to the surface through convection and turbulence. The rates at which these processes proceed is different – IR at the speed of light and turbulent and convection processes at much
lower rates – leaving the skin perpetually cooler than the underlying water.
The ‘skin’ is constantly being mixed with warmer water from below – which immediately cools through IR flux.
The quantum of net IR flux up can of course be influenced by greenhouse gases.
Fred,
“Basic greenhouse effect mechanisms have been well addressed here by”
So you wouldn’t be interested in correcting any errors then?
The basic science of the Greenhouse effect goes back well into the 19th century but I don’t remember there being any opposition to it until quite recently. Or, if I missed it, maybe someone can show me that it has always been a contentious issue.
What new scientific evidence has arisen which has led to this increased scepticism?
Fears of global cooling and an impending ice age by the same scientiests who now fear global warming.
Ah yes…The global cooling mole. That would be “Skeptic” Talking Point #27: http://aerosol.ucsd.edu/classes/sio217a/sio217afall08-myth1970.pdf
Joel, do warmist such as yourself have talking points or only skeptics? Or are all of persons of your ilk origianl thinkers and never use anything that may be valid that someone in the past has said?
The validity is the rub, isn’t it? I don’t mind people repeating correct things, but repeating nonsense over-and-over gets a little tiresome.
Wag whoever did or did not have fears in the past or present is besides the point of the physics. As you know the science is not settled and that entails that somewhere sometime someone will have been wrong. One should not focus on the men who did or did not hold certain beliefs and then change them. Very simply, if you look at the physics of GHGs, physics I should add that are a part of everyday engineering, you’ll understand that GHGs contribute to warming. Adding GHGs doesnt make the planet cooler. There is no evidence of that whatsover, and no physics, no physics being used today, suggests that GHGs will cool the planet. They warm the planet. How much? that’s a good question.
TT – If you visit Spencer Weart’s Discovery of Global Warming site, you’ll find a wealth of history on this topic. After Fourier and then Tyndall described the basic effects earlier in the 19th century, Arrhenius in 1896 provided a formal theory of atmospheric warming from CO2 that was resisted for about the next 50 years, until mid-twentieth century. The opposition stemmed from the belief that the atmosphere was already “saturated” with CO2 so that more CO2 would have no additional effect. It was not until an understanding developed of the critical role of the atmospheric adiabatic profile (declining temperature with altitude) that the notion of saturation could be refuted, and at that point the greenhouse effect was recognized as following basic geophysics principles. If you visit the Physics Today site I linked to above, you’ll see the notion of a temperature profile explored in more detail.
Fred,
I have read Spencer Weart’s history before and I have just been back to have a look at what he said about Ravelle.
http://www.aip.org/history/climate/Revelle.htm
The Ravelle & Suess paper really is a bit bizarre considering the attention it sometimes gets. Weart’s perspective is good in the detail but the initial highlight paragraph follows the “breakthrough” theme concerning Ravelle’s contirubtion at that time and in that paper.
Link to paper:
http://uscentrist.org/about/issues/environment/docs/Revelle-Suess1957.pdf
The “important” bits do indeed run contrary to the main findings and seem to be more like interjections of eiterh a nagging doubt, simply a keeping of the Callendar conjecture in play, or as a ploy to encourage funding as part of the IGY.
On another tack, the quality and clarity of the writing of some of the old papers is in contrast to some modern ones. I suspect that journals simply had more space and allowed a higher ratio of words to significance. Alternatively the authors were more literary or simply more literate.
Alex
Alex – I can’t testify to the accuracy of all of Spencer Weart’s historical perspectives, but the half-century pause after Arrhenius in accepting the greenhouse principle has been attributed elsewhere as well to the saturation fallacy. Perhaps there is a more detailed account in some other source, or maybe one historian got it wrong and everyone else just copied. In any case, there does seem to have been a pause, and even today, we sometimes see the saturation concept still argued.
Fred,
Sorry I think we may be at cross purposes. I was referring to the other falacy that the oceans would take up the CO2 which I think was the last shoe to drop. Ravelle is creditted for this due to the Ravelle & Suess paper (1957). Curiously the paper argues stabilisation at a low level and for non-accumulation (stop the emissions and the level returns to its original value.
It may be just that there is a need to pin the overturning of the ocean will absorb it all falacy to a man and to a paper, to tidy up the story.
Weart does this at least twice in the text but then in his analysis points out that the main thrust of the paper doesn’t support views that Ravelle held intuituvely and independently. The paper seems to argue that that CO2 levels will stabilise a level corresponding to the rate of emissions which is essentially the ocean will cope falacy.
Weart does mention Bolin and Erikson and they do produce a forever rising CO2 reaching 20-40% increase by 2000 but again it is not clear whether that is due to accumulated permanent residency or simply the use of an exponential growth in emissions (it is a technical paper and more than a five minute read).
http://nsdl.org/archives/onramp/classic_articles/issue1_global_warming/n8._Bolin___Eriksson__1958corrected.pdf
What R&S did do was to include the statement:
“Human beings are now carrying out a large scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future.”
which Weart highlights but adds that it was not as prescient as it seems and should be read as merely factual and of interest as it allows for study much like letting off nukes in the atmosphere or in the ocean allows for study.
On the line saturation effect:
I am not sure whether to this day this is correctly described to the lay reader. As I recall it is of relevance to one aspect of the radiative effect, the radiation from the atmosphere to the ground and the closing of the window. This would maximise if the lines became saturated and hence the wings come into play.
The other part of the effect, the reduction of the radiation into space from the atmosphere seems more tied in with lower temperature of final emissions due to the lapse rate and I suspect would and should still occur if the line is saturated.
Also the “log” law may not be adequately explained as it would also occur, I believe, in saturated lines where it results from the pressure decreasing exponentially with height but the temperature linearly.
I.E. if one doubled the concentration then (for that line) the effective height would rise a certain distance and doubling again would result in it rising by the same distance and the same drop in temperature. That would give rise to a log relationship bewtween the temperature and increasing concentrations. This combined with Planck’s law as opposed to Stefan’s should that relationship over the range were it approximates a linear relationship between intensity and temperature. Many bands are effectively saturated yet I suspece the logarithmic realtionship holds in these bands.
I think in the lay literature the wing effect is highlighted and perhaps that is correct it is dominant and must be at least in a test cell without a temperature gradient. However for some reason I thought that the line shape gave rise to the square root law (more below) but my knowledge is quite vague.
However the strong tie in with the lapse rate (for without it I can not see how the reduction in the emission into space could occur) seem to favour a role for the effect I have described. This is not something I have scoured the literature for but the role of the lapse rate does not seem to be described with the clarity I should like in the lay literature. I do have Goody and Yung but the answer has never jumped out at me.
As ever I did some calculations on this which indicated the above effects are plausible but that is never to say I was correct.
Also the origin of the transition between the square root phase and log phase of the curve (increase as the square root for low concentrations) is not dealt with in the lay literature. This has lead to some suggestions that CH4 is a “stronger” GHG than CO2 whereas I believe that is simply still in the square root phase and may in fact track below CO2 (concentration for concentration) as I believe is the case. Although I am not sure of the origin of the square root phase but I suspect that it is a common property shared by CO2 and H2O and is why the “halving calamity” does not occur. The conjecture that if you halve the concentration of CO2 enough times you end up with negative forcings or something like that.
All I can say is that I am not at all sure how all this works and I am so bold to say that many people who think they know possibly don’t. It all comes down to calculations in model atmospheres based on measurements done in test cells. I have thought perhaps erroneous, that the log law is largely due to atmospheric profiles but this is either not the case or not how it is explained.
Alex
Alex,
The question of the relationship between saturation and the lapse rate is a bit more complex.
The simple saturation effect is valid for radiation that originates at the surface and escapes to the space without being absorbed. The reduction of this component is an important part of the GHE.
For the rest, it’s informative to look down from TOA. When the saturation is strong as it is near the center of the 15 um band, we can see only the very top of the troposphere and this remains essentially unmodified independently of modest increases or decreases of the CO2 concentration. When we start moving to the wings, the first effect is that we can see deeper down to warmer layers of the atmosphere, but not to the surface or the very lowest troposphere. For these wavelengths the added CO2 makes the upper troposphere more opaque. Thus the escaping radiation comes from higher altitudes on the average. The more opaque the atmosphere is to start with, the less can the average altitude change as it’s already closer to the top of the troposphere.
The saturation effect is important, but fully saturated should be interpreted to mean so strongly saturated that the radiation cannot penetrate far enough to reach layers significantly warmer than the tropopause, when looked from TOA. That’s a far more demanding requirement than making the surface invisible from the space.
Pekka,
Any available linked literature to the relative magnitudes of emission height vs. “wings” i.e. collisional broadening?
Bill
I don’t know references for that.
Pierrehumbert’s recent Physics Today article has a nice diagram that tells, how the wings are important rather independently of the strength of broadening because their most evident feature is the succession of progressively weaker lines, but of course the broadening influences the quantitative results.
Bill – If you visit Pierrehumbert’s Physics Today article, you’ll see that Figure 3 shows a dip in emissions as a function of CO2 wavenumber signifying the effect of different positions in the main absorption band – the further into the wings you go, the smaller the dip. The right hand panel in the top of the figure shows the altitudes (in pressure coordinates, not kilometers) at which those different emissions are occurring, with the lowest parts of the curve (where there is greater net absorption) at the coldest and highest altitudes. The only exception is the small spike right in the middle, representing the altitude at which temperature increases rather than declines with height because of stratospheric temperature inversion.
Those “wings” are not the result of collisional broadening but rather of the declining IR absorption coefficients of individual absorption lines as one departs further and further from the 667 wavenumber (15 um) at the center of the absorption band.
The band itself, including the wings, is composed of hundreds of individual absorption lines representing different quantum transitions at different photon energy levels. Collisions broaden individual lines, but that would not greatly change the overall contours of the band and its wings.
Thanks for the info, Fred. This is certainly relevant to an understanding of the enhanced Greenhouse effect.
But rather, what I was getting at, is there seems to be a lot of people around, including many on this blog, who don’t even accept the natural greenhouse effect. Even when scientists had overlooked the key factors you mention, and were of the opinion that atmospheric CO2 was saturated they still didn’t dispute that the natural GH effect is the explanation for the Earth being some 33 degC warmer than it would otherwise be.
So, I’m just wondering why we now have all these climate “fundamentalists” who can’t accept that there is any such thing as a GH effect when they weren’t any at all for nearly all the of the 20th century.
tempterrain says
,,,,,”So, I’m just wondering why we now have all these climate “fundamentalists” who can’t accept that there is any such thing as a GH effect when they weren’t any at all for nearly all the of the 20th century.”……
Actually support for an atmospheric greenhouse effect largely disappeared after the famous experiment by R W Wood in the early 1900’s.
It is now popular again since about 1970 even though there is still no experimental evidence that it exists.
Bryan,
RW Wood showed that the primary mechanism of a physical greenhouse worked by the prevention of convection.
Yes, Wood’s did show there is a difference, and that is all that has been shown, and it would be good if there were some other name for the atmospheric greenhouse effect but it looks like we’re stuck with it.
There is experimental evidence that it exists. Anyone can see by simply using a thermometer. The Earth is 33 degC warmer on average than would be expected on the basis of its black body radiation temperature.
This has never been in dispute until recently, as far as I know. So I am asking why. What new scientific evidence has suggested any other possible explanation?
No, that was not the main point of his experiment.
That greenhouses work mainly by stopping convection was known to every Tom Dick or Harry that opened a greenhouse door or window.
The main purpose of the experiment was to find the radiative contribution to the heating.
He found it was almost negligible.
He then drew conclusions about radiative heating in the open atmosphere.
If he did , maybe they were the wrong conclusions.
In a real greenhouse there is an easy escape path upwards by convection if, as you say, a window is opened. There isn’t in the atmosphere – the only mechanism for heat loss is by radiation. Any absorber of that radiation in the atmosphere is going to slow the heat loss or make the cooling process less ‘efficient’ – if you’d like to think of it in engineering terms.
In any case, there is no other rational explanation for the Earth’s temperature being what it is unless this process is taken into account.
tempterrain
This is an interesting paper especially as it comes from a source with no “spin” on the AGW debate.
The way I read the paper is it gives massive support for the conclusions of the famous Woods experiment.
Basically the project was to find if it made any sense to add Infra Red absorbers to polyethylene plastic for use in agricultural plastic greenhouses.
Polyethylene is IR transparent like the Rocksalt used in Woods Experiment.
The addition of IR absorbers to the plastic made it equivalent to “glass”
The results of the study show that( Page2 )
…”IR blocking films may occasionally raise night temperatures” (by less than 1.5C) “the trend does not seem to be consistent over time”
http://www.hort.cornell.edu/hightunnel/about/research/general/penn_state_plastic_study.pdf
Dry adiabatic lapse rate
I take all this as an admission that you don’t have any alternative explanation for the Earth not being a snowball!
Bryan,
Nick Stokes pulled a similar paper on me a couple years ago. It showed significant improvement in heat retention overnight. A careful reading of the specifications showed that the plastic included a coating to minimize moisture buildup. Apparently the moisture absorbs the IR and conducts it to the plastic and out so preventing the buildup did the trick without the IR treatment. Nick, of course, denied the decreased condensation on the inner surface of the plastic had anything to do with it!!
Tempterrain, so, you don’t have any alternative explanation why the earth isn’t a hothouse with peak temps approaching the moon on the dayside? Our atmosphere absorbs quite a bit of energy across the spectrum before it gets to the ground. Would be a bit warmer if it didn’t!!
tempterrain
I agree with the insulating properties of the atmosphere.
The blanket effect but not the electric blanket effect
That’s the scientific position too. No-one is saying that the atmosphere generates heat, even with the presence of IR absorbers. That heat ultimately does come from the sun. Like most analogies, the blanket one isn’t perfect, but its a good illustration of how the GH effect actually works. More GH gases is the equivalent of having a thicker blanket.
They point to the woods experiment. which is just a paragraph with no data that fundamentally misunderstands the the real issue
tempterrain,
Professor Wood debunked the greenhouse effect (GHE) with his famous experiment in 1909.After World War Two interest in the GHE was briefly resurrected again. But the American Meteorological Society shot this down in 1951 after it reviewed all the available data and produced the “Compendium of Meteorology” appearing to kill off the cultist claims.
However, fearmongers were finally able to resurrect the notion of a GHE in the mid 1980’s when a certain ‘science adviser’ to Margaret Thatcher, Christopher Monckton (not then a Lord), helped promote the idea so as to aid the defeat of Britain’s striking coal miners.
Why are there still those in the West who fear CO2 and global warming? It is not that hard to understand. Most rational people who knew or should have known better expected all of us to be far more critical, skeptical, and to probe much deeper for an understanding of the world around us. In other words most scientists thought science would prevail. Meanwhile, however, these same scientists failed to realize that people with ideologically-motivated preconceptions would knowingly collude to participate in a fraud to take advantage of the ignorance, superstition and fears of others to advance their global warming politics.
And who are these “most scientists”? It is strange that when scientists have actually expressed their views through their scientific societies, scientific academies, physics textbooks, and so forth, those views have not agreed with your point-of-view (which is the one which is in fact actually ideologically-motivated).
At any rate, this thread is supposed to be about the greenhouse effect.
How about those dependent on taxpayer funds for a living? Not a good move to support a sceptical viewpoint.
So, your hypothesis is that people go into the field of science when they could much more easily make much more money doing something else in order to participate in a grand conspiracy whereby they distort the science in order to continue to make the relatively meager living that a career in science provides?
Why are there still those in the West who fear CO2 and global warming?
That’s a good question. Unless they are very young there’s no reason at all.
For most of us on this blog any measures designed to curb CO2 build up will certainly cost us much more than any benefits we might obtain in return.
tempterrain
I could certainly agree with that!
The “actionable proposals” I have seen (from Hansen’s coal-fired plant shutdown in US to CCS schemes for US coal-fired plants to the recent WWF proposals involving renewables, they are all VERY costly and achieve virtually NOTHING.
Typically we have a theoretical temperature reduction of 0.08C by 2100 (when the youngest inhabitants of today’s world will be long gone) for an investment cost today of $1.5 trillion (Hansen’s scheme).
The point is, we are unable to change our climate, no matter how much money we throw at it.
Max
Any comment that CO2 was pretty high in the past according to GISP2?
“The GISP2 ice core has 120 data points between 10,200 – 16,490 YBP. The Vostok ice core has only 6 data points for the same range. Yet it is the Vostok ice core that dominates the discussion. The GISP2 also has 324.8 ppmv which is the same level that Mauna Loa recorded for 1969. GISP2 said that was the same level that happened 10,960 YBP. There is also the evidence of the high frequency changes when the period from 11-19K years ago is looked at.”
http://theinconvenientskeptic.com/2011/08/why-the-co2-ice-core-reconstructions-matter/
Chris Colose | August 10, 2011 at 7:28 pm | asked
“How would you go about the problem of breaking up the greenhouse effect by contribution?”
Either by replicating Tyndall’s physical experiments of 1861, or by using the regression techniques of econometrics, as I have done in my paper
(available at http://www.timcurtin.com). Both Tyndall and I show that water vapor is by far the determining factor, and that atmospheric CO2 is trivial.
BTW, the computer models used by the IPCC & co, eg MAGICC, CMIP5, all exclude atmospheric H2O as a prime mover (generated by solar-powered evaporation) , reducing it to secondary “feedback” arising only from the increased temperature (0.0125 oC p.a. since 1950) ascribed only to the rising [CO2]. This derives from Trenberth’s view that solar-powered evaporation is irrelevant because it “rains out” within 9 days, while temperature-powered evaporation NEVER rains out, hence its amazing feedback ability to more than triple temperature change from 2X [CO2].
With scientists like Trenberth, who needs enemies?
The best way to get the relative radiative contributions is probably by modeling. Estimating the relative radiative effects of various constituents is well-settled science based on radiative transfer and verified by lots of empirical work in remote sensing, among other fields. It does not have the same uncertainties that arise in the issue of climate sensitivity and feedbacks.
What does “solar-powered evaporation” even mean? To the extent that changes in solar luminosity cause an increase in temperature, the water vapor feedback operates in the same way as it does in the case of an increase in temperature due to a rise in CO2. Needless to say, your claim that Trenberth treats water vapor differently in the case of solar effects than in the case of CO2 effects is completely without foundation. (That is a polite way of saying that you apparently made it up.)
Water vapor is a feedback and not a forcing simply because we can’t presently inject it into the atmosphere at high enough rates to significantly alter its concentration, at least on a global scale. And, indeed, as Trenberth apparently noted, this is because water vapor cycles through the atmosphere quite rapidly and also because its total concentration is much higher…so it would take a larger absolute change in concentration to produce a certain fractional change in concentration…and it is the fractional change in concentration that matters when the radiative forcing has an logarithmic dependence on concentration.
Joel – I’ll give Tim Curtin the benefit of the doubt. I don’t think he necessarily “made it up” that Trenberth treated solar and greenhouse effects differently, but rather that he simply misunderstood the concept. The important point, as you note, is that warming requires a change in the rate of water vapor accumulation in the atmosphere. When the climate is balanced (or close to it), it doesn’t matter how brightly the sun shines as long as it’s constant – it can’t change the water vapor content of the atmosphere, and therefore can’t change temperature as a response . Only a change (e.g., solar forcing) could do that, and in fact has been a small factor over the decades, but much less than CO2 forcing, at least during the past 60 years. Solar forcing is a topic in its own right, but it’s not really relevant to Tim Curtin’s mistaken belief that the important figure is the 339 W/m^2 solar irradiance entering the climate system That quantity has no effect on the water vapor contribution to temperature as long as it doesn’t change.
Actually the amount of bright sunshine has changed in the 20th century. It was up in the early part of the century, down in the middle and up again at the end.
“Observed increase at BSRN sites since 1992: +2.4 Wm-2/decade”
http://www.iac.ethz.ch/education/master/radiation_and_climate_change/download/ChangeinRadiationbalance_2011_part2
“Scientists who support the man-made greenhouse gas theory disregard information from centuries ago when exploring the issue of global warming.”
~Akasofu
what info?
I don’t think so.
For instance, I’m sure we have all heard the scientific argument that 1000 centuries ago the Earth was just a couple of degrees warmer, than now, but sea levels were 6 metres higher.
Global warming caused by increased CO2 concentration in the atmosphere is indeed on very shaky ground. Lines of evidence fall apart upon scrutiny. Consensus scientists managed to make things simpler than possible. It’s not basic physics, it’s an abuse of basic physics. It’s a travesty.
Nice opinion piece. Now what are the arguments.
Temperature drives the bus, CO2 sits in the back.
Just like the motion of the bus turns the engine – even when its going uphill!
Thanks to Joel Fred and Bruce for their comments:
First, Joel, you said “The best way to get the relative radiative contributions is probably by modeling”.
Why? what’s wrong with regression analysis using http://rredc.nrel.gov/solar/old-data/nsrdb/1961-90/dsf/data and http://rredc.nrel.gov/solar/old-data/nsrdb/1991-2005/statistics/data for 1200 sites in the USA, showing LOCAL solar radiation AT THE SURFACE, atmospheric water vapor [H2O], RH, opacity, windspeed etc.? Or the ESRL-NOAA reanalysis data going back to 1948 for the whole of the globe giving [H2O], SH, RH, and temperatures etc. for anywhere you specify see Kalnay, E. et al. 1996. The NCEP/NCAR Reanalysis 40-year project. Bulletin American Meteorological Society, 77, 437-471.
.
Precipitable water, [H2O], is NOT the same everywhere, as you imply, while Trenberth says it is always NIL because “it rains out” – here is the direct quote from Trenberth (12 July 2011 at Skeptical Science: “water has a short lifetime in the atmosphere of 9 days on average before it is rained out. Carbon dioxide (CO2), on the other hand, has a long lifetime, over a century [sic], and therefore plays the most important role in climate change while water vapor provides a positive feedback or amplifying effect: the warmer it gets, the more water vapor the atmosphere can hold by about 4% per degree Fahrenheit”. Could it be plainer than that? what I call primary or solar-induced evaporation is irrelevant because it “rains out” so is not a long-lived GHG (i.e. average level zero), while water vapor has a “positive feedback or amplifying effect…” and never rains out because a warmer atmosphere holds more of it!
So I ask that you withdraw this uncalled for comment of yours: “Needless to say, your claim that Trenberth treats water vapor differently in the case of solar effects than in the case of CO2 effects is completely without foundation”.
Please note that Pierrehumbert et al caution against “wholly indefensible statements which simply invoke the Clausius-Clapeyron relation…[as being] at the root of the behavior of water vapor, but the proper use of the relation hinges on identifying the temperature to which the relation should be applied; it’s not the surface temperature, and the effect of the relation on evaporation is of little relevance to water vapor feedback” (2007:180). Try and get Trenberth to see that, but perhaps you can?
Joel, I also think you are misleading when you say “Water vapor is a feedback and not a forcing simply because we can’t presently inject it into the atmosphere at high enough rates to significantly alter its concentration, at least on a global scale”. If you care to check my paper Econometrics and Climate Science at my website (full version at http://www.timcurtin.com; short version has been submitted), you will see that water vapor generated by the combustion of hydrocarbons is in the same ballpark as the CO2 emissions therefrom, at around 16 GtH2O as against 32 GtCO2 in 2010, but has 4 times the radiative forcing potential of CO2 (Pierrehumbert et al.). So while you are right that anthropogenic H2O is small relative to what I call solar (natural, if you prefer), it has much the same warming potential as actual increases in [CO2] – and much more when you add in the water vapor emissions from the cooling processes of thermal power generation (c 300 GtH2O p.a.). Trenberth is right that precipitation soon results in “raining out” – but the average value is what matters, and it is NOT zero.
Also it is interesting to observe that at these 4 contrasting locations, Barrow (Alaska), Hilo (Hawaii), Albuquerque and NYC-JFK, the strongest rising LSR linear trend for [H2O] is at NYC-JFK. So yes, when you say “it is the fractional change in concentration that matters when the radiative forcing has a logarithmic dependence on concentration”, very true, as that varies by location, and is not invariant across the globe.
As for [CO2], TAR and Houghton (2004) both indicate that because of the large annual fluxes between the earth’s surface and the atmosphere, the average life of [CO2] is around 8-12 years. So Trenberth is once again an unreliable source.
Fred: you are too kind! But also I fear as wrong as Joel, not least when you say “warming requires a change in the rate of water vapor accumulation in the atmosphere. When the climate is balanced (or close to it), it doesn’t matter how brightly the sun shines as long as it’s constant – it can’t change the water vapor content of the atmosphere, and therefore can’t change temperature as a response”. But as I just noted, atmospheric water vapor varies enormously by location, and has different trends at each: Hilo shows a very high but declining level compared with Barrow (low but rising).
And Fred, please don’t put words into my mouth, leave that to me, as when you say “Tim Curtin’s mistaken belief that the important figure is the 339 W/m^2 solar irradiance entering the climate system” – I have NEVER expressed any such belief and I agree with you “that quantity has no effect on the water vapor contribution to temperature as long as it doesn’t change”, but the water vapor concentration is different everywhere and changes at different rates everywhere, not least because the solar radiation reaching the surface varies enormously and is modified by a whole range of climatic variables including but not restricted to albedo, sky opacity, tau, windspeed etc. etc. Data on these are all available at the link I gave above, but are studiously ignored by Team Trenberth and its fellow travelers like your good selves.
With respect to both of you, why not do some checking of observational data instead of your heavy reliance on a priori reasoning and the dubious science of KT et al. which led the IPCC into eliminating [H2O] from AR4 except as a feedback.
Finally, Bruce, your comment is very interesting. However what ESRL-NOAA call AVGLO (AVErage daily GLObal horizontal total solar radiation) also varies by level and trend, place by place, e.g. down at Albuquerque, NYC-JFK, and Barrow, up at Hilo (1960-2006)!
Tim – I don’t wish to be rude, but while your piece may have political traction in opposition to a carbon tax in Australia, it has no scientific merit at all. Your explanation above evades the main criticism I made earlier, which is that the absorbed solar flux you quote in the article tells us nothing about the sun’s ability to warm via changes in atmospheric water vapor. The fact that there are regional differences may be true, but doesn’t change your original fallacy, which by itself invalidates your argument more or less completely. I found other serious flaws that I won’t dwell on, because I think you have probably gone too far out on a limb publicly with this piece to acknowledge errors here. However, if you are serious about understanding climate change, I invite you to email me with questions about specific points.
I wouldn’t have made the effort to go even this far except that what I see happening is that you are offering your treatise, with political implications, in scientific venues such as this blog, and I believe it’s important for readers to understand that whatever your tax policy positions might be, your article can’t legitimately be used to support them.
I don’t wish to be rude
You’re just too nice to these guys, Fred!
To continue:
Fred,
You ask Tim the question ” if you are serious about understanding climate change”
There’s no question that Tim is serious about opposing a carbon tax and to do that he needs some sort of cooked up pseudo-scientific theory which may seem just about half plausible. So, to that extent, an actual “understanding” of climate change is probably more of a hindrance to Tim than a help.
If Tim finds that somewhat rude, then I’ll take it as a compliment.
Tim,
I think that you have an element of complexity nicely.
So what do we know?
– people are burning fossil fuels to survive and thrive
– the carbon oxidised is a small part of atmospheric dynamics.
‘So, contrary to all our modern instincts, political progress on climate change simply cannot be solved by injecting more scientific information into politics. More information does not automatically reduce uncertainty and increase public confidence, which is the common politicians’ assumption. But, in consequence of that assumption being present and potent in this (or any) politically hot field, there is a constant temptation for experts to overstate and to oversimplify: something that is plainly revealed in the recent history of climate issues…
Contrast two sources. On the one hand, the visually imposing folder ‘Science: driving our response toclimate change; announcing that it is “… providing a clear and impartial response to those who cling to
doubts …”’ (the ‘deficit model’ choice of language is of interest too), published in late 2009 by the Met Office’s Hadley Centre with the imprimatur of three departments of state of HM Government, the seal of State and the logos of many academic institutions. On the other hand, the evident awareness of doubt and puzzlement about matters that the brochure presents confidently, that can be read in the private exchanges between climate scientists in the CRU e-mail archive that was posted at around the same time.’ The The London School of Economics – 2010 Hartwell Paper.
The 2010 Hartwell Paper was written by 14 internationally regarded policy experts – and included an IPCC lead coordinating author.
The authors go on to say more ‘fundamentally than in the realm of politics, over-stating confidence about what is known is much more likely to lead us astray in basic research than admitting ignorance. It locks us into rigid agenda and framings such as the one that gave us the dead end of Kyoto, rather than leaving open multiple, even competing options, that allow for learning and adaptability in moving understanding forward. This dynamic tension has always been the motor force in scientific revolutions.’
There are many people who are incapable of or unwilling to engage in more than a simple minded narrative. So this is the other thing we know? We are dealing with both lies and stupidity.
I have written a new post on measuring DLR
http://claesjohnson.blogspot.com/2011/08/how-to-fool-yourself-with-pyrgeometer.html
I’ve engaged with Claes over at his blog (see above link and related pages). His last comment so far “I will look more closely into this.” – I hope he does!
Has anybody of those modellers try to run a GCM with nothing changed but ALL GHE taken at concentration 0?
An Earth with the same astronomical parameters but with no water and with an atmosphere constituted of only N2+O2.
I have been looking for that during the last year or so but found nothing.
No papers, no models, no computer runs.
Somebody here who was more lucky?
My guess is that the existing models cannot do that, because the effects that would dominate in the pure N2, O2 atmosphere are so weak that they are not taken properly into account in the models. The models have been developed assuming that the basic features of the atmosphere are not totally different from the existing one.
Building a remotely realistic model for such an imaginary atmosphere might be a major task.
Even the theoretical calculations of optically thin atmosphere that can be found from the book of Pierrehumbert and certainly elsewhere assume that radiative heat transfer dominates over conduction and leads to the existence of adiabatic lapse rate over some part of the atmosphere.
Building a remotely realistic model for such an imaginary atmosphere might be a major task.
Not so at all Pekka . It should even be very trivial for any GCM that has a correct dynamical core .
There are no pesky clouds , no precipitation , no chaotic oceanic oscillations , no ice polar caps .
This waterless Earth obeys only to pure Navier Stokes , standard thermodynamics and very easy radiation/convection laws .
The latter could be made by hand , so easy it is .
The only real difficulty is the Navier Stokes part which governs the horizontal winds and the vertical circulation but if a GCM can’t get that at least semi-realistically right , then it can get nothing right .
Tomas,
I agree that the situation is probably easier to model, but it might still be a major effort, because the outcome would be controlled by energy flows that are all very weak in comparison to those considered in standard GCM’s.
One difference is that the atmosphere would be controlled with processes of even more different time scales than the present GCM’s handle. There would be continuous input from the diurnal variations, but conduction would also be important and the influence of conduction is really slow for a system like the atmosphere. The issues related to this must be quite unfamiliar to all. Thus it may be reasonably easy to get a model running, but more difficult to get convinced that the results are correct even at a very approximate level. In addition it would take for ever for the model to converge unless it has been developed to handle effectively the different time scales.
I’m not saying that anything of this would be unachievable, but only that the effort may be too large in comparison to the significance or scientific value of the results.
Pekka, sorry but this is complete nonsense. Conduction would be irrelevant except in a thin boundary layer. The main heat transfer mechanism would be convective circulation, as Tomas says.
Conduction dominates, when nothing else exists. It’s very weak, but more than nothing.
Convection is not ‘very weak’. I wish you would not clog this thread with incorrect comments on a subject about which you know nothing.
I propose the following experiment for Pekka and all those who think that convection is weak compared with radiation.
Light a candle and hold your hand 30cm to the side of the candle. How much radiative heat do you feel?
Now hold your hand flat 30cm above the candle. How much heat do you feel now?
We are discussing a situation, where the convection has stopped, because it cannot continue based on energy balance.
Pekka PaulM is right .
The atmosphere would be dominated by convection which is several orders of magnitude stronger than conduction. Radiation (of the atmosphere) would be the smallest but non zero too even for N2+O2 .
The overall energy transfers would be dominated by radiation but in a much easier way than in the water case. This can be (almost) analytically solved. I have it done on my computer, no hard work.
You somehow seem to suffer of the illusion that all dynamics of the system is only due to GHG . Remove the GHG and all dynamics disappears .
The reality is very different . With or without GHG there would be radiation, convection and conduction . What there wouldn’t be are the HUGE complexities of the water cycle with clouds , ice , rain and oceanic oscillations . So it’s really quite simple and that’s why I thought that I’d find easily a paper or a model .
It should be very obvious for everybody or at least to those who did a minimum of fluid mechanics that even the GHGless atmosphere would exhibit different more or less complex flow modes.
Did you really think that it’d be isothermal and static?
Then give me your estimation of this constant temperature – a number or a finite interval I don’t care.
And then I will show you that your estimation violates the laws of thermodynamics .
The proof is actually rather easy undergrad level and I am surprised that you didn’t think of it yourself already.
Let’s do that, it will at least evacuate some misconceptions.
Tomas,
If we are looking at a situation, where radiative heat transfer is weak, but much stronger than conduction, then the analysis presented in the book of Pierrehumbert for the optically thin atmosphere can be used. That allows doing much of the work analytically, and that does indeed mean that convection dominates over conduction in part of the atmosphere, or stated differently we do have also a troposphere, not only the stratosphere essentially down to the surface.
My comments were specifically for the case where radiative heat transfer is too weak to have much effect, i.e. it’s so weak that conduction can provide easily all the energy that is radiated from any level of the atmosphere in addition of that provided by the absorbed solar radiation at the same altitude.
Tomas
Even better would be Earth as we know it but with CO2 and H2O gaseous molecules having no significant IR emission/absorption.
Oceans, liquid water and clouds allowed.
The liquid water and clouds allowed to radiate/absorb normally.
My guess is that the climate would not alter to a great extent.
Of course you are right Brian . A CO2 less Earth with water would show no significant difference . But my point is more to understand the pure Navier Stokes underlying dynamics . That’s why I look for a model that eliminates ANY and ALL GHG . Jupiter’s atmosphere might be near to that but even there are some GHG .
What do you mean?
A snowball Earth not significantly different from the present?
As for me, what I mean is that there is no reason to have specifically a snowball Earth ad vitam eternam.
The probability for it would be higher than with CO2 but the snowball Earth mode is possible with or without CO2.
So basically what I mean is that the allowed dynamical modes for a CO2less Earth would be the same as for the CO2full Earth but with different probabilities. Snowball Earth included but not limited to.
Tomas,
//”So basically what I mean is that the allowed dynamical modes for a CO2less Earth would be the same as for the CO2full Earth”//
This does not follow. The stable equilibrium solutions depend on the intersection curves of the outgoing radiation and absorbed solar radiation; modern Earth appears to be stable in multiple states, including a snowball. See the following image. The intermediate-temperature solution is unstable and separates the attractor basin of the upper warm state from the lower Snowball state. This can also be plotted vs. CO2 (as in the link you seen above) and for either current insolation or for Neoproterozoic insolation, the zero CO2 mark falls to the left on the bifurcation structure, allowing only a snowball state.
http://www.skepticalscience.com/pics/2_solarbifurcation.jpg
Dynamically, there are many major differences between modern Earth and a snowball. Most noticeably, the high thermal inertia of the ocean is replaced by a low thermal inertia surface of ice, allowing for extreme diurnal and seasonal cycles resembling Mars. Ray Pierrehumbert also has a few papers showing that in the low optical thickness state, the thermal structure of the winter hemisphere relaxes into a stratosphere-like state, becoming inverted or isothermal, which creates an extremely weak greenhouse effect and has a lot of dynamic implications, including increased static stability, which helps determine the natural horizontal
scale for large-scale atmospheric dynamics
Well, they have done a somewhat similar “modeling experiment” of removing all the non-condensable greenhouse gases (i.e., they did not even explicitly take the water out) and the climate got a whole lot colder: http://www.sciencemag.org/content/330/6002/356.abstract
Yes I would think so in some average case where cloudiness and oceanic oscillations are postulated inchanged .
Whether the consequence would be or not an iceball Earth would depend on what the clouds do and nobody has a clue about that .
Tomas,
I think the uncertainties are not even remotely so large. Taking off the CO2 would open the way for so much radiation to escape that there is no doubt about the outcome, the snowball Earth.
Tomas,
Maybe
http://www.realclimate.org/index.php/archives/2005/04/water-vapour-feedback-or-forcing/
or
http://www.skepticalscience.com/co2-free-atmosphere.htm
Thanks .
Looked at both . The second is rather simplist but neither answers what I am interested in . What would be the atmospheric dynamics without ANY GHG?
Here they focus only on CO2 vs H20.
Did you see the Lacis reference in Skeptical science? There are others which you might want to take a look at also.
This says ” removing the CO2 from the atmosphere generates a cooling of around 30 C ”
I’d guess this means a removal of all other GH gases too, and also takes into account feedback effects. In simple terms: the GH effect just about collapses.
Although I didn’t remember off-hand any specific estimate, I knew that the immediate effect is very large and that it’s unavoidable that such an effect leads to the loss of almost all H2O from the atmosphere as well. Even little water can produce some clouds in very cold atmosphere, but there’s no way they could stop cooling. The change in albedo of the surface is another unavoidable feedback.
The Earth would indeed become a really cold snowball.
The situation seems a trifle too theoretical to a natural philosopher such as myself.
‘On geological time scales, the ocean and atmosphere are in equilibrium with respect to CO2 and can be treated as a single reservoir. CO2 is supplied to this reservoir by volcanic and metamorphic emanations, and is removed as sediment in the form of CaCO3 (limestone) and organic matter (roughly CH2O). The atmospheric CO2 forms carbonic acid rain, which is neutralized (protons are consumed) by silicate rock “weathering” (conversion to soil). The resulting solutes include Ca2+ and HCO3- (bicarbonate) ions that rivers carry to the ocean, where CaCO3 is precipitated by calcifying organisms and organic matter by primary producers like cyanobacteria and algae. The entire process is often simply referred to as “silicate weathering”, because that is the rate-limiting step. Silicate weathering rate is sensitive to climate, faster where hot and wet, slower where cold and dry.’
There were probably multiple factors leading to runaway ice growth – resulting in a 50% albedo. There have been no snowball Earths since the evolution of complex organisms – partly the origin of the concept of the ecosphere regulated by the biosphere – the Gaia Hypothesis. Terrestrial vegetation acts to increase the rate of silicate weathering substantially – even in cold conditions.
Oh – and we can’t pretent that we understand the dimensions and topology of the real world climate phase space.
Satellites did not exist prior to 1979. “And since 1979 there’s been an increasing divergence between the thermometers on the ground and those in the satellites. Those on the ground show more warming, and since it’s documented that they’re near air conditioning exhaust vents, concrete slabs, heated buildings and at airports, it seems likely that they’re in the wrong.”
OK, let’s check the satellite records since 1979 with the surface record and see how that pans out.
http://www.woodfortrees.org/plot/uah/from:1979/to:2011/trend/plot/rss/from:1979/to:2011/plot/rss/from:1979/to:2011/trend/plot/hadcrut3vgl/from:1979/to:2011/offset:-0.15/plot/hadcrut3vgl/from:1979/to:2011/offset:-0.15/trend/plot/uah/from:1979/to:2011
Hmm, they look a pretty good match to me. And I’m pretty certain that we would find that the trend for all three records is statistically significant.
The agreement is reasonably good, perhaps even surprisingly good taking into account that the satellites cannot measure the surface temperature but deduce through very complex calculations and based on many assumptions something, which is said to be the temperature of the lower troposphere, bat can be defined precisely only as the result of the analysis. The result is roughly a weighted average of temperatures at various altitudes in the troposphere with some contamination from mountaintops that influence the results.
I’m totally sure that the skeptics would not believe the satellite temperatures at all, if the methodology had not been developed by “their men”, and unless the deviation from other estimates had not been on the side of indicating a little less warming (with a larger difference until some errors were corrected).
The satellite data have clear advantages as well. They can be processed more rapidly, and their coverage is somewhat better, although the extension to highest latitudes introduces additional uncertainties due to the unfavorable viewing angels.
The hilarious thing is that skeptics believe satellite data without realizing that the temperatures they calculate are the result of RTE that they deny.
If any one of them ever looked at radiance at the sensor and then the math required to get , say, LST in the MODIS product, or sea ice area they’d have some serious cognitive dissonance.
Chris, what happens to an IR photon that strikes the water? As state above it essentially disappears and does no warming (may cause evaporation).
What happens to an IR photon that strikes a person?
What happens to an IR photon that strikes any vegetation?
What happens to an IR photon that strikes any objest not the ground?
When IR photon gets absorbed by anything, it practically always causes warming. All contrary claims are just claims not supported by anything.
Warming influences evaporation, but it does so, whatever the mechanism of warming.
An IR photon that is absorbed by any molecule, including water, increases the vibrational energy of that molecule and therefore adds heat to that molecule. The molecule may conduct some of the absorbed energy to nearby molecules. Even if the absorbed heat is latent, i.e. it causes vaporization but does not increase sensible heat measurable by a thermometer, it still counts as warming. And if that IR photon originated from outside the Earth then it adds to the net total heat content of the Earth.
Mkelly
When an IR photon strikes a molecule in a person , vegetation or in anything with an electrical dipole AND has the right frequency then it gets absorbed .
If the molecule has not an electrical dipole OR the photon has not the right frequency then nothing happens , the photon is scattered and travels farther .
This is half of the story . The second half of the story is that in the former case the molecule reemits exactly the same photon but in a random direction . This is basically what Kirchhoff’s law is about . So from the energy point of view nothing happens in either case . The molecule stays as it was and is neither warmer nor cooler . At least as long as we have LTE .
Of course the same is true if the molecule is stricken by anything else and there is a kinetic energy transfer instead of radiation energy transfer .
Tomas,
That particular molecule that absorbs the photon emits only very seldom (typically with probability of 1:10000 or so, but of course this varies widely depending on the material) a photon of the same energy to return to lower energy state. It’s hugely more common that the energy is released in a collision.
Kirchoff’s law tells, that some molecules of that type do occasionally emit radiation of the same wavelength, but those molecules are in almost all cases been brought to the excited state by molecular collisions.
Pekka
This a very common misconception that has been known wrong for more than 100 years.
The Kirchhoff’s law is solidely established physics both experimentally and theoretically.
Collisions don’t make it invalid.
Or do you think that Kirchoff did the validating experience with a single molecule so as to eliminate all collisions and established the law as being valid for only a single molecule?
Collisions are irrelevant for Kirchhoff’s law for the simple reason that collisions work both ways – they excite CO2 AND deexcite CO2 .
And equilibrium is obtained exactly at he point when the rates of both processes are equal.
Just make an easy experiment – put a volume of gas containing CO2 in a spherical IR detector and send 15µ radiation in it.
Without surprise you will observe that the detector registers EXACTLY the same amount of 15 µ radiation as what you sent in and that it is independent of the CO2 concentration.
That’s Kirchhoff’s law for you regardless of how many collsions there take place and how could it be otherwise?
That the temperature at which equilibrium is established may vary is something completely different. Kirchhoff’s law holds in all cases and QM explains why it must hold. There is always exactly as much IR absorbed as emitted for any (absorbed) frequency.
Kirchoff’s law is valid at thermal equilibrium. I didn’t read anything in Pekka’s comment that claimed collisions or anything else made Kirchoff’s law invalid. Your comments did imply that the same molecule always emits the same wavelength, and that there was no scenario in which neighboring molecules were thermalized. At least that’s how I read it. That’s misleading at best.
That particular molecule that absorbs the photon emits only very seldom (typically with probability of 1:10000 or so…
This says very clearly that the (particular) molecule emits very seldom implying that it is independent of what it absorbs.
This violates Kirchhoff’s law.
Of course , as I wrote, we don’t deal here with particular molecules which is where Pekka introduced the confusion.
I even mentionned specifically that Kirchhoff did not establish his law for a single molecule.
We deal here with a large number of molecules. And what I am saying is that for every molecule that absorbs, there is A molecule that emits.
It seemed to me that it would be trivial fo those who write about radiation transfer would know that the Kirchhoff’s law doesn’t apply on individual molecules but on a large number of them and that it is independent fo the collisions that take place within that ensemble.
But to evacuate this strawman, i will onfirm that for a large number molecules in a volume in LTE, this volume emits EXACTLY as much of X frequency photons as it absorbs.
And this result is independent on concentrations and collisions.
Clear enough?
No, what it says is the spontaneous emission rate may be less than the collision rate. Nobody denied Kirchoff’s law, even by implication. A misunderstanding of your comment, whether it is your fault or mine, is not the same as a “straw man.” What I want to know is why you keep assuming thermal equilibrium when we are talking about things that are being heated?
Tomas,
You misrepresent my statement. It’s content was to tell that the succession of absorption and emission without intervening de-excitation and excitation through collisions is a rare exception rather than rule.
I know perfectly well, what’s the content of the original Kirchoff’s law, and I have discussed on this site that and several more recent formulations that are basically equivalent, while formulated quite differently.
In general I agree with your recent comment, but I protested to that one statement of the earlier one, which contradicts in my interpretation the latter one.
How can anyone read the arguments above and still claim there is no scientific debate? Clearly we are struggling to understand, with lots of confusion along the way. That is the nature of science at the frontier.
David like the discussion much farther below shows, we were more struggling with words to make sure that we talked about the same thing than with the actual science.
This is where blogs find their limits because the natural language of physics are mathematics and not words.
As long as we stay with rather easy and superficial questions, words may do.
When it gets really deeper and not intuitively obvious, only maths may convey accurately the concepts. Words will be misinterpreted, not understood, double edged. It will take an unholy amount of time and space to converge to something at least reasonnably correct.
But that’s the plight of science blogs.
Looking at Chen 2007 which compare radiation leaving the earth from 1970 to 2007, it appears while there is a drop in the CO2 range, the
amount of energy leaving is actually up not down.
CO2’s effect seems very small. CH4 seems to have a much bigger effect.
It appears the earth is just radiating more energy to space in different wavelengths.
http://www.eumetsat.int/Home/Main/Publications/Conference_and_Workshop_Proceedings/groups/cps/documents/document/pdf_conf_p50_s9_01_harries_v.pdf
It appears someone opened a window in the greenhouse.
@ Judith Curry
Physicist, Joseph E. Postma publishes a groundbreaking paper that refutes the standard greenhouse gas hypothesis.
It lays out in detail how a model that had originally been devised by astrophysicists to model the energy output of stars have wrongly become the foundation of terrestrial climate models for over twenty years.
http://www.tech-know.eu/uploads/The_Model_Atmosphere.pdf
Isn’t it funny to see “skeptics” be completely not skeptical! No, what it does is show how easily so-called “skeptics” can be confused by lots of equations with some nonsense sentences thrown in.
I love the way the paper he refers to uses exclamation points! someday I think we should do a study of the correlation between exclamation points in a scientific “discovery” and the actual truth
What is the actual truth?
Freshman philosophy was last quarter grasshopper
steven mosher
Another interesting study would be to establish the correlation between the use of the terms very likely or very high confidence in a scientific report and the actual truth.
Max
…Not to mention the fact that opastun just copied verbatim (some would say “plagiarized”) the description from these two sources (or something equivalent):
http://principia-scientific.org/supportnews/latest-news/109-court-orders-university-to-surrender-global-warming-records
http://slayingtheskydragon.com/en/blog/169-evidence-from-top-climatologist-backs-greenhouse-effect-critics
Joel,
I almost agreed with your previous posting, except to say that not all sceptics are 100% wrong 100% of the time.
But to this post, I have to say, “So what!”
Why do you feel the need to dredge up even the most petty and inconsequential nothingness, in an apparent effort to make others look bad?
Leave that sort of nonsense to other individuals, which I shan’t name.
Peter,
I think it is relevant because it shows that the person posting the link to this paper has made no attempt to digest the paper himself and re-explain it in his own words. He has just blindly copied from the “press releases”. Is that skepticism?
Or it could be simply the case that they just thought they’d bring it to our attention in case it would be of some interest to us.
Perhaps the contents of the paper are a bit beyond them being able to digest it themselves.
I have no opinion on the paper because I’ve not read it. I will only read it if and when I get sufficiently interested in doing so.
Based on a very rapid check, the the paper is based on a single layer model of the atmosphere. As that model is totally false the conclusions of the paper are also totally false.
@ Pekka Pirilä
“Based on a very rapid check, the paper is based on a single layer model of the atmosphere.”
Not at all. It is only using this reduced model to explain the common basics of all “Greenhouse Effect” theories i.e. invoking some “extra energy” or “back radiation”. It than shows that these theories originally were developed from astrophysics, where the master pattern is used for self emitting stars and is therefore not sufficient to be applied to a planetary atmosphere. All of this in order to introduce a new radiation budget model for rotating planets with an atmosphere.
For your convenience: it starts from page 19. The summary starts at page 39 and in there at page 41 your “single layer” is referred to as “planes” Have a less rapid check.
I was very brief in my comment. To say a bit more, I think that Jole Shore makes full justice to the paper below. The paper is really total nonsense.
It gets sometimes really difficult to understand, how people, who claim to have related education can continue to produce such material. Are they really so ignorant or are they dishonest?
Pekka says about Postma paper
I was very brief in my comment.
To say a bit more….. The paper is really total nonsense.
Then moves quickly on.
You have to prove your statement by some examples or otherwise your comment is just hot air.
I dont think you can!
Bryan,
You don’t think. Should I be surprised?
My earlier message and the message of Joel Shore told enough. The counterclaims by opastun didn’t change anything. As long as the paper is totally dependent on false claims, there is no point in digging deeper.
Pekka
You say the paper is full of false claims.
Yet you cannot name one.
You endorse Joel Shore.
Joel says that Postma is a liar and of low moral character.
Yet does not advance any reasons for these outrageous claims.
This is the Slayers thread so Postma is most definitely “on topic”
Why are you so frightened?
Burying your head in thesand fools no one.
Bryan,
You can read my formulation of, what I think of people, who behave like Postma, above in message of 3:25 am.
Pekka
You say the paper is full of false claims.
Yet you cannot name one.
Burying your head in sand fools no one.
If you or Joel could find an actual mistake you would not hesitate to bring it to our attention
I think that Joseph Postma should take pride in the fact that Pekka, Joel Shore and other comentators cannot find one false claim in his paper.
His paper is “on topic” here as he is loosely associated with the slayers.
However the thread is still active.
I have done it many times.
I think Bryan should take pride in the fact that he has failed to read the rest of this thread and that he has emerged as the #1 peddler and defending of pseudo-scientific nonsense on at least two websites!
Pekka
Still wainting for ONE mistake in a paper you say is full of them.
Joel
Still more smears but no science content
Bryan,
David N identified one, at http://judithcurry.com/2011/08/10/greenhouse-dragon-technical-discussion-thread/#comment-97728
Bryan: I have explained the basic problems elsewhere in this thread and the other one. I am not going to waste my time further with someone like yourself who just wants to peddle pseudoscience.
In fact, I would recommend that you go far and wide over the internet broadcasting G&T’s paper and Postma’s paper and your opinion that they are brilliant and most people can’t find any serious fault in them. I recommend doing this particularly on sites with lots of scientists and I would love it even more if you would tell them that your views are representative of most AGW “skeptics” (although this would not really be quite true). I am sure it would do a great job of increasing the credibility of yourself, Postma, G&T, and of the AGW “skeptics” in general if you were to do this!
Peter: Okay, but I think if you bring something to someone’s attention, you can do it without quoting the advertisement for it verbatim (and not tell people that you are quoting it but leaving the impression that it is your description).
Pekka: Yeah…although it is rather worse than that. He uses the single layer model, claims it is the “standard model” of the greenhouse effect and then when it fails, he claims that this means the greenhouse effect is not real. He also writes a bunch of nonsense to try to convince people that the effective radiating temperature of 255 K vs the average surface temperature of 288 K has no meaning. (E.g., he computes local effective radiating temperatures based on local insolation, argues that you have to distinguish between night and day…and basically does everything to hide the fact that the effective radiating temperature comes from satisfying a ***global*** energy balance equation between the sun, the earth, and space.) In other words, it is written to fool the people who want to be fooled. I guess it shows that when people want to be lied to, liars flourish.
Joel says of Postma
He also writes a bunch of nonsense to try to convince people that the effective radiating temperature of 255 K vs the average surface temperature of 288 K has no meaning. .
Bunch of …..!!!!!!
Not very specific.
Take it slowly
Some examples please
Joel
What proof do you have that Postma is a liar and of low moral character.
Bryan: Examples? It constitutes most of the paper. Postma is deceiving people on the very basic relationship governing the surface temperature in the absence of a greenhouse effect. He does all these sort of backflips about night vs day and solar zenith and all this other nonsense to avoid dealing with the fact that the simple criterion is that, on a global scale, the total amount of energy received by the planet has to equal the total amount emitted when it is in radiative balance. (And, if it is significantly out of radiative balance, the planet will rapidly heat or cool. For all the talk about the rapid warming that doubling CO2 is expected to cause, we are talking about being out of radiative balance by on the order of 1%.) There is no such criterion about what must happen locally, as there are plenty of mechanisms for moving energy from place to place on the earth and within its atmosphere.
As for my personal assessment of Postma and people like him who write pseudoscientific treatises like this: People who have the background to know that what they are saying is scientifically nonsense but say it anyway for the purpose of deceiving others are, in my view, people of low moral character. I suppose one could alternatively argue that Postma is really this self-deluded. However, I find that extremely difficult to believe (although obviously I can’t prove it is not so).
Joel
You say that Postma is a liar and of low moral character because he does not believe in the greenhouse theory.
Yet you not advance any other reasons for these outrageous claims.
The last person who thought a smear was a good tactic to advance was the late and unlamented Senator Joe McCarthy.
This is a despicable tactic and you should be thoroughly ashamed of yourself
Perhaps we should contrast Postmas model with one that Joel approves of.
He should because he part wrote it.
http://scienceblogs.com/stoat/upload/2010/05/halpern_etal_2010.pdf
On page 1318
We have a two layer model which produces 80K temperature distribution in the troposphere.
The authors did not need to include the Earths Gravitational Field acting on the air or any other thermodynamics to get this distribution.
In page 1317 they seem quite happy to talk about the single slab model that Postma used.
On 1316 you should ignore the part about heat moving from a cold surface to a hotter one.
Joel admits that this was a mistake and that all the authors were a bit vague about the meaning of heat at the time.
Of course Joel will by now have written to the Journal and admited the mistake.
Its that kind of approach that distinguishes a real scientist from a pseudoscientist
Bryan,
At a few points in our paper, we used the term “heat” where we should have used “energy”. You seem to be the only one who is incapable of making the change at the appropriate places. Journal editors are not interested in issuing corrections for minor wording issues.
So Joel for a “real” scientist like yourself there is no distinction between the term heat and the term energy.
Joel says
“At a few points in our paper, we used the term “heat” where we should have used “energy”.
Joel expects the readers of the Journal to second guess what the authors were trying to say.
This surely, is the hallmark of a “real” scientist!
Bryan: We are all human and capable of mistakes. It is possible to forget conventions of terminology that are basically arbitrary. That in radiative transfer, the term “heat” is reserved only for the net flow of radiative energy and not the individual flows (and hence the term “net heat” that we used is redundant) is a convention that I had forgotten, so we slipped a few times in the paper. That you can’t stop harping about this shows how small-minded you are.
What is more important is to get the concepts correct. You apparently defend conceptual nonsense as long as people use correct terminology in expressing their nonsense.
I have explained it to you and yet you still refuse to understand it. Nobody else has seemed to have any problem with it. I am now more careful to use the terminology correctly. Lesson learned.
On the other hand, you defend G&T but refuse to even explain what they were trying to say in regards to the Second Law. On the other hand, I don’t blame you since if you did try to explain it you would run into the problem that there is no coherent explanation because it is complete nonsense.
Bryan,
I don’t think your harping on this is adding anything but noise to the thread. On the other hand, since it is the goal of those peddling pseudoscience to try to obfuscate and distract people from the science, I guess you are just doing what you do best.
Okay…I just realized that someone would have to have three hands in order to read my last post. Sorry for the overuse of trite expressions.
Joel after careful reading gives his assessment.
This is how a “real” scientist with withering logic eliminates false or pseudoscience?
1. Postma is deceiving people on the very basic relationship governing the surface temperature in the absence of a greenhouse effect.
Joel gives a factless assertion here.
2.He does all these sort of backflips about night vs day.
Joel gives a factless assertion here.
3.solar zenith and all this other nonsense
???????????????????
4.to avoid dealing with the fact that the simple criterion is that, on a global scale, the total amount of energy received by the planet has to equal the total amount emitted when it is in radiative balance.
Postma and Joel agree(radiative balance) I can give you page numbers.
5. For all the talk about the rapid warming that doubling CO2 is expected to cause, we are talking about being out of radiative balance by on the order of 1%.)
I think Joel would lose people with the relevance of this remark.
6. there are plenty of mechanisms for moving energy from place to place on the earth and within its atmosphere.
Postma and Joel agree
That s how a “real” scientist disposes of pseudoscience.
You are surely impressed!
Now Postma must pay for doubting the greenhouse theory
“As for my personal assessment of Postma and people like him who write pseudoscientific treatises like this: People who have the background to know that what they are saying is scientifically nonsense but say it anyway for the purpose of deceiving others are, in my view, people of low moral character. I suppose one could alternatively argue that Postma is really this self-deluded. However, I find that extremely difficult to believe (although obviously I can’t prove it is not so).”
News for you Joel
You have not proved anything at all other than you can make smears that outdo Senator Joe McCarthy
@ Peter317
“Or it could be simply the case that they just thought they’d bring it to our attention in case it would be of some interest to us.”
So it is.
“Perhaps the contents of the paper are a bit beyond them being able to digest it themselves.”
No it isn’t or to some content perhaps.
“I have no opinion on the paper because I’ve not read it.”
Fair enough.
Peter: “Leave that sort of nonsense to other individuals, which I shan’t name”. (@joel) Thanks for stating this in the first place. I now am beginning to understand the modus of replying at this blog and there is some delay in my answering as well (’cause living at the other side of a rotating planet?).
Some visitors here seemed to have had problems with my “verbatim”.
Sorry for that, it was only to be efficient and not wanting to spend all day with blogging.
Are you asking Judith to peer review this?
Pekka: “I think that Jole Shore makes full justice to the paper below.”
How did he?
“The paper is really total nonsense.”
Why?
“It gets sometimes really difficult to understand, how people, who claim to have related education can continue to produce such material.”
Aren’t climatologist a related education branch of e.g. geologists and astrophysicists? (the other way around is what I meant)
-Competence tends to produce HQ-
“Are they really so ignorant or are they dishonest?”
Does this refers to “travesty” or “hide the decline”?
Pekka:”As long as the paper is totally dependent on false claims, there is no point in digging deeper.” (from your comment @ Bryan)
Could you please be so kind and mention just only one of these “false claims”? Would be helpful to understand your point of view.
As long as there is no correct description of the atmosphere including the role of the adiabatic lapse rate and of the radiative heat transfer, nothing of interest can be presented.
Even mentioning the one layer model without immediate continuation to multilayer models or preferably to continuously changing temperature leads the paper to totally false paths.
There is nothing relevant in it. Some parts certainly agree with accepted physics, but as soon as the paper differs from that, it goes astray.
Whatever your opinion of his paper Postma does say “Greenhouse theorists treat the entire Earth as a fully-illuminated disk (with no night-time)”. Is he right about this? If so would that not make the GCMs very seriously flawed?
No…He is wrong on that. He just looked at one simple model of the greenhouse effect and claimed this is “the standard model” of the greenhouse effect. It is not. It is just the simplest model that qualitatively illustrates the effect.
Joel,
By that simple model, the average insolation at the surface is 0.7(1374 / 4) = 240W/m2, which gives a radiative equilibrium temperature of -18C
Is that accurate, or do other models give a different figure?
No…That is accurate. It is simply based on global energy balance requirements.
[There are some things to point out, such as that what must balance is the radiative output, i.e., proportional to epsilon*T^4, so you have to average this quantity of the surface, which is not exactly the same same as averaging epsilon and averaging T and then taking that average to the fourth power. However, in practice, the emissivity epsilon is very close to 1 for ,most terrestrial surfaces and T does not vary enough over the earth’s surface for the difference between averaging T^4 and taking the fourth root to give a result very different from averaging T. However, it becomes important for bodies like the moon that have little atmosphere and very large temperature swings.]
Joel,
You see, that is what I have a problem with.
The average surface temperature is 15C, which means it must radiate 390W/m2, which is 150W/m2 more than it’s receiving.
Now I know that averaging T^4 is not the same as (ave(T))^4, but, as you yourself say, the difference isn’t large.
But the surface is still radiating around 150W/m2 (or 62.5%) more than it’s receiving, so where does that extra energy come from?
Either I’m missing something fundamental, or there’s something fundamentally flawed in the model. Which is it?
Joel,
Don’t bother answering my last post – I think I’ve just answered my own question
Pekka: “As long as there is no ………, ”
Give me a break, read the paper! Should I call you page AND line number? It is all in there! Especially the “the role of the adiabatic lapse rate”.
“Even mentioning the one layer model without….., ”
Common, we’ve had that one above. You were wrong by not having read the paper, which you now are tentatively admitting.
“Some parts certainly agree with accepted physics, but as soon as the paper differs from that……, ”
Were exactly differs this paper from accepted physics?
Please mention just only one example.
I have read enough of the paper, and I have told in several messages, how it fails. Why should I do it once more, or why should I discuss the paper any more, when the basic model used in it’s argumentation is neither correct nor proposed by main stream scientists as a valid model.
It is sometimes used as a first step in derivation of more complete and more correct models, but that’s a completely different matter. Willis Eschenbach has used that approach at WUWT. In this comment he explains why the single layer model fails. He doesn’t claim that the single layer model would be anything else than a simple first step in one approach of understanding GHE.
Pekka: It is sometimes used as a first step in derivation of more complete and more correct models, but that’s a completely different matter….
opastun 2:21 :: It is only using this reduced model to explain the common basics of all “Greenhouse Effect” theories i.e. invoking some “extra energy” or “back radiation”. It than shows…….
forgotten?
No…He doesn’t. He uses it to conclude: “The model which is presented, as we have presented here, is obviously incorrect with a minimum of analysis and application of logic, so we must ask: Why do we not have a valid simplified model of the GHE?”
The answer is that no model, particularly a very simplified one, is ever completely correct. Our model of gravity is not correct, as noone has been able to reconcile it with quantum mechanics. You can get a more correct model by adding additional complexity. That’s the way the Universe works.
The abstract of his paper claims:
“This is a model whose boundary conditions are widely accepted ..”
That’s nonsense. The boundary conditions are known to be seriously wrong. The model can explain that there is a GHE, but nobody thinks that it can describe even remotely correctly the whole effect (OK, I have seen one skeptic’s article, which has used this model claiming that it proves that GHE is very weak, thus at least one person thinks otherwise).
He claims that he presents in the paper a better model, but he doesn’t do that. He presents some discussion on, what he thinks important to include, i.e. day/night variation, but he doesn’t get even close to presenting a model.
There are the standard errors like claiming that adiabatic lapse rate is automatic even without convection (but what about stratosphere).
It’s so stupid to disregard well known and solid physical understanding and to start from essentially scratch leaving essential things out of the consideration and making all kind of errors all around.
=====
Why don’t we have a simple and correct description of the GHE. That’s because the effect is so dependent on many details. The basics of radiative energy transfer must be understood. The result depends on the absorption spectra of various gases. The explanation has to include a correct description of the lapse rate. We have seen reasonably good short descriptions of many of the related issues, but the whole is not so simple. The recent Physics Today article of Pierrehumbert is, however, a good starting point, but even that is written for the audience of Physics Today, i.e. to physicists.
Pekka says
The abstract of his paper claims:
“This is a model whose boundary conditions are widely accepted ..”
I think he is referring to the IPCC type greenhouse model here, but I might be wrong
Pekka says
“There are the standard errors like claiming that adiabatic lapse rate is automatic even without convection (but what about stratosphere).”
If we had a very still dry column of air- very difficult to arrange I know.
Heated from the bottom and with radiation at the top escaping to space.
Would the temperature profile of the column not follow the dry adiabatic lapse rate?
The stratosphere would be a separate physical situation to the troposphere.
No convection to speak of.
Bryan,
He is definitely referring to the model that he presents as “the standard model”, i.e. the model he presents at the beginning of the paper.
Reading the paper he returns to this model time after time using its failures as proof of failure of main stream understanding of GHE, but that is a pure case of strawman argumentation, because the model is not a model of main stream science.
Concerning your second question.
As far as understood your description that column would have the temperature profile of adiabatic lapse rate. When a gas column is heated from below and otherwise insulated but capable of radiating from the top, the column would rapidly approach the adiabatic lapse rate. How fast the approach goes depends on the heating power and the rate of radiation at the original temperature of the top.
When sufficiently time has gone the column becomes stationary with that temperature at the top that radiates with the power of the heating of the bottom. The temperature profile of the whole column is then very close to the adiabatic lapse rate (slightly larger to maintain the required rate of convection).
The point of the stratosphere is that in contrast to it, convection is needed to reach the adiabatic lapse rate. Postma made the claim that convection is not essential. In some cases the convection may be very weak and stop occasionally, but it’s necessary in practice for the adiabatic lapse rate.
Pekka
Perhaps you wont want to comment on Joels model.(see post above)
Joel does not mention the role of the adiabatic lapse rate.
Yet Postma not only describes it he has derived the formula for it.
The one layer model is discussed in both papers.
Pekka Pirilä | August 11, 2011 at 11:12 am
David N | August 11, 2011 at 11:24 am
Tomas Milanovic | August 11, 2011 at 11:53 am
I should have said IR photons produced by CO2. Apologise.
However, you show that because the earth is covered by oceans, lakes, rivers, and vast tracts of vegetation thus increasing evaporation and eventual cooling. It is hard then to say that IR from CO2 heats the ground when it is difficult for it to get to the ground.
Tomas, did you mean to say “reemits exactly the same photon” that would be impossible. Further at what point does entropy cause either a frequency change (cooler). In any energy exchange with a dT involved entropy must enter in I would think.
David if we cannot measure it with a thermometer it is tough to argue it got warmer.
Pekka I would only agree if the object being struck is “cooler” than the photon. A 15 micro emission from CO2 is not going to warm water that is already at 75 F.
Mkelly – to that last statement – sure it will. It just has to find a molecule vibrating with the right energy somewhere in the water.
However, a packet or parcel of CO2 at less than 75F will not warm the 75F water, because the water is busy radiating faster than the CO2.
BillC says: However, a packet or parcel of CO2 at less than 75F will not warm the 75F water, because the water is busy radiating faster than the CO2.
You inferred what I implied.
mkelly, if you have ice at 0 C, then water at 0 C, it’s hard to argue that it didn’t get warmer.
Ya that 0 C thing is different. I understand your contention, but the way that global warming is shown is with a measured temperature. If you cannot measure a change it is hard to argue it got warmer.
latent heat added to a system may become sensible heat elsewhere. Evaporated water molecules have added kinetic energy and may later transfer that energy to something else, raising it’s temperature.
A photon doesn’t have a temperature. it’s just a packet of energy (for these considerations). A longer wavelength photon is a smaller packet of energy and heats therefore less than a shorter wavelength photon, but both heat the absorbing material independently of its temperature.
A photon has a temperture associated with it via it frequency. A material at a higher temperature than what the recieved photon can impart will not gain in temperature at least this is what I was always taught.
That’s not a temperature. A body of certain temperature has an emission spectrum peaking at some wavelength, but the temperature is a property of the body, not of the photons. The individual photons do not have a temperature.
Sometimes the concept of color temperature is used, but that refers again to the temperature of a body that emits light which appears similar to the eye. It’s a property of the whole spectrum form by all related photons, not of any single photon.
No. Photons don’t have temperature, but can have different energy levels, if I may put it that way.
Think of photons as raindrops and temperature being the level of water in a container. The raindrops have no ‘level’, but they are larger or smaller, equivalent to a photon’s energy level.
The larger the drops, the faster the water level will rise.
I didnot say photons have temperture I said they have one associated with them via freqency.
The most serious error was your statement:
That’s totally wrong, and that’s the reason for my reaction.
What is it you disagree with?
First every photon heats the body that absorbs it.
Second any radiation from any source heats a body compared to a situation, where that radiation doesn’t exist.
Temperature is a property of a body, not of a photon.
If you continue to bombard a body with photons, the temperature of the body will continue to rise, for as long as the energy flow to the body exceeds the energy flow from the body. Hypothetically, if there’s no energy flow from the body, its temperature will continue to rise towards infinity regardless of the energy level of the photons.
mkelly, could you provide the formula for a photon’s temperature?
David again I never said photons have a temperature. I said the have one associated with them via frequency. Wiens Law.
But, that is just characterizing the distribution. How does a warm body know if the photon is from a cold body or it is just one in the tail of the distribution from a warmer body?
Anyway, we can lead you through this Socraticly but the simple point is that your notion of reality is in complete conflict with over a century of physics. In other words, it is simply nonsense.
Wien’s Law describes the distrubition of wavelengths of light emitted by an ideal blackbody at a given temperature. The temperature is of the emitter, not of the photons.
“Pekka I would only agree if the object being struck is “cooler” than the photon. A 15 micro emission from CO2 is not going to warm water that is already at 75 F.”
This misconception deserves its own thread. Just looking at one small part of a larger process is fine if you don’t lose track of the whole. A photon from one object can be absorbed by another without regard to temperature, but at the same time the warmer object is trying to cool by warming the cooler object. That is why you should think of the net flow or flux.
When CO2 releases a photon it just happens to be in the 15 micron range due to the spectrum unique to CO2. That 15 micron wavelength limits the depth of penetration in water leading to the magic skin layer heat transfer debate which seems to confuse the heck out of people. Heat still flows from warm to cold, the 15 micron photon that randomly happens to go against the direction of flow is just an example of how greenhouse gases retard the rate of flow. At the surface, CO2 has little impact because it makes up only a tiny fraction of the molecules and only impacts a small portion of the IR spectrum. That should be the main point of the conversation.
At the top of the troposphere, CO2 becomes more significant because there are fewer players in the game. So you could define layers where CO2 has different degrees of significance. So at what point in the atmosphere does CO2 photons emitted opposite of the direction of heat flow equal 0.1 percent of the net heat flow?
At the surface, CO2 has little impact because it makes up only a tiny fraction of the molecules and only impacts a small portion of the IR spectrum.
Dallas – The fraction of the total at the surface is about the same as at other altitudes. The portion of the IR spectrum is a relatively small but significant fraction of Earth’s IR emissions, because it is situated near the peak of those emissions at average surface temperatures, and because CO2 is changing from anthropogenic emissions (which also changes water concentration and its own greenhouse effect at other parts of the spectrum). The reason that high troposphere CO2 is more critical to greenhouse effects is that it is at these altitudes where changes in concentration most affect the ability of radiation to escape to space, not because the concentration of CO2 as a fraction of the total is higher.
Water vapor decreases with altitude, so CO2 has a lower impact close to the surface especially over the oceans. Also the concentration of nitrogen and oxygen decrease with altitude. They have heat so they emit IR plus the higher their concentration the more likely there is CO2 heat transfer via collision which has a broader spectrum. So I disagree that the fraction of the IR emitted by CO2 is relatively constant with altitude. As water vapor decreases, the IR spectrum changes for that layer of the atmosphere. So while CO2 is pretty well mixed, its IR impact as a fraction of the total outgoing IR changes with altitude and water vapor concentration.
At the surface of the ocean, CO2 is much more likely to transfer heat via collision, so its IR emission at 15 microns, the greenhouse component, is extremely low, it may as well be nitrogen, or any other gas. So the question is, at what point is the 15 micron IR emission component of CO2 equal to 0.1 percent of the outgoing IR?
Dallas – Nitrogen and oxygen emit almost no IR at all at atmospheric temperatures. You are right in saying that CO2 has more impact at higher altitudes, but your earlier statement that it constituted a tiny fraction of total molecules at low altitudes and much more at higher altitudes was wrong – the fraction is about the same (ppm is typically expressed as a fraction of dry atmosphere, but even if water is included, its lower ppm at high altitudes makes little difference to CO2 ppm)..
Fred, at low altitude CO2’s overall contribution is higher than its 15 micron contribution. With water vapor at roughly 1% at the surface of a warm ocean and CO2 at 0.038 percent, that would be a small fraction in my way of thinking. Once you include the much broader spectrum of water vapor the small fraction borders on insignificant at sea level. That is why CO2 is more significant at higher altitudes and the polar regions. That is simple to understand I think.
The issue of Nitrogen and Oxygen emitting “almost” no IR is more interesting. With no greenhouse gases, the Earth would be roughly 33 degrees cooler. With no atmosphere at all it would be cooler than that. So that almost no IR is not zero though the conductive/collisional heat transfer is much more important. They still make a contribution to increasing the average temperature of the surface.
Then even more interesting is the point where doubled CO2 15 micron emissions become significant. The spaceward window is wide while the surface window is much narrower. Since there does seem to be lower sensitivity to CO2 doubling than expected, I would suspect the simple two dimensional radiation models were seriously lacking and the better models could use some tweaking.
“With no greenhouse gases, the Earth would be roughly 33 degrees cooler. With no atmosphere at all it would be cooler than that”
Dallas- With no greenhouse gases, I estimate the Earth would be almost as warm as it is currently (probably about 8 C cooler). That’s because a world without water to form snow and ice will have a much lower albedo and therefore absorb much more solar energy. Diurnal variations would be far greater, however. With no atmosphere at all, it would probably be slightly warmer than a world simply without greenhouse gases, because atmospheric molecules themselves contribute to albedo via Rayleigh scattering.
For all practical purposes, nitrogen and oxygen can be considered to have zero IR emitting properties at the temperatures and pressures of the Earth’s atmosphere. Their main contributions to IR emissions involve pressure broadening of CO2 and H2O emission lines.
The reason CO2 is significant at high altitudes has less to do with the paucity of water and is instead due mainly to the fact that it is only at these altitudes that enough radiation can escape to space for changes in optical thickness (tau) to make a discernible difference.
” because a world without water…”
That’s is the difficulty with thought experiments and estimating the impact of greenhouse gases, you have to tightly constrain the possibilities. So I should invoke magic to maintain a constant albedo.
The point I was trying to make is that at the surface much more than just radiative transfer in the narrow band of 15 microns is going on. So with all factors held constant except for the radiative impact of greenhouse gases, you would have an average surface temperature above that of a like planet with no atmosphere. Then you add water vapor and CO2 resulting in another average surface temperature that is higher. Remove the water vapor and there is another temperature. With CO2 only, the temperature would be closer to the no greenhouse gas average than the water vapor planet. You do the same thing at the tropopause which has a much lower water vapor concentration and CO2 makes a much large difference.
So I think it is ill advised to try and explain the CO2 role in the greenhouse effect at the surface or with any analogy that impacts anything other than 15 micron radiative heat transfer. The space blanket analogy is limited because it reduces convection and retains moisture as well as having a radiative impact.
My best explanation is the sky has a temperature. Then you can explain how as the average temperature of the sky increases, the surface temperature increases, the top down effect. To do that you find the layer in the atmosphere where CO2 has the most impact and work your way down.
The low altitude CO2 is important in absorbing radiation from surface at wavelengths where the absorption is relatively weak as it is further out in the tails. The higher altitude CO2 is more important, at wavelengths of somewhat stronger absorption. At the center of the 15 um peak, where the absorption is very strong, the amount of CO2 has little effect as the absorption is saturated on those wavelengths even in a rather thin layer of atmosphere.
Another way of looking at the importance of CO2 is that it’s not important in situations, where convection changes automatically to compensate the effects due to a change in CO2 concentration. That’s more true in the lower atmosphere than close to the tropopause, where the amount of CO2 is one of the factors that determine the altitude and temperature of the tropopause.
Mkelly
Sorry . I wanted to say reemits a photon with exactly the same frequency.
As photons are bosons, the can’t be distinguished “individually”.
I don’t understand why you introduce entropy.
Entropy is a statistical measure of the number of microstates and we are talking here about a single molecule and a single photon.
If one takes a vast number of molecules and of photons then if you count the numbers of photons of different frequencies , they will be distributed so that the second law is respected.
But if you take a BB curve of any body f.ex at room temperature, you will see that it emits both UV photons and radio waves. There is only very few of them ;)
It is not because you happened to catch an UV photon that the body has a temperature of thousands of degrees or because you happened to catch a radio wave photon that it is near absolute 0 K.
What counts for entropy are the proportions of all of them.
I can accept that. It is different than what was taught in class, that all interactions involving energy tranfer and heat there must be an entropy change. dS = dQ/T
If you say that individual interactions don’t have to obey then we are left with hoping that the correct amount will obey in the end.
Entropy will increase with T, chaos increases(chaos disperses), radiation for example =εσT1^4. Emissivity being equal to absorptivity, means that an object cant heat above the source… because it would be radiating equal to what it absorbs at equilibrium. But that dosnt mean that it dosnt absorb radiation from a cooler object, it just means that this energy will just offset loses.(it will be radiating more energy than what it receives from a cooler object)
A T increase causes a negative feedback, the emissivity of the ground is higher than the emissivity of the atmosphere… but it has to heat first.
Yes you were taught well Mkelly and yes that is what I (kinda sorta) say.
Yet what I say is not different (e.g in contradiction) with what you have been taught.
It is extremely dangerous to jump from the macroscopical representations symbolized by dS = dQ/T to microscopical representations symbolized by S = k.LogW if one doesn’t know EXACTLY what one is doing.
The macroscopic representation is easier and doesn’t ask for too much knowledge. That’s why it is taught first. At that stage S is just a mysterious function of thermodynamical macroscopic variables that has an universal interesting property called the second law.
The microscopic representation is much harder and necessitates to master more mathematics and physics (mostly statistical and Hamiltonian mechanics).
The vocabulary, the equations and the concepts are different from the macroscopical representation too. But it is this view that explains that there is no problem of having very high energy photons (that must NOT be equated with very high temperature macroscopical bodies!) absorbed by very low temperature bodies.
It is only when one sloppily mixes together the macroscopical and microscopical views that one may (wrongly) think that there is a second law problem.
There is no problem of having very high energy photons (that must NOT be equated with very high temperature macroscopical bodies!) absorbed by very low temperature bodies
Yes that too but I think that you have no problem with this case.
But of course it is also true that :
There is no problem of having very low energy photons (that must NOT be equated with very low temperature macroscopical bodies!) absorbed by very high temperature bodies
Tomas,
It appears that my reaction above was wholly based on that you were not careful in saying, what you thought.
Pekka
One is never too carefull and to be fair I also admit that my reaction much farther above was triggered by a formulation of yours which seemed to doubt Kirchhoff’s law.
Such things may happen and that’s why in some (technical) threads there may be up to 50% of the content and discussion that is in fact only reformulating so that the participants are sure that they really talk about the same thing.
On the other hand I have read so often people saying that CO2 can NOT radiate on absorbed frequencies (what would of course lead to a perpetuum mobile among others) BECAUSE it deexcites exclusively by collisions, that I see it implied in not carefully formulated statements.
So we agree on that point which is only rather basics QM anyway.
What stays is that I don’t agree at all that the CO2 (or other non condensing trace GHG gases) play a leading role in Earth dynamics.
I do not see the system as a statical deterministic equilibrium system.
I certainly disagree with statements like
The stable equilibrium solutions depend on the intersection curves of the outgoing radiation and absorbed solar radiation; modern Earth appears to be stable in multiple states, including a snowball.
There are NO stable solutions, the system is perpetually and violently out of equilibrium, the phase space is infinite dimensional, the dynamics are chaotic and the attractor is infinite dimensionnal too.
Only probabilities of states are computable and there is no unique deterministic state where the system MUST go with 100% certainty.
Yes, when all is said and done, the GHGs have an insulating property which would lead to an equilibrium state with certain other properties IF AND ONLY IF the system really went to this equilibrium state.
It never did and will never do. On the contrary it kept chaotically oscillating during 4.5 billions years at all time scales. No stable states (fixed points in phase space) exist as long as the Sun provides energy and the system dissipates it by travelling through its infinite dimensionnal attractor.
Some degrees of freedom rather contribute to warming and others to cooling. It’s their non linear interaction and the strength of the coupling functions that make the system oscillate between warming phases and cooling phases.
That’s why I find these discussions about “greendragons” and radiative properties of this or that gaz amusing but irrelevant.
To use an analogy – I mostly feel like if people tried to throw QM (also a field theory in an infinite dimensional Hilbert space) away , arbitrarily choose 1 or 2 degrees of freedom of the fields, neglected the infinity minus 1 or 2, and came out with a purely deterministic 1 or 2 dimensional model.
Actually there are such people and their theories may even match the reality here and there.
But they are of course hopelessly wrong because they use a wrong paradigm.
Tomas,
We both have evidently worked enough with physics to agree on much. When we move to areas, where solid knowledge is lacking and subjective judgment has a major role, it’s natural that we often disagree on what’s most likely to be true, or on the relative weight of arguments that lead to different quantitative conclusions.
Words like “stable” or “equilibrium” are commonly used imprecisely, sometimes totally against the true state of matter, sometimes as a reasonable approximation of the truth. Specifically the word “equilibrium” may refer to full equilibrium or partial equilibrium. Nothing related to climate or the Earth system is ever in full equilibrium, at best the system may be close to a stationary state. A partial equilibrium is on the other hand often a useful description for the relationship between some specific variables.
Pekka
Well I can subscribe to that unconditionnaly :)
So let’s only say that what I regret is that there are too few scientists that work on the Earth’s dynamics from the point of view of field theory, a kind of generalised and much more rigorous Tsonis approach.
What I see is that those who understand the tools of field theory and non linear dynamics consider climate science as a minor disciplin and prefer to work on other fields while those who do climate science have neither training nor understanding of field theory and non linear dynamics.
This is of course detrimental to progress because it is much easier and more convincing to “downgrade” a theory by demonstrating that this or that assumption is a fully legal simplification than to postulate (or hope) that a simplist theory will be shown one day as being a valid approximation of a more correct and detailed theory.
Sometimes it works – Newton is a valid approximation of GR for infinite speed of propagation of interaction even if the assumption of infinite speed is itself wrong . But this insight had been only discovered the day when GR was established .
But sometimes it doesn’t work .
In the climate case my experience with non linear dynamics leads me rather to the conviction that the current low dimensional quasi equilibrium deterministic theories are no valid approximations of the full dynamical field theory of the climate which has yet to be established.
There’s still some discussion of the GHE on Venus on the original dragon thread. There are also some basic issues discussed on this thread that have been discussed innumerable times before. Several of these issues are in my view resolved using the following relatively simple way of looking at the issues.
Thick atmosphere with some GH gases provides an efficient insulation of the surface from the open space. GH gases are essential in that, because the connection to the space that must be cut off by the insulation is IR radiation. The planet (Earth or Venus) as whole must radiate as much IR as it absorbs solar SW, but the insulation moves the origin of escaping radiation to higher levels of the atmosphere and makes the energy transfer from the surface to those layers weaker.
It’s important that neither radiation nor convection or any other mechanism couples the surface to the upper atmosphere too strongly. For the radiative heat transfer this requires enough GHGs and that part of the insulation is the stronger the higher the concentration of GHGs and the more complete the coverage of the whole IR spectrum.
Convection is a very effective mechanism for energy transfer as long as the adiabatic lapse rate is exceeded, but it stops at the adiabatic lapse rate. Thus convection determines the maximal lapse rate that can have good insulating properties.
When the insulation is good, little heating of the surface can make it very hot. This is, what happens on Venus. The heating of the surface is not strong, but the insulation is so good that the surface gets very hot with that heating.
The Earth is not nearly as extreme a case as Venus, but the same principles hold here as well.
pekka: “The Earth is not nearly as extreme a case as Venus, but the same principles hold here as well.”
They sure do.
http://www.ilovemycarbondioxide.com/pdf/Understanding_the_Atmosphere_Effect.pdf
Venus is explained from page 22 on.
Nothing that Postma has written on these issues is worth reading. I have done enough of that to become fully convinced that one cannot learn anything correct from him, only get confused.
Yet, you ignore that the atmospheric effect on Venus is actually made up of reflective clouds along with standard radiative theory.
On Venus the radiative temperatures in the upper atmosphere are very similar to earth yet it is dumping far more energy due to the volume of the radiative area.
These are things that must be studied in far more detail before we can make such positive statements about what exactly is happening. I reject the idea that we fully understand what is happening in our own atmosphere much less Venus!!
opastun: All Postma has done is succeeded in fooling you. Yes, you can calculate the surface temperature in the atmosphere by starting at the place where the temperature is equal to the effective blackbody temperature and extrapolating down to the surface using the adiabatic lapse rate (assuming that the adiabatic lapse rate holds over this whole range, which it will provided that you are in the part of the atmosphere sufficiently heated from below that it undergoes convection).
However, the question that Postma has failed to address adequately is: “What determines where the temperature is equal to the effective blackbody temperature?” And, the answer is that this is determined by the point at which the optical thickness of the atmosphere above to the (IR) radiation emitted by the planet is small enough that most of the emitted radiation escapes to space rather than being absorbed. And, this is of course determined by the composition of the atmosphere, and specifically by its IR-absorbing properties…in other words, by the greenhouse effect.
This is all well-understood science that is found in any serious textbook on climate science or planetary atmospheres or atmospheric radiation. Of course, Postma knows that his intended audience won’t be familiar with those books and thus he can fool them as he has you.
By the way, consider this sentence on p. 23 on the Postma piece that you cite: “So on Earth, we see that the atmosphere has a net cooling effect, because the average ground temperature is less than the maximum temperature the Sun can provide underneath its zenith.” If you read that sentence and don’t see that it is utter nonsense then you frankly don’t have the background or understanding to distinguish between real science and the pseudoscientific nonsense that Postma is snowing you with.
Joel Shore says: “Of course, Postma knows that his intended audience won’t be familiar with those books and thus he can fool them as he has you.”
So Joel are you specifically accusing Mr. Postma of intentionally of telling a huge fib.
By the way Joel please don’t declare a sentence to be false show us it is false. Use your calculator and SB and show us.
mkelly:
Well, I know the saying is “Never attribute to malice that which can be adequately explained by stupidity”. However, in this case, we know that the person in question has some competence in this area. He is either capable of self-deception beyond my abilities to comprehend or he is intentionally deceiving others.
As for the sentence I quoted, I think enough has been said by myself and others here for you to figure out what is wrong with that sentence. Just ask yourself: Why would the AVERAGE temperature of the earth’s surface have to match the highest temperature that could possibly be produced (considering local radiative balance) on a part of the earth’s surface receiving the absolute MAXIMUM solar intensity that any part of the earth’s surface receives?
Joel I think you misread the sentence. Put another way “On average the surface temperature is lower than the maximum calcuated when the sun is overheard.” SOD has an example of this on his site with measured irradiance from the sun on a praire in Saskachewan of 700 W/m^2 but a temperature reading much lower than what could be calculated. So again Joel please don’t declare something wrong demonstrate it. Or we will begin to think you can’t.
You are missing the point, mkelly. Yes, he is correct that the average temperature is lower than that which you would calculate on the basis of the sun’s being overhead. However, that doesn’t show you that the atmosphere has a net cooling effect because the average temperature should be lower. You have to compare the total power in to the total power out. Hint: You don’t get the total power in by looking at the place getting the maximum W/m^2 and multiplying this by the area of the earth.
Thanks for the hint. But you still have not demsonstrated via any heat transfer, physics, chemical or financial equations that what he wrote was wrong.
You infer he lied then won’t prove him inaccurate.
mkelly, I am not going to waste my time just for your amusement. If you want to believe nonsense, then go ahead. There are plenty of other people here who will be able to understand this simple point.
Joel Shore: “….the answer is that this is determined by the point at which the optical thickness of the atmosphere above to the (IR) radiation emitted by the planet is small enough that most of the emitted radiation escapes to space rather than being absorbed. And, this is of course determined by the composition of the atmosphere, and specifically by its IR-absorbing properties…in other words, by the greenhouse effect.”
You are basically right however this effect is negligibly and therefore only partly covered. The optical thickness of the atmosphere (to stay in your terms) from were (IR) heat easily escapes is there were it is thin enough and therefore depending on gravity and volume of the atmosphere.
So now you can try to calculate the change in the adiabatic lapse rate by assuming to increase CO² up to 1% and predict a new earth temperature. The mass/volume weight goes up and I will give you also the benefit of, say, volume is added (by humans) as well. Using “accepted physics” , I estimate a rise in temperature at about the value of error bars in global mean temperature and therefore almost undetectable.
opastun,
I recommend reading a textbook like Ray Pierrehumbert’s to get a grounding in this. I am not talking about additional CO2 changing the adiabatic lapse rate. I am talking about it changing the “effective radiating level”…i.e., the level in the atmosphere where the average temperature has to be equal to the effective blackbody temperature, which for the earth is 255 K.
And, no, it is not a negligible effect…It is the entire effect. If the earth’s atmosphere did not contain IR absorbing materials (greenhouse gases or clouds), then the effective radiating level will be at the surface of the earth and thus the earth’s average surface temperature (modulo the issues of averaging T vs. averaging epsilon*T^4 that I have discussed elsewhere) would have to be 255 K (for the same albedo).
Joel says
“Never attribute to malice that which can be adequately explained by stupidity”.
So if you don’t agree with Saint Joel you have
Malice
Stupidity
Liar
Low moral character
Or perhaps all four
If you don’t agree with nearly everyone in the scientific community (including AGW skeptics like Roy Spencer and Willis Eschenbach because you are talking utter and complete scientific nonsense, then yes, some combination of those 4 things is probably coming into play.
Pekka,
Working the other way, can you calculate the maximum surface temperature possible on Earth, given current conditions?
And then, bearing in mind that the same principles apply, calculate the maximum surface temperature possible on Venus, also given current conditions?
I forgot to add:
And then recalculate the maximum Earth surface temperature given a doubling of CO2 concentrations.
Peter,
I don’t really know what you mean by “maximum surface temperature possible on Earth, given current conditions”. Given current conditions we have the present Earth with it’s present temperature. Something must be different to have another temperature. Thus the maximum possible depends on, how large deviations we allow.
Performing a full calculation from basic physics is beyond our capability. That’s what the Earth system models try to do, but cannot give a precise answer. A different way of describing the issue doesn’t automatically bring with it any new methods of calculation. Having a different point of view may help in getting new ideas, but that’s certainly not automatic.
Everything included in the basically correct but simplified descriptions of the Earth system can be translated to the way of looking at the things that I propose. It may be easier to some to understand the issues as question of insulation than something involving back radiation as an example. With insulation nobody can think (or perhaps somebody still can) that the explanation would be in contradiction with the second law, but the explanation is based on exactly the same physics as the other ways of looking at it.
I thought that this approach is particularly helpful for the case of Venus where the heating flux from sun at the surface is very small. In the language of insulation all large fluxes are netted immediately before they are combined with other fluxes. Thus we avoid the situation where we may wonder, how the back radiation can be hugely stronger than solar SW, which is anyway the ultimate source that does the heating (with the help of the good insulation). In the language of insulation we do not discuss back radiation, but only net radiation. That’s analogous to the wall insulation where nobody mentions the fact that molecules and phonons move in all directions, but everybody thinks only the net flow of heat.
tempterrain said “I don’t wish to be rude You’re just too nice to these guys, You ask Tim the question ‘if you are serious about understanding climate change’. There’s no question that Tim is serious about opposing a carbon tax and to do that he needs some sort of cooked up pseudo-scientific theory which may seem just about half plausible. So, to that extent, an actual ‘understanding’ of climate change is probably more of a hindrance to Tim than a help.”
I have never discussed a carbon tax here, but if you want my actual views
on that go to
http://tv.afr.com/video/channel/122/160214?play=1
where I debate the tax with Melbourne university professor Ian Harper at the Australian Financial Review podcast.
That deals only with the economics of the proposed carbon tax, and I argue that it will have zero impact on Australia’s emissions, because energy demand is both price inelastic and income elastic, so that the compensation via tax reductions for virtually all Australian households will actually allow them to consume more CO2-intensive electricity, while all electricity generators will have no difficulty in passing on the full cost of the carbon tax via tariff increases, and therefore will see no need to switch to 300% more expensive renewable sources for their electicity supplies.
Next question?
Bryan Aug 12 9:14
“On 1316 you should ignore the part about heat moving from a cold surface to a hotter one.
Joel admits that this was a mistake and that all the authors were a bit vague about the meaning of heat at the time”
Where did you find Joel’s admission?
simon
Well he first admitted it over at WUWT.
His excuse was that he had not been in academia at the time and had forgotten some of his thermodynamics.
Now that he is a teacher he has had a chance to read up the textbooks and now knows better.
I’m not sure when he decided he was a “real” scientist
Simon,
The point is simply an issue of the standard terminology. We used the term “net heat” in a few places where the more correct terminology is just to say “heat”, as heat is really already defined as the net energy flow from hot to cold. And, in a few places, we talked about a heat flow from cold to hot and a larger flow from hot to cold where we should have said a radiative energy flow from cold to hot and a larger flow from hot to cold.
Bryan seems unable to get past this because he is more interested in terminology than the major conceptual errors made by G&T, Postma, etc. that he is unable to understand.
Joel “in a few places, we talked about a heat flow from cold to hot”.
I agree with you, that was some mistake. simon
Joel, I’m going to stick my neck out and object to your term “energy flow” as well. Energy doesn’t flow. Energy is the capacity or potential for doing something: it is equivalent to a force. (To talk about “force flows” would be confusing and meaningless, no?). Rgds simon
Simon,
As for “energy flow”, it is a commonly used term although some might argue that “energy transfer” is better. For example, I just looked in my copy of the latest (13th) edition of Young and Freedman’s “University Physics” (which I believe is the best-selling textbook for calculus-based introductory physics, or something like that) and they even have “energy flow” in the index. The page referenced has a subsection entitled “Electromagnetic Energy Flow and the Poynting Vector”.
Reluctantly accepted. The problem is emerging disciplines borrowing terms and subtly changing meanings. Thus is precision of definition compromised.
From Postma page 6:
Now here‟s the clincher: imagine that you take a mirror which reflects infrared light, and you reflect some of the infrared light the blackbody is emitting back onto itself. What then happens to the temperature of the blackbody? One might think that, because the blackbody is now absorbing more light, even if it is its own infrared light, then it should warm up. But in fact it does not warm up; it‟s temperature remains exactly the same. The reason why is very simple to understand but extremely important to physics: the blackbody is already in radiative thermal equilibrium with a hotter source of energy, the higher radiative energy spectrum light from the light-bulb.
Incorrect. If a mirror reflects back some portion of emitted energy back to the blackbody then that fraction of the surface cannot contribute to radiative heat loss. The reduced surface area must therefore emit at higher power and can only do that through a temperature increase.
A simple thought experiment will show this. Take a thin slab blackbody of unit area. Behind the blackbody is an infinite parabolic IR mirror. In front of the black body, on axis, is a point source of light. Incident power on the front face of the slab is 1 W. The slab without a mirror behind it could radiate 0.5 W from each side. Power per unit area is 0.5; the slab’s temperature is 0.84 “normalized degrees.” (The Stefan-Boltzman constant is set to 1.) The slab with a mirror behind it must lose all heat from the front face. P/A = 1; the slab’s new temperature is 1. It must get warmer to maintain radiative equilibrium.
I think this is the insulation effect.
If we insulate something that continues to output power then it will increase its temperature.
In this case the radiation is the radiative component of insulation
This is by reducing its heat loss.
A passive object cannot heat the object which is heating it is the second law reference .
Radiation is a two way exchange
Energy transfer is two way
Heat transfer is one way.
Yeah…David N. I agree that one is a really doozy! It is a wonder why anybody would believe anything that Postma says after that!
Almost as stupid as having heat travel spontaineosly from a colder to a warmer surface!
So you agree that Postma is wrong.
yes or no
Wrong about what?
If he says heat can travel spontaneously from a colder to a warmer object then he is wrong.
What page are you referring to.
Wrong about the whole thing. He claims the blackbody’s temperature stays the same. It doesn’t.
On net you are correct. In detail you are wrong, or you have some very nice Maxwell;s demons that you can rent out for serious dough.
Basically, if two objects are close to each other, thermal radiation from one will fall on the other and they will exchange thermal energy no matter what their temperature. On net, since the warmer one is radiating at a higher rate, it will transfer more energy to the colder one than the colder one will send to it.
To Bryan and Opastun –
I have a suggestion for settling the issues raised by Postma so that we don’t have to keep debating them. In an earlier version of his treatise, he proposed a simple model for testing experimentally the existence of a greenhouse effect he claims to be non-existent. In the current version, his experiment (see page 28) is more complicated but the principle is the same – if the greenhouse effect exists, then the box with the IR-absorbing top will heat more than the one that is IR transparent. If it doesn’t exist, the IR absorbing properties of the top will be irrelevant and the boxes will warm equally. (He later proposes some equations, but these are questionable because they neglect such phenomena as downwelling solar IR and the conductive properties of the box, among other things – the important question remains as to whether the boxes warm equally or not).
Postma is to be congratulated for proposing an experimental test of his thesis. He says the boxes will warm equally, while I claim that because of the greenhouse effect, the IR-trapping box will warm more. As with his earlier model, I am willing to make a wager on this. My suggestion is that we do the test, and that the loser pay the winner $50,000 (50 thousand U.S. dollars) and cover all the experimental costs. Are either you, Bryan, or you Opastun, interested in pursuing this?
If so, we can work out the details. However, it is easy to claim to be interested and then back down on the basis of one or more quibbles. If you are truly interested, I would ask you to preface any further discussion with a description of how some important technical issues will be resolved. Most critically, what specific material for the top pane of the box will you use that is totally transparent to solar shortwave radiation but totally opaque to all thermal IR emitted from the bottom (i.e., with no “window” region), how will you ensure that the boxes are adequately insulated to minimize conductive losses, and how will you ensure that the insolation is equalized within both boxes if the top pane blocks solar IR?
If you are interested, and find it possible to address the technical issues I raise, then we can pursue the legalities further regarding the financial part.
Fred Moolten |
Why do you see science as a battle?
Must there always be winners and losers?
Why not do the experiment in the interest of knowledge.
Making money in this way is quite foreign to me.
Marie Currie refused to patent radioactivity.
Have these old fashioned values completely disappeared in this materialistic world?
Making money in this way is quite foreign to me.
Actually, I wasn’t proposing it as a way for you to make money.
Italics off i hope.
In thinking about it further, I regret suggesting a bet. That’s not because there’s much uncertainty about the outcome in this case, but because I would hate to see this become a debating tactic in these blogs, with each argument accompanied by a bet offer, and a refusal to bet interpreted as an acknowledgment of error. In that sense, I agree with Bryan that we should stick to the science.
On the other hand, if someone wanted to cover the experimental costs of the test, I’d be happy to participate in the actual design and conduct of the experiment.
Here’s the thing Bryan. someone like fred could put time and effort into the experiment and then after the fact, everyone and his brother will come up with some kind of post hoc excuse. The bet concept would require agreement beforehand on rules for abiding by the outcome.
That is what we are missing here. common ground on what it takes to “win” an argument
steven mosher
” agreement beforehand on rules for abiding by the outcome.”
I agree.
I personally feel there must be some heating caused by IR active gases.
But it could be so small that its almost negligible.
I think some greenhouse effect believers think the heating is quite substantial.
So there’s a spectrum of opinion here.
DeWitt Payne or someone similar would no doubt rise to the challenge and come up with a calculated value..
To a first order we know the effect is `~1.2C per doubling.
If people want to prove that the second order effects drive it higher OR lower, then I’d hold them both to the same standard of proof. On that, Id say those arguing for positive feedbacks have a more complete case than those arguing for negative. But if I stick with what we know, we know the first order effect. speculate that its lower? I want to see proof. speculate that its higher.. I want to see proof.
Postma’s equations also neglect the fact that both boxes will act like ordinary greenhouses in blocking convection, but although this changes the quantitation, it shouldn’t change the fact that a greenhouse effect will cause one box to heat more than the other.
Fred,
Unfortunately, it’s not as simple as removing convection from both sides of the equation as being a common-mode factor, as convection is dependent on temperature, so is not an independent parameter.
Increasing temperature by blocking radiation (or by any other means) will increase convection, which in turn will remove energy and so reduce the temperature increase.
And there’s also a similar effect from evaporation.
So yes, the ‘greenhouse effect’ box will warm more, but the experiment will not show the same effect as happens in the real world.
Peter – I didn’t try to suggest anything that disagrees with your comment. My point was that the quantitative comparisons would be affected by the confounding effects of convection, which as you state, would vary with temperature, as would evaporation and conduction.
I’d just suggest they explain how a space blanket works.
Perhaps the better thing to ask them to do is to predict how fast the unlit side of the earth will cool.
hmm.
Hang on, isn’t this the same as the Woods experiment?
yes it is.
In a very rough sense, yes, but the IR absorbing properties of the material would have to be more powerful and their solar transparency known to be more complete to detect significant differences. Given that the IR blocking would operate only on net IR (upwelling minus downwelling), very partial IR blocking might have only minimal effects that are swamped by the convection-blocking properties of a greenhouse-type enclosure.
Fred: Save money and time and read here:
http://principia-scientific.org/publications/Experiment_on_Greenhouse_Effect.pdf
and here (sorry German but lots of pics and tabs):
http://www.schmanck.de/TreibhausMessung.pdf
Of course you can try the experiment as described by Postma by yourself.
I’m very familiar with Woods, which I addressed above in response to Peter. As I mentioned above, betting is probably not a good practice to encourage here, but it would actually be easier and less expensive to design a much simpler model than Postma’s to demonstrate his error.
There are some true controversies in climatology, Opastun, but the greenhouse effect is not one of them.
There are commercial devices that are taking advantage of the radiative greenhouse effect, namely certain types of solar heat collectors. They might provide an example that Postma could try to explain without the effect.
See the flat plate collector here
http://www.solarserver.com/knowledge/basic-knowledge/solar-collectors.html
Such collectors may overheat to more than 180 C, when no heat is taken from the collector.
“Such collectors may overheat to more than 180 C, when no heat is taken from the collector.”
Gee no convection allowed and it heats up. Who would have
thought?
With the level of solar radiation at the surface, 180C is more than the balance of solar radiation and the IR from the collector plate allows without GH effect.
Exactly. Greenhouse by reduced convection heat loss.
There is reduced convection heat loss, but that’s not enough for the result. The radiative effect is needed as well.
What exactly is the radiative effect? Take for example solar wax melters. Or greenhouse.
The surface at 180C radiates with a power of 2.3 kW/m^2. The heating must be that strong. That’s almost twice the power of solar radiation at the earth surface under ideal conditions. The rest comes from the GHE of the selective glazing with some help from the GHE of the atmosphere.
Pekka,
Did you read the link? I don’t think the transparent cover does what you think it does.
“Basically, it is the product of the rate of transmission of the cover and the absorption rate of the absorber.”
“In order to reduce energy loss through heat emission, the most efficient absorbers have a selective surface coating. This coating enables the conversion of a high proportion of the solar radiation into heat, simultaneously reducing the emission of heat.”
Good absorbers (surface coating) + reduced convextion = heat. Glas lets the sun through and stops convection.
The coating of the absorbing surface is also a component in the efficency, but even with that the emissivity will be high enough at 180C to require a significant contribution from the radiative GHE of the glazing.
It’s actually funny that people want to argue against that one factor, when they are prepared to apply the same theories to other components, which lead also to the conclusion that the radiative GHE is true.
I don’t know the relative significance of each factor, but I do know that all the factors that have been discussed are true including the radiative GHE.
Pekka,
Now I am very sceptical of that. See their graph for efficiency.
“Basically, it is the product of the rate of transmission of the cover and the absorption rate of the absorber.”
I think any “trapping” of the absorbed heat by the transparent cover would trap more solar radiation and make it less transparent and therefore less efficient. Where do you get 180 °C?
I said I think. I would have to look selective glazing up and give it some thought. Maybe I’m wrong.
Pekka, with “Greenhouse effect” in the context of the solar panel technology you refer to, do you actually refer to the cover glass?
IMHO this collector is basically covered with selective glass, and I find that the comparison to greenhouse effect is not very illustrative.
Selective glass refers to precisely the radiative greenhouse effect. That’s the meaning of the word “selective”.
More precisely that’s exactly the idea of the Postma experiment. It’s already done in the solar collector.
And yet it is strange how that “uncontroversial” greenhouse effect fails to materialize in those above mentioned experiments à la Wood. Especially when considering following.
“… It is worth noting that, in the absence of convection, pure greenhouse warming would lead to a globally averaged surface temperature of 72ºC given current conditions (Möller and Manabe 1961). Our current average temperature, 15ºC, is actually much closer to the black body temperature (temperature without any greenhouse warming), -18ºC, than to the pure greenhouse result. …”
Richard S. Lindzen, Some Coolness Concerning Global Warming
http://www-eaps.mit.edu/faculty/lindzen/cooglobwrm.pdf
The atmospheric effect takes place over 10 km. Thus the difference is 5.5 C/km of 0.0055 C/m. That’s not measurable with Wood’s methodology. (The experimental setting would change that value, but the direction is not clear.)
javs – You misunderstood Lindzen’s 1990 article if you interpreted it to mean that the greenhouse effect was controversial in his opinion. He was referring to modifying influences on the basic effect – for him, clouds have been one of the modifiers that he has focused on, but that’s a topic for a different thread. (You can write to Lindzen if you wish, to clarify this if you disagree).
If you look at Lindzen’s reasoning carefully in his article, what he is saying in the quoted passage is that the greenhouse effect warming of the Earth’s surface is potent enough to raise the temperature considerably, but this effect is partially dissipated by convection. This is well understood, and has been mentioned in this thread by Pekka, and by myself and others elsewhere as well. Lindzen and Postma are in substantial disagreement on basic principles, with Lindzen accepting them and disputing some of the modifying effects, while Postma fails to understand them and gets the basic principles wrong.
Fred, I was referring intentionally to the standard greenhouse model fully aware of Lindzen’s acceptance of it. So, no misunderstanding.
With all the 200+ trillion the greenies want us to spend, no one has done the experiments?
More or less did this The lamp heated up from 160 to 300 C.
The problem in thinking about this is that the IR transparent window will not radiate in the IR so the net emission will be the flux from the interior, while the IR absorbing window will radiate at the temperature of the box
That does seem to be the rub. The space blanket is listed in Wiki as blocking convection, retaining moisture and to some extent reflecting radiation. Maybe a better experiment would be a red light with a perforated red space blanket?
Placing an tight aluminum foil shield over a lamp does not limit convection away from the lamp. In fact convection will be stronger because the surface warms. There is no moisture on the glass surface or inside the lamp. There has been no change in the interior of the lamp, so convection inside the lamp is identical, and you could do the same experiment with a vacuum in the lamp. In short the experiment at the link has anticipated both of your objections.
Joel Shore | August 12, 2011 at 2:21 pm | mkelly, I am not going to waste my time just for your amusement. If you want to believe nonsense, then go ahead. There are plenty of other people here who will be able to understand this simple point.
Please understand Joel I am not amused by folks who infer someone lied, then refuse to demonstrate how they lied. I take your refusal to show proof as though you have none.
I explained it to you. I don’t have time to spoon-feed it to you. Everyone else reading this can see how (purposefully?) dense you are being…and, if they can’t, well they can choose to believe your nonsense and look as foolish as you.
Joel
As Co2 is a reasonably well dispersed gas with al parts of the world registering around 380ppm plus or minus 10ppm or so, can you clarify why around 30% of the globe has been cooling for a climatically meaningful period of time -around 30 years or more? Thanks.
tonyb
Hi, tonyb! The effect of CO2 is a fairly small pertubative effect (~1%) on the global radiance balance of the earth. How the resulting temperature change gets distributed across the earth is a function of lots of factors, basically all having to do with the fact that the troposphere is a very active place with lots of convection, weather systems, etc.
Thinking that you can predict the pattern of the temperature change on the basis of the pattern (or lack of pattern) in the change in CO2 concentration is not just a poor approximation…It is in fact completely without justification and, indeed, it is not what the climate models predict.
True only for the free troposphere and above, which is why measurements are done in various isolated places. At ground level, esp, in urban areas, the concentrations can be much higher, 50 ppm and more, and there are significant effects from plants, both positive and negative going in agricultural regions. In Paris, for example, the CO2 mixing ratio at the Place de la Nation was 562 ppm one fine day.
What Joel, Chris, and Eli always fail to mention is that H20 vapour is usually very thin at the poles at only a few ppm and up to 40000 ppm in the tropics, on average H20 its about 25 times that of CO2 (400ppm)
And, that leads you to conclude what exactly?
You present an incomplete picture. Some would conclude that H2O is not as important as CO2. You will may lump the 2 together sometimes and say something like “CO2 and water vapour” but you will lead with CO2 and make water vapour implying that H2O the lesser of the 2 or just continue one ignoring H2O. You will show a ppm comparison of the CO2 compared to Nitrogen, methane and oxygen and the other trace gases but not H2O.
I don’t know why. Tell us why do you do it?
To answer your last question first, I would guess that the reason that people sometimes omit water vapor from a list of the various concentrations of gases in the atmosphere is that, unlike the others, there can be huge variations in concentration from place to place.
As to water vapor as a greenhouse gas: Everyone accepts it is the most important greenhouse gas. However, its concentration in the atmosphere is basically slave to the temperature, so it is not a gas whose concentration we can change directly. The way its concentration changes is by heating up (or cooling down) the atmosphere in some other way, like by adding long-lived greenhouse gases to the atmosphere. That is why water vapor is considered as a feedback, not a forcing.
if its the most important then shouldn’t you say its the driver of temp not the slave?
CO2 is slave to the temperature as well. It’s becoming obvious. But not settled.
Joel Shore
You realy are a malignant poster.
The ready turn to insult total strangers.
Have you any redeaming features at all?
Bryan,
Coming from someone whose judgement is that Postma and G&T represent good science and who seems to be trying to win the title of #1 peddler of pseudoscience in this corner of the internet, I will take that as a compliment.
By the way, just to be clear, while mkelly may be a “total stranger” in the sense that I have never met him in person, I certainly have interacted with him a lot in regards to the greenhouse effect, e.g., in this thread: http://wattsupwiththat.com/2011/05/07/visualizing-the-greenhouse-effect-light-and-heat/ where some of us very patiently tried to explain things to him. However, it is clear that he is one of those who is unteachable because their science and dictated by what they want to believe. It is not honest to waste other people’s time asking for evidence and proof of things when you are not the least bit interested in evidence because your mind is already made up and you will believe any nonsense you can cling to in order to do that.
Here, I gave mkelly more than enough information to understand what is wrong with Postma’s statement and giving him more information won’t change his view. At some point, one has to say enough is enough.
Joel all you gave was lose generalised opinions with no facts to back them up.
You also gave a number of blatant smears.
The smears are a bad tactic on your part because it makes you seem like an irrational bigot.
Now I’m sure that’s not how you like your persona to be portrayed.
I must say I’m disappointed in your critique of Postmas paper.
I was expecting a detailed challenge with calculations showing what errors(if any) you can find.
Instead – nothing of substance.
Perhaps its to early for a considered response and I can understand that.
Generally however if you are having a rational dialog with someone and you fail to come to an agreed position then stop posting to him/her on that topic.
This sends a polite but definite message that further dialog is pointless.
You don’t always have to get the last word.
Bryan,
Frankly, it is a waste of time to go through and talk about every mistake that Postma made because
(1) It is such a morass.
(2) it is not published anywhere and where does it end with people putting up nonsense and then others having to waste their time to respond to the nonsense.
(3) It doesn’t seem to do any good because you and the others who believe that paper are not convinceable by any amount of reason, as the G&T situation has shown.
But, we’ve gone over the basic problems with the paper many times now. For example, he attacks a model which is the simplest model of the greenhouse effect and uses it as a strawman to show that it is too simplistic in some ways. Well, duh!!!
And, then most of the rest of the paper is devoted to attacking the strawman of the greenhouse effect neglecting night and day and other such nonsense. Again, this comes down to what level of detail of model that you are talking about, although it also represents an extremely important conceptual error, which is that the reason for looking at average quantities is that the actual radiative balance that must be obeyed is between the average (or total, either is fine) energy received from the sun and the average (or total) radiated back out into space. It makes no sense to get too hung up on the local amount of radiation received at a given spot at a given time because the earth and its atmosphere is a highly interactive so it is essentially meaningless to take the amount of W/m^2 that is received at the surface at the sun’s zenith and convert that to a temperature via the Stefan-Boltzmann Law.
With errors this fatal, there is no reason to delve further into Postma’s nonsense. As I have said, the only question worth debating about his work is whether someone of his intelligence and background could be this seriously deluded or whether he is purposely trying to deceive others. Again, I have said that I find the former hypothesis to be implausible, but I am willing to entertain counterarguments.
Sorry to but in,
” he attacks a model which is the simplest model of the greenhouse effect and uses it as a strawman to show that it is too simplistic in some ways. Well, duh!!!”
Wouldn’t it be better to simply update this back of the envelope effort to a level equivalent to what Mr. Postma did to show how he got it wrong rather than leaving this easy pick on the table?
kuhnkat,
What does that even mean? It is not like he used the model to do a specific calculation (well…okay maybe he did a specific calculation in regards to Venu). What he did is showed that the model breaks down in a certain way. I suppose one could demonstrate how a multi-layer graybody atmosphere does not have this same issue if one were so inclined and maybe someone will. However, why do we have to waste our time because somebody who wants to fool you puts a bunch of nonsense up on the internet?
That is what these people want to do is waste everybody’s time. (And, some of us are not getting paid to do this kind of stuff. Whether Postma is or not, I do not know. Perhaps he would be willing to inform us of any and all sources of compensation that he has received.) I think it is better to just note that he has attacked an obvious strawman and say that it is now up to him to demonstrate that a century of scientific work is wrong by actually putting up a credible argument instead of a hokey one.
I am getting a little annoyed with the idea that anyone can put some nonsense up on the internet that says that the entire scientific community is wrong and they have absolutely no responsibility beyond that, that the onus of responsibility shifts to everyone else to disprove them. That is frankly ridiculous. They have the onus of responsibility, particularly when their work hasn’t even undergone peer review.
The simplistic model has one specific use: to present the simplest known explanation that GHE exists. In order to make the example simple, it’s presented for a totally unrealistic model of atmosphere. Postma has not presented anything that could serve the same purpose, actually he doesn’t propose any ready alternative, only some vague ideas of what it could be.
It can certainly be argued, whether this toy model is useful or whether it has caused more confusion than supported understanding. Many people think that it’s a good educational tool, but highly unrealistic toy models create always also problems as this one has done. There is always the question: Should I accept, what I’m taught by such an example, when I’m told that it’s highly unrealistic anyway?
It’s reasonable to ponder, what’s the best way of teaching this kind of issues.
kuhnkat
The Postma model compares very well with the model supplied by Joel.
Joels model has an 80K contribution from radiative transfer alone.
If you then add in the effects of the gravitational field and convection you can see his model is pure pseudoscience.
If you look carefully at Joel and Pekkas responses you will find no substance there.
Both will tell you that they are busy men with no time to analyse the Postma model.
Yet they have endless amount of time to write posts like the two responses here.
Be assured if they could prove Posta wrong by a calculation they would not hesitate.
Perhaps we are being a little harsh with them since the Postma paper is quite new and they need time to come up with a substantial considered response
Pekka and Joel,
The problems I encounter are when people like Joel and Chris and to a certain extent you, claim his work is garbage, pseudo science… Yet I now see just past his equation 20 that he claims the he gets the same -18c as the original. Well, since this is well past the point he is being called names, it makes me wonder. Of course, this would also appear to show there is nothing wrong with the computations for either side TO THIS POINT!!! The simple computation does not go past this point. Joe does. Why?? Because the -18c actually is not representative of the surface temp and we should understand why it differs. To the discredit of you and the other apologists, I would point out that even by saying this Mr. Postma has STILL not deviated from the idea that GHG’s have made a difference in the temperature BELOW whatever level in the atmosphere best epitomizes the -18c!!
In other words, the reason the location of the -18c is not the surface could still be GHE’s or a combination of thermal mass, without which GHG’s have less to work with, and GHG’s. So when you are talking pseudo science we have to look further into what he has done.
At this point he starts on the idea that it is incorrect to average the incoming energy over the full surface when it is only absorbed on one hemisphere. By doing this he unsurprisingly finds that he gets a different temperature for the day side. The night side would, of course, have to be less, BUT, due to the unattributed reasons, we still don’t know exactly where this unphysical single layer temperature exists on either hemisphere. He then extends this to an even smaller area to demonstrate that this basic radiative handling of the system will exceed the temps of the physical system. As these numbers are implicitly included in the average it shows the basic method exceeds physicality for the system.
His logic that the -18c is used to mislead as to the actual temperatures of the system by computing and showing that the maximums are not met due to apparently non-radiative losses are quite appropriate in my opinion. There is no pseudo science in simply showing how a more detailed breakdown of the straightforward SB numbers go into non-physical realms that must be explained by non-radiative factors. In other words the method should not be used as it presents unreal results. Evaluating the night side would also show unphysical low temperatures as there is no thermal mass in the pure radiative system.
The fact that there are unphysically high temperatures in the pure radiative model would detract from the message that GHE INCREASES temps. In reality we see that the system is moderated cooler on the day side and warmer at night which is NOT consistent with GHE effects, but, is consistent with the physical world. The averaging hiding these extremes DOES allow the idea that GHE increases temps to be promoted.
So, through page 12, it would seem that complaints of pseudo science are untrue. In fact, through Page 12 he has only shown that the simplistic computations minimize the actual temp extremes and we need more physics to explain observations. In this he is absolutely correct and is why the -18c misleads and is NOT a good simplistic model. It is used to imply something that does not actually occur, to the degree suggested, in reality. Therefore, when people like Chris and Joel start expounding on the total garbage of his paper, these sections that are more accessible for me to understand shows that they are at least exagerating or worse. So, for those who do NOT understand the physics or math it is easy for us deniers to point out that you are making incorrect statements when you attack this perfectly acceptable presentation TO THIS POINT!! I think you know what happens after that. They lied, science died and other extremist BS.
So, my suggestion is again to treat the paper, at least if not serious science, as a serious threat to your credibility due to the way you respond to it. Take it in detail and point out the real errors rather than concentrating on hyperbole. Especially get over the crap about someone paying him to do it when we all know that the largest corporations are rooting at the trough of Green Energy and other enviro schemes filtered through corrupt politicians. This type of dialogue you will also lose as the corruption and failures of wind, solar, and other schemes start hitting people’s pocketbooks.
Rather than addressing the whole paper, exactly where does he get the math and physics wrong through page 12. (we can exclude his speculations about ice ages as that is all anyone can do, speculate) When that is cleared up, we can maybe look at the rest.
Joel,
I wish to concede the T^4 averaging issue. I was wrong in what I tried to present.
Hi joel
So the IPCC is wrong on this matter then? They say that there is only cooling in South Greenland and a few areas of the tropics. Cooling is much more widespread than this as you know.
tonyb
tonyb,
I don’t know what the actual data show. Where do you get your evidence?
I was just answering your question on a theoretical level: i.e., what is the relation between the spatial distribution of the CO2 and the spatial distribution of the warming.
Joel
Interesting. Of the 30,000 or so temperature stations wordwide what % do you believe show warming and what % show cooling? (over a meaningful time scale)
tonyb
Tony – Your data appear to be incorrect, but we can address this in more detail if you link us to detailed source material. Your figure for current CO2 is incorrect – it now exceeds 390 ppm, with less variability over any large area than you quote. Similarly, global, Northern Hemisphere, and Southern Hemisphere temperatures have been rising over the past 30 years, not declining, albeit at uneven rates. If one looks at very restricted areas, they can deviate from the larger trends, and adding them up can yield a distorted picture. Perhaps this is what your sources suggested, but without the details, we can’t really say. There is no conflict, however, with the general principles of CO2-mediated greenhouse effects, as modified over short term intervals by various other climate factors that have been discussed in many threads of this blog.
Fred, i do believe tony is right on the variability of co2, here are some results from gosat(Japanese greenhouse observing satellite) Its quite variable, even month to month, which you would expect, with seasonal variation in sea T and terrestrial uptake through photosynthesis etc. (give or take about 30ppm)
http://www.gosat.nies.go.jp/eng/result/download/GOSAT_20100216_en.pdf
Fred
All fingers and thumbs-I meant to type 390. They should put the 8 and the 9 on opposite sides of the keyboard. :)
Co2 is reasonably well mixed but there are variations as KingOchaos shows. By the way would you like to hazard a guess as to the percentage of cooling and warming stations?
tonyb
That’s fine. Regarding cooling vs warming, the evidence I’m aware of shows almost regions to have been warming over the last 30 years. Of course, global temperature is mainly SST, and so to show something different, one would have to show substantial fractions of the ocean to have been cooling for 30 years. I don’t think you had that in mind.
The countable number of land-based stations showing 30 years of cooling is something I don’t know, but it seems to be something you had in mind. However, unless that number can be translated into a temperature trajectory for any given region, it has little meaning. I would say no meaning at all in terms of CO2 effects, which by the nature of atmospheric thermodynamics can’t exert one set of effects for 30 years in one city and a radically different set for another city – local differences of that type will reflect factors other than CO2.. To summarize, warming has been the trend more or less everywhere for the past 30 years, consistent with the greenhouse effect properties of CO2 as modulated by both temporal and regional variations in other factor.
Fred
I first wrote about cooling stations here;
http://wattsupwiththat.com/2010/09/04/in-search-of-cooling-trends/
The total number of cooling stations (for at least 30 years) is around 30% of the total stations. Their trend varies considerably. Some 15% are neutral, the remaining are warming to one degree or another. UHi affects a good proportion of these.
tonyb
Thought experiment #2:
A thin blackbody disc with 10 cm radius is electrically heated to 500 K. In front of it is a large IR lens which focuses onto a 1 cm radius blackbody target. It’s easy to see that the source disc radiates 222.7 W and that half of that is focused onto the target. To attain thermal equilibrium the target disc must radiate 111.3 W, therefore its temperature is 1,329 K.
Did I just say a lower temperature object is transfering energy to a higher temperature object? I guess I did.
You can’t focus thermal radiation to a flux density higher (i.e. a higher temperature) than what it was emitted at. Solar can be focused only to about 5000 K, which is the temperature of the Sun’s visible surface. In your example, the emitted radiation from the disc is directed at all possible angles from the source, so a neighboring lens can’t focus it at all.
Simply put, the disc emits IR in all directions so that only a fraction can be focused at a point (or in a small area). For your experiment to work you would have to recruit some of Bryan’s Maxwell’s demons to force all the photons to move in parallel.
These sorts of arguments are amusing finger exercises for learning thermo.
I knew something had to be wrong with it but optics was never my forte…
Eli Rabett
Earlier I gave a link to your earlier very flawed “comment” paper.
http://scienceblogs.com/stoat/upload/2010/05/halpern_etal_2010.pdf
In it you show a 3 layer model of the atmosphere producing a 80K effect all on its own by radiative transfer.(pg 1318,1319)
Now such a model must be considered to be at the pinnacle of research
from the Golden Age of the Greenhouse Theory.
Yet the action of the gravitation field on the air is represented by the adiabatic lapse rate(See Postma pg 16) will in itself produce a similar range of temperature given that the Sun directly heats the ground.
This doubling of the expected temperature range to 160K for the troposphere shows that your model has some fatal flaws.
You might argue that even more slabs or layers are required.
If we have a very large number of slabs then the ” f ” factor will tend to 2 .
See Postma 12 and 13.
This results in the ground temperature being independent of the Sun.
I find it hard to comprehend that such a fantasy model is seriously considered.
Yet I will not assume you are a liar or of low moral character.
So could you please get your puppet Joel Shore to moderate his language when addressing other posters.
Bryan,
The chapter discussing the three layer model presents its conclusions as follows (emphasis mine).
It’s only you and Postma (and perhaps some other denialist, and I use this word here by purpose), who try to claim that this model is presented as a model of the real atmosphere. There seems to be no way to stop you from repeating this falsehood, or should I say lie.
Pekka
Postma made similar reservations about his model.
But because you have decided he is a liar you don’t mention them.
Since the Halpern paper has already accounted for 80K by radiative transfer how are these other major factors to be accommodated?
I have decided that you are an old windbag from evidence from your posts.
Yet I have not accused you of being a liar or of low moral character.
People who make wild unsubstantiated smears because of supposed internet safety had better take care as prosecutions are now underway in similar cases
Postma made the reservation, but that didn’t stop him from using the false implications against main stream science. That made him even more culpable of dishonesty.
Pekka,
Keep libeling Postma and see if you aren’t hit with a defamation suit.
Pekka
…”the false implications against main stream science. “…..
You have yet to substantiate what these “false implications” are.
The proof for being dishonest is set much higher.
You imply that Postma does not believe in his own work and is knowingly misleading people.
Where is the evidence for that?
We can make our conclusions only based on what we see. Parts of that are in my thinking really difficult to explain without some dishonesty. That’s as much as I can say.
Pekka
I always try to think the best of people.
I would need overwhelming evidence to call someone a liar
Therefore I don’t say that they are liars. I say only that they behave in a way that is most easily explained by that alternative.
Pekka
I would go a bit further than that.
I would not use langage that might imply there is even a possibility that they are lying.
Do you say that there’s not that possibility?
I’m 100% certain that some people are knowingly dishonest in these discussions. They have been caught too many times in ignoring direct facts that have been presented to them. In those cases that’s really the only remaining explanation. (Even if there would be another explanation once, that cannot be true for all those cases.)
I don’t say, where I’m so certain, and where I consider that only as a possibility, but I would be really naive, if I would not consider that as a possibility.
My answers are getting more and more rude, when the likelihood that the other side is dishonest grows in my judgment. When you observe that in my answers, you may guess, what it implies.
@ALL, after a while:
Being a “lurker” at a couple of blogs, stumbling on the “Greenhouse dragon technical discussion” thread, I felt the urge to post a link to a new paper from J. Postma. (http://www.tech-know.eu/uploads/The_Model_Atmosphere.pdf).
Naive as I was, I have been using verbatim to announce the link. Now that
was worn out wrong, wrong, wrong. (thanks Peter317 for pointing at this)
After that, I was bluffed with a overwhelming flood of attacking comments, varying from accusations to defamatory statements. All along, I’ve been left with the bad feeling, that out there is a task force, watching day and night, with which I can’t hold up. It took days to see the first mentioning of an (possible) error in the discussed paper.
It was David N | August 12, 2011 at 11:38 am
He also came up with a “simple thought experiment”. Apart from the very fact that “thought experiments” only count when they are transposable to real experiments, he states something about mirrors. I suggest the following “simple thought experiment”: Put your room full of mirrors, even the ceiling if possible. Then light as many candles as you can. Then sit tight till “SHE” enters the room. Will you be willing to tell me where the “heat” came from? We humans are so easy to be mislead. (Sorry David, don’t take this personally)
It was about there and then and in this context, as Eli Rabett (surprisingly?) appears with the following (partly quoted):
“On net you are correct. . …Basically, if two objects are close to each other, thermal radiation from one will fall on the other and they will exchange thermal energy no matter what their temperature. On net, since the warmer one is radiating at a higher rate, it will transfer more energy to the colder one than the colder one will send to it.”
Wow! Concluding: Net flow is what counts… Thanks for being so clear once in a while.
You might see this as a misquote of course.
opastum,
The example of a mirror reflecting back on to part of the surface of a blackbody was taken directly from Postma’s paper. He claimed the blackbody stays the same temperature, which is incorrect. If you can demonstrate what’s wrong with my comment please do so. Otherwise there are many real experiments you can perform for yourself that will show you without doubt surrounding something hot with something reflective will slow the rate of heat loss. If you’re too lazy to do that or too busy writing this amazing witty stuff like above, just ask yourself why people would go to the trouble of selling spare ribs in a foil lined bag, or silver the inside of a thermos.
It should also be clear to you that when heat is added to a system at a constant rate, and is lost from that system at a reduced rate, all other things being equal, the equilibrium temperature must increase.
If either of these two points remain unclear or you are unable to synthesize the two to see how Postma is wrong, at least you’ve got your comedy to fall back on.
David,
Thanks for your reply. I was certainly not intending to ridicule your comment that I referred to. I was rather happy with it, because it was the first serious one.
The point you are raising is interesting and I will certainly have to explore this. Your further explanation above helped me to see what your original point was. I can’t tell if this will be in short ’cause WE is over and having not time enough during the working week, in contrast to others here, seemingly supplying a 7×24 full service with no content. You are right with the “witty stuff”, that was not helpful and waste of time that I do not have either.
Perhaps others can go into this.
David
I think your point is from Postmas first paper, am I right?
When the first paper was being discussed on (Jo Nova I think) I said it had been badly expressed.
His point is only true if the hot body stops its power supply.
Then it makes sense, otherwise I would not agree with it.
I don’t think its central to his new paper.
But congratulations for identifying the only serious point discussed so far.
This is also wrong. If the hot body stops it’s power supply the rate of heat addittion is still constant, at zero. The blackbody cools, but like the ribs in the bag, more slowly for the presence of the mirror.
It’s really not on to say that what Postma wrote is wrong unless you totally change the premise, in which case he’s right. Reread the passage on page 6; it’s a fundamental error about something he claims is “very important.” He said it was very important, you say it’s “not central.” I sounds like you’re saying if Postma is wrong he simply misspoke. I hope that’s not what you’re saying.
And frankly, your link to Postma in a comment was preceded by the post itself and many other links and comments; you can’t expect everyone to drop their other discussions and focus on yours, that’s hijacking the thread. Maybe Dr. Curry will give Postma his own post and then you’ll get more “serious” responses.
David read page 6 again.
Its not clear if Postma is taking about the light bulb or the blackbody illuminated by the light bulb.
Does the mirror get between the BB and the light bulb for instance?
Whats the temperature of the surroundings?
If you place a mirror facing a light bulb then you reduce the heat loss from the light bulb and its temperature will rise.
If your object is already cooling, again a mirror will slowdown the rate of cooling.
The mirror cannot in these circumstances increase the temperature of the cooling object
….” your link to Postma in a comment “…..
Postma is associated with the dragons faction and so my link was most definitely “on topic”
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Bryan,
I’ll ask the same question here that you failed to answer at Science of Doom:
How do you reconcile the calculation of average temperature of a half illuminated sphere by G&T in section 3.7.4 with Postma’s calculation? Only one can be correct and it’s not Postma.
Hi DeWitt
I’m still thinking about your question and as yet have not come to a firm conclusion.
G&T agree with McKitrick et al that there is no such a thing as a global surface temperature.
Postma with his background in astrophysics stays pretty close to consensus science radiative transfer theory.
He uses the widely accepted value of 15C without much comment.
His big contribution is to examine what happens if you treat day and night separately.
This allows a much more realistic view of the planetary processes.
He also finds if you adopt this view point the need to account for an imaginary 33K temperature gap vanishes. .
Pekka Pirilä,
You’re wrong about a transparent atmosphere having a zero lapse rate. The meridional surface temperature gradient will cause a meridional pressure gradient at constant altitude which will cause flow from the equator toward the poles. That will lead to increased surface pressure at higher latitude and circulation. Eventually that will cause the formation of something like the Hadley cells and jet streams in the northern and southern hemisphere. The end result will not be an isothermal atmosphere.
There will be no equivalent to a stratosphere because there is no mechanism like the absorption of UV radiation by oxygen to cause a temperature inversion. You’ll have an exponential atmosphere with a lapse rate near the adiabatic rate everywhere until the pressure gets low enough that local thermal equilibrium no longer applies. Eddy diffusion driven by turbulence from the pressure gradient flow will pump heat down the temperature gradient at high latitudes. The energy required to do the work to pump the heat comes from the temperature difference between the poles and the equator. Atmospheric flow will act to minimize this difference and maximize entropy.
De Witt Payne, thanks for your comment.
“You’ll have an exponential atmosphere with a lapse rate near the adiabatic rate everywhere”
Are you saying the lapse rate would be similar in magnitude to the one in our current atmosphere, and/or similar in principle?
Thanks
Similar in principle. The actual lapse rate would depend on the heat capacity at constant pressure of the atmosphere and the value of the acceleration of gravity at the surface. It would also depend on whether there were a condensable gas in the atmosphere that was also transparent and its properties.
Convection and eddy diffusion will be the dominant modes of heat transfer. The height at constant pressure, say 200 hPa for a surface pressure of 1000 hPa, is proportional to temperature. That means that at a given altitude, the pressure will be higher at the equator than it is at the poles. That pressure difference causes flow. That flow will reduce the pressure at the surface at the equator and raise it at the poles. So the flow toward the poles at high altitude will be matched by flow toward the equator near the surface. That also means that air will rise and cool at the equator and fall and heat at the poles. Maximum circulation will occur when the lapse rate is close to the adiabatic rate. I’m ignoring the probability of having more than one circulation cell per hemisphere.
I was wondering the same thing myself. I came to the same conclusion as DeWitt, but based on the idea that a random mover encountering a soft boundary (one that it doesn’t bounce off) is likely to stick to it. In the case of lapse rate, random temperature fluctuations will eventually run into the adiabatic lapse rate at least locally, very quickly in the case of very small neighborhoods.
Zero lapse rate, or any lapse rate below the adiabatic rate, has the feel of a system in unstable equilibrium.
(Typing this during the questions at the end of Microsoft’s talk on the hardware design behind the Kinect.)
DeWitt Payne,
I’m pretty sure that I’m right. I’m totally sure, that your argument doesn’t hold. I know that the issue is not simple, but I keep to my views. I have noticed that a couple of working climate scientists presented views similar to mine. I cannot give links to those messages, and I don’t tell their names, because I’m not 100% sure, who they were.
There will be some effect of the type you, describe, but my conclusion is that the cells remain very low and local. My view of the transparent atmosphere is that it’s temperature is rather high, close to that of the equatorial daytime temperature. If that’s true the upwards flow stops very close to the surface and cannot build any large cell. In areas, where the surface is cooler than the atmosphere, a temperature inversion forms near the ground. The gradient becomes very strong, as the only form of heat transfer is conduction and conduction is weak.
The strength of the circulation is not determined by the heat transfer from the hot surface to the air, but by the heat transfer of heat from the warm atmosphere, which is inefficient. The atmospheric temperature is determined as that where the efficient heat transfer from a small area of hot surface is equal to the inefficient heat transfer from the warm atmosphere to the large area of cold surface.
There will always be some circulation, but only at very low altitudes. The stratosphere extends essentially to surface, and almost all of the atmosphere is isothermal.
Hi Pekka,
This is an interesting theoretical discussion. I’m wondering how much your transparent atmosphere and the surface would change if we reintroduced water vapour with it’s real properties in it, but no co2. How different would it be to what we have?
Perhaps we could consider two scenarios, a low sensitivity scenario such as Lindzen and a high sensitivity scenario such as IPCC, while we think about the magnitude of the effect of taking co2 out of the atmosphere.
tallbloke,
That’s not easy to say without a proper and rather complex calculation, because the there would certainly be some moisture in the atmosphere and that would be enough to maintain a troposphere.
Looking at the problem from the other end, i.e. starting from the present atmosphere and removing CO2 from that, it can be concluded that the atmosphere would cool very much, enough to lead to essentially a snowball Earth, when the feedback from certain reduction in water vapor is taken into account. The snowball Earth would, however, still have enough moisture in the atmosphere to maintain some troposphere.
That’s all that I can feel certain about: very cold compared to present, but with a troposphere and some GHE.
There has been some discussion also on the absortptivity/emissivity of a N2/O2 atmosphere, when the very weak interactions are taken into account. Even that might be enough to maintain a thin troposphere, but that’s again something that I haven’t tried to estimate.
My previous comment was based an the assumption that no radiative energy transfer occurs in the atmosphere (or that it’s weaker than conduction, which is very weak).
Pekka Pirilä,
“There will always be some circulation, but only at very low altitudes.”
Pressure gradient flow increases with altitude.
“The stratosphere extends essentially to surface, and almost all of the atmosphere is isothermal.”
But the surface isn’t isothermal. The atmosphere above the poles cannot be the same temperature as the atmosphere above the equator. In the stratosphere, the temperature increases with altitude. Without radiative heating, that can’t happen.
From an email from Gavin Schmidt:
“The latitudinal gradient in convection will set up a Hadley-like
circulation, which may (or may not) extend to the poles (depending on
whether the conditions for baroclinic instability are achieved in the
mid-latitudes). In the regions of subsidence, there is no expectation
that the adiabatic lapse rate will hold and indeed, you should expect
very stable conditions.”
I misremembered that communication and went too far by saying the lapse rate would be adiabatic everywhere. But a transparent atmosphere cannot be isothermal.
DeWitt,
Yes, I do agree that Postma follows many standard equations and assumptions from the consensus view but then he markedly diverges from that to factor in day and night. The GHE creates an Earth model in 24 hour twilight in which temps never rise high enough to give Earth liquid water.
I agree with Postma that is a fatal flaw in the standard equations. His paper has accurately factored in for the changes in insolation due to day and night and those changes make all the difference in explaining the so-called ‘missing’ 33K that makes the consensus model cooler. By accommodating day and night and and calculating insolation accordingly Postma’s numbers show that the imaginary 33K temperature gap claimed by GHE advocates (absent a GHE) suddenly vanishes.
If climatologists had started from Postma’s numbers instead of K&T’s 1997 budget then no one would now claim claim that Earth has a missing 33K and there would be no need to claim any such GHE to make up the temperature shortfall.
To my mind, the abject failure of climatologists to model day and night had a huge impact on temperature inertia and insolation. Sticking to the known standard numbers we see that:
Earth’s thermal emission with a greenhouse effect = 239 W/m²
Earth’s thermal emission without a greenhouse effect = 239 W/m²
But Postma’s model gives us liquid water yet the GHE numbers cannot because a world in 24hrs of twilight never gets warm enough to provide for liquid water.
Pekka, thanks for your response.
If the cause of ice ages was more to do with orbital and orientation parameters than is currently supposed, and was less to do with co2 levels, then given the lack of marine data for precipitation, and the uncertainty around any trend resulting from that, what would the situation be for a no-co2 scenario if there is very little water vapour feedback to a change in co2 levels?
My rough calculation gives around 17C lower rather than 33C, but I’d appreciate your estimate.
DeWitt and Tallbloke
One reason that 33 degrees is way out is that the Earth’s surface is not insulated from either the atmosphere nor the crust beneath. A perfect blackbody is assumed to be fully insulated (ie in a vacuum) so that no energy is lost by diffusion, conduction, evaporation etc. Such losses reduce what’s left for radiation.
In fact, the surface is usually maintaining the first 1mm of the atmosphere at a very similar temperature by diffusion (molecular collision) and thus there is very little radiation and none at all if the temperatures are identical.
Obviously much (if not most) radiation comes from the atmosphere. Yes you can view the whole Earth plus atmosphere system as a blackbody from space, but then the 255K is just a mean temperature somewhere in the atmosphere – which tells you nothing about surface temperatures.
There is absolutely no way you can apply S-B to determine the temperature of the surface under any circumstances.
In any event, radiation from the cooler atmosphere cannot transfer thermal energy to a warmer surface and cannot even melt a bit of frost on the ground.
SST have risen at a greater rate prior to WWII than at any time since that war. Valid projections show no more than 0.5 deg.C increase in the trend by 2100. More importantly, long-term natural cycles indicate potential cooling in the not-too-distant future.
Relax! There’s nothing to worry about. There is no atmospheric greenhouse effect.
See http://principia-scientific.org/supportnews/latest-news/130-latest-study-confirms-no-atmospheric-warming-from-carbon-dioxide