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Comments 4901 to 4950:

4901. Charlie_Brown at 03:09 AM on 2 January 2022
      From the eMail Bag: the Beer-Lambert Law and CO2 Concentrations
      

      Bob @ #7

      Thank you for providing the graph for HITRAN data. The point that I wanted to make is that increasing CO2 increases the individual high resolution absorption lines in the wings. That is why the effect of CO2 is not “saturated,” but is diminishing with increasing CO2. Moderate transmission programs use algorithms to simplify the detailed line-by-line calculations into an absorption band. Essentially, it is an approach to average the lines within an absorption band, which makes the calculations easier. With this approach, increasing CO2 increases the width of the band, effectively by increasing the inclusion of small lines at the end of the wings.

      I have used the version of MODTRAN hosted by the University of Chicago quite a bit, and I find it to be an excellent tool for understanding atmospheric radiation. It is similar to the free demo version from Spectral Sciences, Inc  Fortunately, it makes all of the calculations, including Beer’s Law, molar density, temperature, pressure, etc., for you. There is no need to do a lot of math on your own. It is easy to run several cases and plot the Upward IR Heat Flux as a function of increasing CO2. The upward IR heat flux is the energy lost to space. It becomes apparent that the diminishing effect is logarithmic. Because it is an atmospheric radiation model and not an energy balance model, it is a little bit trickier to resolve the overall heat balance to determine the effect on surface temperature, but it can be done. The surface temperature is an input with a default value of 299.7 K for a tropical atmospheric profile and 288.2K for the 1976 U.S Std atmosphere. One can adjust the surface temperature manually, then use trial-and-error to find a surface temperature that causes the overall global energy balance to be closed. This means the upward IR heat flux needs to be constant, since the only other factor in the balance is solar energy in. The logarithmic diminishing effect of increasing CO2 is the same.

4902. Bob Loblaw at 02:26 AM on 2 January 2022
      From the eMail Bag: the Beer-Lambert Law and CO2 Concentrations
      

      Eclectic:

      I think that CD = Climate Detective, so you may have a tough ride ahead trying to convince CD that something on his web site is not worth linking to.

4903. Bob Loblaw at 02:25 AM on 2 January 2022
      From the eMail Bag: the Beer-Lambert Law and CO2 Concentrations
      

      CD @ 8:

      Well, on your own web site, equation 88.1 is stated to describe the situation when the atmosphere is in "thermal equilibrium".  (I assume you mean that temperature is not changing with time, rather than the atmosphere is isothermal.)  You also claim that this implies an equality between absorbed radiation and emitted radiation. You are wrong, in more ways than one.

      1. Conservation of energy applies to all forms of energy. Much of the energy in the atmosphere comes from thermal transfer between the surface (hot) and the air (cooler), and this energy flux extends throughout the troposphere. Additional energy is moved from the surface to the atmosphere as latent heat (evaporation at the surface, condensation in the atmosphere). This is not a "secondary issue".
      2. The atmosphere is also absorbing some solar radiation, but it is not emitting any radiation at all at those wavelengths. That energy needs to be dissipated  by other means - either moved away from where it was absorbed by convection, or emitted as IR radiation at completely different wavelengths. There is no equality between absorbed solar and emitted solar - at any height.
      3. All radiation energy absorbed in the atmosphere will be shared with all gases at that height (both GH and non-GH gases) by molecular collision. The emission at that height is not dictated by the absorption, but by Planck's Law, which includes temperature and emissivity. Since temperature is affected by all energy fluxes, not just radiation, you cannot assume that other energy fluxes are "secondary" or that radiation absorbed = radiation emitted.
      4. "Conservation of energy" applies to the total of all gases. Since all gases share thermal energy through collisions, the emission of IR radiation by any single GH gas requires that the temperature of that gas be determined in combination with all other gases. The emitted IR at any height will be the sum of the Planck's Law emissions for all individual gases, and this process does not at all resemble "scattering" or "transmission".
      5. The absorption of IR radiation at any height is a combination of the absorption of upwelling IR and the absorption of downwelling IR. In an atmosphere with a temperature gradient these will not be equal - in the tropsphere, where temperature decreases with height, upwelling IR is larger than downwelling. The emission will be equal up and down, though, so we immediately see that treating the change in IR radiation as a "transmission/scattering" issue leads to the absurd result that your "scattering" process leads to a case where "scattering" causes more downward IR than is received.

      Look at the graphs provided by the MODTRAN web site I mentioned previously. It defaults to "looking down" - i.e., upwelling IR. Choose altitudes of 2, 5, 10 km etc and see how the IR flux decreases as height increases.

      Now, repeat with the "looking up" option (downwelling IR). See how the fluxes increase as altitude decreases - i.e., as the IR radiation continues in the downward direction, more and more IR radiation is added to the stream. You cannot interpret this as "scattering with transmission <1". If your theory of the mathematics is correct, this increasing IR radiation requires a transmission coefficient that exceeds 1.

      Your mathematics are not correct. They assume things that are not true (absorption = emission, non-radiative energy fluxes are not important).

      If you follow the link to Schwarzschild’s equation, you will see that it has independent terms for absoprtion and emission - terms that cover the Beer-Lambert absorption and the Planck emission. This is the correct way to do it.

      You started your comments here with the statement that the Beer-Lambert Law does not apply. The argument that you have presented appears to implicitly suggest that Planck's Law also does not apply. You have invented your own theory of radiation transfer, and it has some serious problems.

4904. Eclectic at 12:51 PM on 1 January 2022
      From the eMail Bag: the Beer-Lambert Law and CO2 Concentrations
      

      CD @ #8 and prior :

      Best if you avoid the blogsite you have linked to [ClimateScienceInvestigations blogspot by "Climate Detective"].

      It is one of those sad blogsites where much is correct, but much is wrong.

      Rather like the famous "Curate's Egg"  ~  where parts of it are quite good, but parts of the egg are rotten.

      The "good" parts can never compensate for the bad parts.

4905. CD at 07:54 AM on 1 January 2022
      From the eMail Bag: the Beer-Lambert Law and CO2 Concentrations
      

      @6 Bob Loblaw

      Ok, perhaps saying the Beer-Lambert Law was not applicable was a bit strong. But my point is that relying on it, and it alone, gives the wrong answer for the amount of radiation that is transmitted through the gas. More importantly it underestimates the transmission for large thicknesses of gas as my original comment (@5) states, and so underestimates the impact of any large increases in the CO₂ concentration.

      As for the idea that my "concept of transmission" leads to a transmissivity > 1, the equations 88.8 and 88.14 set out here clear demonstrate otherwise. It is also true from the equations set out in the link that the reflected radiation flux I_d is always less than that upward IR flux I_u at all altitudes x.

      Finally, before claiming that energy transfers from CO₂ to non-GHG molecules (and back again) invalidate my analysis, I suggest you look again at the principle of detailed balance. In thermal equilibrium, what goes in must come out, otherwise you start to violate the 1st & 2nd laws of thermodynamics. Yes there are complicating factors such as convection and direct heating of the atmosphere from the Sun, but these are secondary issues.

      I am aware that the atmosphere is a complicated body, but that does not mean it cannot be largely understood by considering idealized models in the first instance. That is how modellers approach the problem. The Beer-Lambert Law is one such idealized model.

4906. Bob Loblaw at 06:55 AM on 1 January 2022
      From the eMail Bag: the Beer-Lambert Law and CO2 Concentrations
      

      charlie_brown:

      The image from figure 1 of the SpectralCalc document you link to would be this one:

      

       

      This diagram clearly shows the high level of variation with wavelength. Radiation transfer codes vary in their spectral resolution. You mention HITRAN. There is also a web site here that lets you work with an older lower-resolution model: MODTRAN. You can select different temperature profiles, change gas concentrations, cloud cover, etc., and choose looking up or down at selected altitudes.

      All of the equations discussed - Beer-Lambert Law, Schwarzschild equation, etc. - are most properly applied to spectral radiation where properties such as absorption coefficients are highly variable with wavelength. For solids and liquids, some ranges of wavelengths can be treated as having proprties that are fairly constant. That is a Bad Idea (tm) for gases though.

      The "cylinders" in the blog post diagrams and discussion are theoretical ones: the walls are perfectly transparent and do nothing to impede any sort of energy transfer. In the real world, the equations are differential ones. Keeping things simple usualy means not doing Calculus, though.

      Introductory meteorology courses love talking about "parcels of air" (e.g. for explaining atmospheric instability), but of course the atmosphere is made up of continuous flows of air, not small balloons of air. Likewise, radiation does not work with distinct cylinders of air, but with air as a continuous medium. Your "shells" are an infinite number of identical stacks of columns, side by side.

4907. Bob Loblaw at 06:14 AM on 1 January 2022
      From the eMail Bag: the Beer-Lambert Law and CO2 Concentrations
      

      CD:

      You are making some pretty strong assertions for someone that has clearly not read the entire post and comments in detail.

      As is stated at the end of the original post, "For IR radiation, the earth and atmosphere are also doing the reverse of absorption – thermal energy is being transformed into photons, resulting in the emission of IR radiation in all directions." This is also discussed in more detail in the comments by charlie_brown and myself. You are not introducing any concept that has not already been mentioned. The post acknowledges that there are additional concepts that are needed for the full picture.

      It may be a matter of semantics, but you are wrong in saying that the Beer-Lambert Law "is not applicable here". It is only part of the story, but is is clearly applicable to the absorption part of the story.

      Where you go wrong is in claiming that the process of re-emission "looks like scattering". It most certainly does not. Scattering results in changing the direction of travel of radiation - but the radiation is still the same wavelength as the incident radiation, and each photon carries the same energy it had before it was scattered. You cannot create new radiation travelling in a new direction at a new wavelength through scattering, and scattering will not create new radiative energy. Emission does create new radiation.

      For absorption/re-emission, the emitted IR radiation will not necessarily be at the same wavelength as any radiation what was absorbed. The absorbed radiation energy  is not immediately emitted as new IR radiation - it virtually always gets lost by the GHG molecule to other molecules (including non-GHG ones). There is a good description of this over at Eli's. The energy that appears as emitted IR radiation does not need to come from the absorption of radiation - it almost always comes from collisions with other molecules that can get their energy from anywhere.

      As a result, any emitted IR radiation is dependent on two factors:

      1. The number of all GHG molecules present that can pick up thermal energy through collisions with other molecules. The emitted IR radiation may not be coming from CO₂, and its wavelength will depend on the emission spectra of that other GHG molecule.
      2. The temperature of the surrounding air. This controls the overall availability of thermal energy to drive IR emission. If the atmosphere is very cold, IR emissions will be less than if the air is very warm.

      As mentioned in comment #2, Schwarzschild’s equation covers the case where an atmosphere is both absorbing and re-emitting, and the net change in IR radiation with height is dependent on the temperature gradient.

      One thing you have correct: IR radiation is equal in all directions, and in this sense it resembles scattered light (which occurs in all directions, but is not exacly equal in all directions), but that is the only similarity.

      A key aspect of the dependence of net IR radiation on the temperature gradient is that upward IR fluxes normally decrease with increasing height, while downward IR fluxes normally increase as you go lower in the atmosphere. If we applied your concept of "transmission" to the downward flux, we would have transmissivity >1, This makes no sense.

      "Transmission" is not a useful concept when the air can create new IR radiation and add it to the stream. It is a concept that only applies to IR radiation that originates elsewhere and is passing through the air. And that is exacly what the Beer-Lambert Law describes.

      I have briefly looked at the URL you provided. It suffers from the same basic errors: confusing re-emission with scattering, and treating the addition of emitted IR to the upward stream as if it is a "transmission" question. It is not.

      Proper radiation transfer theory and the effects in the atmosphere take into account all energy fluxes, and properly account for the process of absorbing IR radiation, transforming it into thermal energy contained in all gases, possibly moving it through convection, and then re-emitting that energy as IR radiation (by all GH gases).

4908. CD at 02:10 AM on 1 January 2022
      From the eMail Bag: the Beer-Lambert Law and CO2 Concentrations
      

      An interesting article, but I have to disagree with the main point: The Beer-Lambert law is not applicable here.

      The Beer-Lambert law applies to attenuation or absorption. But in the case of the interaction of IR radiation with CO₂ we also have re-emission. That, after all, is how we get downwelling radiation and hence the Greenhouse Effect.

      The principle of detailed balance dictates that in thermal equilibrium the re-emission must reverse the absorption process, so the combined process looks like scattering. And the maths of scattering is different to that of attenuation.

      The big difference is that the transmission coefficient is no longer exponentially dependent on layer thickness, x, as e^-kx, but instead has a reciprocal dependence of the form 1/(1+ax). For an explanation see here.

      The net result is that the transmission tends to zero much more slowly as x increases than it would with just attenuation. In practical terms it is a small point because the transmission is still less than 2%. But what it does mean is that the temperature rise with increasing CO₂ is greater (but still small).

4909. Charlie_Brown at 10:24 AM on 28 December 2021
      From the eMail Bag: the Beer-Lambert Law and CO2 Concentrations
      

      The figure that I wanted to show is very similar to Figure 1 from this document from SpectralCalc.com Calculating Gas Spectra.
      The diminishing effect of increasing CO2 is due to the increasing absorptance (decreasing transmittance since a = 1 – t) of the absorption lines on the “wings” or “shoulders” of the spectrum between 14 to 16 microns (wavenumbers 625 to 714 cm-1). The major peak at 15 microns (668 cm-100) reaches an absorptance of 1.0 with increasing path length or increasing CO2 first, then the other peaks follow with further increases.

      The graph can be replicated or plotted for other concentrations and conditions using the Gas Cell Simulator in the free demo version of SpectralCalc.com. The gas cell is the same as the cylinder in the previous discussions, but as used for the graph, it illustrates the strength of each absorption line. The transmittance is different for each wavelength.  The free version is limited to wave numbers.  This is another way to interface with the HITRAN line-by-line database.

4910. Charlie_Brown at 04:36 AM on 28 December 2021
      From the eMail Bag: the Beer-Lambert Law and CO2 Concentrations
      

      Bob, thank you for your prompt and detailed reply to my reply. I enjoy technical discussions on the details of the warming mechanism and find few willing to engage at this level. I also think that it is important to have a solid understanding of the concepts to counter claims made by deniers, which often are based on a kernel of truth with explanations that are badly distorted. The concepts are complex, but they can be simplified. One does not have to be a climate scientist expert, university professor, or math whiz to work through them. I am a retired chemical engineer who took some radiation heat transfer courses in college, and have developed most of my thinking about global warming over the last 2 years.

      Regarding measurements of attenuation by CO2 in a cylinder, the photons that are absorbed by a CO2 molecule are re-emitted, most likely toward the wall where they will be absorbed and converted to thermal energy. The energy will not be re-emitted from the walls at the same wavelength as emitted by CO2. It is unlikely that they will travel in a straight line and be measured at the end of the cylinder. Beer’s Law of attenuation describes the fate of the photons that are emitted from a source until they strike a target, not what happens with re-emitted photons. This is why I like to describe the atmosphere as layers of shells that have no sidewalls. Multiple stacked cylinders with adjacent, transparent walls is the same thing.

      Regarding re-emission, it took me a long time to think through the problem of attenuation of surface IR through layers of the atmosphere and trying to figure out how many layers it would take as half of absorbed/emitted energy does up and half goes down. Finally, I realized that it is unnecessary to start at the surface and think about re-emission, convection, conduction, evaporation and condensation. Global warming is the result of the overall system energy balance, which is simply:
      Solar energy in = IR emitted to space from the uppermost emitting layer for each IR wavelength + Accumulation
      In the 13-17 micron range, Beer’s Law explains that the uppermost emitting layer is the lower stratosphere for many wavelength peaks emitted by 400 ppm CO2. The uppermost emitting layer for other GHG depends on their molecular density. For water vapor, the uppermost emitting layer is the troposphere, where the temperature is warmer than the bottom of the stratosphere. At wavelengths transparent to GHG, the emitting surface is the earth’s surface. It doesn’t matter how many layers, or cylinders, of 1% or of 90% attenuation are stacked in the lower atmosphere. Again, radiant energy lost to space depends only on the uppermost emitting layer. Where there are CO2 molecules, photons will be emitted at an intensity related to the temperature. There does not need to be conservation of photons from those emitted from the surface. Any imbalance in the photon count will be manifested as thermal energy changes, including by conduction to adjacent non-GHG molecules.

      The link that you provided to Schwarzschild’s equation provides excellent descriptions of the essential role of the lapse rate, as well as attenuation. If I am not expressing my thoughts clearly enough, I recommend reading the sections on “Origins of the greenhouse effect,” “Saturation,” and “Applications to climate science” in that linked Wikipedia article.

4911. Bob Loblaw at 02:19 AM on 28 December 2021
      It's albedo
      

      blaisct @ 106:

      Although it has been almost two weeks since your post, and others have commented, I wish to respond to one statement you have in your opening paragraph. You state:

      My understanding has been expanded to include: AGHs hotter temperature will reduce humidity and thus reduce cloud cover, expose more earth surface to the sun thus reduce earths albedo; therefor, albedo vs time for AGHs may not be flat.

      The "hotter temperatures will reduce humidity" does not follow. If air temperature increases and absolute humidity does not change, then yes, relative humidity will decrease, but we have no a priori reason to expect this to be the case.

      I suggest that you review the use of differnt terms for "humidity", which can get quite confusing at times. Wikipedia has a decent page covering this.

      A warmer atmosphere is expected to increase evaporation, which will add water vapour to the atmosphere. This cannot go on indefinitely, and globally we expect a new equilibriium where increased evaporation is matched by increased precipitation. At this new equilibrium, we expect global absolute humidity to be higher, and global relative humidity to be roughly the same as now.

      Spatial variation will almost certainly be different, and exactly how cloud cover will respond has uncertainties, but it is not as simple as you describe.

      Usually, the incorrect assumption you will see in the comments here goes along the lines of "more evaporation = more cloud". This is also far too simplistic. The balance between temprature, evaporation, cloud formation, and precipitation is a complex and delicate one.

4912. Bob Loblaw at 01:57 AM on 28 December 2021
      From the eMail Bag: the Beer-Lambert Law and CO2 Concentrations
      

      Charlie Brown:

      Yes, your discussion touches on some of “the complexity of radiation transfer in the atmosphere” that I dismissed in a single paragraph at the end of the blog post. The blog post was only intended as a counter to the “CO₂ exists in small concentrations” misinterpretation of the Beer-Lambert law, and leaves a whole host of other fundamental principles in atmospheric radiation transfer to the imagination of the reader.

      You refer to several issues that deserve more discussion – issues that take entire university courses or textbooks to cover. You mention at least four specifics I’d like to elaborate on:

      • re-emission of IR radiation
      • the three-dimensional aspect of the atmosphere
      • the vertical structure of the atmosphere
      • the concept of “saturation”

       

      With regard to re-emission, the amount of IR radiation leaving the cylinder is the sum of what was transmitted through the cylinder plus the amount that was emitted within the cylinder (and manages to leave before being re-absorbed within the cylinder). With regard to the emitted IR:

      • Any CO₂ that absorbs energy will lose it by collision with other molecules, so chances are that it will be a different gas that is emitting, which means it might be at a different wavelength. Thus, to look at the whole situation we need to consider all the greenhouse gases in combination.
      • The emissions of IR radiation will depend on the temperature of the gases within the cylinder, which will depend on the balance of all energy fluxes, not just radiation.
      • Just as adding CO₂ increases the absorbance within the cylinder, adding CO₂ increases the overall emissivity within the cylinder, so more IR can be emitted at the same temperature.
      • The emission of IR happens in all directions, as you state, which means that only half of the emitted radiation can be said to be continuing in the same direction as any IR radiation that entered the cylinder (figure 4).

       

      You mention IR lost through the side walls of the cylinder. There is also IR gained through the side walls, coming from adjacent cylinders that are behaving the same way as the one in figure 4. If the adjacent cylinders are identical, then each cylinder will be gaining and losing identical IR radiation amounts through the sides, so the net effect is zero.

      Can we say the same things about the IR transfers between cylinders in the vertical stack of cylinders (figure 4b)? No, and there is a very important reason why. The net effect between adjacent cylinders (side by side, or top over bottom) depends on the temperature within each. If the temperatures are equal, the net IR transfer effect will be zero – but if they are not equal, there will be a net transfer from the warmer one to the cooler one. In the horizontal direction, temperature gradients are very small, so it is reasonable to ignore that direction. Vertically ,however, we see strong temperature gradients – the environmental lapse rate averages 6.5 C°/km. So, the top cylinder tends to be colder than the bottom cylinder, and the net IR transfer is upward.

      So, we get to think in terms of up/down fluxes of IR radiation, and need to consider the thermal stratification of the atmosphere, as you mention. The up/down aspect has a formal label: the two-stream approximation. The extension of the use of the Beer-Lambert Law to include the emissions of IR radiation and the net IR flux along a temperature gradient also has formal solutions, one of which is called Schwarzschild’s equation.

      Of course, the vertical temperature structure of the atmosphere is not purely due to radiation, so we can’t model it purely using radiation theory. Weather and climate models need to include convection, etc. - anything that transfers energy.

      We also can’t leave the 3-d atmosphere discussion without mentioning clouds. Although gases in the atmosphere have absorption/emission characteristics that are highly dependent on wavelength, clouds (either as liquid or solid/ice) are essentially black bodies. In the same way that the two-stream approximation treats radiation transfer as either up or down, we can begin to cover cloud effects by dividing the atmosphere into a clear sky portion and a cloudy portion. Clouds have layers, too, and three-dimensional characteristics of clouds become quite complex, but the clear/cloudy categorization is place to start.

      Lastly, you discuss saturation. I tend to dislike the use of that term, because it seems to mean so many different things to different people. One of the issues not mentioned in the blog post is pressure broadening, where overall increases in atmospheric pressure reduce the absorbance coefficient of the greenhouse gases such as CO₂. This leads to a “law of diminishing returns” as CO₂ concentrations increase, but we are far from running out of space on that one.

      You use “saturation” in the context of IR radiation leaving the surface and escaping to space – and point out that nearly all the IR escaping to space is lost from the upper atmosphere. This is correct, and one way of looking at this is to ask “how many times will IR emitted from the surface be absorbed and re-emitted before the energy reaches the upper atmosphere and can finally be lost to space?” Even now, the probability that surface-emitted IR escapes directly to space is very small – but if adding CO₂ increases the number of absorb/re-emit cycles from two to four, to eight to sixteen, etc., there is a reduction in the efficiency of transfer of energy from the surface to space.

      For each absorb/emit cycle, only half gets emitted upwards. The half that emits downwards must go through at least one more absorb/emit cycle to get moving upwards again – and it only has a 50% chance that the next absorb/emit cycle will get it going in that direction. If it emits downward again, then it needs another absorb/emit cycle – with only a 50% chance again that it will emit in the upward direction. Adding more and more CO2 will always increase the number of absorb/emit cycles involved, but there is a law of diminishing returns here, too, which leads to the closing paragraph of yours where doubling CO₂ from 200 to 400, or 400 to 800 ppm will have the same warming effect. Remember that convection is involved in that warming response, too – as radiation transfer becomes less efficient, convection takes a more dominant role (and it is already important).

4913. MA Rodger at 22:49 PM on 27 December 2021
      Was Greenland really green in the past?
      

      dpc @33,

      The original name for Greenland was Inuit Nunaat meaning 'country of human beings'. So perhaps there was once a burgeoning population living there. Or perhaps such names are poor descriptors which would be why, apparently, "people often say that Iceland and Greenland should switch names since Iceland is green and Greenland is so icy."

4914. dpc21240 at 16:56 PM on 27 December 2021
      Was Greenland really green in the past?
      

      I was just looking around for some discussion around the topic of origin of the name Greenland and it's striking to me that people uncritically use the

       

      "Because," said he, "men will desire much the more to go there if the land has a good name."

       

      as any argument. It's a huge jump to conclusions.

       

      If a company releases a product named "ecofleebus" trying to market it as a very ecological fleebus how can one hop to conclusion that this fleebus has no ecological design aspects to it at all? Quite the opposite - for marketing to work, it has to be very believable. Marketing is more about exagerating, over-selling, etc. and rarely about calling black color white.

       

      Men will desire to go somewhere if it has an appealing name. No duh. Doesn't mean such appealing name is complete lie.

       

      So while it's still a huge guesswork, I think it's far more likely to assume that Greenland was "green enough" to try to "(over-)sell it".

4915. Charlie_Brown at 11:07 AM on 27 December 2021
      From the eMail Bag: the Beer-Lambert Law and CO2 Concentrations
      

      This is an excellent description of Beer’s Law. The distinction between concentration (ppm or molecules per million molecules) and molar density (molecules per cubic meter) is very good. However, the described application to the atmosphere has a few shortcomings that leave an incomplete description of the effect of saturation. The description does not account for re-emission, nor the multiple absorption lines for CO2 of different intensities. It also does not describe the role of temperature stratification in the atmosphere.  The conclusion does allude to some of these issues.

      Rather than as cylinders, the atmosphere is better described as layers of shells. One problem with the description lies in the third path for the fate of radiation in a cylinder (Quantity C): “3. Be absorbed, through interactions with the mass inside the cylinder, so that the energy in the photons is transformed from radiation energy into thermal energy. The radiation ‘is no more’ (although the energy is conserved as heat).” However, as energy absorbed by a molecule, it is re-emitted to maintain thermal equilibrium. Re-emitted energy occurs in all directions, not just in a straight line. Therefore, re-emitted energy is lost to the walls of the cylinder. Meanwhile, in the atmosphere, there are no walls and re-emitted energy is absorbed and re-emitted again elsewhere in the atmosphere. In this manner, there are multiple absorptions and re-emissions in a convoluted path with some net energy flowing upward and some downward.

      The key concept behind saturation lies in the different absorptances for each IR wavelength. Saturation occurs when the absorptance equals 1.0. The major peak at 14.98 microns is saturated first, then smaller peaks become saturated as CO2 increases. I wish that I could insert a graphic, but I haven’t figured out how to do it yet. Absorption lines can be seen using bytran, which is an open-source interface under the MIT License for the HITRAN database (Pliutau, D. and K. Roslyakov, “Bytran -|- spectral calculations for portable devices using the HITRAN database,” Earth Science Informatics, 10 (3), pp. 395-404. Feb 2017.)

      Beer’s Law as related to the atmosphere comes into play with determining the uppermost layer that limits the escape of radiant energy to space through the 13 to 17 micron window for CO2 absorption/emission of IR. This layer turns out to be the bottom of the stratosphere at an altitude of about 30 km, just above the tropopause. At this altitude and considering a path length of 1000 meters, which is a reasonable distance in the atmosphere, there are still sufficient CO2 molecules to form an emission layer for CO2. It is a little harder to see the difference in the absorption lines at 400 and 800 ppm under these conditions, but this explains the diminishing effect of saturation.

      It is common to think of radiant energy leaving the surface and trying to explain what happens as it works its way through the atmosphere. However, it is instructive to focus on the radiant energy exiting the top of the atmosphere rather than the energy leaving the surface. The lower stratosphere is the uppermost CO2 layer with sufficient molecules for an emittance of 1.0. Since absorptance equals emittance, this is the maximum emittance for that wavelength. This layer of the atmosphere is cold, so the radiance, total emitted energy, from this layer is less than the radiance emitted from the warmer surface. As the uppermost emitting layer, it becomes the limiting layer for radiant energy loss to space.

      There is a saturation effect, but it is better illustrated using an atmospheric radiation model than using Beer’s Law with a number of cylinders. Using a simplified model, it can be illustrated that increased radiant IR energy flux lost to space from doubling CO2 from 200 ppm to 400 ppm is the same as doubling CO2 from 400 ppm to 800 ppm. This forms a logarithmic curve. The warming effect due to CO2 is saturating, but it is not saturated.

      Moderator Response:

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4916. Cedders at 05:43 AM on 27 December 2021
      Medieval Warm Period was warmer
      

      Thanks to Daniel Bailey for the useful update links. I wonder if these could be incorporated into the rebuttal?

      Link rot means PAGES 2K work is now best found at  https://pastglobalchanges.org

4917. Cedders at 05:35 AM on 27 December 2021
      Major PAGES 2k Network Paper Confirms the Hockey Stick
      

      A bit more link rot.  The PAGES pages disappeared from UniBe within the past year.  They can now be found at for example https://pastglobalchanges.org/about

      Also wonder if worth cross-referencing to more recent PAGES 2k work, eg Neukom et al (2019), 'No evidence for globally coherent warm and cold periods over the preindustrial Common Era', https://doi.org/10.1038/s41586-019-1401-2

4918. Anoo at 05:00 AM on 27 December 2021
      CO2 measurements are suspect
      

      Came across this post today after looking at some statistics that got stuck in my head.

      Today the total landmass area of the world is 149 million sq km.

      The total forested area of the world in 2016 was 30.7 million sq km, down from 49.8 in 1996.

      Up to at least 2013 science had stated that the Amazon rainforest, at 5.5 million sq km, the Canadian Boreal Forest, at 2.7 million sq km, and the Congolese rainforest, at 1.7 million sq km, along with the rest of the boreal zone, were all CO2 sinks. In total it comes up to over 20 million sq km, out of a total of 30.7 million.

      Now I am reading that all of these are net CO2 emitters. So up until 2013 they were sucking in CO2, now they are pumping out CO2. 

      Here's my question for all of you: Why isn't the CO2 level rising exponentially? If these combined forests were sequestering more than they were producing, but are now not able to sequester as much CO2 as they produce, this means that since 2013, with deforestation, and a loss of carbon sinks, we should have had at least a doubling of CO2, should we not have? Yet, when I look at the numbers, it would seem that the CO2 level increases are actually slowing, while emissions are increasing.

4919. sekwisniewski at 04:59 AM on 27 December 2021
      Is Nuclear Energy the Answer?
      

      The following paper provides a comprehensive assessment of the environmental footprint of the French nuclear power generation around 2010. Specifically, it compares the material throughput of once-through (UOX) and twice-through (UOX+MOX) fuel supplies. For example, it finds that both fuel supplies generate around 1.5 m³/TWh_e of HLW+ILW-LL that requires geologic disposal, but twice-through requires 3.5 times less geologic storage volume due to a smaller proportion of HLW/ILW-LL. In terms of emissions there is almost no difference - 5.29 vs 5.45 gCO₂eq/kWh_e for twice-through and once-through, respectively. (If I’m not mistaken, this paper hasn’t appeared in this long discussion yet.)

      Poinssot, Ch, et al. "Assessment of the environmental footprint of nuclear energy systems. Comparison between closed and open fuel cycles." Energy 69 (2014): 199-211.

      

      

      

4920. Mick James at 09:59 AM on 26 December 2021
      Thanksgiving advice, 2021: How to deal with climate change-denying Uncle Pete
      

      The Pentagon predictions weren't wrong: they were about what might happen were an abrupt climate change to occur (as happened 8000 years ago) rather than the gradual change currently observed and predicted.  They didn't suggest such an event was likely or imminent.  The report should be read in the same light as one outlining the consequences of, say, a nuclear war between Russia and China in 2004. 

4921. djinghis at 11:05 AM on 23 December 2021
      Why Senator Manchin Should Support Build Back Better
      

      This article is treating Manchin as though he deserves any respect even though he's obviously acting in self interest. Simply analysing his voting record on environment, and military spending should give us a clue. Re-re-re-negotiating on an already watered down bill was his plan all along – delay/obstruct and kill the bill.

4922. dana1981 at 16:47 PM on 22 December 2021
      Why Senator Manchin Should Support Build Back Better
      

      Manchin has said he's basically an independent.  But I think he'll reach some sort of agreement.  For one thing he is technically a Democrat and the party will be screwed in the 2022 midterms if they don't pass anything.  For another he's got pressure from the White House and his colleagues and even the coal miners union.  And he did outline a deal he'd be willing to agree to.

4923. nigelj at 07:35 AM on 22 December 2021
      Why Senator Manchin Should Support Build Back Better
      

      Looking at Machin's  views and voting record on wikipedia, its a little bit hard to see why hes even in the Democrats Party.  Someone like this would typically stand as an independent surely? 

      Hes certainly causing a lot of trouble for the Democrats, and I agree his affiliations to coal interests look like they would be the main factor. Probably not the only factor. I don't live in America. Just curious.

4924. Doug Bostrom at 04:24 AM on 22 December 2021
      Why Senator Manchin Should Support Build Back Better
      

      Dana, I'm sorry to say that what I see is Manchin continuing to play Lucy, and we're Charlie Brown. He's had stunning success with running out the clock while pretending to negotiate an ever-changing roster of "concerns"— why change tactics now? 

      All Manchin need do is to dive a bit deeper into "negotiations" so as to reach  fast approaching crush depth. 

      If he gets explosive pushback from his actual legitimate constituency in the unlikely event they grasp how they're being screwed, maybe he'll pull up on the dive planes.  That seems unlikely.

4925. dana1981 at 03:28 AM on 22 December 2021
      Why Senator Manchin Should Support Build Back Better
      

      Worth noting that Manchin and Biden seem to be reconciling and planning to re-engage in January, and Manchin seems to be on board with most of the climate investments.

4926. Eclectic at 21:48 PM on 21 December 2021
      Why Senator Manchin Should Support Build Back Better
      

      Doug, yes indeed.  Occam would approve your explanation.

      For many months, I found it quite painful to see the disingenuous prevarications, the footshuffling evasions, the motivated reasonings.

      And I speak as someone who has, for many years, been hardened by reading the crackpot & bizarre motivated reasonings to be found daily (indeed hourly) on the WattsUpWithThat  blogsite.  But at least, the denizens of WUWT  are only trying to fool themselves, and mentally rub shoulders with their tribe.  (And vent some of their anger.)

4927. Doug Bostrom at 18:01 PM on 21 December 2021
      Why Senator Manchin Should Support Build Back Better
      

      I'll take the simplest interpretation, the one that is not so much as interpretation as what is in plain sight.

      Made rich by coal, Manchin intends to stay rich by coal. He did what he must to make that happen.

      All the rest is peripheral, relevant only as expedient excuses to block the package. 

      It's our nature to make excuses for people, to strive to find the good or at least not as bad side, even if we have to invent it. Here we're inventing a lot of chaff to cloud our perception of naked, insatiable greed. 

4928. Eclectic at 14:58 PM on 21 December 2021
      Why Senator Manchin Should Support Build Back Better
      

      Historians can no doubt list many many points in the past when the actions of an individual had a pivotal effect on the course of events.  Sometimes for the good, sometimes for the bad.

      Manchin, inscrutable or not, is having that effect here. But such is life, under a democracy, when opposing forces are finely balanced in the legislature.

      Doug, I have yet to read the summaries you have indicated.  An additional point is the impression received by a number of reporters/interviewers, that Manchin does really very much enjoy being in the limelight.  So it may all be as much his inner personality, as his standard political desire to improve his re-electability through exposure/publicity.

4929. One Planet Only Forever at 14:53 PM on 21 December 2021
      Why Senator Manchin Should Support Build Back Better
      

      I have frequently opined that harmful leaders (all wealthy and powerful people are leaders by example) fight against actions that would limit harm done if they sense that helpful harm reduction actions would 'harm' their ability to maintain their developed perceptions of status.

      Senator Manchin claims he is not able to explain the merits of BBB to his constituents. And I suspect that his motivations against BBB are more than the popularity of people in W. Virginia benefiting from harmful fossil fuel activity.

      Essentially he is saying that although he is a leader and undeniably has the ability to be more aware and better understand what is harmful and what actions would limit and correct harmful developments, and that that understanding enables him to explain how the BBB helps correct many harmful developments, he chooses to be unwilling to better educate his constituents, likely out of fear of losing status because he suspects many of his supporters would resist learning to be less harmful and more helpful.

      Maybe an Independent Senator candidate who would be willing and able to explain the merits of BBB to voters in W. Virginia should be supported by the likes of Senator Sanders. Then Manchin would have to fight his Republican opponent to try to win the votes of the remainder of voters in W. Virginia. The majority of voters in that state may indeed dislike being educated about what is harmful and how harmful developments can be corrected. But Manchin losing the support of the voters who want a leader who will limit harm done could help him realize he needs those voters to maintain his status.

      Sometimes the wealthy and powerful need 'helpful motivation' to 'fear losing status'. The threat of a well supported Independent Senate candidate in his state may more powerfully motivate Manchin to support BBB than the many good reasons BBB deserves his support.

4930. Doug Bostrom at 08:11 AM on 21 December 2021
      Why Senator Manchin Should Support Build Back Better
      

      Given the failure of any other explanation as a matter of self-consistency and adherence to widely agreed facts, the parsimonious interpretation of Manchin's prolonged dance is that he's not honest and is acting for narrow interests not least his own, tactically slow-walking a Gish Gallop of spurious objections so as to kill BBB by simply exploiting the inexorable calendar.

      Other interpretations require increasingly elaborate speculation leading to "Manchin is both stupid and ignorant," while clearly he is not. Avoiding that, we're left with a more fundamental matter of character. 

       

      Appeals to reason wil fail with Manchin, because reasoning this out as a matter of best effort public policy based on best information is outside of the context of Manchin. Manchin's context is far narrower, as we can plainly see. Our eyes don't lie; Manchin is an owned creature of the fossil fuel industry, an embedded agent concertedly working to freeze the clock at a self-advantageous point. 

      Here's a fairly comprehensive summary:

      https://electrek.co/2021/12/20/the-real-reason-joe-manchin-is-sabotaging-the-us-clean-energy-plan/

      And a more concise version which captures many basics while also swerving a bit into needless speculation:

      https://talkingpointsmemo.com/edblog/the-demise-of-the-bbb/sharetoken/a8OQSS58igat

4931. One Planet Only Forever at 03:24 AM on 21 December 2021
      How machine learning holds a key to combating misinformation
      

      This is an excellent development within the scope of SkS (to identify and counter climate science misinformation and disinformation). Hopefully others outside of the SkS scope will be able to extend this learning to help identify, restrict and penalize individuals and organizations who are the prime harmful motivators of the development and dissemination of misinformation and disinformation. The ‘whack-a-mole’ challenge of addressing harmful actions, like misleading appeals to easily impressed people, after the fact has a limited ability to limit the harm done.

      ‘After the fact’ of the development of harmful beliefs and actions it is hard to completely amend and end the harm being done. Effectively and pro-actively limiting the harm done requires the high status people associated with, and benefiting from, harmful actions to be identified and be effectively corrected and limited by:

      • hopefully changing their mind so they become helpful members of humanity rather than continuing to be harmful.
      • having them effectively make amends for the harm their unjust pursuits of status caused
      • limiting their ability to benefit more harmfully, if they won’t change their mind.
      • essentially being diligent about Corrective efforts that include severe restrictions and penalties. That is ultimately needed for matters of persistent harm. Corrective efforts and limits of Freedom need to be applied to those who are the most harmfully resistant to learning to be less harmful and more helpful to Others

      Note: The current legal need for an identifiable person with ‘standing - recognition’ in a legal system to provide substantial proof that they were personally physically or monetarily harmed by specific provable ‘actions of another identifiable person or corporation that the legal system applies to’ has failed to protect humanity from many harmful developments, not just the harm of climate change impacts. Many people are working to develop improved legal systems that address inter-generational and inter-national harm. But they lack popular support among global leadership. And they are attacked just like climate scientists are attacked, typically as promoters of Evil Socialist Global Government. Also note that Government can be understood to mean ‘To act collectively to Guide and Limit everyone’ and that really irritates people who are determined to have more freedom to believe and do as they please.

      That is my perspective as a Professional engineer in Canada who obtained an MBA in the 1980s and has tried to pay attention to what is going. I have learned that engineers sustainably succeed by self-governing their pursuit of learning about ways to limit harm done. They seek increased awareness and constantly improved understanding of what is potentially harmful. Limiting harm done requires understanding the root causes. Repairs to an identified harmful result can look like the harm has been dealt with. But if the cause of the harm has not been properly identified, what appears to be a repair has not solved the problem. The harm will re-occur like whack-a-mole, or climate-zombie beliefs.

      Responsible engineers can’t just try to create the appearance that a harmful result, or risk of harm, has been addressed. They need to pursue understanding of what caused the harmful result. Then they pursue ways to properly rebuild things to avoid future problems. They will also extend their new learning to everything that has been built. And they will take things out of service until the harmful problem is able to be corrected. To a responsible engineer, nothing harmful is so important that it must be allowed or continue in service (compromised bridges and buildings can stay in service with reduced use limits).

      Responsible engineers limit freedoms of others for the benefit of everyone. Their actions even benefit the people they place limits on in spite of some of those people being so determined to personally benefit that they angrily resist understanding that their actions should be limited, or be more expensive (Note: it clearly can be understood that being able to afford to be harmful is unacceptable. An engineer should not accept a higher payment as the ‘marketplace based justification’ for providing a more harmful or less safe service).

      A key understanding is that “pursuits of personal interest in competition for perceptions of superiority relative to Others” compromise that fundamental engineering understanding of “Do not allow harm to be done”.

      The engineering pursuit of the root of the problem leads me to consider 4.3.2 “Low Public Support” to be the key objective of the climate science denial system. And closely related points are 4.1.1 “Policy increases cost” and 4.3.5 “Limits Freedoms”. Increased public awareness and understanding will lead to support for policy that makes it more expensive or more difficult to continue to benefit from the harmful systemic developments. The required action is to limit the ability of people to believe whatever they want as the excuse for doing as they please. And “Limiting Freedom” is an insidious argument. More awareness and increased evidence limits the freedom to believe things to the subset of beliefs that are not contradicted by the evidence. And the “Limiting Freedom” complaint is easily liked by anyone who wants to be freer to do as they please in defiance of being able to learn that what they want to do is harmful or risks causing harm. The “Limits Freedom” and “makes things more expensive” arguments are powerful ways to make something “Less Popular”. The many other categories of made-up claims are also ways to get a diversity of people to have a stronger harmful selfish attitude.

      A master stroke is the use of nonsense claims about 4.1.4 “Rich future generations”. That fairy tale is based on the fatally flawed holy grail belief in the Constantly Richer Future because GDP per capita has continued to increase so far. Increased awareness and improved understanding has amply exposed how destructive the continued Growth of GDP has been because harmful activity counts and, as a result, harmful GDP contributions won’t be shut down unless a cheaper and easier alternative is developed that maintains the fatally flawed belief that growing GDP is required to develop lasting improvements.

      The evidence harmfully contradicts developed popular beliefs that unjustly excuse or defend harmful activities that some people benefit(ed) from to the detriment of others, especially to the detriment of poor people, people in other nations, or future generations (people with little or no legal or marketing power). So the people who pursue increased awareness and improved understanding of the harm of developed beliefs and actions need to be attacked in order to delay the correction of harmful unjust developments. The result is the powerful need for the harmfully selfish who are learning resistant to harmfully unjustly impugn with impunity.

      Significant system changes are required. Popularity and profit have proven repeatedly to be a poor basis for deciding winners in socioeconomic competition. Perceptions of good results from a system do not excuse or make up for harmful results produced by the developed system. Even perceptions of poverty reduction due to fossil fuel use are a harmful unsustainable developed perception.

      The current systems are the developed results of people who have (had) status allowing them to form and transform the systems they are part of. And the evidence indicates that there is a long history of the problem being “people who develop a willingness to benefit from harmful actions winning higher status”. Wealth and power enables the harmful to make the system more harmfully suit, and defend, their interests.

      An example would be the case of people who have developed or obtained and shared “what wealthy powerful people wanted to keep hidden”, like Chelsea Manning, Edward Snowden and Julian Assange, being tracked down for punishment. People who pursued information they could twist into attacks on increased awareness and improved understanding of climate science and attacks on people who try to increase other’s awareness and understanding have not been “as powerfully pursued for punishment”. There are laws that were broken by Manning, Snowden and Assange that powerful wealthy people applied, along with considerable resources they control for their interests, to the maximum capability. Comparatively, very little has been done by powerful wealthy people about Climategate, other than the actions by many of them to maximize the personal benefit they obtain from the unjust impugning with impunity they could get away with.

      Returning to engineering, doing something helpful should not absolve a person of any harm they continue to cause. Ending harmfulness is required to get any credit for helpfulness. Imagine a temptation for personal benefit leading to a lack of diligence to properly review all aspects of the design and construction of a building, with the result being a building where the majority of the structure is perfectly sound, but small parts are fatally flawed (like some: balconies or railings failing, windows not keeping the rain out or falling off). Do the parties who were less diligent than they could and should have been deserve “massively net-positive evaluations” because the vast majority of the building was well designed and well built?

      Learning to be less harmful and more helpful to Others (especially the future generations), and understanding that the non-human non-technological environment needs to be protected and improved, is anathema to harmful individualists (Libertarian Freedom demanding types – the types demanding that all opinions are equally valid). Helpful collectivists need to also be diligent to protect against authoritarian rule. They need to try to help Righteous Minded people avoid becoming harmfully righteous. The Righteous Mind, by Jonathan Haidt, explains some human predispositions that are potentially serious impediments to efforts to get everyone to learn to be less harmful and more helpful, especially concerning when those traits are connected to the evidence-based concerns presented by Timothy Snyder in On Tyranny.

      The roots of a problem need to be understood in order to develop a sustainable solution. A root of this climate science denial problem appears to be the developed harmful cheaper and easier ways of enjoying life that are an undeniable legacy, and continuing to grow, problem of humans who develop harmful attitudes and pursue “improvements that are restricted to what they benefit from”. Humans who have developed that bias, rather than a bias for learning to be less harmful and more helpful, can be expected to fight against increased awareness and improved understanding that what they benefit from is harmful. From the perspective of the harmfully selfish, that type of learning is “not an improvement”. They see it as a threat.

4932. Daniel Bailey at 00:32 AM on 21 December 2021
      Animals and plants can adapt
      

      @Hal Kantrud

      Your NPR link is about the postulated Toba bottleneck some 70,000 years ago (not 2 million).  There's a lot of problems with that postulate (the most obvious of which is that the "Hobbits" on Flores just 2,767.5 km or 1,719.6 miles away survived that "bottleneck" by many thousands of years).  A volcanic eruption, while it might provide some short-term climate impacts (a few years to a few decades), has no mechanism by which it can drive atmospheric CO2 levels down over any meaningful period.  Temperatures, CO2 and sea levels had been declining before Toba and continued apace afterwards.  The global impacts of Toba on human evolution are considered to be minimal (more similar discussions).

      

4933. Hal Kantrud at 08:36 AM on 20 December 2021
      Animals and plants can adapt
      

      "ost extinctions have been linked to immense volcanic events, called Large Igneous Province (LIP) eruptions. These events spew billions of metric tonnes of carbon dioxide (CO2) and sulfur dioxide (SO2) into the atmosphere, in many cases triggering marine anoxia (oxygen loss) and ocean acidification due to rapid greenhouse warming. Of the Big Five mass extinctions, the one exception is the end-Cretaceous event. The current scientific consensus is that the end-Cretaceous mass extinction (that wiped out the dinosaurs 66 million years ago) was primarily caused by a large meteor strike (and a resulting, jarring change in climate). In Figure 1, the past three events (end-Permian, end-Triassic, and end-Cretaceous) are positioned at their respective, estimated short-term CO2 spike levels. These CO2 spikes which triggered their respective mass extinctions are not captured in the grey CO2 concentration curve due to its coarser temporal resolution."

      I read where the Tubo volcano about 2MYA resulted in a long cooling period caused by the sun's rays reflecting off the ash in the air.  I would think that would decrease atmospheric greenhouse gasses.  Mass extinctions resulted including nearly all our homonid ancestors, with survivors limited to small populations in Africa.  

      https://www.npr.org/sections/krulwich/2012/10/22/163397584/how-human-beings-almost-vanished-from-earth-in-70-000-b-c

4934. michael sweet at 09:34 AM on 19 December 2021
      Is Nuclear Energy the Answer?
      

      Sekwisniewski:

      This article from the Washington Post describes scientists in France and Germany arguing about wether or not nuclear power is safe and should be considered "green".  If you get a bunch of nuclear scientists together they often conclude that nuclear power is "green" while environmental scientists conclude that nuclear is not green.  I think the report you cite will be pushed by nuclear advocates but ignored by opponents.  I doubt that anything we say here will change anyones mind.

      Nuclear power is not economic and the materials to build the reactors do not exist.

4935. sekwisniewski at 07:19 AM on 19 December 2021
      Is Nuclear Energy the Answer?
      

      michael sweet wrote @280:

      The paper you linked is an attempt by the nuclear industry to get certified as green.

      The report was authored by 16 scientists working for the Joint Research Centre (JRC), which is the European Commission's in-house science and knowledge service. It lists references at the end of each section. How did the nuclear industry manipulated the conclusions of this report?

4936. michael sweet at 03:57 AM on 19 December 2021
      Is Nuclear Energy the Answer?
      

      France has temporally closed 4 nuclear power stations because of cracks and corrosion found near welds.  That is about 13% of France's nuclear power.  There is also a natural gas (methane) shortage this winter in the EU.  Electricity prices are expected to rise.  If there is a cold spell there will be difficulty dealing with it.  Hopefully it will be windy so wind can help out.  

      Tell me again about "always on" nuclear power.  These plants also shut down during hot spells in summer because there is not enough cooling water.

      Sekwisniewski:  The paper you linked is an attempt by the nuclear industry to get certified as green.  It does not address most of the objections to nuclear in Abbott (2012) (linked in the op) or Jacobson's problems with the very long build times for reactors.  Opponents of nuclear will note that in the discussion of major accidents there is no mention of large expanses of land rendered unusable for decades in Japan and Russia.  

      John Hartz: In the article you link (originally posted in the Financial TImes of London) they claim nuclear fusion might be producing electricity in the 2030's.  When I was 15 I remember reading an article about nuclear fusion that claimed they would produce electricity in 20 years.  That was 50 years ago and their objective is no closer.  I would not put a lot of weight on an article in a financial newspaper.

4937. Eclectic at 00:29 AM on 19 December 2021
      We're coming out of the Little Ice Age
      

      Atom @75 , when you look at the general atmospheric CO2 level, as demonstrated at Mauna Loa Hawaii, you see a large annual fluctuation cycle.   The fluctuation is so large, that it dwarfs the quite small & brief reduction in fossil fuel combustion that occurred during the early phase of the Covid-19 pandemic.  The pandemic-related signal is lost among the regular annual cycle events.

      Certainly, for us humans the psychological & financial impact of the pandemic appears very large - but the total output of our CO2 emissions was only minimally altered. 

       

      Interesting is John Hartz's linked article @74.  As I understand it, the mainstream view is that the causation of the LIA [Little Ice Age] was a combination of increased volcanic eruption of global-dimming aerosols, plus some episodes of reduced solar output.  The new suggestion of oceanic changes (in the AMOC of the North Atlantic) being a major contributor to the LIA, seems a bit of a stretch when considering simultaneous cooling of the extensive Pacific & Southern oceans.  But perhaps the authors Lapointe et alia can supply plausible quantification?

4938. Atom at 20:15 PM on 18 December 2021
      We're coming out of the Little Ice Age
      

      This question may be off topic, but I'm not used to posting anything here. I'm interested to know what is the prevailing thinking about the lack of any change or signal in global CO2 levels as a result of the decline in CO2 emissions in 2020.

4939. John Hartz at 02:26 AM on 18 December 2021
      We're coming out of the Little Ice Age
      

      Suggested supplemental reading:

      Scientists discover ‘surprising’ cause of Europe’s little ice age in late medieval era

      Change in ocean currents – similar to phenomena seen today – likely cause behind substantial cooling, US scientists say.

      by Harry Cockburn, Climate, The independent (UK), Dec 16, 2021

      https://www.independent.co.uk/climate-change/news/little-ice-age-ocean-currents-b1976776.html

4940. MA Rodger at 09:45 AM on 17 December 2021
      It's albedo
      

      blaisct @108,
      You talk of a "correlation in figure 2(f) CERES 20 years 2 (aka Loeb et al 2021)" which I find most odd as I see no correlation there. The figure 2(f) simply presents an attribution of the increasing IEE 2005-20, the sum of the attributions presented in figs 2(d) & 2(e). I thus fail to see any "conflict" between Fig 2(f) & fig 1. The total of the attributed components presented in fig 2(f) (+0.41Wm^-2/decade) is also the trend for the data shown in fig 2(c), CERES data which differs from fig1 only in that it covers a slightly extended period. I am thus not seeing any "conflict".
      And do be aware that the "in situ" (data which is in the main Ocean Heat Content data) is presented as a check on the CERES net values. If there was not a good fit between the OHC & CERES data, the CERES data would be seen as le robust with its use within the analysis thrown into some doubt. So the view that CERES should show less trend than "situ data if GHGs were a significant effect" doesn't stack up at all.

      Loeb et al (2021) is saying that CERES shows an increasing trend in downward radiation of +0.65Wm^-2/decade, part balanced by an increasing trend of +0.24Wm^-2 upward radiation, yielding a net downward EEI trend of +0.41Wm^-2. And a 'Partial Radiative Perturbation Analysis' attributes this net EEI trend almost entlrely to factors directly or indirectly resulting from AGW, these factors being:-
      +0.25Wm^-2/decade due to cloud albedo (which will comprise a reduction in cloud fraction and an indirect aerosol effect which presumably will be negative through this period).
      +0.31Wm^-2/deacde due to increasing water vapour (this due to global warming).
      +0.22Wm^-2/decade due to "other" effects (dominated by increased GH gases as well as a small solar variation which would have been negative through the period).
      +0.18Wm^-2/decade due to secreasing surface albedo (this shown in polar and mountain ragions and thus again a product of global warming reducing ice/snow cover.
      +0.01Wm^-2/decade due to a reduced direct aerosol effect.
      -0.53Wm^-2/decade due to a warmer planet increasing outward radiation.

      I do not see any correlation between albedo and global temperature, certainly not in Loeb et al (2021). Perhaps you could explain where you see it.

      These EEI trends acting since 2005 have collectively added some 0.7Wm^-2 to the EEI over the period to a start-of-period EEI of 0.4Wm^-2. Finally there is a concern that these 2005-20 trends are perhaps not representitive of the long-term trend. One factor not addressed by the analysis is the potential for significant short-term effects due to the situation prior to the period (thus the start-of-period EEI of 0.4Wm^-2 may be a poor start point). Loeb et al do consider short-term effects acting during the period 2005-20 that may abate long-term, specifically the PDO.

4941. blaisct at 01:39 AM on 17 December 2021
      It's albedo
      

      MA Rodger @107
      Thanks for your comments. The correlation in figure 2(f) CERES 20 years 2 (aka Loeb et al 2021) to GHG was noted but it is in conflict with the extremely good fit of CERES data to in situ in figure 1 CERES 20 years 2 which should show a smaller slope (of the statical fit) than the in situ data if GHGs were a significant effect. The conflict could be explained by the GHG if their effect on cloud formation is so strong that the GHG effect can not be seen in Figure 1 only the cloud effect can be seen; or that the GHG data in Figure 2(f) is confounded with another variable. With just 20 years of data, we can’t tell yet.
      My biggest takeaway from the reports in @106 was finally seeing a correlation to albedo that fit the observed temperature rise over 20 years. You are right in that this is only 20 year and not the 150 years of concern.
      The unproven theories at the bottom of @106 are just possible theories of unknown significance that may explain the Figure 1 correlation. I put them there incase someone had someone data on the subject.

4942. BaerbelW at 15:31 PM on 16 December 2021
      The Conspiracy Theory Handbook: Downloads and translations
      

      The Conspiracy Theory Handbook is now also available in Polish as the 13th available translation.

4943. MA Rodger at 21:07 PM on 15 December 2021
      It's albedo
      

      blaisct @108,
      I would strongly suggest that you take the assertions regarding the underlying causes of trends in EEI set out in the papers you call "Earthshine 20 years" (aka Goode et al 2021) and "CERES 20 years 1" (aka Dübal & Vahrenholt 2021) with a large pinch of salt. Their speculations about the reasons for the EEI data are entirely unsubstantiated.

      The third paper you cite as "CERES 20 years 2" (aka Loeb et al 2021) is a more considered analysis as it uses a modelled analysis (setout in its section 2.3) to derive the underlying causes of recent trends in EEI. Shown in their Fig 2f, Loeb et al find the overall EEI trend is dominated by 4 positive and 1 negative factor. You appear not to grasp that the positive factor "other" is the GHG forcing (with a small negative contribition from solar forcing through the period 2002-20). Also the water vapour factor results from a GHG forcing feedback. Thus your speculation doubting the contribution of "any AGH global warming mixed In with the TOA (red) data" is entirely misplaced. And do note that this is the change in EEI through the period. An EEI had been established by GHG forcing prior to this period while the analysis looks solely at the trends (ie changes) 2002-20.
      Simply I do not see Loeb et al (2021) anywhere "express doubts on the current understanding of climate change."

      I find most of the latter part of your comment most bizarre. I refrain here from explaining where you appear to be in error as you do run such a long way with your theorising. But if you wish such explanation, do say.

4944. blaisct at 05:08 AM on 15 December 2021
      It's albedo
      

      Once again thanks for your comment (MA Rodger and the editor) and the additional papers on the subject. I will try to do better with the links.

      
      The earlier data I was referring to was earthshine 10 years and CERES 10 years which showed that the data for the earths albedo was very noisy and flat. The flat part was what was expected for anthropogenic greenhouse gas , AGH, global warming. My initial understanding of AGH radiative forcing was that AGHs absorbed radiation (got hot) and that the higher the AGH concentration (at constant radiation) the more heat it could hold back thus the temperature would increase but the energy in vs out of the zone where this occurred would be the same (albedo would be flat). My understanding has been expanded to include: AGHs hotter temperature will reduce humidity and thus reduce cloud cover, expose more earth surface to the sun thus reduce earths albedo; therefor, albedo vs time for AGHs may not be flat.
      The new (new to me) data I sited Earthshine 20 years showed a decrease albedo from both earthshine and CERES data – my only interest is this report was the agreement with earthshine an CERES data. The editor’s link CERES 20 years 1  and another link CERES 20 years 2 provided a lot more CERES data with different analyses. These three papers are the first time I have seen data showing a decrease in albedo (increase in TOA radiation) vs time. If all climate change was due to AGHs this graph would be flat. Using the CERES 20 years 2  graph for TOA radiation out. (of the three links I chose this one because it has the In Situ data (earth surface temperature)) one can see the good correlation between In Situ data and CERES data

      

      Figure 1
      “Comparison of overlapping one-year estimates at 6-month intervals of net top-of-the-atmosphere annual energy flux from the Clouds and the Earth's Radiant Energy System Energy Balanced and Filled Ed4.1 product (solid red line) and an in situ observational estimate of uptake of energy by Earth climate system (solid blue line). Dashed lines correspond to least squares linear regression fits to the data.”

      
      . If there was any AGH global warming mixed In with the TOA (red) data it would have a slope lower than the In Situ data. The report CERES 20 years 1  did look for the AGH flat line signal and found it in the “Clear Sky” LW (long wave) data but nowhere else (1 of four graphs).
      Two of these reports put a lot of emphasis on clouds decrease (new to me). (Decrease in cloud cover increased surface exposure to suns radiation and heats the earth more.) The report CERES 20 years 2  also found correlation to Water vapor, trace gases, surface albedo, as well as clouds. Both of these reports express doubts on the current understanding of climate change and make recommendation to further understand what is causing cloud cover to change.
      While this new data is interesting and worth following up on it is still very noisy (low R^2) and another 20 years would be better.

      I recognize that AGH global warming would promote other forcing including reduce clouds, reduced ice, reduced snow cover all exposing more surface to direct rays of the sun. Other man-made albedo changes can do the same thing. Here are two examples that may relate to the new papers.
      Let’s start with the “heat island effect”, UHI. While the global warming from UHI’s lower albedo is small it does have observable effect on cloud formation, CERES 20 years 2.

      

      “Figure 3
      Attribution of Clouds and the Earth's Radiant Energy System net top-of-atmosphere flux trends for 2002/09–2020/03. Shown are trends due to changes in (a) clouds, (b) surface, (c) temperature, (d) combined contributions from trace gases and solar irradiance (labeled as “Other”), (e) water vapor, and (f) aerosols. Positive trends correspond to heat gain and negative to loss. Stippled areas fall outside the 5%–95% confidence interval. Numbers in parentheses correspond to global trends and 5%–95% confidence intervals in W m−2 decade−1.”

      
      When air rises from a UHI it is hotter than the incoming air without a source of moisture to saturate it; so, it leaves as dryer air. This air generally rises and moves to the east. Look at figure 3 (a) and see the lower cloud formation change off the coast of east USA, Tokyo, and downwind Europe. With time (1880-2021) the UHI does not get hotter but it gets bigger thus the volume of low moisture air gets bigger. I am not going to argue the significances of the albedo part of UHI other than to recognize it is lower than 1 W/m^2 but not zero. What UHI is not given credit for is what happens downwind to this hotter low humidity air. Does it cool the ocean, reduce the snow line, melt ice, or reduce the cloud cover down wind, since this hot dry air should rise the clouds should be the first target.  I can also see a chain of events: Hot low moisture air (from AGHs, UHIs, or other land changes) rises and go downwind, reduces cloud cover, over water the sun heats the ocean, the hotter ocean currents circulate to the poles, and melt some ice.
      I’ll leave the quantification of this observable (figure 3 (a)) new (to me) correlation to others. A new UHI contribution to GW will be the albedo effect + the lower cloud effect + any other.

      
      Second, is land use changes such as forest to crop or pasture land or grass land to crop land.  Albedo decrease in grass land to crop land change is documented in Grass to Crops.   Forest to crop land change increase in albedo is documented in Forest to Crops.  Over 205 years the paper Global albedo study  calculates that all the pluses and minuses add up to little change in albedo from land use changes. It is assumed (by me) that decreased albedo of a parcel of land means an increase in temperature and vs/vs. The study Amazonia Forest to Crops shows that increasing albedo does not always mean cooler temps. This report shows that when rain forest was replaced with crop land that the temperature increased, the rain decreased, and the cloud cover decreased. The Figure 3 (e) above shows bright red spot for “water vapor” (I assume that is change to lower humidity) in Amazonia. This is not an uncommon effect from replacing forest with crop or pasture land. The report Forest study  observes that forests vs crop/pasture conversion gets warmer as the conversion gets south of 35’N latitude.

      
      This unintuitive (to me) observation that an increase in albedo does not always result in a decrease in temperature can be explained by moisture. The resulting temperature depends on a constant enthalpy (total heat in the air= gases + moisture). Enthalpy is usually determined by the albedo (higher albedo lower enthalpy vs/vs); therefore, land exposed to the same albedo (enthalpy) can have a wide range of temperatures depending on the moisture (relative humidity) of the albedo (enthalpy). This relationship has been captured in a psychrometric chart,

       

      

      (Sorry for the poor quality of this chart)
      Example of a rain forest conversion to crop land: Start out with a rain forest at 25’C (bottom scale) go straight up to 90% humidity curve; this is our hot humid rain forest. If we convert this rain forest to crop land with a higher albedo, we move to a lower enthalpy line (anyone will do). The constant enthalpy line run diagonal (upper left to lower right). If the moisture is maintained at 90% the temperature will drop as expected for the higher albedo. Following the same enthalpy line (same albedo) go to a lower humidity curve that may result (and does in Amazonia) and one will see the temperature will increase (even to above the starting rainforest temperature at very low humidity).
      A concern is how NASA and the IPCC pair surface temperature data with relative humidity and albedo. The three all connected in enthalpy. A misunderstanding of climate change could occur if Amazonian (rain forest to crop land) high albedo, high temperature, lower humidity type data was included in correlations with Canadian (forest to crop land) lower albedo, cooler temperatures, high humidity, type data. Does anyone know if this has been looked at? The report CERES 20 years 1 has looked at ocean enthalpy correlations. I have not seen any land enthalpy data.

4945. David Hawk at 01:16 AM on 15 December 2021
      How machine learning holds a key to combating misinformation
      

      There seem to be two important points in the posted statement. The first favors the capability of machine learning. The second illustrates a belief in the value of more efficient fact-checking, and that such will better expose wrongful information, thus making the world a better place.  I would suggest two books for review, one for each topic of false hope in the science that brought us climate change.

      1. Shockwave Rider, John Brunner, 1975: somewhat of a bible for hackers that used its terminology for their purposes. Brunner makes an important distinction between artificial (machine-based) intelligence and natural (nature-based) intelligence. With this he outlines an eternal weakness always found in machine-based anything as it is presented in science fiction, thus carrying over into presentation of science fact.

      2. On Bullshit - Harry Frankfurt, Princeton U Press. 2005: A philosophical doorway into why fact-checkers are to become irrelevant to general public discourse. Speakers/writers that intend to lie once cared about lies and how best to cover their basis up, as in science articles with weakness but purpose, yet need to be withdrawn. That has now changed. Such personalities with immortality complexes now work to create systems of lies. These are tightly bound into bundles where concern with the true and false are replaced by emphasis on anything it takes to persuade the listener/reader. You will see why this became one of Princeton U Press's best selling books. It explains why politics has changed, and why we should avoid problem solvers that act like German leadershp of the 1930s. They came to ban discussion of "politics, off topic comments and ad hominem" statements, or anything else that questioned their assumed basis for their statements of the central problem of the society supporting them.  (My keynote lecture to the annual meeting of the Leibnitz Society in 2007 was on this use of a qualifier in England that year, and no longer in Germany. Now its widely used in the US.) 

      Yes, discourse on the when, why and where of climate change has evolvled since the work of Eunice Foot in 1856, but those are noise factors, not a basis for the essential change that humans over 20 years old are not prepared to make.

      This comes from my 1979 book at the University of Pennsylvania, then its 2019 reprint "Too Early, Too Late, Now what?. That book illustrated why politics are key, where a political point of view defines your relations with nature, each other and self. The two year study it was based on, with 20 companies and 6 govenments, illustrated why analaytic politics would make regulation of climate change irrelevant to the problematique; the system of problems, not a narrow problem from whatever you decided to analyze that day.

      Moderator Response:

      [BL] Repeated posting about the same book from the 1970s deleted. You have been warned about this before.

4946. Nick Palmer at 00:33 AM on 15 December 2021
      How machine learning holds a key to combating misinformation
      

      John - you wrote "It turns out these were the least common forms of climate misinformation. Instead, the largest category of climate misinformation was attacks on scientists and on climate science itself."
      
      I agree that smearing the science and scientists has indeed been the predominant form of denial/pathological scepticism for a long time - it's what I've found from my own experience tackling the toughest exponents, however I think the mechanisms they use to achieve the 'smear' are still the old tried and true 'Skepsci' favourites - Soon's 'it's the Sun', Climategate, Briffa's Yamal tree rings, Curry's 'uncertainty monster', Mann's hockey stick PCA's, Svensmark's cosmic rays, Morner on sea level etc. etc., although the originators are not nowadays mentioned by name so often these days - they don't need to be - their 'sceptical' objections have become established as canon in the denialosphere.

4947. Eric (skeptic) at 23:26 PM on 14 December 2021
      How machine learning holds a key to combating misinformation
      

      Machine learning is only as good as the annotation of the examples.  I doubt that the team of "climate literate" volunteers can do that objectively.  Do they really understand climate policy?  The lackluster recall for the "climate solutions won't work" suggests another problem: drift.  ML performance is also determined by the sample set and using the 1998 to 2020 corpus, because that's the data you happen to have gathered, causes a problem.

      Examples of contrarian climate solution claims from 1998 are not similar to examples from 2020 (and vice versa) because climate solutions have changed too much.  A related problem shows up in the further analysis of contrarian funding.  Cato, as just one example, has changed a lot from the days of climate contrarian Pat Michaels to the current climate policy writings which appear to be headed by a lawyer writing about policy.  The bulk of the paper appears to be a rehash of those old grievances, and not a precise critique of what is actually wrong about so-called contrarian policy.

4948. John Hartz at 03:44 AM on 13 December 2021
      Is Nuclear Energy the Answer?
      

      Suggested supplemental reading:

      Nuclear Fusion: Why the Race to Harness the Power of the Sun Just Sped Up

      Fusion companies have now raised $2.3 billion in investment, believing they can begin producing unlimited amounts of zero emissions energy by the 2030s.

      by Tom Wilson & Ian Bott, Financial Times/Inside Climate News, Dec 8, 2021

      https://insideclimatenews.org/news/08122021/nuclear-fusion-why-the-race-to-harness-the-power-of-the-sun-just-sped-up/

4949. sekwisniewski at 21:46 PM on 12 December 2021
      Is Nuclear Energy the Answer?
      

      EU scientists at JRC examined nuclear from the do-no-significant-harm perspective for the purpose of including it in preferential, environment-oriented financing and I found it a good, comprehensive overview that may answer OP's questions.

      "Technical assessment of nuclear energy with respect to the ‘do no significant harm’ criteria of Regulation (EU) 2020/852 (‘Taxonomy Regulation’)" 

      https://publications.jrc.ec.europa.eu/repository/handle/JRC125953

      Moderator Response:

      [PS] Link fixed. Please learn how to make links yourself with the comment editor.

4950. One Planet Only Forever at 07:32 AM on 11 December 2021
      2021 SkS Weekly Climate Change & Global Warming News Roundup #49
      

      swampfoxh @22,

      I wish you the best of luck in getting a helpful change of mind from policymakers by delivering "new information" or "a different presentation of information" to policymakers (decisionsmakers).

      My observation is that the attitude (beliefs and interests) of voters and the resulting "set of elected policymakers" matters far more than "the provision of information to policymakers".

      The threat of misleading marketing attacks on a political competitor can powerfully influence the choices they make (the power of misleading marketing is real and significant).

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