Guest essay by Dr. Ira Glickstein
We’ve reached a turning point where it is hard for any Global Warming Alarmist to claim (with a straight face) that the world as we know it is about to end in the coming decades unless we stop burning fossil fuels. Anyone deluded or foolish enough to make such a claim would be laughed at by many audiences.
GLOBAL WARMING IS REAL
Yes, the world has warmed 1°F to 1.5°F (0.6°C to 0.8°C) since 1880 when relatively good thermometers became available. Yes, part of that warming is due to human activities, mainly burning unprecedented quantities of fossil fuels that continue to drive an increase in carbon dioxide (CO2) levels. The Atmospheric “Greenhouse” Effect is a scientific fact!
BUT GLOBAL WARMING IS NOT A BIG DEAL
Alarmist Theory is Handcuffed to High Estimates of Climate Sensitivity
As the animated graphic clearly indicates, the theoretical climate models used by the Intergovernmental Panel on Climate Change (IPCC) are handcuffed to inordinately high estimates of climate sensitivity (how much temperatures are expected to rise given a doubling of CO2). Since the advent of good satellite-based global temperature data in 1979, observed temperatures have risen at a fraction of the IPCC predicted rate even as CO2 continues to rise.
Relax, there is not and never has been any near-term “tipping point”. The actual Earth Climate System is far less sensitive to CO2 than claimed the IPCC climate theory, as represented by their computer models. Global Warming since 1880 is mainly due to Natural Cycles and Processes not under human control. Yes, the same Natural Cycles and Processes that were responsible for the many Ice Age cycles that repeatedly occurred about every 100,000 years or so.
A GREAT TIME TO PUT ALARMISTS IN THEIR PLACE
Last week, by a stroke of good fortune, I happened to be scheduled to present “Visualizing the Atmospheric ‘Greenhouse’ Effect – Global warming is real, but how much is due to human activities and how big is the risk?” to the Philosophy Club in the Central Florida retirement community where I live.
Everyone in the highly interactive and supportive audience was aware of newspaper and TV reports of the drama of those ill-fated Global Warming “Research” activists whose Russian ship, the Academik Shokalskiy, got stuck in the summer ice of the Antarctic. (Fortunately, those people are safe, having been rescued by a helicopter from a Chinese icebreaker.) In addition to the Antarctic adventure gone wrong, in the week leading up to and following my talk, the media was overrun by stories of the “polar vortex” literally freezing large parts of the US and even causing Florida temperatures to drop below 30°F (0°C).
Of course, everyone knows that the cold wave is only anecdotal evidence and “weather is not climate”. However, photos and videos of researchers stuck in the Antarctic summer ice as well as scenes of American life frozen in place for days on end, when combined with clear and irrefutable evidence of a slowdown in warming since 1979 and no statistically significant warming since 1996 (as depicted in the graphic above), has considerable emotional impact. Audiences often react more to emotions than their reason.
My animated PowerPoint Show, which should run on any Windows PC, is available for download here. (NOTE: I knew that many members of the Philosophy Club audience, while highly intelligent and informed, are not particularly scientifically astute. Therefore, I kept to the basics and invited questions as I proceeded. Since most of them think in Fahrenheit, I was careful to give temperatures in that system. By contrast, my 2011 talk to the more scientifically astute members of our local Science and Technology Club Skeptic Strategy for Talking about Global Warming was more technical. Both presentations make use of animated PowerPoint charts and you are free to download and use them as you wish.)
My presentation is based on my five-part WUWT series entitled “Visualizing the ‘Greenhouse Effect'” – 1 – A Physical Analogy, 2 – Atmospheric Windows, 3 – Emission Spectra, 4 – Molecules and Photons, and 5 – Light and Heat. The series, which ran in 2011, generated tens of thousands of page views at WUWT, along with thousands of comments. I wrote the series this website attracts some viewers who reject the basic physics of the Atmospheric “Greenhouse” Effect.
HOW A REAL GREENHOUSE WORKS
I explained how a real physical Greenhouse works and how that is both similar and different from the Atmospheric “Greenhouse” Effect. The Greenhouse descriptions I learned in high school, as well as those available on the Internet, consider only the RADIATIVE effect. The glass roof of the Greenhouse allows visible light to pass through freely, heating the soil, plants, and air, but is opaque to the resultant infrared radiation, which is partly re-radiated back down into the Greenhouse, warming it further. That part is true, but far from the whole story. The MAIN reason a Greenhouse stays warm is that it is airtight to restrict CONVECTION and it is insulated to restrict CONDUCTION. In fact, it is possible to construct a successful Greenhouse using a roof made from materials that allow both visible and infrared to pass freely, but is impossible to make a working Greenhouse that is not both airtight and insulated.
HOW THE ATMOSPHERIC “GREENHOUSE” EFFECT WORKS
All warm objects emit radiation at a wavelength dependent upon the temperature of the object. The Sun, at around 10,000 °F, emits “short-wavelength” infrared radiation, centered around 1/2 micron (one millionth of a meter). The soil, plants, and air in the Greenhouse, at around 60°F to 100°F (15°C to 40°C), emit “long wavelength” radiation, centered around 10 microns (with most of the energy between 4 and 25 microns).
The Atmospheric “Greenhouse” Effect works because:
- Short-wavelength radiation from the Sun passes freely through the gases that make up the Atmosphere,
- About a third of this Sunlight is reflected back by white clouds, dust, and light-colored objects on the Surface, and that energy is lost to Space,
- The remaining two-thirds of the Sunlight energy is absorbed by the Sea and Land Surface and causes it to warm,
- The warm Surface cools by emitting long-wavelength radiation at the Bottom of the Atmosphere, and this radiation passes towards the Top of the Atmosphere, where it is ultimately lost to Space,
- On the way to the Top of the Atmosphere, much of this radiation is absorbed by so-called “Greenhouse” gases (mostly water vapor and carbon dioxide) which causes the Atmosphere to warm,
- The warmed Atmosphere emits infrared radiation in all directions, some into Space where it is lost, and some back towards the Surface where it is once again absorbed and further warms the Surface.
- In addition to the RADIATIVE effects noted in points 1 through 6, the Surface is cooled by CONVECTION and CONDUCTION (thunderstorms, winds, rain, etc.)
THANK GOODNESS FOR THE ATMOSPHERIC “GREENHOUSE” EFFECT
If not for the warming effect of “Greenhouse” gases, the Surface of the Earth would average below 0°F (-18°C), which would prevent life as we know it. This effect is responsible for about 60°F (33°C) of warming. According to the Intergovernmental Panel on Climate Change (IPCC), the Earth Surface has warmed about 1.5°F (0.8°C) since good thermometer data became available around 1880. Some skeptics (including me) believe the actual warming is closer to 1°F, and that government agencies have adjusted the thermometer record to exaggerate the warming by 30% or more. However, it doesn’t really matter whether the actual warming is 1°F or 1.5°F (0.6°C or 0.8°C) because we are arguing about only 0.5°F (0.2°C), which is less than 1% of the total warming due to the Atmospheric “Greenhouse” Effect.
HOW SENSITIVE IS THE CLIMATE TO HUMAN ACTIVITIES?
The IPCC claims that the majority of the warming since 1880 is due to human activities. It is true that we are burning unprecedented amounts of fossil fuel (coal, oil, gas), and that we are making land use changes that may reduce the albedo (reflectiveness) of the Surface. Most of the increase in Atmospheric CO2 (a 40% rise from about 270 to nearly 400 parts per million by volume) is due to human activities.
The IPCC claims that Climate Sensitivity (the average increase in Surface temperatures due to a doubling of CO2) is between 3°F and 8°F (1.5°C and 4.5°C). Some skeptics (including me) believe they are off by at least a factor of two, and possibly a factor of three, and that Climate Sensitivity is closer to 1°F to 3°F (0.5°C to 1.5°C). As evidence for our conclusions, we point to the fact that virtually ALL of the IPCC climate models have consistently over-estimated future temperature predictions as compared to the actual temperature record. Indeed, for the past 17 years as CO2 levels continue their rapid climb, temperatures have leveled off, which is proof that Natural Cycles, not under human control or influence, have cancelled out warming due to CO2 increases. Thus, Natural Cycles must have a larger effect than CO2.
VISUALIZING THE ATMOSPHERIC “GREENHOUSE” EFFECT
As I noted above, I wrote the “Visualizing” series for WUWT (1 – A Physical Analogy, 2 – Atmospheric Windows, 3 – Emission Spectra, 4 – Molecules and Photons, and 5 – Light and Heat) because some WUWT viewers are “Disbelievers” who have had an “equal and opposite” reaction to the “end of the world” excesses of the Global Warming “Alarmists”. By failing to understand and accept the basic science of the Atmospheric “Greenhouse” Effect, they have, IMHO, “thrown the baby out with the bathwater”.
Albert Einstein was a great theoretical physicist, with all the requisite mathematical tools. However, he rejected purely mathematical abstraction and resorted to physical analogy for his most basic insights. For example, he imagined a man in a closed elevator being transported to space far from any external mass and then subjected to accelerating speeds. That man could not tell the difference between gravity on Earth and acceleration in space, thus, concluded Einstein, gravity and acceleration are equivalent, which is the cornerstone of his theory of relativity. Einstein never fully bought into the mainstream interpretation of quantum mechanics that he and others have called quantum weirdness and spooky action at a distance. He had trouble accepting a theory that did not comport with anything he considered a reasonable physical analogy!
So, if you have trouble accepting the atmospheric “greenhouse” effect because of the lack of a good physical analogy, you are in fine company.
Well, getting back to the Atmospheric “Greenhouse Effect, a “disbelieving” commenter on WUWT suggested we think of the Sunlight as truckloads of energy going from the Sun to the Earth Surface, and the infrared radiation from the Surface as equal truckloads going the other way. How, he asked, could these equal and opposite truckloads do anything but cancel each other out as far as the amount of energy on the Surface of the Earth? In reply, I posted a comment with an analogy of truckloads of orange juice, representing short-wave radiation from Sun to Earth, and truckloads of blueberry juice, representing longwave radiation between Earth and the Atmosphere and back out to Space.
That thought experiment triggered my creativity. I imagined the Sun as a ball-pitching machine, throwing Yellow balls towards the “Earth” Surface (representing short-wave radiation) and Purple balls (representing long-wave radiation) bouncing back towards Space and interacting with the Atmosphere. The graphic below is one of my depictions of the physical analogy. Follow this link for more graphics and detail.
I imagined the Earth as a well-damped scale. The Yellow balls would bounce off the Surface and turn into Purple balls (representing long-wave radiation as the Earth absorbed the short-wave radiation and then emitted an equal quantity of long-wave radiation). The scale would read “1” unit.
If there was no Atmosphere, or if the Atmosphere contained no “Greenhouse” gases to obstruct the flight of the Purple balls, they would fly out towards Space.
I then imagined the Atmosphere as an obstacle that absorbed the Purple balls, split them in two, and emitted half of the smaller balls to Space and the other half back towards the Earth. The balls going towards Earth would be absorbed, further heating the Earth, and the warmed Earth would emit them back towards the Atmosphere. The process would be repeated with the balls being absorbed by “Greenhouse” gases in the Atmosphere, and then emitted with half going out to Space, and half back to the Earth. The sum of 1 + 1/2 + 1/4 + 1/8 +1/16 … = 2 (approximately), so the scale reads “2” units.
Thus, in my simplified analogy, the “Greenhouse” gases in the “Atmosphere” cause the scale reading to double. So, the Atmospheric “Greenhouse” Effect causes the Earth Surface to be warmer than it would be absent the “Greenhouse” gases. I think Einstein would be pleased! Read more detail, including the 340 responses.
A real greenhouse has windows. So does the Atmospheric “greenhouse effect”. They are similar in that they allow Sunlight in and restrict the outward flow of thermal energy. However, they differ in the mechanism. A real greenhouse primarily restricts heat escape by preventing convection while the “greenhouse effect” heats the Earth because “greenhouse gases” (GHG) absorb outgoing radiative energy and re-emit some of it back towards Earth.
There are two main “windows” in the Atmospheric “greenhouse effect”. The first, the Visible Light Window, on the left side of the graphic, allows visible and near-visible light from the Sun to pass through with small losses, and the second, the Longwave Window, on the right, allows the central portion of the longwave radiation band from the Earth to pass through with small losses, while absorbing and re-emitting the left and right portions.
Sunlight Energy In = Reflected Sunlight Energy Out + Thermal Energy Out
The graphic is an animated depiction of the Atmospheric “greenhouse effect” process.
On the left side:
(1) Sunlight is shortwave radiation with a wavelength centered around 0.5μ (microns, millionths of a meter). That energy streams through the Atmosphere towards the surface of the Earth.
(2) A portion of the Sunlight is reflected by clouds and other high-albedo surfaces and heads back through the Atmosphere towards Space. The remainder is absorbed by the Surface of the Earth, warming it.
(3) The reflected portion is lost to Space.
On the right side:
(1) The warmed Earth emits longwave radiation with a wavelength centered around 10μ towards the Atmosphere. This consists of thermal energy from about 4μ to about 25μ. For convenience in description, I have divided this range into three bands: ~7μ, ~10μ, and ~15μ.
(2) The ~10μ portion passes through the Atmosphere with litttle loss. The ~7μ portion gets absorbed, primarily by water vapor (H2O), and the 15μ portion gets absorbed, primarily by H2O and CO2. The absorbed radiation heats the H2O and CO2 molecules and, at their higher energy states, they collide with the other molecules that make up the air, mostly nitrogen (N2), oxygen (O2), ozone (O3), and argon (A) and heat them by something like conduction. The molecules in the heated air emit radiation in random directions at all bands (~7μ, ~10μ, and ~15μ). The ~10μ photons pass, nearly unimpeded, in whatever direction they happen to be emitted, some going towards Space and some towards Earth. The ~7μ and ~15μ photons go off in all directions until they run into an H2O or CO2 molecule, and repeat the absorption and re-emittance process, or until they emerge from the Atmosphere or hit the surface of the Earth.
(3) The ~10μ photons that got a free-pass from the Earth through the Atmosphere emerge and their energy is lost to Space. The ~10μ photons generated by the heating of the air emerge from the top of the Atmosphere and their energy is lost to Space, or they impact the surface of the Earth and are re-absorbed. The ~7μ and ~15μ generated by the heating of the air also emerge from the top or bottom of the Atmosphere, but there are fewer of them because they keep getting absorbed and re-emitted, each time with some transfered to the central ~10μ portion of the longwave band.
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The Atmospheric “Greenhouse” effect has been analogized to a blanket that insulates the Sun-warmed Earth and slows the rate of heat transmission, thus increasing mean temperatures above what they would be absent “greenhouse gases” (GHGs). Perhaps a better analogy would be an electric blanket that, in addition to its insulating properties, also emits thermal radiation both down and up. The graphic below, based upon actual measurements of long-wave radiation as measured by a satellite LOOKING DOWN from the Top of the Atmosphere as well as from the Surface LOOKING UP from the Bottom of the Atmmsphere, depicts the situation.
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Description of graphic (from bottom to top):
Earth Surface: Warmed by shortwave (~1/2μ) radiation from the Sun, the surface emits upward radiation in the ~7μ, ~10μ, and ~15μ regions of the longwave band. This radiation approximates a smooth “blackbody” curve that peaks at the wavelength corresponding to the surface temperature.
Bottom of the Atmosphere: On its way out to Space, the radiation encounters the Atmosphere, in particular the GHGs, which absorb and re-emit radiation in the ~7μ and ~15μ regions in all directions. Most of the ~10μ radiation is allowed to pass through.
The lower violet/purple curve (adapted from figure 8.1 in Petty and based on measurements from the Tropical Pacific looking UP) indicates how the bottom of the Atmosphere re-emits selected portions back down towards the surface of the Earth. The dashed line represents a “blackbody” curve characteristic of 300 K (equivalent to 27ºC or 80ºF). Note how the ~7μ and ~15μ regions approximate that curve, while much of the ~10μ region is not re-emitted downward.
“Greenhouse Gases”: The reason for the shape of the downwelling radiation curve is clear when we look at the absorption spectra for the most important GHGs: H2O, H2O, H2O, … H2O, and CO2. (I’ve included multiple H2O’s because water vapor, particularly in the tropical latitudes, is many times more prevalent than carbon dioxide.)
Note that H2O absorbs at up to 100% in the ~7μ region. H2O also absorbs strongly in the ~15μ region, particularly above 20μ, where it reaches 100%. CO2 absorbs at up to 100% in the ~15μ region.
Neither H2O nor CO2 absorb strongly in the ~10μ region.
Since gases tend to re-emit most strongly at the same wavelength region where they absorb, the ~7μ and ~15μ are well-represented, while the ~10μ region is weaker.
Top of the Atmosphere: The upper violet/purple curve (adapted from figure 6.6 in Petty and based on satellite measurements from the Tropical Pacific looking DOWN) indicates how the top of the Atmosphere passes certain portions of radiation from the surface of the Earth out to Space and re-emits selected portions up towards Space. The dashed line represents a “blackbody” curve characteristic of 300 K. Note that much of the ~10μ region approximates a 295 K curve while the ~7μ region approximates a cooler 260ºK curve. The ~15μ region is more complicated. Part of it, from about 17μ and up approximates a 260ºK or 270ºK curve, but the region from about 14μ to 17μ has had quite a big bite taken out of it. Note how this bite corresponds roughly with the CO2 absorption spectrum.
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In this part, we consider the interaction between air molecules, including Nitrogen (N2), Oxygen (O2), Water Vapor (H2O) and Carbon Dioxide (CO2), with Photons of various wavelengths. This may help us visualize how energy, in the form of Photons radiated by the Sun and the Surface of the Earth, is absorbed and re-emited by Atmospheric molecules.
The animated graphic has eight frames, as indicated by the counter in the lower right corner. Molecules are symbolized by letter pairs or triplets and Photons by ovals and arrows. The view is of a small portion of the cloud-free Atmosphere.
- During the daytime, Solar energy enters the Atmosphere in the form of Photons at wavelengths from about 0.1μ (micron – millionth of a meter) to 4μ, which is called “shortwave” radiation and is represented as ~1/2μ and symbolized as orange ovals. Most of this energy gets a free pass through the cloud-free Atmosphere. It continues down to the Surface of the Earth where some is reflected back by light areas (not shown in the animation) and where most is absorbed and warms the Surface.
- Since Earth’s temperature is well above absolute zero, both day and night, the Surface radiates Photons in all directions with the energy distributed approximately according to a “blackbody” at a given temperature. This energy is in the form of Photons at wavelengths from about 4μ to 25μ, which is called “longwave” radiation and is represented as ~7μ, ~10μ, and ~15μ and symbolized as violet, light blue, and purple ovals, respectively. As noted above, the primary “greenhouse” gases (GHG) are Water Vapor (H2O) and Carbon Dioxide (CO2). The ~7μ Photon is absorbed by an H2O molecule because Water Vapor has an absorption peak in that region, the ~10μ Photon gets a free pass because neither H2O nor CO2 absorb strongly in that region, and one of the 15μ Photons gets absorbed by an H2O molecule while the other gets absorbed by a CO2 molecule because these gases have absorption peaks in that region.
- The absorbed Photons raise the energy level of their respective molecules (symbolized by red outlines).
- The energized molecules re-emit the Photons in random directions, some upwards, some downwards, and some sideways. Some of the re-emitted Photons make their way out to Space and their energy is lost there, others back down to the Surface where their energy is absorbed, further heating the Earth, and others travel through the Atmosphere for a random distance until they encounter another GHG molecule.
- This frame and the next two illustrate another way Photons are emitted, namely due to collisions between energized GHG molecules and other air molecules. As in frame (2) the Surface radiates Photons in all directions and various wavelengths.
- The Photons cause the GHG molecules to become energized and they speed up and collide with other gas molecules, energizing them. NOTE: In a gas, the molecules are in constant motion, moving in random directions at different speeds, colliding and bouncing off one another, etc. Indeed the “temperature” of a gas is something like the average speed of the molecules. In this animation, the gas molecules are fixed in position because it would be too confusing if they were all shown moving and because the speed of the Photons is so much greater than the speed of the molecules that they hardly move in the time indicated.
- The energized air molecules emit radiation at various wavelengths and in random directions, some upwards, some downwards, and some sideways. Some of the re-emitted Photons make their way out to Space and their energy is lost there, others back down to the Surface where their energy is absorbed, further heating the Earth, and others travel through the Atmosphere for a random distance until they encounter another GHG molecule.
- Having emitted the energy, the molecules cool down.
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As noted above, Sunlight Energy In = Reflected Sunlight Energy Out + Thermal Energy Out ! That’s old news to those of us who understand all energy is fungible (may be converted to different forms of energy) and energy/mass is conserved (cannot be created nor destroyed).
Answering Some Objections to the Atmospheric “Greenhouse”Effect
Some WUWT commenters seem to have been taken in by scientific-sounding objections to the basic science behind the Atmospheric “Greenhouse” Effect. Their objections seemed to add more heat than light to the discussion. This section is designed to get back to basics and perhaps transform our heated arguments into more enlightened understanding :^)
The main scientific question for me, is how much does the increase in human-caused CO2 and human-caused albedo reduction increase the mean temperature above what it would be with natural cycles and processes? My answer is “not much”, because perhaps 0.2ºC to 0.4ºC (0.1ºC to 0.2ºC) of the supposed 1.5ºF (0.8ºC) increase since 1880 is due to human activities. The rest is due to natural cycles and processes over which we humans have no control. The main public policy question for me, is how much should we (society) do about it? Again, my answer is “not much”, because the effect is small and a limited increase in temperatures and CO2 may turn out to have a net benefit.
So, my motivation for this Visualizing series was not to add to the Alarmist “the sky is falling” panic, but rather to help my fellow Skeptics avoid the natural temptation to fall into an “equal and opposite” falsehood, which some of those on my side, who I call “Disbelievers”, do when they fail to acknowledge the basic facts of the role of H2O and CO2 and other gases in helping to keep temperatures in a livable range.
Objection #1: Visual and near-visual radiation is merely “light” which lacks the “quality” or “oomph” to impart warmth to objects upon which it happens to fall.
Answer #1: A NASA webpage targeted at children is sometimes cited because they say the near-IR beam from a TV remote control is not warm to the touch. Of course, that is not because it is near-visual radiation, but rather because it is very low power. All energy is fungible, and can be changed from one form to another. Thus, the 240 Watts/m^2 of visible and near-visible Solar energy that reaches and is absorbed by the Earth System, has the effect of warming the Earth System exactly as much as an equal number of Watts/m^2 of “thermal” mid- and far-IR radiation.
Objection #2: The Atmosphere, which is cooler than the Earth Surface, cannot warm the Earth Surface.
Answer #2: The Second law of Thermodynamics is often cited as the source of this falsehood. The correct interpretation is that the Second Law refers to net warming, which can only pass from the warmer to the cooler object. The back-radiation from the Atmosphere to the Earth Surface has been measured (see lower panel in the above illustration). All matter above absolute zero emits radiation and, once emitted, that radiation does not know if it is travelling from a warmer to a cooler surface or vice-versa. Once it arrives it will either be reflected or absorbed, according to its wavelength and the characteristics of the material it happens to impact.
Objection #3: The Atmospheric “Greenhouse” Effect is fictional. A glass greenhouse works mainly by preventing or reducing convection and the Atmosphere does not work that way at all.
Answer #3: I always try to put “scare quotes” around the word “greenhouse” unless referring to the glass variety because the term is misleading. Yes, a glass greenhouse works mainly by restricting convection, and the fact that glass passes shortwave radiation and not longwave makes only a minor contribution.
Thus, I agree it is unfortunate that the established term for the Atmospheric warming effect is a bit of a misnomer. However, we are stuck with it. But, enough of semantics. Notice that the Earth System mean temperature I had to use to provide 240 Watts/m^2 of radiation to Space to balance the input absorbed from by the Earth System from the Sun was 255 K. However, the actual mean temperature at the Surface is closer to 288 K. How to explain the extra 33 K (33ºC or 58ºF)? The only rational explanation is the back-radiation from the Atmosphere to the Surface.
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David A:
re your post at January 18, 2014 at 5:44 am.
There is nothing to “forgive”, and if I did ‘talk over’ you then I apologise because I genuinely did try to engage with you using ‘layman’s language’.
Richard
However I do maintain the GHG molecules in general increase residence time of energy from upwelling LWIR radiating energy, and decrease residence time of conducted energy from non GHG molecules. Also, via receiving dowelling TSI within the atmosphere, GHG like Water Vapor, reduce said TSI residence time, via often preventing said energy from reaching the surface.
Thanks Richard, yet I fear that you have not comprehended that Ira’s comments support my statements in many ways.
David A:
re your comment to me at January 18, 2014 at 6:02 am.
Please do not “fear”. We learn from honest and mutually respectful disagreement.
If you can show me to be wrong then I shall learn and be grateful for it.
Richard
Please reread Ira’s post at Ira Glickstein, PhD says:
January 17, 2014 at 7:23 pm
A small flame under a pot of water will, over time equalize at a certain T, providing a small consistent flow of water into the pot to keep the water level. Put a lid on the pot, and the temperature will rise due to the fact that the energy from the flame stays in the pot :”system” longer.
David A:
I understand you to be addressing me at January 18, 2014 at 6:32 am when you request
OK. I have done, and I still do not see anything other than in the post from Mario Lento at January 17, 2014 at 11:30 am which I agreed at January 17, 2014 at 11:39 am.
I said I would withdraw in favour of Ira unless points were specifically addressed to me, and I have only addressed such points since then.
I now ask you to consider that none of us is completely ‘right’ and we are all ‘wrong’ to some degree because the world is as it is and we ‘view it through a glass darkly’. These conversations exist because we are trying to remove some of the distortions in what we ‘view’.
Your ‘view’ will be accepted if it turns out to be more useful than mine. I see no purpose in championing my view because I have stated it.
Ira concludes his post you commended to me by saying
Assuming his conclusion is true, then your task is now to convince me that his conclusion is useful. I see that conclusion as being a trivial consequence of alterations to inputs and outputs which are capable of measurement (at least in theory).
Richard
PS If you want to see the inevitable outcome of a “I am right” crusade then follow the comments of Terry Oldberg in this thread.
Richard, I think that the antagonistic style of many posters prohibits rational discourse. I am not them, so no need to engage on that level.
As I have found, and reasonably established that an increase or decrease of the residence time of any form of energy within our system, leads to an increase or decrease of total energy, and that all the physical properties of matter composing our system follow this principle, which I have coined “David’s Law” , it is useful to ask if any change, anthropogenic or otherwise, changes the residence time of some aspect of energy within the earth’s system.
Specifically I have pointed out how an increase of GHG both increases and decreases the residence time of disparate aspects of earths thermodynamic properties, all the while admitting I lack the math and physics to accurately quantify these energy gains or losses; and att he same time assert that it is likely that present day climate science also falls short in ability to determine this also
However I think the understanding of the relationship of energy residence time to understanding these many disparate processes, is useful in attempting observational and experiential quests for greater scientific understanding..
To move from the general to the particular; can a unit of energy, transferred from a non GHG molecule to a GHG molecule, reduce the residence time of that unit of energy with our “system” and lead to less energy? More specific, how often does this happen?
I have asked at least five or six such questions in this thread, outlining several possible ways for a GHG molecule to reduce residence time of earth’s energy, and never received a direct quantifying
answer, or even had the general principle acknowledged, except by Ira.
David A:
At January 18, 2014 at 7:23 am you say
Sorry, but I DID address those questions in my post addressed to you at
http://wattsupwiththat.com/2014/01/12/global-warming-is-real-but-not-a-big-deal-2/#comment-1536767
Furthermore, Phil. quoted my reply and pointed out that that the effect is trivial. As he says in his post, it is trivial because it is so rare that – for practical purposes – it can be ignored. His pertinent post is at
http://wattsupwiththat.com/2014/01/12/global-warming-is-real-but-not-a-big-deal-2/#comment-1540060
The time between excitation and de-excitation of a molecule is a few nanoseconds whether or not it releases the energy radiatively or collisionally.
If I missed any of your questions then it was not intentional.
Richard
I am grateful we have progressed to question if understanding the veracity of disparate matters thermodynamic residence time within earths system is useful. I have outlined above several other examples of why this is useful;
I have, on the basis of residence time, questioned the veracity of Willis’s proposition that if the watt per square meter down welling LWIR due to clouds, is equal to the same watt per meter down welling SW , sans clouds, then they make the same contribution to earth’s energy budget.
I have questioned the assumption that geothermal heat flows from ocean depths. be discounted due to their very small watt per sq meter flow, again based on the very long residence time of such energy input, and on the law of the conservation of energy. Again, I assert this understanding to be useful.
David A:
I hope you will understand that I am writing in attempt to be helpful.
You conclude your post at January 18, 2014 at 7:47 am saying
How is it useful?
Richard
Richard, I do find your posts informative, and this in particular,.. “Simply, the energy from the photon is stored in the GHG molecule and the GHG molecule does not change its speed. If that stored energy is supplied by a collision to e.g. a nitrogen molecule then the nitrogen molecule is accelerated: the energy that was stored in the GHG molecule becomes kinetic energy in the nitrogen molecule so the gas gets hotter..”
This process would move energy which the GHG molecule could potentially zip off to space, to a non GHG molecule, increasing the residence time of that energy, and converting that energy to higher T. The fact that such transfers happen rapidly does not quantify how often they happen, nor does it quantify how the GHG received that energy, which could happen in disparate ways. I have not seen any numbers which quantify the percentage of conducted energy within our atmosphere, nor have I seen any numbers which quantify how often such conducted energy encounters a GHG molecule, and reduces that energies residence time, nor have I seen numbers on how a reduction in GHG molecules would increase the relative percentage of conducted energy within the atmosphere, as well as increase the amount of conducted energy..
I have posted many rational questions, all based on the principle of energy residence time within our earth’s system. I find these questions useful. .
Reply to Richard stating,
David A:
I hope you will understand that I am writing in attempt to be helpful.
You conclude your post at January 18, 2014 at 7:47 am saying
“Again, I assert this understanding to be useful.”
How is it useful?
Richard
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If the SW radiation in Willis’s analogy has a far longer residence time then the LWIR due to clouds, then it will have a large net gain to earth’s energy budget, despite the fact that the watt per sq meter is equal.
I postulate that the SW radiation will enter the earths oceans to depth, having far longer residence time. I postulate that the LWIR will expand much if its energy in accelerating the water cycle, be lost in evaporation, and released at altitude, to be liberated by GHG molecules, the more numerous, the more likely to be quickly liberated from our “system”
Typo correction, ” I postulate that the LWIR will expand” Change “expand” to expend. Apologies’.
David A:
Your post at January 18, 2014 at 8:00 am continues to press me on unknowns which I have already pointed out.
As I said, the energy budgets are based on assumptions because so much is not known. Saying things are not known is not an evasion: it is acceptance of our state of knowledge.
Simple calculations indicate that almost all the IR in the 15 micron band emitted from the Earth’s surface is absorbed by molecules in the lowest 100 m of the atmosphere. And – as I said – excited molecules release their energy in nanoseconds. Almost exactly half of the IR released from those molecules goes down and the other half goes up.Can you say with certainty what happens to that energy next? Or, in common with everybody else, do you adopt assumptions?
Questions are only useful if they have answers or if they point to needed information. We know the information we need about the climate system and it is almost everything.
Richard
Concerning this comment of mine…”I postulate that the SW radiation will enter the earths oceans to depth, having far longer residence time. I postulate that the LWIR will expend much if its energy in accelerating the water cycle, be lost in evaporation, and released at altitude, to be liberated by GHG molecules, the more numerous, the more likely to be quickly liberated from our “system”
In this scenario the GHG has increased the residence time of the initial energy from the surface, but, at the cost of reducing SW to the surface and the far longer residence time of an equal wattage of SW energy. All the pluses and minuses must be quantified, and our science is not yet at this level of understanding.
Richard, a question on this statement of yours, ” And – as I said – excited molecules release their energy in nanoseconds.”
You also said this, ” The time between excitation and de-excitation of a molecule is a few nanoseconds whether or not it releases the energy radiantly or collisionally.”
Yes! and I have pointed out how if the release is via collision, (conduction) it has a different affect on the residence time of the energy. If a GHG molecules energy is released via collision to a non GHG this increases residence time. I have pointed out to Ira’s barrel analogy that GHG molecules increase the residence time of radiant energy, (enlarge the exit hole) and decrease the residence time of conducted energy. (shrink the exit hole) . The fact that both happen in nano seconds does not answer how often they happen, and how relative changes in the percentage of, and total amount of conducted energy in an atmosphere change, depending on the amount of GHG within the atmosphere.
Your post here richardscourtney says: January 18, 2014 at 8:16 am strikes me as contradictory
“As I said, the energy budgets are based on assumptions because so much is not known. Saying things are not known is not an evasion: it is acceptance of our state of knowledge.”
followed by…” We know the information we need about the climate system and it is almost everything”
I am saying that we do not know our earth’s inflow and outbound budget to the accuracy necessary to capture changes caused by long term (decades to centuries) minor variations in aspect of energy within our system that have very long term residence times, (also decades to centuries) despite their minor flux in wattage per square meters. I am talking solar changes, ocean residence times, jet stream movements affecting them, etc.
David A:
re your point to me at January 18, 2014 at 8:33 am.
Both effects happen in nanoseconds so it would make negligible difference to the total energy in the molecules if either effect were solely responsible for discharging the energy. The change to the flux would be extremely small.
At the atmospheric densities in the lower atmosphere it is likely that almost all the discharge is collisional but – again – that depends on assumptions.
I yet again strongly commend that you refer to standard texts because these basics are well understood. Of interest is how these phenomena translate into energy fluxes through the atmosphere system. And – as I also said – the GCMs are constructed as an attempt to determine these fluxes.
Science is numbers and we don’t have most of the needed numbers. Any quantifications you can derive you should publish.
Richard
richardscourtney says:
January 18, 2014 at 8:48 am
David A:
re your point to me at January 18, 2014 at 8:33 am.
Both effects happen in nanoseconds so it would make negligible difference to the total energy in the molecules if either effect were solely responsible for discharging the energy. The change to the flux would be extremely small.
One small correction, for the 15 micron band of CO2 the average time for an emission of a photon is of the order of millisecs whereas the collisions occur about 10 times per nanosec which is why collisional deactivation dominates in the lower atmosphere. In the upper atmosphere the density is lower so the collisions are less frequent and emission becomes more important.
At the atmospheric densities in the lower atmosphere it is likely that almost all the discharge is collisional but – again – that depends on assumptions.
Phil.:
Thanks for your clarification at January 18, 2014 at 9:11 am.
Yes, again you are right in all you say.
This stuff really is detail when what needs to be considered is the (un)reality of the ‘big picture’ as expressed in the different energy budgets. When people start to grasp that then they will gather how and why almost everything about the climate system is unknown.
I summarised my view of the important information in my first post to this thread. This link jumps to it.
http://wattsupwiththat.com/2014/01/12/global-warming-is-real-but-not-a-big-deal-2/#comment-1533823
But, as your post indicates, simplification should not mislead, and I am grateful for both your comments on what I have been trying to say. Again, thankyou.
Richard
In Ira’s post:
6.The Photons cause the GHG molecules to become energized and they speed up and collide with other gas molecules, energizing them. NOTE: In a gas, the molecules are in constant motion, moving in random directions at different speeds, colliding and bouncing off one another, etc. Indeed the “temperature” of a gas is something like the average speed of the molecules. In this animation, the gas molecules are fixed in position because it would be too confusing if they were all shown moving and because the speed of the Photons is so much greater than the speed of the molecules that they hardly move in the time indicated.
According to Richard Courtney’s simple kinetic theory guide GHG molecules do not speed up on quantized photon absorption but increase their vibrational and rotational energies instead. The mechanism for transferring this increased GHG energy to O2 and N2 molecules must be by collisions which increase average speeds and therefore gas temperature ; a ‘pinball’ type transfer quantized of course.
I would like to hear Ira’s comments, if he read this far;
Richard stated..”as I also said – the GCMs are constructed as an attempt to determine these fluxes.”\====================
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Me, Yes, and I think we agree they have not done a very good job. They are informative however. They uniformly run to warm. CO2 is the dominant uniform factor, and they would universally run closer to observations if the C.S. to CO2 was reduced.
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Richard states,
Science is numbers and we don’t have most of the needed numbers. Any quantifications you can derive you should publish.
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I agree that we do not have the numbers. I think a proper understanding of energy residence time as a universal factor in all thermodynamic processes is useful. Without overcomplicating things, please comment on my one example with Willis.
I have, on the basis of residence time, questioned the veracity of Willis’s proposition that, if the watt per square meter down welling LWIR due to clouds, is equal to the same watt per square meter down welling SW , sans clouds, then they make the same contribution to earth’s energy budget.
I postulate that the SW radiation will enter the earths oceans to depth, having far longer residence time. I postulate that the LWIR will expend much if its energy in accelerating the water cycle, be lost in evaporation, and released at altitude, to be liberated by GHG molecules, the more numerous, the more likely to be quickly liberated from our “system” I assert that (as an example) 10 straight days of SW pumping into the tropical ocean, will accumulate for the entire 10 days, losing little to space; whereas 10 days of LWIR from clouds, will lose far more total energy to space. I postulate that the residence time of the WL of radiation, as well as the materials encountered, are the reason the residence time and total accumulated energy within the system varies, despite an equal wattage flow per square meter.
I have given the illustration of an open pot of water, of fixed dimensions, as a defined system, in a balance with a small flame and a steady trickle of water of the invariable temperature and volume, to keep the water level the same, achieving a thermodynamic balance. One can think of many ways to change the energy content of the pot. Everyone of those ways requires either a change in input, a hotter or cooler flame, or a change in the residence time of the energies currently in the pot, if the input remains constant. Placing a lid on the pot, increases the residence time of the energy within the pot. Thinning the thickness of the pots metal, or changing the metal to a more conductive metal, would reduce the residence time of the energy entering the pot, etc.
The GH affect is, in the end, an increase in the LWIR residence time within the atmosphere.
GHG molecules have the potential to both increase and decrease energy residence time. The greater the increase in residence time of the energy, the greater the potential energy accumulation. Understanding the disparate affect of different WL on the materials encountered relative to residence time of energy, is always informative of a gain or loss in a defined systems total energy. Understanding that an equal flow of wattage, does not equate to an equal amount of energy within a defined system, as in the example with the observations Willis reported, is conducive and useful to understanding the energy budget of our earth.